Keep places and accesses at the terminal, and refuse a line break in any setting

Through the settings verb a caller could place a module's directory at /etc
with an owner of its own and have root hand it over at the next send, or mount
any of the machine's paths into a container (hq ADR 0266). Both keys are now
the terminal's and never at the machine's own trees; a plans line that acts is
refused wherever its subcommand stands; and a line break in a setting, which a
file it is written into reads as a directive, is refused where it is kept and
where it is composed.

cmd/mesh-builder/main.go

@@ -27,6 +27,8 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/nats-io/nats.go"
+
 	"github.com/novox/mesh-controller/internal/broker"
 	"github.com/novox/mesh-controller/internal/builder"
 	"github.com/novox/mesh-controller/internal/link"
@@ -175,7 +177,9 @@ func dialFor(credential Credential) (*broker.JetStream, string, error) {
 	if !credential.onTheNewBus() {
 		return nil, "", fmt.Errorf("the credential at hand names %q, which is not the mesh's bus", credential.URL)
 	}
-	js, err := broker.DialPinned(credential.natsURL(), credential.Fingerprint)
+	// Named for what it is, not the controller whose code dials it (novox/hq issue 327).
+	host, _ := os.Hostname()
+	js, err := broker.DialPinned(credential.natsURL(), credential.Fingerprint, nats.Name("build agent on "+host))
 	if err != nil {
 		return nil, "", err
 	}

cmd/mesh-controller/acting.go

@@ -8,6 +8,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/nats-io/nats.go"
 	"github.com/nats-io/nats.go/jetstream"
 
 	"github.com/novox/mesh-controller/internal/broker"
@@ -187,7 +188,8 @@ func (a *actor) serveUnderTheLease(ctx context.Context, inv *inventory.Inventory
 	a.mu.Lock()
 	a.serving = true
 	a.mu.Unlock()
-	js, err := broker.Dial(address)
+	// Its own connection, held as long as the lease, and named so (novox/hq issue 327).
+	js, err := broker.Dial(address, nats.Name(broker.ConnectionName+" lease"))
 	if err != nil {
 		return nil, fmt.Errorf("the mesh is on the bus at %s and this control plane cannot reach it to take the "+
 			"lease: %w", broker.BareAddress(address), err)

cmd/mesh-controller/agent_account.go

@@ -0,0 +1,175 @@
+package main
+
+// The account agents run as (novox/hq ADR 0266).
+//
+// On the control node every agent session ran as the operator's account, which may become root without a
+// password — so any agent there could become root without a person, and ADR 0259 §8 (an answer from the
+// operator's phone authorises an act) rests on that being false where the router and its channels run. The
+// decision: a node may name an account its agents run as, of their own and without sudo; the operator's
+// account keeps its sudo.
+//
+//   - **Named at the controller's terminal only** (`node agent-account`): not a verb, not a setting, so no
+//     agent can name itself another account. Empty is a real state: agents run as the operator there.
+//   - **Composed** as `${machine:agent-account}`, `${machine:agent-home}` and `${machine:agent-root}` for the
+//     agent's module, which declares the account with `root: never`, and as MESH_AGENT_ACCOUNT and
+//     MESH_AGENT_HOME for its tools (catalogue/machine_into_files.go, runtime.go).
+//   - **Judged by the machine itself.** The node-engine reads, on every look, whether an account declared
+//     `root: never` can become root without a person — uid 0, a group that grants root, a sudo rule, a
+//     secret of the mesh it may read — and says it as the declaring module's account verdict, marked
+//     Root "never". agentConfined reads that verdict; the self-check (probe DA) raises
+//     `agent-can-become-root` while it does not hold, and `node show` says it.
+//
+// A verdict not given is never a pass: an engine older than the judging, an account not yet declared, a
+// statement that says nothing of it — each is "not judged", and fails.
+
+import (
+	"context"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// kindAgentCanBecomeRoot is the condition raised while a machine's agent account can become root without
+// a person, or is not judged (ADR 0266).
+const kindAgentCanBecomeRoot = "agent-can-become-root"
+
+// agentAccountProbe is the self-check's probe of it.
+const agentAccountProbe = "DA"
+
+// agentConfined says whether the agents of a machine that names an agent account are confined: the
+// machine's newest statement holds a healthy account verdict, judged for root, on that account. named is
+// false for a machine that names none — agents run as the operator account there, which this does not
+// judge. why is said either way, in the mesh's words; err is a store that could not be read.
+//
+// The one judgement: `node show`, the self-check, and ADR 0259's router honouring a verified sender read
+// it here.
+func agentConfined(ctx context.Context, inv *inventory.Inventory, node string) (named, confined bool, why string, err error) {
+	n, err := inv.NodeByName(ctx, node)
+	if err != nil {
+		return false, false, "", err
+	}
+	if n.AgentAccount == "" {
+		return false, false, fmt.Sprintf("%s names no agent account: agents run as the operator account (%s)",
+			node, orNoneKnown(n.Account)), nil
+	}
+	h, had, err := inv.HealthOf(ctx, node)
+	if err != nil {
+		return true, false, "", err
+	}
+	confined, why = judgedConfined(n.AgentAccount, h, had, time.Now())
+	return true, confined, why, nil
+}
+
+// verdictFreshFor is how old the statement holding the verdict may be, by this controller's clock. A
+// node-engine states its health on every change and at least every five minutes (mesh-host's sayAnyway), so
+// three statements missed is a node-engine stopped, or a machine away. **A stale verdict is not a pass**: an
+// agent that stopped the node-engine must not leave "cannot become root" standing from before.
+const verdictFreshFor = 15 * time.Minute
+
+// judgedConfined is the judgement over one statement, without the store, at now.
+func judgedConfined(agent string, h inventory.NodeHealth, had bool, now time.Time) (bool, string) {
+	if !had {
+		return false, fmt.Sprintf("the agent account %s is not judged: the machine's node-engine has stated "+
+			"nothing of what it runs", agent)
+	}
+	if age := now.Sub(h.HeardAt); age > verdictFreshFor {
+		return false, fmt.Sprintf("the agent account %s is not judged: the machine's newest statement was heard at "+
+			"%s, more than %d minutes ago, and a verdict that old is not a verdict on now", agent,
+			h.HeardAt.Local().Format("2006-01-02 15:04"), int(verdictFreshFor.Minutes()))
+	}
+	if h.Contract < link.RootContract {
+		return false, fmt.Sprintf("the agent account %s is not judged: the machine's node-engine is older than "+
+			"the judging of an account's root (its statement's contract is %d, the judging is %d)",
+			agent, h.Contract, link.RootContract)
+	}
+	var verdicts []inventory.ResourceHealth
+	for _, r := range h.Resources {
+		if r.Kind == link.KindAccount && r.Target == agent && r.Root == link.RootNever {
+			verdicts = append(verdicts, r)
+		}
+	}
+	if len(verdicts) == 0 {
+		return false, fmt.Sprintf("the agent account %s is not judged: the machine's newest statement holds no "+
+			"verdict on it — no module there declares it never to become root, or the declaration naming it "+
+			"has not been applied", agent)
+	}
+	sort.Slice(verdicts, func(i, j int) bool {
+		return verdicts[i].Module+verdicts[i].Resource < verdicts[j].Module+verdicts[j].Resource
+	})
+	for _, v := range verdicts {
+		switch v.State {
+		case link.StateHealthy:
+		case link.StateUnhealthy:
+			// The engine's own words, which start with link.ReasonRoot when it found a way to root.
+			return false, fmt.Sprintf("the agent account %s %s (said by %s's %s)", agent,
+				orNoneKnown(v.Reason), v.Module, v.Resource)
+		default:
+			return false, fmt.Sprintf("the agent account %s is not judged: %s (%s's %s, %s)", agent,
+				orNoneKnown(v.Reason), v.Module, v.Resource, v.State)
+		}
+	}
+	return true, fmt.Sprintf("the agent account %s cannot become root without a person (judged %s)", agent,
+		h.SaidAt.Local().Format("2006-01-02 15:04"))
+}
+
+// probeAgentAccounts is DA: every machine that names an agent account has it judged, on its node-engine's
+// newest statement, unable to become root without a person (ADR 0266).
+func probeAgentAccounts(ctx context.Context, d *doctor) ([]conditions.Observation, error) {
+	inv := d.open.inventory
+	nodes, err := inv.Nodes(ctx)
+	if err != nil {
+		return nil, err
+	}
+	var out []conditions.Observation
+	for _, n := range nodes {
+		if n.AgentAccount == "" {
+			continue
+		}
+		h, had, err := inv.HealthOf(ctx, n.Name)
+		if err != nil {
+			return nil, err
+		}
+		confined, why := judgedConfined(n.AgentAccount, h, had, time.Now())
+		if confined {
+			continue
+		}
+		out = append(out, conditions.Observation{Scope: conditions.ScopeMachine, ID: n.Name, Token: "agent-root",
+			Machine: n.Name, Severity: conditions.Urgent,
+			Summary: fmt.Sprintf("on %s, %s (ADR 0266): an agent there may become root without a person, and "+
+				"no answer from a channel authorises an act there (ADR 0259 §8)", n.Name, why),
+			Said: why})
+	}
+	return sortedFound(out), nil
+}
+
+// agentAccountLines is what `node show` says of the account agents run as.
+func agentAccountLines(ctx context.Context, inv *inventory.Inventory, n inventory.Node) []string {
+	if n.AgentAccount == "" {
+		return []string{fmt.Sprintf("  agents run as      the operator account (%s); no agent account is named",
+			orNoneKnown(n.Account))}
+	}
+	_, confined, why, err := agentConfined(ctx, inv, n.Name)
+	if err != nil {
+		return []string{fmt.Sprintf("  agents run as      %s (home %s); whether it can become root could NOT be read: %v",
+			n.AgentAccount, n.AgentHome(), err)}
+	}
+	verdict := "CAN become root, or is not judged: " + why
+	if confined {
+		verdict = why
+	}
+	return []string{fmt.Sprintf("  agents run as      %s (home %s)", n.AgentAccount, n.AgentHome()),
+		"                     " + verdict}
+}
+
+// orNoneKnown is a value, or that none is known.
+func orNoneKnown(s string) string {
+	if strings.TrimSpace(s) == "" {
+		return "none known"
+	}
+	return s
+}

cmd/mesh-controller/agent_account_test.go

@@ -0,0 +1,199 @@
+package main
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/conditions"
+	snapshot "github.com/novox/mesh-controller/internal/facts"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The agent account's judgement (novox/hq ADR 0266): confined only on a healthy account verdict judged for
+// root, on the very account; every verdict not given — no statement, an older engine, no verdict on it, a
+// verdict of unknown — is "not judged" and fails, never a pass.
+func TestAnAgentAccountIsConfinedOnlyOnAHealthyVerdictJudgedForRoot(t *testing.T) {
+	at := time.Date(2026, 10, 8, 19, 21, 0, 0, time.UTC)
+	verdict := func(target, root, state, reason string) inventory.ResourceHealth {
+		return inventory.ResourceHealth{Module: "claude-code", Resource: "claude-code.agent-account",
+			Kind: link.KindAccount, Target: target, State: state, Reason: reason, Root: root, Account: target}
+	}
+	statement := func(contract int, rs ...inventory.ResourceHealth) inventory.NodeHealth {
+		return inventory.NodeHealth{Node: "anchor", Contract: contract, SaidAt: at, HeardAt: at, Resources: rs}
+	}
+	for _, c := range []struct {
+		name     string
+		h        inventory.NodeHealth
+		had      bool
+		confined bool
+		says     string
+	}{
+		{"judged and unable", statement(link.RootContract, verdict("agent", link.RootNever, link.StateHealthy, "")),
+			true, true, "cannot become root without a person"},
+		{"judged and able", statement(link.RootContract, verdict("agent", link.RootNever, link.StateUnhealthy,
+			link.ReasonRoot+": in the group docker, which grants root")), true, false, "in the group docker"},
+		{"a verdict of unknown", statement(link.RootContract, verdict("agent", link.RootNever, link.StateUnknown,
+			"sudo could not be read")), true, false, "not judged"},
+		{"no statement", inventory.NodeHealth{}, false, false, "not judged"},
+		{"an older engine", statement(link.ReadinessContract, verdict("agent", "", link.StateHealthy, "")),
+			true, false, "older than the judging"},
+		{"a verdict on groups only", statement(link.RootContract, verdict("agent", "", link.StateHealthy, "")),
+			true, false, "no verdict on it"},
+		{"a verdict on another account", statement(link.RootContract, verdict("ops", link.RootNever, link.StateHealthy, "")),
+			true, false, "no verdict on it"},
+	} {
+		confined, why := judgedConfined("agent", c.h, c.had, at.Add(time.Minute))
+		if confined != c.confined || !strings.Contains(why, c.says) {
+			t.Errorf("%s: confined %v, %q; want %v saying %q", c.name, confined, why, c.confined, c.says)
+		}
+	}
+	// A verdict heard longer ago than the bound is no verdict: an agent that stopped the node-engine must not
+	// leave "healthy" standing.
+	fresh := statement(link.RootContract, verdict("agent", link.RootNever, link.StateHealthy, ""))
+	if ok, _ := judgedConfined("agent", fresh, true, at.Add(verdictFreshFor)); !ok {
+		t.Error("a verdict exactly at the bound is still one")
+	}
+	if ok, why := judgedConfined("agent", fresh, true, at.Add(verdictFreshFor+time.Second)); ok ||
+		!strings.Contains(why, "not judged") {
+		t.Errorf("a stale healthy verdict passed: %q", why)
+	}
+}
+
+// DA raises an urgent condition, with plain words, on a machine whose agent account is not judged unable to
+// become root; a machine that names none is not its to judge.
+func TestTheSelfCheckSaysAnAgentAccountThatCanBecomeRoot(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	inv := open.inventory
+	for _, n := range []string{"anchor", "laptop"} {
+		if _, err := inv.NodeByName(ctx, n); err != nil {
+			if _, err := inv.AddNode(ctx, n); err != nil {
+				t.Fatal(err)
+			}
+		}
+		if err := inv.SetAccount(ctx, n, "ops", ""); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := inv.SetAgentAccount(ctx, "anchor", "agent", ""); err != nil {
+		t.Fatal(err)
+	}
+	d := &doctor{open: open}
+	found, err := probeAgentAccounts(ctx, d)
+	if err != nil {
+		t.Fatal(err)
+	}
+	found = onlyMachine(found, "anchor")
+	if len(found) != 1 || found[0].Machine != "anchor" || found[0].Severity != conditions.Urgent ||
+		!strings.Contains(found[0].Said, "not judged") {
+		t.Fatalf("a named agent account with no verdict: %+v", found)
+	}
+	w := plainWordings[kindAgentCanBecomeRoot](conditions.Observation{Kind: kindAgentCanBecomeRoot, Machine: "anchor"})
+	if w.Headline == "" || w.Needs == "" || w.Resolved == "" {
+		t.Errorf("the condition has no plain words: %+v", w)
+	}
+
+	healthy := inventory.ResourceHealth{Module: "claude-code", Resource: "claude-code.agent-account",
+		Kind: link.KindAccount, Target: "agent", State: link.StateHealthy, Root: link.RootNever, Account: "agent"}
+	if _, err := inv.RecordHealth(ctx, inventory.NodeHealth{Node: "anchor", Contract: link.RootContract,
+		SaidAt: time.Now(), HeardAt: time.Now(), Resources: []inventory.ResourceHealth{healthy}}); err != nil {
+		t.Fatal(err)
+	}
+	if found, err = probeAgentAccounts(ctx, d); err != nil || len(onlyMachine(found, "anchor")) != 0 {
+		t.Fatalf("a judged agent account still fails: %+v %v", found, err)
+	}
+	if named, confined, why, err := agentConfined(ctx, inv, "anchor"); err != nil || !named || !confined {
+		t.Fatalf("agentConfined on anchor: %v %v %q %v", named, confined, why, err)
+	}
+	if named, _, why, err := agentConfined(ctx, inv, "laptop"); err != nil || named ||
+		!strings.Contains(why, "operator account") {
+		t.Fatalf("agentConfined on a machine naming none: %v %q %v", named, why, err)
+	}
+}
+
+func TestTheAgentRootWordsArePlain(t *testing.T) {
+	w := plainWordings[kindAgentCanBecomeRoot](conditions.Observation{Kind: kindAgentCanBecomeRoot, Machine: "anchor"})
+	if why, ok := conditions.PlainWords(w, "anchor"); !ok {
+		t.Fatalf("not plain: %s: %+v", why, w)
+	}
+}
+
+func onlyMachine(obs []conditions.Observation, machine string) []conditions.Observation {
+	var out []conditions.Observation
+	for _, o := range obs {
+		if o.Machine == machine {
+			out = append(out, o)
+		}
+	}
+	return out
+}
+
+// The snapshot a merge check composes from carries the agent account as a pseudonym (novox/hq ADR 0266),
+// so a change is judged against machines that name one, and the name never leaves.
+func TestTheFactsCarryTheAgentAccountAsAPseudonym(t *testing.T) {
+	open, _ := aMeshWithSecrets(t)
+	ctx := t.Context()
+	if err := open.inventory.SetAccount(ctx, "anchor", "keeper", ""); err != nil {
+		t.Fatal(err)
+	}
+	if err := open.inventory.SetAgentAccount(ctx, "anchor", "warden", ""); err != nil {
+		t.Fatal(err)
+	}
+	f, err := gatherFacts(ctx, open, "2.11.17")
+	if err != nil {
+		t.Fatal(err)
+	}
+	body, _ := f.Encode()
+	if strings.Contains(string(body), "warden") {
+		t.Error("the agent account's name is in the snapshot")
+	}
+	m, ok := f.Machine(snapshot.Pseudonym("machine", "anchor"))
+	if !ok || m.AgentAccount != snapshot.Pseudonym("account", "warden") || m.Account == m.AgentAccount {
+		t.Fatalf("the anchor's agent account reads as %q (operator %q)", m.AgentAccount, m.Account)
+	}
+}
+
+// No verb runs a `node` command that sets something: through the generic `command` verb, `node account`,
+// `node agent-account` and every other `node` subcommand but list and show are refused, naming the terminal.
+func TestNoVerbSetsANodesAccounts(t *testing.T) {
+	for _, line := range []string{
+		"node agent-account novox --clear",
+		"node agent-account novox ops",
+		"node account novox agent",
+		"node account novox",
+		"node add intruder",
+		"node public-domain novox --clear",
+		"node",
+		"node frobnicate",
+	} {
+		argv, err := argvFor("command", map[string]any{"command": line})
+		if err == nil || !strings.Contains(err.Error(), "controller's terminal") ||
+			!strings.Contains(err.Error(), "ADR 0266") {
+			t.Errorf("%q ran as %v (%v); want a refusal naming the terminal", line, argv, err)
+		}
+	}
+	for _, line := range []string{"node show novox", "node list --json", "status --json"} {
+		if _, err := argvFor("command", map[string]any{"command": line}); err != nil {
+			t.Errorf("%q, a read, was refused: %v", line, err)
+		}
+	}
+	if err := terminalOnly([]string{"node", "account", "a", "b"}); err == nil {
+		t.Error("the refusal is not only the command verb's")
+	}
+}
+
+// Naming the agent account is the controller's terminal's alone: the `node` verb only shows.
+func TestTheNodeVerbOnlyShows(t *testing.T) {
+	argv, err := argvFor("node", map[string]any{"node": "anchor"})
+	if err != nil || strings.Join(argv, " ") != "node show anchor" {
+		t.Fatalf("the node verb runs %v (%v)", argv, err)
+	}
+	for _, v := range catalogue.ControllerVerbs {
+		if strings.Contains(v.Name, "agent") {
+			t.Errorf("a verb %q may name the agent account", v.Name)
+		}
+	}
+}

cmd/mesh-controller/build.go

@@ -879,6 +879,10 @@ func heldBy(ctx context.Context) map[string]string {
 // the mesh runs on today this needs the controller's own connection, so it is handed one; on the bus
 // being built it dials, because a build request is a one-shot and holds nothing else.
 func askOverOn(seat string) (link.Builders, error) {
+	// The serving controller asks on its own connection (novox/hq issue 327).
+	if serving := servingBus.Load(); serving != nil {
+		return link.BuildsOn(serving, seat), nil
+	}
 	address, err := broker.BusAddress()
 	if err != nil {
 		return nil, err
@@ -937,11 +941,7 @@ func buildSeatAmong(entries []inventory.Entry) string {
 // with a consumer of its own that is gone when this returns, so nothing accumulates in the server
 // for the reading, and filtered by subject, so one build's lines are all that travel.
 func buildLog(ctx context.Context, id string) error {
-	address, err := broker.BusAddress()
-	if err != nil {
-		return err
-	}
-	js, err := broker.Dial(address)
+	js, err := aBus()
 	if err != nil {
 		return fmt.Errorf("cannot reach the bus to read a build's log: %w", err)
 	}

cmd/mesh-controller/calls_verb_test.go

@@ -37,8 +37,6 @@ func TestAPushAnswersBeforeItSends(t *testing.T) {
 	}{
 		{"push", map[string]any{"node": "anchor", "why": "w"}, true},
 		{"push", map[string]any{"why": "w"}, true},
-		{"command", map[string]any{"command": "push anchor --why w"}, true},
-		{"command", map[string]any{"command": "push --behind --why=w"}, true},
 		{"command", map[string]any{"command": "builds"}, false},
 		{"status", map[string]any{}, false},
 		{"assign", map[string]any{"node": "anchor", "module": "m"}, false},

cmd/mesh-controller/conditions.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"io"
 	"os"
 	"slices"
 	"strconv"
@@ -107,19 +108,20 @@ func conditionsCommand(ctx context.Context, args []string) error {
 	}
 	switch sub {
 	case "list":
-		return listConditions(ctx, args)
+		return listConditions(ctx, args, os.Stdout)
 	case "show":
-		return showCondition(ctx, args)
+		return showCondition(ctx, args, os.Stdout)
 	case "silence":
 		return silenceCondition(ctx, args)
 	case "history":
-		return conditionHistory(ctx, args)
+		return conditionHistory(ctx, args, os.Stdout)
 	}
 	return errors.New(conditionsUsage)
 }
 
-func listConditions(ctx context.Context, args []string) error {
+func listConditions(ctx context.Context, args []string, w io.Writer) error {
 	set := flag.NewFlagSet("conditions", flag.ContinueOnError)
+	usageTo(set, w)
 	scope := set.String("scope", "", "only this scope: "+strings.Join(conditions.Scopes, ", "))
 	severity := set.String("severity", "", "only urgent, or only warning")
 	machine := set.String("machine", "", "only those about this machine")
@@ -144,20 +146,20 @@ func listConditions(ctx context.Context, args []string) error {
 		}
 	}
 	if *asJSON {
-		return printJSON(map[string]any{"conditions": inBrief(out), "open": len(open), "counted": counted(out),
+		return printJSONTo(w, map[string]any{"conditions": inBrief(out), "open": len(open), "counted": counted(out),
 			"note": "urgent first, then oldest first; a condition clears when observation says so, never by hand; " +
 				"each with its newest evidence — `conditions key=<key>` gives one whole"})
 	}
 	if len(out) == 0 {
 		if len(open) == 0 {
-			fmt.Println("no open conditions")
+			fmt.Fprintln(w, "no open conditions")
 		} else {
-			fmt.Printf("none of the %d open condition(s) is about that\n", len(open))
+			fmt.Fprintf(w, "none of the %d open condition(s) is about that\n", len(open))
 		}
 		return nil
 	}
 	for _, line := range conditionLines(out, time.Now()) {
-		fmt.Println(line)
+		fmt.Fprintln(w, line)
 	}
 	return nil
 }
@@ -233,8 +235,9 @@ func conditionLines(list []conditions.Condition, now time.Time) []string {
 	return out
 }
 
-func showCondition(ctx context.Context, args []string) error {
+func showCondition(ctx context.Context, args []string, w io.Writer) error {
 	set := flag.NewFlagSet("conditions show", flag.ContinueOnError)
+	usageTo(set, w)
 	asJSON := set.Bool("json", false, "as data")
 	rest, err := parseAround(set, args)
 	if err != nil {
@@ -266,34 +269,34 @@ func showCondition(ctx context.Context, args []string) error {
 			"history --key %s` what became of it", key, key)
 	}
 	if *asJSON {
-		return printJSON(c)
+		return printJSONTo(w, c)
 	}
 	now := time.Now()
-	fmt.Printf("%s  %s\n  %s\n\n", strings.ToUpper(string(c.Severity)), c.Key, c.Summary)
-	fmt.Printf("  kind       %s\n  about      %s %s", c.Kind, c.Subject.Scope, c.Subject.ID)
+	fmt.Fprintf(w, "%s  %s\n  %s\n\n", strings.ToUpper(string(c.Severity)), c.Key, c.Summary)
+	fmt.Fprintf(w, "  kind       %s\n  about      %s %s", c.Kind, c.Subject.Scope, c.Subject.ID)
 	if c.Subject.Machine != "" {
-		fmt.Printf(", on %s", c.Subject.Machine)
+		fmt.Fprintf(w, ", on %s", c.Subject.Machine)
 	}
-	fmt.Printf("\n  raised by  %s\n  since      %s (%s ago), observed %d time(s), last %s ago\n",
+	fmt.Fprintf(w, "\n  raised by  %s\n  since      %s (%s ago), observed %d time(s), last %s ago\n",
 		c.Source, c.Raised.Local().Format("2006-01-02 15:04:05"), roughly(now.Sub(c.Raised)), c.Observations,
 		now.Sub(c.LastObserved).Round(time.Second))
 	if c.Count > 1 {
-		fmt.Printf("  raised     %d times, each within ten minutes of clearing\n", c.Count)
+		fmt.Fprintf(w, "  raised     %d times, each within ten minutes of clearing\n", c.Count)
 	}
-	fmt.Printf("  resolved   by %s\n", resolverWords(c.Resolver))
+	fmt.Fprintf(w, "  resolved   by %s\n", resolverWords(c.Resolver))
 	if c.Silenced != nil {
-		fmt.Printf("  silenced   until %s by %s: %s\n", c.Silenced.Until.Local().Format("2006-01-02 15:04"),
+		fmt.Fprintf(w, "  silenced   until %s by %s: %s\n", c.Silenced.Until.Local().Format("2006-01-02 15:04"),
 			c.Silenced.By, c.Silenced.Why)
 	}
 	if len(c.Tried) > 0 {
-		fmt.Println("\n  tried:")
+		fmt.Fprintln(w, "\n  tried:")
 		for _, t := range c.Tried {
-			fmt.Printf("    %s  %s — %s: %s\n", t.At.Local().Format("2006-01-02 15:04"), orHealer(t.By), t.What, t.Outcome)
+			fmt.Fprintf(w, "    %s  %s — %s: %s\n", t.At.Local().Format("2006-01-02 15:04"), orHealer(t.By), t.What, t.Outcome)
 		}
 	}
-	fmt.Println("\n  evidence, newest first:")
+	fmt.Fprintln(w, "\n  evidence, newest first:")
 	for _, e := range c.Evidence {
-		fmt.Printf("    %s  %s\n", e.At.Local().Format("2006-01-02 15:04:05"), e.Said)
+		fmt.Fprintf(w, "    %s  %s\n", e.At.Local().Format("2006-01-02 15:04:05"), e.Said)
 	}
 	return nil
 }
@@ -378,8 +381,9 @@ func parseFor(s string) (time.Duration, error) {
 	return d, nil
 }
 
-func conditionHistory(ctx context.Context, args []string) error {
+func conditionHistory(ctx context.Context, args []string, w io.Writer) error {
 	set := flag.NewFlagSet("conditions history", flag.ContinueOnError)
+	usageTo(set, w)
 	days := set.Int("days", 7, "how many days back, at most 90")
 	key := set.String("key", "", "only this condition")
 	asJSON := set.Bool("json", false, "as data")
@@ -420,10 +424,10 @@ func conditionHistory(ctx context.Context, args []string) error {
 		if out == nil {
 			out = []conditions.Event{}
 		}
-		return printJSON(map[string]any{"history": out, "days": *days})
+		return printJSONTo(w, map[string]any{"history": out, "days": *days})
 	}
 	if len(out) == 0 {
-		fmt.Printf("nothing was raised, changed or cleared in the last %d day(s)\n", *days)
+		fmt.Fprintf(w, "nothing was raised, changed or cleared in the last %d day(s)\n", *days)
 		return nil
 	}
 	for _, e := range out {
@@ -440,7 +444,7 @@ func conditionHistory(ctx context.Context, args []string) error {
 				line += " — " + e.Why
 			}
 		}
-		fmt.Println(line)
+		fmt.Fprintln(w, line)
 	}
 	return nil
 }

cmd/mesh-controller/deadletters.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
-	"sync/atomic"
 
 	"github.com/nats-io/nats.go"
 
@@ -22,10 +21,6 @@ import (
 // serving controller is already on it. A verb run as a fresh process would open a connection of its own
 // for each call (novox/hq issue 327).
 
-// deadLettersOn is the serving controller's bus, set when it starts watching the mesh; nil in a
-// process that serves nothing.
-var deadLettersOn atomic.Pointer[busHandles]
-
 // busHandles are the serving controller's connection and JetStream handle.
 type busHandles struct {
 	conn *nats.Conn
@@ -41,11 +36,12 @@ const causeDeadLetter = "dead-letter"
 // deadLettersAnswer is what `dead-letters` answers: the list, one whole, or what came of delivering one
 // again or dropping it.
 func deadLettersAnswer(ctx context.Context, a *verbArguments) (any, error) {
-	on := deadLettersOn.Load()
-	if on == nil {
+	serving := servingBus.Load()
+	if serving == nil {
 		return nil, errors.New("this controller is not serving, so it does not read DEAD_LETTERS: ask again, " +
 			"and the serving controller answers")
 	}
+	on := &busHandles{conn: serving.Conn(), js: serving.Context()}
 	// The shape first, and every argument it reads; one given beside it is refused before anything is
 	// done, as every verb refuses what it would pass over (novox/hq issue 244).
 	var deliver, drop, why, cause, idText, consumer, limit string

cmd/mesh-controller/deadletters_test.go

@@ -26,9 +26,9 @@ func servingDeadLetters(t *testing.T) *broker.JetStream {
 	if err := js.EnsureControllerBuckets(); err != nil {
 		t.Fatal(err)
 	}
-	before := deadLettersOn.Load()
-	deadLettersOn.Store(&busHandles{conn: js.Conn(), js: js.Context()})
-	t.Cleanup(func() { deadLettersOn.Store(before) })
+	before := servingBus.Load()
+	servingBus.Store(js)
+	t.Cleanup(func() { servingBus.Store(before) })
 	return js
 }
 

cmd/mesh-controller/doctor.go

@@ -116,6 +116,16 @@ var probeRegistry = []probe{
 	{ID: probeDeliveriesID, Asserts: "no delivery is held past its state's bound unsaid: mesh-delivery's " +
 		"`stalled`, each with the transition its table lets healer H2 take", From: "ADR 0239",
 		Kind: kindDeliveryStalled, Phase: 3, run: probeDeliveries},
+	// A client of the bus reconnecting in a loop (novox/hq issue 327), from the server's record of closed
+	// connections, which the bus's own module reads.
+	{ID: probeReconnectsID, Asserts: "no user of the bus had its connection dropped more than twelve times in the " +
+		"last hour: the bus module's nats_closed_connections", From: "issue 327", Kind: kindBusReconnects,
+		Phase: 1, run: probeReconnects},
+	// The account agents run as (novox/hq ADR 0266): where a machine names one, its node-engine has judged it
+	// unable to become root without a person — what ADR 0259 §8 rests an authorised answer on.
+	{ID: agentAccountProbe, Asserts: "every machine that names an agent account has it judged, on its node-engine's " +
+		"newest statement, unable to become root without a person", From: "ADR 0266, ADR 0259 §8",
+		Kind: kindAgentCanBecomeRoot, Phase: 1, run: probeAgentAccounts},
 	{ID: "DW", Asserts: "the watchdogs of the signals table ran within three of their intervals",
 		From: "ADR 0227 rule 6: the watchers are watched", Kind: "watchdogs-silent", Phase: 1, run: probeWatchdogs},
 	// The core's health definitions (novox/hq to-be 45 §8, ADR 0236): what a core component's new build is

cmd/mesh-controller/facts.go

@@ -269,7 +269,8 @@ func gatherFacts(ctx context.Context, open *stores, busVersion string) (snapshot
 	engines := map[string]bool{}
 	for _, n := range nodes {
 		m := snapshot.Machine{Name: scrub.Machine(n.Name), Length: len(n.Name), Adopted: n.Adopted,
-			AccountHome: scrub.Text(n.AccountHome), NodeEngine: n.HostVersion, PublicDomain: domains[n.Name]}
+			AccountHome: scrub.Text(n.AccountHome), NodeEngine: n.HostVersion, PublicDomain: domains[n.Name],
+			AgentAccount: scrub.Account(n.AgentAccount), AgentAccountHome: scrub.Text(n.AgentAccountHome)}
 		switch n.Account {
 		case "", "root":
 			m.Account = n.Account

cmd/mesh-controller/handacts.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"io"
 	"os"
 	"slices"
 	"sort"
@@ -14,7 +15,6 @@ import (
 
 	"github.com/nats-io/nats.go"
 
-	"github.com/novox/mesh-controller/internal/broker"
 	"github.com/novox/mesh-controller/internal/conditions"
 	"github.com/novox/mesh-controller/internal/link"
 )
@@ -154,14 +154,10 @@ func onTheBus(f func(*nats.Conn) error) error {
 	if handActConn != nil {
 		return f(handActConn)
 	}
-	address, err := broker.BusAddress()
+	js, err := aBus()
 	if err != nil {
 		return err
 	}
-	js, err := broker.Dial(address)
-	if err != nil {
-		return fmt.Errorf("cannot reach the bus: %w", err)
-	}
 	defer js.Close()
 	return f(js.Conn())
 }
@@ -252,7 +248,13 @@ func handActCommand(ctx context.Context, args []string) error {
 	if len(args) > 0 && args[0] == "list" {
 		args = args[1:]
 	}
+	return listHandActs(ctx, args, os.Stdout)
+}
+
+// listHandActs is `hand-acts`: what was done by hand lately, and the causes done more than once.
+func listHandActs(ctx context.Context, args []string, w io.Writer) error {
 	set := flag.NewFlagSet("hand-acts", flag.ContinueOnError)
+	usageTo(set, w)
 	days := set.Int("days", 14, "how many days back")
 	asJSON := set.Bool("json", false, "as data")
 	if _, err := parseAround(set, args); err != nil {
@@ -270,27 +272,27 @@ func handActCommand(ctx context.Context, args []string) error {
 			if err != nil {
 				return err
 			}
-			fmt.Println(string(body))
+			fmt.Fprintln(w, string(body))
 			return nil
 		}
 		if len(acts) == 0 {
-			fmt.Printf("nothing was done by hand in the last %d day(s)\n", *days)
+			fmt.Fprintf(w, "nothing was done by hand in the last %d day(s)\n", *days)
 			return nil
 		}
 		for i := len(acts) - 1; i >= 0; i-- {
 			a := acts[i]
-			fmt.Printf("%s  %s  %s %s\n    by %s — %s (cause: %s", a.At.Local().Format("2006-01-02 15:04"), a.ID,
+			fmt.Fprintf(w, "%s  %s  %s %s\n    by %s — %s (cause: %s", a.At.Local().Format("2006-01-02 15:04"), a.ID,
 				a.Verb, strings.Join(a.Args, " "), a.By, a.Why, a.Cause)
 			if a.Condition != "" {
-				fmt.Printf(", condition %s", a.Condition)
+				fmt.Fprintf(w, ", condition %s", a.Condition)
 			}
-			fmt.Println(")")
+			fmt.Fprintln(w, ")")
 			if pushedRecorded(a) {
 				carried := strings.Join(a.Carried, "; ")
 				if carried == "" {
 					carried = recordedBefore[a.ID]
 				}
-				fmt.Printf("    a push of recorded builds, no repair: %s\n", carried)
+				fmt.Fprintf(w, "    a push of recorded builds, no repair: %s\n", carried)
 			}
 		}
 		if len(repeated) > 0 {
@@ -299,7 +301,7 @@ func handActCommand(ctx context.Context, args []string) error {
 				causes = append(causes, fmt.Sprintf("%s ×%d", c, n))
 			}
 			sort.Strings(causes)
-			fmt.Printf("\ndone by hand more than once in a fortnight — a healer is wanted (to-be 45 S15): %s\n",
+			fmt.Fprintf(w, "\ndone by hand more than once in a fortnight — a healer is wanted (to-be 45 S15): %s\n",
 				strings.Join(causes, ", "))
 		}
 		return nil

cmd/mesh-controller/handacts_test.go

@@ -22,10 +22,6 @@ func TestARepairByHandWithoutAReasonIsRefused(t *testing.T) {
 		{"plans", map[string]any{"close": "plan-1"}},
 		{"plans", map[string]any{"stop": "plan-1"}},
 		{"hand-act", map[string]any{"what": "restarted the proxy", "cause": "proxy-stuck"}},
-		{"command", map[string]any{"command": "push anchor"}},
-		{"command", map[string]any{"command": "plans close plan-1"}},
-		{"command", map[string]any{"command": "broker consumer-reset EVENTS controller"}},
-		{"command", map[string]any{"command": "hand-act record restarted --cause x"}},
 	} {
 		argv, err := argvFor(c.verb, c.args)
 		if c.verb == "plans" && err == nil {
@@ -65,7 +61,6 @@ func TestARepairByHandCarriesItsReason(t *testing.T) {
 		{"plans", map[string]any{"retry": "plan-1"}, "plans retry plan-1"},
 		{"hand-act", map[string]any{"what": "restarted", "why": "hung", "cause": "proxy", "condition": "machine.a.silent"},
 			"hand-act record restarted --why hung --cause proxy --condition machine.a.silent"},
-		{"command", map[string]any{"command": "push anchor --why stuck"}, "push anchor --why stuck"},
 		{"command", map[string]any{"command": "plans plan-1"}, "plans plan-1"},
 	} {
 		argv, err := argvFor(c.verb, c.args)

cmd/mesh-controller/main.go

@@ -15,6 +15,7 @@ import (
 	"os/signal"
 	"syscall"
 
+	"github.com/novox/mesh-controller/internal/broker"
 	"github.com/novox/mesh-controller/internal/identity"
 	"github.com/novox/mesh-controller/internal/inventory"
 	"github.com/novox/mesh-controller/internal/licences"
@@ -53,6 +54,9 @@ func run() error {
 		return fmt.Errorf("no command given")
 	}
 
+	// Every connection this process dials says what it is (novox/hq issue 327).
+	broker.ConnectionName = connectionName(args[0], os.Getenv(verbVar))
+
 	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
 	defer stop()
 	// Whatever this process holds of the controller's lease is given back as it ends (novox/hq to-be
@@ -416,3 +420,18 @@ func (b builds) Built(ctx context.Context, result link.BuildResult) error {
 	statusFrom.nudge()
 	return nil
 }
+
+// verbVar carries the seat verb a command runs for, from the serving controller to the process it starts.
+const verbVar = "MESH_VERB"
+
+// connectionName is what this process's connections say they are in the bus's list (novox/hq issue 327):
+// the serving controller, a verb's own process and which verb, or a command run at a shell and which.
+func connectionName(command, verb string) string {
+	switch {
+	case command == "serve":
+		return "mesh-controller serving"
+	case verb != "":
+		return "mesh-controller verb " + verb
+	}
+	return "mesh-controller command " + command
+}

cmd/mesh-controller/merge_gate.go

@@ -1013,6 +1013,11 @@ func raiseFromFacts(ctx context.Context, open *stores, f snapshot.Facts, shelf m
 				return notes, err
 			}
 		}
+		if m.AgentAccount != "" {
+			if err := inv.SetAgentAccount(ctx, m.Name, m.AgentAccount, m.AgentAccountHome); err != nil {
+				return notes, err
+			}
+		}
 		if m.PublicDomain != "" {
 			if err := inv.SetPublicDomain(ctx, m.Name, m.PublicDomain); err != nil {
 				return notes, err

cmd/mesh-controller/module_health.go

@@ -73,7 +73,7 @@ func stateHealth(ctx context.Context, inv *inventory.Inventory, k *conditions.Ke
 	for _, r := range h.Resources {
 		kept := inventory.ResourceHealth{Module: r.Module, Resource: r.Resource, Kind: r.Kind, Target: r.Target,
 			State: r.State, Reason: r.Reason, Since: r.Since, Streak: r.Streak, Restarts: r.Restarts,
-			Check: r.Check, Needs: r.Needs, Account: r.Account}
+			Check: r.Check, Needs: r.Needs, Account: r.Account, Root: r.Root}
 		resources = append(resources, kept)
 		if r.State == link.StateUnhealthy && r.Module != "" {
 			unhealthy[r.Module] = append(unhealthy[r.Module], kept)

cmd/mesh-controller/modules.go

@@ -414,6 +414,9 @@ func settingsCommand(ctx context.Context, args []string) error {
 	// word (novox/hq issue 304). Adding and changing keys needs nothing; removing one needs this.
 	replace := set.Bool("replace", false, "for set: remove the keys the new layer does not name")
 	history := set.Bool("history", false, "for show: the layers this one replaced, the latest first")
+	// Set by the settings verb on every line it composes (novox/hq ADR 0266): a verb may not change where a
+	// module's directories are placed or which of the machine's paths it reaches.
+	throughVerb := set.Bool("through-verb", false, "the line came from the settings verb: places and accesses are refused")
 	positionals, err := parseAround(set, args[1:])
 	if err != nil {
 		return err
@@ -445,6 +448,11 @@ func settingsCommand(ctx context.Context, args []string) error {
 		if err != nil {
 			return err
 		}
+		if *throughVerb {
+			if key := terminalSettingChanged(before, values); key != "" {
+				return terminalSettingRefusal(key, positionals[0], where)
+			}
+		}
 		added, changed, removed := settingsChange(before, values)
 		if len(removed) > 0 && !*replace {
 			return fmt.Errorf("%s on %s: this layer would no longer set %s. A layer is replaced whole; "+
@@ -596,6 +604,15 @@ func settingsCommand(ctx context.Context, args []string) error {
 		if len(positionals) != 1 {
 			return errors.New("settings clear <module> [--node <node>]")
 		}
+		if *throughVerb {
+			before, _, err := inv.Layer(ctx, *node, positionals[0])
+			if err != nil {
+				return err
+			}
+			if key := terminalSettingChanged(before, nil); key != "" {
+				return terminalSettingRefusal(key, positionals[0], where)
+			}
+		}
 		if err := inv.ClearSettings(ctx, *node, positionals[0]); err != nil {
 			return err
 		}
@@ -1051,3 +1068,28 @@ func declaresTools(m catalogue.Manifest) bool {
 	}
 	return false
 }
+
+// terminalSettings are the keys a verb may not change (novox/hq ADR 0266). `places` says where the node-engine
+// creates and, as root, owns a module's directories, with an owner the setting names; `accesses` says which of
+// the machine's paths are mounted into a module's container. Set through a verb, either would let any caller —
+// an agent among them — have root hand it a directory, or mount one of the machine's into a container it
+// reaches. They are the operator's, at the controller's terminal.
+var terminalSettings = []string{catalogue.PlacesSetting, catalogue.AccessesSetting}
+
+// terminalSettingChanged is the first of those keys a layer change would add, change or remove, or "".
+func terminalSettingChanged(before, after map[string]any) string {
+	for _, key := range terminalSettings {
+		was, _ := json.Marshal(before[key])
+		now, _ := json.Marshal(after[key])
+		if string(was) != string(now) {
+			return key
+		}
+	}
+	return ""
+}
+
+func terminalSettingRefusal(key, module, where string) error {
+	return terminalRefusal("%s of %s on %s is set at the controller's terminal only, never through a verb: it says "+
+		"where root creates and owns a module's directories, or which of the machine's paths reach its container, "+
+		"and whoever may call a verb includes agents (novox/hq ADR 0266). Nothing was changed", key, module, where)
+}

cmd/mesh-controller/nodes.go

@@ -7,7 +7,9 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"io"
 	"net"
+	"os"
 	"strings"
 	"time"
 
@@ -98,6 +100,12 @@ func nodeCommand(ctx context.Context, args []string) error {
 			"containers reaching outward. The machine reports which of its links face outside; see " +
 			"`node show <name>`")
 
+	case "agent-account":
+		// The account agents run as on this machine, when it is not the operator's (novox/hq ADR 0266). Here,
+		// at the controller's terminal, and nowhere else: no verb and no setting names it, so no agent can
+		// name itself another account.
+		return nodeAgentAccount(ctx, inv, args[1:])
+
 	case "account":
 		// The operator's login on this machine (novox/hq to-be 29): what a home-scoped file is
 		// owned by and which account `ssh <node>` uses. Reports with no argument; sets with one;
@@ -105,7 +113,7 @@ func nodeCommand(ctx context.Context, args []string) error {
 		return nodeAccount(ctx, inv, args[1:])
 
 	default:
-		return fmt.Errorf("node has no %q; it has add, list, show, public-domain and account", args[0])
+		return fmt.Errorf("node has no %q; it has add, list, show, public-domain, account and agent-account", args[0])
 	}
 }
 
@@ -176,6 +184,57 @@ func nodeAccount(ctx context.Context, inv *inventory.Inventory, positionals []st
 	return nil
 }
 
+const agentAccountUsage = "node agent-account <name> — what it is now; " +
+	"<name> <account> [home] to name the account agents run as (home defaults to /home/<account>); " +
+	"<name> --clear to have them run as the operator account again"
+
+// nodeAgentAccount reports, names or clears the account agents run as on a node (novox/hq ADR 0266). Read-
+// shaped with no account, like public-domain; clearing is asked for by name.
+func nodeAgentAccount(ctx context.Context, inv *inventory.Inventory, args []string) error {
+	set := flag.NewFlagSet("node agent-account", flag.ContinueOnError)
+	clear := set.Bool("clear", false, "agents run as the operator account again")
+	positionals, err := parseAround(set, args)
+	if err != nil {
+		return err
+	}
+	if len(positionals) == 0 || len(positionals) > 3 {
+		return errors.New(agentAccountUsage)
+	}
+	node := positionals[0]
+	switch {
+	case *clear && len(positionals) > 1:
+		return fmt.Errorf("name an agent account for %s or --clear, not both", node)
+	case *clear:
+		if err := inv.SetAgentAccount(ctx, node, "", ""); err != nil {
+			return err
+		}
+		fmt.Printf("agents on %s run as the operator account again\n", node)
+		fmt.Printf("  run `push %s` to send it; the agent account itself is kept (the mesh never deletes a login)\n", node)
+		return nil
+	case len(positionals) >= 2:
+		home := ""
+		if len(positionals) == 3 {
+			home = positionals[2]
+		}
+		if err := inv.SetAgentAccount(ctx, node, positionals[1], home); err != nil {
+			return err
+		}
+		fmt.Printf("agents on %s run as %s\n", node, positionals[1])
+		fmt.Printf("  run `push %s` to send it; the self-check says once its node-engine has judged it "+
+			"unable to become root\n", node)
+		return nil
+	default:
+		n, err := inv.NodeByName(ctx, node)
+		if err != nil {
+			return err
+		}
+		for _, line := range agentAccountLines(ctx, inv, n) {
+			fmt.Println(strings.TrimPrefix(line, "  "))
+		}
+		return nil
+	}
+}
+
 const publicDomainUsage = "node public-domain <name> — what it is now; " +
 	"<name> <domain> to set it; <name> --clear to take it away"
 
@@ -590,6 +649,10 @@ func showNode(ctx context.Context, inv *inventory.Inventory, name string) error
 	if err := showMode(ctx, inv, node); err != nil {
 		return err
 	}
+	// Whom agents run as here, and whether that account can become root without a person (ADR 0266).
+	for _, line := range agentAccountLines(ctx, inv, node) {
+		fmt.Println(line)
+	}
 
 	// The domain its routed names are composed under, when it has one (novox/hq ADR 0066). Shown
 	// only when set: a machine that serves nothing to the outside has no domain, and saying so of
@@ -684,11 +747,14 @@ func orNotReported(s string) string {
 }
 
 // printJSON prints a value as indented JSON, the shape every `--json` answers in.
-func printJSON(v any) error {
+func printJSON(v any) error { return printJSONTo(os.Stdout, v) }
+
+// printJSONTo is printJSON to a writer of the caller's.
+func printJSONTo(w io.Writer, v any) error {
 	body, err := json.MarshalIndent(v, "", "  ")
 	if err != nil {
 		return err
 	}
-	fmt.Println(string(body))
+	fmt.Fprintln(w, string(body))
 	return nil
 }

cmd/mesh-controller/plain_words.go

@@ -110,6 +110,15 @@ var plainWordings = map[string]func(conditions.Observation) words{
 				"reaches it. It keeps running what it has.", m),
 			Resolved: m + " can get new instructions again"}
 	}),
+	kindAgentCanBecomeRoot: worded(func(o conditions.Observation) words {
+		m := machineOr(o, "a machine")
+		return words{Headline: "Sessions on " + m + " could become root",
+			Needs: "take the sessions' own account out of every group and rule that grants root; the details say which.",
+			Explanation: fmt.Sprintf("Assistant sessions on %s run under an account of their own, so that none "+
+				"can take over the machine without you. The machine cannot show that this holds now, so an answer "+
+				"from your phone authorises nothing there until it does.", m),
+			Resolved: "Sessions on " + m + " cannot become root again"}
+	}),
 	"own-address-banned": worded(func(o conditions.Observation) words {
 		m := machineOr(o, "a machine")
 		return words{Headline: m + " has banned the mesh",
@@ -543,6 +552,12 @@ var plainWordings = map[string]func(conditions.Observation) words{
 			Explanation: "The bus reports a listener too slow to keep up, so messages to it are late.",
 			Resolved:    "The listener keeps up again"}
 	}),
+	kindBusReconnects: worded(func(o conditions.Observation) words {
+		return words{Headline: "A client keeps losing the bus",
+			Explanation: "One of the mesh's clients lost its connection to the bus again and again in the last hour. " +
+				"While it reconnects, what it says and what it is asked waits.",
+			Resolved: "Resolved: the client stays connected"}
+	}),
 	"max-deliveries": worded(func(o conditions.Observation) words {
 		return words{Headline: "A listener gave up on messages",
 			Needs: "deliver them again or drop them, from the mesh MCP server.",

cmd/mesh-controller/plan.go

@@ -136,7 +136,8 @@ func planFor(ctx context.Context, open *stores, nodeName string) (catalogue.Reso
 	resolved, err := catalogue.Resolve(shelf, assigned,
 		catalogue.Node{Name: nodeName, Site: site, Capabilities: capabilities,
 			At: onNetwork[nodeName], PublicDomain: publicDomain,
-			Account: who.Account, AccountHome: who.AccountHome}, world)
+			Account: who.Account, AccountHome: who.AccountHome,
+			AgentAccount: who.AgentAccount, AgentAccountHome: who.AgentAccountHome}, world)
 	if err != nil {
 		// The node's own set does not compose. Marked, because this is the only failure here that
 		// a mesh-wide gatherer may pass over — see notResolvable.
@@ -885,8 +886,13 @@ func renderingFor(ctx context.Context, open *stores, node string,
 	if err != nil {
 		return catalogue.Rendering{}, inventory.Node{}, err
 	}
+	judgesRoot, err := engineJudgesRoot(ctx, inv, node)
+	if err != nil {
+		return catalogue.Rendering{}, inventory.Node{}, err
+	}
 	return catalogue.Rendering{
 		ReadsHealth:   readsHealth,
+		JudgesRoot:    judgesRoot,
 		BusMembership: memberships[node],
 		Settings:      settings, Generators: gens, Grants: grants, Needed: needed, Foreseen: foreseen, Ports: ports,
 		Certificate: certificate, Authority: authority, Mesh: private, Names: names,
@@ -909,6 +915,16 @@ func engineReadsHealth(ctx context.Context, inv *inventory.Inventory, node strin
 	return had && stated.Contract >= link.ReadinessContract, nil
 }
 
+// engineJudgesRoot says whether a machine's node-engine judges a user's declared `root` (novox/hq ADR 0266),
+// by its own newest statement, for the same reason as engineReadsHealth: an older engine parses strictly.
+func engineJudgesRoot(ctx context.Context, inv *inventory.Inventory, node string) (bool, error) {
+	stated, had, err := inv.HealthOf(ctx, node)
+	if err != nil {
+		return false, err
+	}
+	return had && stated.Contract >= link.RootContract, nil
+}
+
 // zonesInTheMesh is every zone a module in the mesh declares, where the mesh placed it (novox/hq ADR
 // 0199): the zone settled from that node's settings, the node's private address, the port the
 // answering listen is published on there.

cmd/mesh-controller/plan_retry.go

@@ -9,7 +9,6 @@ import (
 	"strings"
 	"time"
 
-	"github.com/novox/mesh-controller/internal/broker"
 	"github.com/novox/mesh-controller/internal/inventory"
 	"github.com/novox/mesh-controller/internal/link"
 )
@@ -98,11 +97,9 @@ func buildSeatPause(ctx context.Context, inv *inventory.Inventory, plans []inven
 	if len(holders) == 0 {
 		return pauseView{}
 	}
-	address, err := broker.BusAddress()
-	if err != nil {
-		return pauseView{}
-	}
-	js, err := broker.Dial(address)
+	// On the serving controller's own connection when this is it: a watchdog tick while a walk waits for a
+	// build dialled one every 30 seconds (novox/hq issue 327).
+	js, err := aBus()
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "could not reach the bus to read whether the build seat is paused: %v\n", err)
 		return pauseView{}

cmd/mesh-controller/push.go

@@ -219,6 +219,10 @@ func serve(ctx context.Context) (err error) {
 	}
 	// The hand-act log is counted for `status` on this connection rather than a new one a minute.
 	handActConn = bus.Conn
+	// And everything else this controller does on the bus for a moment (novox/hq issue 327).
+	servingBus.Store(server.JetStream())
+	// No longer serving: nothing is lent, and dead-letters says it is not read here (novox/hq issue 330).
+	defer servingBus.Store(nil)
 	// And says when it replaced a value given by hand (novox/hq ADR 0228).
 	givenEvents = bus
 	// And a pull request's merge check, asked when the forge announces its head and said when judged

cmd/mesh-controller/queue.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"io"
 	"os"
 	"sort"
 	"strings"
@@ -37,22 +38,21 @@ const (
 	killAnswer = 75 * time.Second
 )
 
-// dialTheBus opens the controller's own connection, for a command that reads or changes the queue.
+// dialTheBus is the controller's connection, for a command that reads or changes the queue: the serving
+// controller's own, lent, when this process is it (novox/hq issue 327).
 func dialTheBus() (*broker.JetStream, error) {
-	address, err := broker.BusAddress()
-	if err != nil {
-		return nil, err
-	}
-	js, err := broker.Dial(address)
-	if err != nil {
-		return nil, fmt.Errorf("cannot reach the bus: %w", err)
-	}
-	return js, nil
+	return aBus()
 }
 
 // queueCommand prints every ask in the build seat's work queue.
 func queueCommand(ctx context.Context, args []string) error {
+	return listQueue(ctx, args, os.Stdout)
+}
+
+// listQueue is `queue`: the build queue, as a person reads it or as JSON.
+func listQueue(ctx context.Context, args []string, w io.Writer) error {
 	set := flag.NewFlagSet("queue", flag.ContinueOnError)
+	usageTo(set, w)
 	asJSON := set.Bool("json", false, "the queue as JSON")
 	if _, err := parseAround(set, args); err != nil {
 		return err
@@ -72,10 +72,10 @@ func queueCommand(ctx context.Context, args []string) error {
 		if err != nil {
 			return err
 		}
-		fmt.Println(string(body))
+		fmt.Fprintln(w, string(body))
 		return nil
 	}
-	fmt.Print(queueText(q, time.Now()))
+	fmt.Fprint(w, queueText(q, time.Now()))
 	return nil
 }
 

cmd/mesh-controller/reconnects.go

@@ -0,0 +1,173 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/nats-io/nats.go"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// D15: no client of the bus reconnects in a loop (novox/hq issue 327).
+//
+// The server's connection total was the one number that would show a client reconnecting, and every verb
+// the controller served opened and closed a connection of its own, hundreds an hour, so a loop was
+// invisible in it. The bus's own module reads the server's record of closed connections
+// (`nats_closed_connections`); this asks it every run, and says each user whose connections were dropped —
+// closed by anything but the client itself: a read or write error, a stale connection, a slow consumer, a
+// refused login — more often than reconnectBound in the last hour.
+
+const (
+	probeReconnectsID = "D15"
+	kindBusReconnects = "bus-reconnects"
+	// reconnectBound is how many dropped connections in an hour one user may have before it is said:
+	// a client that loses its connection every five minutes. Provisional.
+	reconnectBound = 12
+	// busModule is the module that is the bus, and closedTool its tool that reads closed connections.
+	busModule  = "nats"
+	closedTool = "nats_closed_connections"
+	closedAsk  = 20 * time.Second
+)
+
+// closedConnections is what the bus's module answers.
+type closedConnections struct {
+	Hours   float64 `json:"hours"`
+	Reaches bool    `json:"reaches"`
+	Users   []struct {
+		User           string  `json:"user"`
+		Closed         int     `json:"closed"`
+		Dropped        int     `json:"dropped"`
+		DroppedPerHour float64 `json:"dropped_per_hour"`
+		Names          []struct {
+			Name    string         `json:"name"`
+			Closed  int            `json:"closed"`
+			Dropped int            `json:"dropped"`
+			Reasons map[string]int `json:"reasons"`
+		} `json:"names"`
+	} `json:"users"`
+}
+
+// probeReconnects is D15.
+func probeReconnects(ctx context.Context, d *doctor) ([]conditions.Observation, error) {
+	if d.js == nil {
+		return nil, fmt.Errorf("no bus to ask the bus's module over")
+	}
+	on, err := d.open.inventory.Running(ctx, busModule)
+	if err != nil {
+		return nil, err
+	}
+	if len(on) == 0 {
+		return nil, nil // no bus module assigned: a mesh whose bus is not the mesh's module
+	}
+	return reconnectsOn(ctx, d.js.Conn(), on[0])
+}
+
+// reconnectsOn asks the bus module on its machine and says who reconnects in a loop.
+func reconnectsOn(ctx context.Context, conn *nats.Conn, node string) ([]conditions.Observation, error) {
+	read, err := askClosed(ctx, conn, node)
+	if isNothingServes(err) {
+		// A bus module older than its tool has nothing it can say, which is not a failure of the probe.
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	return reconnecting(read), nil
+}
+
+// askClosed asks the bus's module, on its machine, who closed connections in the last hour.
+func askClosed(ctx context.Context, conn *nats.Conn, node string) (closedConnections, error) {
+	var read closedConnections
+	answer, err := link.AskModuleToolOn(ctx, conn, busModule, closedTool, node, map[string]any{"hours": 1}, closedAsk)
+	if err != nil {
+		return read, err
+	}
+	if answer.Error != "" {
+		return read, fmt.Errorf("%s on %s answered %s with an error: %s", busModule, node, closedTool, answer.Error)
+	}
+	if err := unmarshalAnswer(answer, &read); err != nil {
+		return read, fmt.Errorf("%s on %s answered %s with something unreadable: %w", busModule, node, closedTool, err)
+	}
+	return read, nil
+}
+
+// reconnecting is one observation per user whose connections were dropped more than reconnectBound times
+// an hour.
+func reconnecting(read closedConnections) []conditions.Observation {
+	hours := read.Hours
+	if hours <= 0 {
+		hours = 1
+	}
+	var out []conditions.Observation
+	for _, u := range read.Users {
+		if u.User == "" || strings.HasPrefix(u.User, "(") {
+			// Refused before it logged in: no client of the mesh's, so nobody's reconnect loop. A login
+			// refused again and again is a question of its own, not this probe's.
+			continue
+		}
+		perHour := float64(u.Dropped) / hours
+		if perHour <= reconnectBound {
+			continue
+		}
+		reasons := map[string]int{}
+		var names []string
+		for _, n := range u.Names {
+			if n.Dropped == 0 {
+				continue
+			}
+			names = append(names, fmt.Sprintf("%q ×%d", n.Name, n.Dropped))
+			for r, c := range n.Reasons {
+				if r != "Client Closed" {
+					reasons[r] += c
+				}
+			}
+		}
+		var why []string
+		for r, c := range reasons {
+			why = append(why, fmt.Sprintf("%s ×%d", r, c))
+		}
+		sort.Strings(why)
+		partial := ""
+		if !read.Reaches {
+			partial = " (at least: the server's record of closed connections does not reach back the whole hour)"
+		}
+		who, machine := busUserWords(u.User)
+		out = append(out, conditions.Observation{Scope: conditions.ScopeBus, ID: u.User, Kind: kindBusReconnects,
+			Machine: machine, Severity: conditions.Warning,
+			Summary: fmt.Sprintf("the bus dropped %s's connection %d times in the last hour%s, more than %d: a "+
+				"client reconnecting in a loop", u.User, u.Dropped, partial, reconnectBound),
+			Said: fmt.Sprintf("%d of %d closed connections dropped in %.0f h; by name %s; why %s", u.Dropped,
+				u.Closed, hours, strings.Join(names, ", "), strings.Join(why, ", ")),
+			Headline: clip(conditions.Capital(who)+" keeps losing the bus", 60),
+			Explanation: conditions.Capital(fmt.Sprintf("%s lost its connection to the bus %d times in the last hour "+
+				"and connected again each time. While it reconnects, what it says and what it is asked waits.", who,
+				u.Dropped)),
+			Resolved: "Resolved: " + who + " stays connected"})
+	}
+	return out
+}
+
+// busUserWords is a bus user as the operator says it, and the machine it is on: `node.<machine>` the
+// node-engine, `<machine>.node-tools` the tool runner, `controller` the controller, `<machine>.<module>` a
+// module.
+func busUserWords(user string) (string, string) {
+	switch {
+	case user == "controller":
+		return "the controller", ""
+	case strings.HasPrefix(user, "node."):
+		m := strings.TrimPrefix(user, "node.")
+		return "the node-engine on " + m, m
+	}
+	if m, module, ok := strings.Cut(user, "."); ok {
+		if module == "node-tools" {
+			return "the tool runner on " + m, m
+		}
+		return module + " on " + m, m
+	}
+	return "a client of the bus", ""
+}

cmd/mesh-controller/reconnects_test.go

@@ -0,0 +1,189 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+	"testing"
+
+	"github.com/nats-io/nats.go"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/link"
+	"github.com/novox/mesh-controller/internal/testbus"
+)
+
+// The serving controller's own connection serves what it does for a moment: no connection is opened,
+// and closing what it was lent leaves the serving one open (novox/hq issue 327).
+func TestTheServingControllerLendsItsOwnConnection(t *testing.T) {
+	bus := testbus.Start(t)
+	serving, err := broker.Dial(bus.ClientURL())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer serving.Close()
+	if err := serving.EnsureControllerBuckets(); err != nil {
+		t.Fatal(err)
+	}
+	was := servingBus.Load()
+	servingBus.Store(serving)
+	defer servingBus.Store(was)
+	t.Setenv(broker.NATSVar, bus.ClientURL())
+
+	before, _ := bus.Varz(nil)
+	lent, err := aBus()
+	if err != nil {
+		t.Fatal(err)
+	}
+	lent.Close()
+	if !serving.Conn().IsConnected() {
+		t.Fatal("closing a lent connection closed the serving controller's")
+	}
+	if err := onTheBus(func(*nats.Conn) error { return nil }); err != nil {
+		t.Fatal(err)
+	}
+	handlers, _, err := seatToolHandlers()
+	if err != nil {
+		t.Fatal(err)
+	}
+	answer, err := handlers["hand-acts"](context.Background(), json.RawMessage(`{}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if a := answer.(verbAnswer); !a.OK || a.Answer == nil {
+		t.Fatalf("hand-acts answered %+v", a)
+	}
+	_, _ = handlers["queue"](context.Background(), json.RawMessage(`{}`))
+	after, _ := bus.Varz(nil)
+	if opened := after.TotalConnections - before.TotalConnections; opened != 0 {
+		t.Fatalf("the serving controller opened %d connection(s) of its own", opened)
+	}
+}
+
+// A verb that still runs as a process of its own says which in the bus's list of connections.
+func TestAVerbsOwnProcessNamesItsConnection(t *testing.T) {
+	bus := testbus.Start(t)
+	setup, err := broker.Dial(bus.ClientURL())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := setup.EnsureControllerBuckets(); err != nil {
+		t.Fatal(err)
+	}
+	setup.Close()
+	asAProcess(t, bus.ClientURL())
+	handlers, _, err := seatToolHandlers()
+	if err != nil {
+		t.Fatal(err)
+	}
+	// A silence acts, so it is still its own process; it dials, and finds no such condition.
+	_, _ = handlers["conditions"](context.Background(),
+		json.RawMessage(`{"silence":"bus.nothing.here","for":"1h","why":"a test"}`))
+	names := closedNames(t, bus)
+	found := false
+	for _, n := range names {
+		found = found || n == "mesh-controller verb conditions"
+	}
+	if !found {
+		t.Fatalf("the verb's connection was named %q", names)
+	}
+}
+
+func TestEachProcessNamesItsConnectionsForWhatItIs(t *testing.T) {
+	for _, c := range []struct{ command, verb, want string }{
+		{"serve", "", "mesh-controller serving"},
+		{"conditions", "conditions", "mesh-controller verb conditions"},
+		{"delivery", "delivery-check", "mesh-controller verb delivery-check"},
+		{"push", "", "mesh-controller command push"},
+	} {
+		if got := connectionName(c.command, c.verb); got != c.want {
+			t.Errorf("%s/%s: %q", c.command, c.verb, got)
+		}
+	}
+}
+
+// D15: a user whose connections are dropped more than twelve times an hour is said, in plain words; one
+// whose client closes its own short connections is not.
+func TestAClientReconnectingInALoopIsSaid(t *testing.T) {
+	var read closedConnections
+	if err := json.Unmarshal([]byte(`{"hours":1,"reaches":true,"users":[
+		{"user":"ace.node-tools","closed":40,"dropped":40,"dropped_per_hour":40,"names":[
+			{"name":"ace.node-tools","closed":40,"dropped":40,"reasons":{"Stale Connection":30,"Read Error":10}}]},
+		{"user":"controller","closed":300,"dropped":0,"names":[
+			{"name":"mesh-controller verb delivery-check","closed":300,"dropped":0,"reasons":{"Client Closed":300}}]},
+		{"user":"(no user: refused before it logged in)","closed":90,"dropped":90,"names":[{"name":"","closed":90,
+			"dropped":90,"reasons":{"Authentication Failure":90}}]},
+		{"user":"node.anchor","closed":5,"dropped":5,"names":[{"name":"mesh-host/anchor","closed":5,"dropped":5,
+			"reasons":{"Read Error":5}}]}]}`), &read); err != nil {
+		t.Fatal(err)
+	}
+	found := reconnecting(read)
+	if len(found) != 1 {
+		t.Fatalf("%+v", found)
+	}
+	o := found[0]
+	if o.ID != "ace.node-tools" || o.Machine != "ace" || o.Kind != kindBusReconnects ||
+		o.Headline != "The tool runner on ace keeps losing the bus" || !strings.Contains(o.Said, "Stale Connection ×30") {
+		t.Fatalf("%+v", o)
+	}
+	if why, ok := conditions.PlainWords(conditions.Words{Headline: o.Headline, Explanation: o.Explanation,
+		Resolved: o.Resolved}, "ace"); !ok {
+		t.Fatalf("not plain: %s", why)
+	}
+}
+
+// The bus's module is asked on its machine, over the bus.
+func TestTheBusModuleIsAskedWhoClosedConnections(t *testing.T) {
+	bus := testbus.Start(t)
+	conn, err := nats.Connect(bus.ClientURL())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	sub, err := conn.Subscribe(link.ModuleToolOn("nats", "nats_closed_connections", "anchor"), func(m *nats.Msg) {
+		_ = m.Respond([]byte(`{"result":{"hours":1,"reaches":true,"users":[{"user":"controller","closed":2,"dropped":0}]}}`))
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = sub.Unsubscribe() }()
+	read, err := askClosed(context.Background(), conn, "anchor")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(read.Users) != 1 || read.Users[0].Closed != 2 {
+		t.Fatalf("%+v", read)
+	}
+}
+
+// A bus module older than the tool answers nothing to the question: the probe passes over it quietly.
+func TestAnOlderBusModuleIsPassedOverQuietly(t *testing.T) {
+	bus := testbus.Start(t)
+	conn, err := nats.Connect(bus.ClientURL())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	found, err := reconnectsOn(context.Background(), conn, "anchor")
+	if err != nil || len(found) != 0 {
+		t.Fatalf("a bus module without the tool: %v %v", found, err)
+	}
+}
+
+// A verb answered in the serving controller says its flag errors in its answer, not in the controller's log.
+func TestAFlagErrorIsSaidInTheAnswer(t *testing.T) {
+	bus := testbus.Start(t)
+	serving, err := broker.Dial(bus.ClientURL())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer serving.Close()
+	was := servingBus.Load()
+	servingBus.Store(serving)
+	defer servingBus.Store(was)
+	answer, read := readHere(context.Background(), []string{"hand-acts", "--bogus"})
+	if !read || answer.OK || !strings.Contains(answer.Output, "flag provided but not defined") {
+		t.Fatalf("answered %+v", answer)
+	}
+}

cmd/mesh-controller/replay327_test.go

@@ -0,0 +1,106 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"os/exec"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/nats-io/nats-server/v2/server"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/testbus"
+)
+
+// novox/hq issue 327, replayed with only what the controller had before its fix, so it can be laid over
+// the older commit. On 2026-10-08 the bus's connection total rose by 5.2 a minute while the same 16
+// connections stayed open, and three calls of `conditions` in one second added three: each verb ran as a
+// process of the controller's own binary, which dialled the bus, logged in and left. The operator's
+// channel reads `conditions` at least once a minute. A verb that only reads, served by the serving
+// controller, opens no connection of its own.
+func TestReplay327(t *testing.T) {
+	bus := testbus.Start(t)
+	serving, err := broker.Dial(bus.ClientURL())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer serving.Close()
+	if err := serving.EnsureControllerBuckets(); err != nil {
+		t.Fatal(err)
+	}
+	keeper, err := keeperOn(context.Background(), serving.Conn())
+	if err != nil {
+		t.Fatal(err)
+	}
+	// The serving controller: its keeper and its connection, as serve sets them.
+	keptBefore, connBefore := conditionsFrom, handActConn
+	conditionsFrom, handActConn = keeper, serving.Conn()
+	defer func() { conditionsFrom, handActConn = keptBefore, connBefore }()
+	// A verb that runs as a process of its own runs this controller's binary, on this bus.
+	asAProcess(t, bus.ClientURL())
+
+	handlers, _, err := seatToolHandlers()
+	if err != nil {
+		t.Fatal(err)
+	}
+	accepted := func() uint64 {
+		v, err := bus.Varz(nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return v.TotalConnections
+	}
+	before := accepted()
+	for i := 0; i < 3; i++ {
+		answer, err := handlers["conditions"](context.Background(), json.RawMessage(`{}`))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if a, ok := answer.(verbAnswer); !ok || !a.OK {
+			t.Fatalf("conditions answered %+v", answer)
+		}
+	}
+	if opened := accepted() - before; opened != 0 {
+		t.Fatalf("three conditions calls opened %d connection(s) to the bus; the serving controller is on it already",
+			opened)
+	}
+}
+
+// asAProcess makes a verb that runs as a process of its own run this package's binary, on the bus at url:
+// built into the test's own directory, which goes with the test.
+func asAProcess(t *testing.T, url string) {
+	t.Helper()
+	path := filepath.Join(t.TempDir(), "mesh-controller")
+	if out, err := exec.Command("go", "build", "-o", path, ".").CombinedOutput(); err != nil {
+		t.Fatalf("the controller could not be built to run a verb as its own process: %v: %s", err, out)
+	}
+	was := ownImage
+	ownImage = func() string { return path }
+	t.Cleanup(func() { ownImage = was })
+	t.Setenv(broker.NATSVar, url)
+	t.Setenv(broker.CertificateVar, "")
+}
+
+// closedNames are the names of the connections the bus saw closed.
+func closedNames(t *testing.T, bus *server.Server) []string {
+	t.Helper()
+	deadline := time.Now().Add(5 * time.Second)
+	var names []string
+	for time.Now().Before(deadline) {
+		connz, err := bus.Connz(&server.ConnzOptions{State: server.ConnClosed})
+		if err != nil {
+			t.Fatal(err)
+		}
+		names = names[:0]
+		for _, c := range connz.Conns {
+			names = append(names, c.Name)
+		}
+		if len(names) > 0 {
+			return names
+		}
+		time.Sleep(50 * time.Millisecond)
+	}
+	return names
+}

cmd/mesh-controller/rollout.go

@@ -131,7 +131,10 @@ func readinessOf(ctx context.Context, inv *inventory.Inventory) (broker.Readines
 		// **Dialled the way the mesh dials it** — credential and pin — because a bare connect to a
 		// bus that requires TLS and a user fails at the handshake, and the check then reported a
 		// standing server as absent (seen live, 2026-09-28).
-		if js, err := broker.Dial(address, nats.Timeout(5*time.Second)); err == nil {
+		// The serving controller's own connection answers it without a second (novox/hq issue 327).
+		if serving := servingBus.Load(); serving != nil && serving.Conn().IsConnected() {
+			state.ServerStanding = true
+		} else if js, err := broker.Dial(address, nats.Timeout(5*time.Second)); err == nil {
 			state.ServerStanding = true
 			js.Close()
 		}

cmd/mesh-controller/seatverbs.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"github.com/nats-io/nats.go/micro"
+	"io"
 	"os"
 	"os/exec"
 	"slices"
@@ -28,6 +29,9 @@ import (
 // answer. It also means a refusal is the same refusal in the same words, because it is the same
 // output.
 
+// verbKey carries the verb a call is for, to the process it runs.
+type verbKey struct{}
+
 // verbAnswer is what a verb answers: what the command printed, whether it succeeded, and — where the
 // command speaks JSON — the same as data.
 type verbAnswer struct {
@@ -51,6 +55,9 @@ func argvFor(verb string, args map[string]any) ([]string, error) {
 		return nil, err
 	}
 	argv, err := a.commandLine()
+	if err == nil {
+		err = terminalOnly(argv)
+	}
 	if len(a.misread) > 0 {
 		// The table and the command line disagree: the verb reads an argument no caller can see
 		// in its schema, so no caller could ever pass it.
@@ -241,6 +248,11 @@ func (a *verbArguments) commandLine() ([]string, error) {
 		if len(argv) == 0 {
 			return nil, errors.New("command names no command")
 		}
+		// The generic verb only reads (novox/hq ADR 0266): what writes has a named verb that composes its own
+		// line, or is the operator's at the controller's terminal.
+		if err := commandReads(argv); err != nil {
+			return nil, err
+		}
 		// The generic verb is no way round the hand-act log (novox/hq to-be 45 §7): a repair through
 		// it says why, as it would through its own verb.
 		if repair := repairingCommand(argv); repair != "" && !slices.ContainsFunc(argv, isWhyFlag) {
@@ -793,13 +805,16 @@ func (a *verbArguments) commandLine() ([]string, error) {
 		var argv []string
 		switch {
 		case on("clear"):
-			argv = []string{"settings", "clear", str("module")}
+			argv = []string{"settings", "clear", str("module"), "--through-verb"}
 		case str("values") != "":
 			argv = []string{"settings", "set", str("module"), str("values")}
 			// What a set removes is refused unless meant (novox/hq ADR 0217).
 			if on("replace") {
 				argv = append(argv, "--replace")
 			}
+			// Through a verb, never places or accesses (novox/hq ADR 0266): the command refuses a change to
+			// either when told the line came from a verb.
+			argv = append(argv, "--through-verb")
 		default:
 			// Neither values nor clear: the layer as it stands, which is what a caller reads before
 			// replacing it (novox/hq ADR 0217) — and with history, the layers it replaced.
@@ -921,6 +936,12 @@ func runVerb(ctx context.Context, argv []string) (verbAnswer, error) {
 		caller = "a seat call whose caller the bus did not name"
 	}
 	cmd.Env = append(cmd.Env, link.CallerVar+"="+caller+", through the "+catalogue.ControllerSeatName+" seat")
+	// And which verb, so the connection it dials says so in the bus's list (novox/hq issue 327).
+	verb, _ := ctx.Value(verbKey{}).(string)
+	if verb == "" {
+		verb = argv[0]
+	}
+	cmd.Env = append(cmd.Env, verbVar+"="+verb)
 	// Two buffers, one answer. What the command *says* is both streams, in the order a person at
 	// a shell would read them; what it *answers as data* is standard output alone — `status --json`
 	// prints its warnings beside the document, and a JSON parsed from the two together parsed
@@ -929,18 +950,7 @@ func runVerb(ctx context.Context, argv []string) (verbAnswer, error) {
 	cmd.Stdout = &stdout
 	cmd.Stderr = &stderr
 	runErr := cmd.Run()
-	answer := verbAnswer{Output: stdout.String() + stderr.String(), OK: runErr == nil}
-	if jsonVerbs[argv[0]] && runErr == nil {
-		var parsed any
-		if json.Unmarshal(bytes.TrimSpace(stdout.Bytes()), &parsed) == nil {
-			answer.Answer = parsed
-			if overviewVerbs[argv[0]] {
-				// Once, as data: the same document again as text doubled an answer that already
-				// outgrew one message of the bus (novox/hq issue 314).
-				answer.Output = stderr.String() + "its answer, as data, is `answer`\n"
-			}
-		}
-	}
+	answer := answerOf(argv, stdout.Bytes(), stderr.String(), runErr == nil)
 	var exit *exec.ExitError
 	if runErr != nil && !errors.As(runErr, &exit) {
 		// Not the command refusing — the command not running at all, which is this process's fault.
@@ -955,6 +965,66 @@ func runVerb(ctx context.Context, argv []string) (verbAnswer, error) {
 	return answer, nil
 }
 
+// answerOf is what a command said, as a verb answers it: both streams as text, and standard output as data
+// where the command speaks JSON.
+func answerOf(argv []string, stdout []byte, stderr string, ok bool) verbAnswer {
+	answer := verbAnswer{Output: string(stdout) + stderr, OK: ok}
+	if jsonVerbs[argv[0]] && ok {
+		var parsed any
+		if json.Unmarshal(bytes.TrimSpace(stdout), &parsed) == nil {
+			answer.Answer = parsed
+			if overviewVerbs[argv[0]] {
+				// Once, as data: the same document again as text doubled an answer that already
+				// outgrew one message of the bus (novox/hq issue 314).
+				answer.Output = stderr + "its answer, as data, is `answer`\n"
+			}
+		}
+	}
+	return answer
+}
+
+// readHere answers a verb that only reads the bus in the serving controller itself, on its own connection
+// and keeper (novox/hq issue 327): the same command, writing to the answer rather than to a process's
+// output, so the answer is the one the command prints. False for any other command line, which runs as a
+// command of its own. Every `conditions` call — the operator's channel reads it at least once a minute —
+// was a process that dialled the bus, logged in and left.
+func readHere(ctx context.Context, argv []string) (verbAnswer, bool) {
+	var read func(context.Context, []string, io.Writer) error
+	args := argv[1:]
+	// Each where this process holds what it reads: the serving keeper, the hand-act log's connection, the
+	// serving connection.
+	switch argv[0] {
+	case "conditions":
+		sub := "list"
+		if len(args) > 0 && !strings.HasPrefix(args[0], "-") {
+			sub, args = args[0], args[1:]
+		}
+		if conditionsFrom != nil {
+			read = map[string]func(context.Context, []string, io.Writer) error{
+				"list": listConditions, "show": showCondition, "history": conditionHistory}[sub]
+		}
+	case "hand-acts":
+		if handActConn != nil || servingBus.Load() != nil {
+			read = listHandActs
+		}
+	case "queue":
+		if servingBus.Load() != nil {
+			read = listQueue
+		}
+	}
+	if read == nil {
+		return verbAnswer{}, false
+	}
+	var out bytes.Buffer
+	stderr := ""
+	err := read(ctx, args, &out)
+	if err != nil {
+		// As the command says it when it fails (main).
+		stderr = "mesh-controller: " + err.Error() + "\n"
+	}
+	return answerOf(argv, out.Bytes(), stderr, err == nil), true
+}
+
 // seatToolHandlers are the handlers for every verb the mesh-controller seat declares, from the
 // store's row, so a verb the row does not carry is not served. A verb it carries that this binary
 // cannot run is named at start and answers the reason when called — never a refusal to serve, which
@@ -1004,7 +1074,8 @@ func seatToolHandlers() (map[string]link.ToolHandler, []string, error) {
 			}
 			continue
 		}
-		if _, err := argvFor(verb, sampleArguments(v)); err != nil {
+		var policy *heldAtTheTerminal
+		if _, err := argvFor(verb, sampleArguments(v)); err != nil && !errors.As(err, &policy) {
 			// **A row ahead of this binary is not a reason to go silent.**
 			//
 			// The row is the store's and a control plane follows it (novox/hq ADR 0154), so a verb
@@ -1038,6 +1109,7 @@ func seatToolHandlers() (map[string]link.ToolHandler, []string, error) {
 			if err != nil {
 				return nil, err
 			}
+			ctx = context.WithValue(ctx, verbKey{}, verb)
 			if verb == "status" && statusFrom != nil {
 				// At once, from the summary the serving controller keeps (novox/hq to-be 45 Phase 0).
 				return statusFrom.answer(ctx)
@@ -1046,6 +1118,9 @@ func seatToolHandlers() (map[string]link.ToolHandler, []string, error) {
 				// Whatever it did, `status` is composed again once it has.
 				defer statusFrom.nudge()
 			}
+			if answer, read := readHere(ctx, argv); read {
+				return answer, nil
+			}
 			if answersFirst(argv) {
 				// Before anything is sent: a push sends the bus's own machine first, and a broker
 				// reloading its user list forgets the answer it was about to permit (novox/hq issue 265).
@@ -1261,3 +1336,131 @@ func seatAnnouncement(handlers map[string]link.ToolHandler) micro.Info {
 		Endpoints:   endpoints,
 	}
 }
+
+// nodeReads are the `node` subcommands a verb may run: the ones that only read.
+var nodeReads = map[string]bool{"list": true, "show": true}
+
+// flagsOnly says a command line's rest names no subcommand: empty, or beginning with a flag. For a command
+// with no subcommands every word is a flag, its value or a name it reads.
+func flagsOnly(rest []string) bool { return len(rest) == 0 || strings.HasPrefix(rest[0], "-") }
+
+// subIn says the rest begins with one of these subcommands.
+func subIn(rest []string, subs ...string) bool {
+	return len(rest) > 0 && slices.Contains(subs, rest[0])
+}
+
+// commandReadForms are the command lines the generic `command` verb may run (novox/hq ADR 0266): **an allow
+// list of the ones that only read**, judged command by command. Anything else — every command that writes a
+// record, sends, builds, issues an account or a token, sets a key, accepts, rotates, recovers or exports a
+// secret — is refused, and a command added later is refused until it is judged a read. Writing has its named
+// verbs, which compose their own lines and are judged by terminalOnly; the rest is the operator's at the
+// controller's terminal.
+var commandReadForms = map[string]func(rest []string) bool{
+	"status": flagsOnly, "version": flagsOnly, "help": flagsOnly, "seats": flagsOnly, "healers": flagsOnly,
+	"hand-acts": flagsOnly, "durations": flagsOnly, "collection": flagsOnly, "images": flagsOnly,
+	"artifacts": flagsOnly, "data": flagsOnly, "builds": flagsOnly, "queue": flagsOnly,
+	// `plan <node>` previews a node's declaration; it sends nothing.
+	"plan": func([]string) bool { return true },
+	// `plans` lists and `plans <id>` shows one; `plans stop|close|go` acts.
+	// Judged on every word, not the first: a flag before the subcommand (`plans --json go <id>`) still acts.
+	"plans": func(r []string) bool {
+		return !slices.ContainsFunc(r, func(w string) bool { return slices.Contains(plansActs, w) })
+	},
+	// `doctor` answers the last run, `probes` and `signals` describe; `doctor run` runs.
+	"doctor":     func(r []string) bool { return flagsOnly(r) || subIn(r, "probes", "signals") },
+	"conditions": func(r []string) bool { return flagsOnly(r) || subIn(r, "list", "show", "history") },
+	"node":       func(r []string) bool { return subIn(r, "list", "show") },
+	"module":     func(r []string) bool { return subIn(r, "list") },
+	"settings":   func(r []string) bool { return subIn(r, "show", "preferences") },
+	"retire":     func(r []string) bool { return subIn(r, "list") },
+	"cleanup":    func(r []string) bool { return subIn(r, "list") },
+	"delivery":   func(r []string) bool { return subIn(r, "plan", "walks") },
+	// `bus` alone says the bus's step; `bus upgrade` takes one.
+	"bus": func(r []string) bool { return len(r) == 0 },
+	// `mirrors` lists; --record and --confirm keep a mirror.
+	"mirrors": func(r []string) bool {
+		return flagsOnly(r) && !slices.ContainsFunc(r, func(w string) bool {
+			return w == "--record" || w == "-record" || strings.HasPrefix(w, "--record=") || strings.HasPrefix(w, "-record=") ||
+				w == "--confirm" || w == "-confirm" || strings.HasPrefix(w, "--confirm=")
+		})
+	},
+}
+
+// plansActs are the `plans` subcommands that act on a walk; no other word of a plans line is one of them.
+var plansActs = []string{"go", "stop", "close", "retry"}
+
+// heldAtTheTerminal is a refusal of policy (novox/hq ADR 0266): the verb is known and served, and this line is
+// the operator's at the controller's terminal. Never read as a verb this binary is behind on.
+type heldAtTheTerminal struct{ msg string }
+
+func (e *heldAtTheTerminal) Error() string { return e.msg }
+
+func terminalRefusal(format string, args ...any) error {
+	return &heldAtTheTerminal{fmt.Sprintf(format, args...)}
+}
+
+// commandReads refuses a line the generic verb may not run, saying what it may.
+func commandReads(argv []string) error {
+	if read, ok := commandReadForms[argv[0]]; ok && read(argv[1:]) {
+		return nil
+	}
+	return terminalRefusal("%q is not a reading command, and the generic command verb only reads (novox/hq ADR 0266): "+
+		"whoever may call a verb includes agents, and a line that writes, issues, sets a key or reveals a secret "+
+		"would be theirs to run. Use the named verb for it, or run it at the controller's terminal. The verb may "+
+		"run: %s. Nothing was done", strings.Join(argv, " "), commandReadNames())
+}
+
+func commandReadNames() string {
+	names := make([]string, 0, len(commandReadForms))
+	for n := range commandReadForms {
+		names = append(names, n)
+	}
+	sort.Strings(names)
+	return strings.Join(names, ", ") + " (each in its reading forms)"
+}
+
+// terminalOnlyCommands are the commands no verb runs, whatever composed them (novox/hq ADR 0266): they set
+// the operator's key, issue a credential or a token that is answered to the caller, or accept, recover or
+// export a secret. Their answers or effects hand whoever calls them what the runtime's account holds.
+var terminalOnlyCommands = map[string]string{
+	"operator": "the operator's key and credential",
+	"identity": "the mesh's identity keys",
+	"token":    "a token a machine joins with, answered to the caller",
+	"broker":   "the bus's accounts",
+	"api":      "the controller's API keys",
+	"licence":  "the licences' secrets",
+}
+
+// terminalOnly refuses, through any verb, a command that is the operator's at the controller's terminal
+// alone (novox/hq ADR 0266). **Every `node` subcommand that is not a read**: `node account` and
+// `node agent-account` above all. Whoever may call a verb includes agents, and an agent that named itself
+// the operator account, or cleared the agent account, would have the next send grant it root through the
+// sudo module's rule. An allow list, so a subcommand added later is refused until it is judged a read.
+func terminalOnly(argv []string) error {
+	if len(argv) == 0 {
+		return nil
+	}
+	if what, kept := terminalOnlyCommands[argv[0]]; kept {
+		return terminalRefusal("%s is run at the controller's terminal only, never through a verb: it holds %s, and "+
+			"whoever may call a verb includes agents (novox/hq ADR 0266). Nothing was done", argv[0], what)
+	}
+	// Of a secret's commands only rotation, which seals the new value to the machine that uses it.
+	if argv[0] == "secret" && (len(argv) < 2 || argv[1] != "rotate") {
+		return terminalRefusal("secret %s is run at the controller's terminal only, never through a verb: accepting, "+
+			"recovering or exporting a secret hands it to whoever asks, and that includes agents (novox/hq ADR "+
+			"0266). Nothing was done", strings.Join(argv[1:], " "))
+	}
+	if argv[0] != "node" {
+		return nil
+	}
+	if len(argv) > 1 && nodeReads[argv[1]] {
+		return nil
+	}
+	sub := "node"
+	if len(argv) > 1 {
+		sub += " " + argv[1]
+	}
+	return terminalRefusal("%s is run at the controller's terminal only, never through a verb: a node's accounts "+
+		"decide who may become root on it (novox/hq ADR 0266). A verb may run node list and node show. "+
+		"Nothing was done", sub)
+}

cmd/mesh-controller/seatverbs_schema_test.go

@@ -268,10 +268,10 @@ var accountedFlags = map[string]map[string]string{
 		"self":    "set by the verb from the repository's form: a path on the forge, or a URL",
 		"dry-run": "withheld: a dry run answers only when the build ends, which a call cannot wait for; `command` reaches it",
 	},
-	"builds": {"n": "=limit"},
-	"plans":  {"n": "=limit", "what-if": "=repository"},
+	"builds":   {"n": "=limit"},
+	"plans":    {"n": "=limit", "what-if": "=repository"},
+	"settings": {"through-verb": "set by the verb on every set and clear: places and accesses are the terminal's (novox/hq ADR 0266)"},
 	// The machine's tunnel key, named as the verb's other arguments are (novox/hq ADR 0169).
-	"token issue": {"overlay-key": "=overlay_key"},
 	"durations": {
 		"json": "set by the verb: the answer is data",
 		"all":  "withheld: every measurement of a fortnight is more than a call should carry; `command` reaches it",

cmd/mesh-controller/seatverbs_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"github.com/novox/mesh-controller/internal/link"
 	"strings"
@@ -108,22 +109,25 @@ func TestRotateTakesAProvisionOrAnOwnSecret(t *testing.T) {
 	}
 }
 
-// `token` is `token issue` at a shell, with the machine's tunnel key (novox/hq ADR 0169).
-func TestTokenIssuesForAMachineAndItsTunnelKey(t *testing.T) {
-	argv, err := argvFor("token", map[string]any{"new": "laptop", "overlay_key": "k", "for": "2h"})
-	if err != nil || strings.Join(argv, " ") != "token issue --new laptop --overlay-key k --for 2h" {
-		t.Fatalf("token: %v %v", argv, err)
+// `token` answers a joining token to its caller, and whoever may call a verb includes agents: it is the
+// controller's terminal's alone (novox/hq ADR 0266), refused through the verb whatever it is given.
+func TestTokenIsRefusedThroughAVerb(t *testing.T) {
+	for _, args := range []map[string]any{{"new": "laptop", "overlay_key": "k", "for": "2h"}, {"node": "ace"}} {
+		argv, err := argvFor("token", args)
+		if err == nil || !strings.Contains(err.Error(), "controller's terminal only") {
+			t.Fatalf("token %v: %v %v", args, argv, err)
+		}
 	}
 }
 
 // `settings` is `settings set|clear` at a shell, with the values passed inline (novox/hq issue 198).
 func TestSettingsSetsOrClearsALayer(t *testing.T) {
 	argv, err := argvFor("settings", map[string]any{"module": "dnsmasq", "values": `{"a":1}`, "node": "ace"})
-	if err != nil || strings.Join(argv, " ") != `settings set dnsmasq {"a":1} --node ace` {
+	if err != nil || strings.Join(argv, " ") != `settings set dnsmasq {"a":1} --through-verb --node ace` {
 		t.Fatalf("set on a machine: %v %v", argv, err)
 	}
 	argv, _ = argvFor("settings", map[string]any{"module": "dnsmasq", "clear": "true"})
-	if strings.Join(argv, " ") != "settings clear dnsmasq" {
+	if strings.Join(argv, " ") != "settings clear dnsmasq --through-verb" {
 		t.Fatalf("clear for the mesh: %v", argv)
 	}
 	// Neither values nor clear reads the layer as it stands (novox/hq ADR 0217): what a caller reads
@@ -237,20 +241,20 @@ func TestAJSONVerbsAnswerIsItsStandardOutput(t *testing.T) {
 	}
 }
 
-// `command` is the generic verb: the command line as given, split as a shell would, nothing added —
-// so an operator's `node account g14 jochen` is one call through the console rather than a shell on
-// the control node (novox/hq ADR 0154, ADR 0175).
+// `command` is the generic verb: the command line as given, split as a shell would, nothing added
+// (novox/hq ADR 0154, ADR 0175). It once carried an operator's `node account g14 jochen` too; a node's
+// accounts are the controller's terminal's alone since ADR 0266 (TestNoVerbSetsANodesAccounts).
 func TestCommandRunsTheLineAsGiven(t *testing.T) {
-	argv, err := argvFor("command", map[string]any{"command": "node account g14 jochen"})
-	if err != nil || strings.Join(argv, " ") != "node account g14 jochen" {
+	argv, err := argvFor("command", map[string]any{"command": "node show g14"})
+	if err != nil || strings.Join(argv, " ") != "node show g14" {
 		t.Fatalf("a plain line: %v %v", argv, err)
 	}
-	argv, err = argvFor("command", map[string]any{"command": `settings set dnsmasq '{"a": "b c"}' --node ace`})
-	if err != nil || len(argv) != 6 || argv[3] != `{"a": "b c"}` {
+	argv, err = argvFor("command", map[string]any{"command": `settings show 'dns masq' --node ace`})
+	if err != nil || len(argv) != 5 || argv[2] != "dns masq" {
 		t.Fatalf("a quoted word stays one word: %q %v", argv, err)
 	}
-	argv, err = argvFor("command", map[string]any{"command": `node add "the box" --adopted`})
-	if err != nil || len(argv) != 4 || argv[2] != "the box" {
+	argv, err = argvFor("command", map[string]any{"command": `plan "the box" --json`})
+	if err != nil || len(argv) != 3 || argv[1] != "the box" {
 		t.Fatalf("double quotes group: %q %v", argv, err)
 	}
 	if _, err := argvFor("command", map[string]any{"command": "   "}); err == nil {
@@ -355,3 +359,59 @@ func TestTheControllerAnnouncesTheVerbsItServes(t *testing.T) {
 		}
 	}
 }
+
+// The generic verb only reads (novox/hq ADR 0266): an allow list of reading forms, and every line that
+// writes, issues, sets a key or reveals a secret refused — the chain a review found ran through it: set the
+// operator's key to one the caller holds, rotate secrets sealed to it, open them.
+func TestTheCommandVerbOnlyReads(t *testing.T) {
+	for _, line := range []string{
+		"operator key set --replace k", "operator issue", "secret accept a b", "secret rotate a b c",
+		"secret recover a", "secret export a", "token issue --new x", "identity show", "broker users",
+		"api key", "licence show", "push anchor --why w", "assign novox m", "settings set m {}",
+		"settings clear m", "module add f", "module check /etc", "module forget m", "module issue m --node a",
+		"seat rename a b", "plans close p --why w", "plans go p", "plans retry p", "plans stop p",
+		"plans --json go p", "plans -n 3 close p", "plans --what-if r retry p", "doctor run", "conditions silence c --why w",
+		"retire approve x", "cleanup delete x", "delivery check", "delivery go x", "bus upgrade",
+		"mirrors --record x", "mirrors --confirm", "hand-act record x --why y --cause z", "serve", "migrate",
+		"prepare", "declare x", "overlay x", "facts", "merge-gate", "check-here", "build x", "rebuild x",
+		"cancel x", "kill x", "clear x", "replay x", "pause", "resume", "pin a b", "unpin a", "take x",
+		"converge", "adopt x", "rollout x", "upgrade x", "collect", "board", "builder", "ask x", "frobnicate",
+	} {
+		argv, err := argvFor("command", map[string]any{"command": line})
+		var policy *heldAtTheTerminal
+		if err == nil || !errors.As(err, &policy) {
+			t.Errorf("%q ran as %v (%v); the generic verb only reads", line, argv, err)
+		}
+	}
+	for _, line := range []string{
+		"status --json", "version", "seats --json", "healers", "hand-acts --days 3", "durations", "collection",
+		"images", "artifacts --collected", "data --machine a", "builds --log b", "queue", "plan ace --diff",
+		"plans", "plans plan-1", "doctor", "doctor probes", "doctor signals", "conditions", "conditions list",
+		"conditions show c", "conditions history", "node list", "node show ace", "module list",
+		"settings show m", "settings preferences", "retire list", "cleanup list", "delivery plan --repository r",
+		"delivery walks", "bus", "mirrors --json",
+	} {
+		if _, err := argvFor("command", map[string]any{"command": line}); err != nil {
+			t.Errorf("%q, a read, was refused: %v", line, err)
+		}
+	}
+}
+
+// What hands a caller a key, a credential or a secret is refused whichever verb composed it.
+func TestNoVerbSetsTheOperatorsKeyOrRevealsASecret(t *testing.T) {
+	for _, argv := range [][]string{
+		{"operator", "key", "set"}, {"operator", "issue"}, {"identity"}, {"token", "issue"}, {"broker", "users"},
+		{"api"}, {"licence"}, {"secret", "export", "x"}, {"secret", "recover", "x"}, {"secret", "accept", "x"}, {"secret"},
+	} {
+		if err := terminalOnly(argv); err == nil {
+			t.Errorf("%v passed", argv)
+		}
+	}
+	if err := terminalOnly([]string{"secret", "rotate", "n", "m", "s"}); err != nil {
+		t.Errorf("rotating seals to the machine that uses the secret, and stays a verb's: %v", err)
+	}
+	// A policy refusal is not a verb this binary is behind on: every verb is still served.
+	if _, behind, err := seatToolHandlers(); err != nil || len(behind) != 0 {
+		t.Fatalf("behind %v: %v", behind, err)
+	}
+}

cmd/mesh-controller/servingbus.go

@@ -0,0 +1,49 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"sync/atomic"
+
+	"github.com/novox/mesh-controller/internal/broker"
+)
+
+// The serving controller's own connection, lent to whatever it does for a moment (novox/hq issue 327).
+//
+// Every place that needed the bus for a moment dialled it: a verb's own process, and in the serving
+// controller a watchdog tick reading whether the build seat paused, a walk's step reading readiness, a
+// queue read. Each paid a connection, a TLS handshake and a login on the control node, and hundreds an
+// hour hid in the server's connection total the one thing it would show: a client reconnecting in a loop.
+// The serving controller is on the bus already; what it does is done on that connection.
+
+// servingBus is the serving controller's connection, set when it starts serving; nil in every other
+// process, which dials its own.
+var servingBus atomic.Pointer[broker.JetStream]
+
+// aBus is a connection for something done for a moment: the serving controller's own, lent — so its
+// Close closes nothing — when this process is it, and otherwise one dialled for it, named for this
+// process (broker.ConnectionName), which its Close closes.
+func aBus() (*broker.JetStream, error) {
+	if serving := servingBus.Load(); serving != nil {
+		return broker.Borrow(serving), nil
+	}
+	address, err := broker.BusAddress()
+	if err != nil {
+		return nil, err
+	}
+	js, err := broker.Dial(address)
+	if err != nil {
+		return nil, fmt.Errorf("cannot reach the bus: %w", err)
+	}
+	return js, nil
+}
+
+// usageTo sends a command's flag errors and usage to where its answer goes when that is not this process's
+// output: a verb answered in the serving controller says them in its answer, not in the controller's log.
+func usageTo(set *flag.FlagSet, w io.Writer) {
+	if w != os.Stdout {
+		set.SetOutput(w)
+	}
+}

cmd/mesh-controller/terminal_settings_test.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// Where root creates and owns a module's directories, and which of the machine's paths reach its container,
+// are the controller's terminal's alone (novox/hq ADR 0266): through the settings verb, a caller who set
+// `places` to /etc with an owner of its own would have the next send hand it /etc.
+
+func TestTheSettingsVerbMarksEverySetAndClearAsAVerbs(t *testing.T) {
+	for _, args := range []map[string]any{
+		{"module": "plex", "values": `{"places":{"data":"/etc"}}`},
+		{"module": "plex", "values": `{}`, "replace": "true", "node": "home"},
+		{"module": "plex", "clear": "true"},
+	} {
+		argv, err := argvFor("settings", args)
+		if err != nil || !strings.Contains(strings.Join(argv, " "), "--through-verb") {
+			t.Fatalf("%v: %v %v", args, argv, err)
+		}
+	}
+	// The generic verb never reaches settings set or clear at all.
+	for _, line := range []string{"settings set plex {}", "settings clear plex"} {
+		if _, err := argvFor("command", map[string]any{"command": line}); err == nil {
+			t.Fatalf("command ran %q", line)
+		}
+	}
+}
+
+func TestATerminalSettingIsChangedOnlyAtTheTerminal(t *testing.T) {
+	cases := []struct {
+		before, after map[string]any
+		want          string
+	}{
+		{nil, map[string]any{"places": map[string]any{"data": "/etc"}}, "places"},
+		{map[string]any{"accesses": map[string]any{"m": "/storage"}}, map[string]any{}, "accesses"},
+		{map[string]any{"places": map[string]any{"d": "/srv/d"}}, nil, "places"},
+		{map[string]any{"places": map[string]any{"d": "/srv/d"}, "a": 1.0},
+			map[string]any{"places": map[string]any{"d": "/srv/d"}, "a": 2.0}, ""},
+	}
+	for _, c := range cases {
+		if got := terminalSettingChanged(c.before, c.after); got != c.want {
+			t.Errorf("%v → %v: %q, want %q", c.before, c.after, got, c.want)
+		}
+	}
+}
+
+// Over the real stores: the verb's line is refused for places, the terminal's is taken, and a clear through
+// the verb of a layer that places a directory is refused too.
+func TestPlacesAreRefusedThroughTheVerbAndTakenAtTheTerminal(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, catalogue.Manifest{Module: "notes", Version: "1",
+		Resources: []map[string]any{{"id": "data", "type": "directory", "mode": "0755"},
+			{"id": "rc", "type": "file", "path": "/etc/notes.conf", "mode": "0644", "content": "x = ${setting:x}\n"}}})
+	if _, err := assign(ctx, open, "laptop", "notes"); err != nil {
+		t.Fatal(err)
+	}
+	set := func(through bool, values string) error {
+		args := []string{"set", "notes", values, "--node", "laptop"}
+		if through {
+			args = append(args, "--through-verb")
+		}
+		return settingsCommand(ctx, args)
+	}
+	if err := set(true, `{"places":{"data":{"path":"/srv/notes","owner":"1000:1000"}}}`); err == nil ||
+		!strings.Contains(err.Error(), "controller's terminal only") {
+		t.Fatalf("places through the verb: %v", err)
+	}
+	if err := set(false, `{"places":{"data":{"path":"/srv/notes","owner":"1000:1000"}},"x":0}`); err != nil {
+		t.Fatalf("places at the terminal: %v", err)
+	}
+	if err := set(true, `{"places":{"data":{"path":"/srv/notes","owner":"1000:1000"}},"x":1}`); err != nil {
+		t.Fatalf("a verb may change another key and keep places as they are: %v", err)
+	}
+	if err := settingsCommand(ctx, []string{"clear", "notes", "--node", "laptop", "--through-verb"}); err == nil ||
+		!strings.Contains(err.Error(), "controller's terminal only") {
+		t.Fatalf("a clear through the verb took places away: %v", err)
+	}
+	// And never at /etc, from anywhere.
+	if err := set(false, `{"places":{"data":{"path":"/etc","owner":"1000:1000"}},"x":1}`); err == nil ||
+		!strings.Contains(err.Error(), "/etc") {
+		t.Fatalf("a place at /etc: %v", err)
+	}
+	// A line break in any setting is refused where it is kept.
+	if err := set(false, `{"places":{"data":{"path":"/srv/notes","owner":"1000:1000"}},"x":"a\nPATH=/tmp"}`); err == nil ||
+		!strings.Contains(err.Error(), "line break") {
+		t.Fatalf("a line break: %v", err)
+	}
+}

cmd/mesh-controller/unseen_test.go

@@ -158,7 +158,7 @@ func TestTheVerbsCarryReadReplaceAndMove(t *testing.T) {
 	}{
 		{"settings", map[string]any{"module": "plex", "node": "home"}, []string{"settings", "show", "plex", "--node", "home"}},
 		{"settings", map[string]any{"module": "plex", "history": "true"}, []string{"settings", "show", "plex", "--history"}},
-		{"settings", map[string]any{"module": "plex", "values": "{}", "replace": "true"}, []string{"settings", "set", "plex", "{}", "--replace"}},
+		{"settings", map[string]any{"module": "plex", "values": "{}", "replace": "true"}, []string{"settings", "set", "plex", "{}", "--replace", "--through-verb"}},
 		{"push", map[string]any{"node": "home", "move": "plex", "why": "w"},
 			[]string{"push", "home", "--wait", "0", "--move", "plex", "--why", "w"}},
 		{"push", map[string]any{"why": "w"}, []string{"push", "--behind", "--wait", "0", "--why", "w"}},

cmd/mesh-controller/watchdogs.go

@@ -660,8 +660,6 @@ func watchTheMesh(ctx context.Context, open *stores, server *link.Server, bus li
 		return nil
 	}
 	conditionsFrom = keeper
-	// What a consumer gave up on is read and acted on by the verb in this process (novox/hq issue 330).
-	deadLettersOn.Store(&busHandles{conn: server.JetStream().Conn(), js: server.JetStream().Context()})
 	logf := func(format string, args ...any) { fmt.Printf(format+"\n", args...) }
 	stopHearing, err := server.HearAdvisories(logf)
 	if err != nil {
@@ -688,8 +686,6 @@ func watchTheMesh(ctx context.Context, open *stores, server *link.Server, bus li
 	return func() {
 		stop()
 		stopHearing()
-		// No longer serving: the verb answers that it does not read DEAD_LETTERS here (novox/hq issue 330).
-		deadLettersOn.Store(nil)
 		flushing, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 		defer cancel()
 		keeper.Close(flushing)

go.mod

@@ -35,4 +35,4 @@ require (
 // committed. Every build (the build agent's `go build`, the Dockerfile) compiles from vendor/ and
 // fetches nothing; go refuses to build when vendor/ and this file disagree, so a pin moved without
 // `go mod vendor` fails loudly, at once, everywhere.
-replace github.com/novox/mesh-host => git.novox.be/novox/mesh-host v0.0.0-20261007162834-56e2ebec4bac
+replace github.com/novox/mesh-host => git.novox.be/novox/mesh-host v0.0.0-20261008191932-c74cf16b755e

go.sum

@@ -4,6 +4,14 @@ git.novox.be/novox/mesh-host v0.0.0-20261007120832-bdd44154ccac h1:KvnKtJ2rWeIE/
 git.novox.be/novox/mesh-host v0.0.0-20261007120832-bdd44154ccac/go.mod h1:VlilMCRZ5yyNXg7SNigNBLr0Gt32jrGw5KSNq5JAVYs=
 git.novox.be/novox/mesh-host v0.0.0-20261007162834-56e2ebec4bac h1:yLtFS0pDCCqIE9Zx8hgXEFG9fUWzf8L9WQoKV+Amk1E=
 git.novox.be/novox/mesh-host v0.0.0-20261007162834-56e2ebec4bac/go.mod h1:VlilMCRZ5yyNXg7SNigNBLr0Gt32jrGw5KSNq5JAVYs=
+git.novox.be/novox/mesh-host v0.0.0-20261008163010-8390fab5cb35 h1:3uag/9Tv4Y3ippY5Yr1rIIBh23Ur9RbhzOB4CLbKz0I=
+git.novox.be/novox/mesh-host v0.0.0-20261008163010-8390fab5cb35/go.mod h1:VlilMCRZ5yyNXg7SNigNBLr0Gt32jrGw5KSNq5JAVYs=
+git.novox.be/novox/mesh-host v0.0.0-20261008183646-5fc37b44a94e h1:+XxiuXJqWj7ZcGMB2b/WGPsC8zpmXgmwXnBvjw9C/CM=
+git.novox.be/novox/mesh-host v0.0.0-20261008183646-5fc37b44a94e/go.mod h1:72ZATZjxMLaJfWdvlSDJrygIoBzCmKIjCDMhEXxVzTo=
+git.novox.be/novox/mesh-host v0.0.0-20261008185244-76f3ca12b8b8 h1:T4Bu9ymmcNC0x57EnDkjfZlJ9dvEeK8BRuHZTqw+uuI=
+git.novox.be/novox/mesh-host v0.0.0-20261008185244-76f3ca12b8b8/go.mod h1:72ZATZjxMLaJfWdvlSDJrygIoBzCmKIjCDMhEXxVzTo=
+git.novox.be/novox/mesh-host v0.0.0-20261008191932-c74cf16b755e h1:oQofUhCNm0m4+pVASxvErqisEOMTkOyWjTAfGqt2lHA=
+git.novox.be/novox/mesh-host v0.0.0-20261008191932-c74cf16b755e/go.mod h1:72ZATZjxMLaJfWdvlSDJrygIoBzCmKIjCDMhEXxVzTo=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op/go.mod h1:FQyySiasQQM8735Ddel3MRojmy4dA1IqCeyJ5jmPMbI=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=

internal/broker/jetstream.go

@@ -28,6 +28,8 @@ import (
 type JetStream struct {
 	conn *nats.Conn
 	js   nats.JetStreamContext
+	// borrowed is a connection lent by its owner (Borrow): closing it is the owner's.
+	borrowed bool
 	// Note is how this says something it decided not to fail over. Nil is silent, which is only
 	// right for a caller that has no way to report; the controller sets it.
 	Note func(string, ...any)
@@ -40,9 +42,17 @@ func (j *JetStream) note(format string, args ...any) {
 	}
 }
 
+// ConnectionName is what a connection this process dials says it is, in the server's list of
+// connections: the controller's role and what it is doing (novox/hq issue 327). Every connection was
+// named `mesh-controller` — the serving controller's, each verb's own process, the build agents' — so the
+// server's list could not say which was which. The process sets it once, at its start; an option a
+// caller passes to Dial names one connection otherwise.
+var ConnectionName = "mesh-controller"
+
 // Dial connects and returns the controller's JetStream handle.
 func Dial(url string, opts ...nats.Option) (*JetStream, error) {
-	opts = append(opts, nats.Name("mesh-controller"), nats.Timeout(10*time.Second))
+	// The name first, so a name the caller gives is the one that stands.
+	opts = append([]nats.Option{nats.Name(ConnectionName), nats.Timeout(10 * time.Second)}, opts...)
 	// **Pinned, not named.** The bus presents the mesh's own certificate, which names nothing a
 	// public verifier would accept (design 25 §4: a host pins the server's exact certificate and
 	// checks nothing else, and so does this). Without this, the first connection failed with
@@ -130,11 +140,20 @@ func (j *JetStream) Conn() *nats.Conn { return j.conn }
 func (j *JetStream) Context() nats.JetStreamContext { return j.js }
 
 func (j *JetStream) Close() {
-	if j.conn != nil {
+	if j.conn != nil && !j.borrowed {
 		j.conn.Close()
 	}
 }
 
+// Borrow is the same connection for a caller that will close what it was handed when it is done: its
+// Close closes nothing, and the connection stays its owner's (novox/hq issue 327). How the serving
+// controller lends its own connection to work that would otherwise dial one of its own.
+func Borrow(j *JetStream) *JetStream {
+	lent := *j
+	lent.borrowed = true
+	return &lent
+}
+
 // EnsureStream creates the stream if it is absent and brings it to match if it is present.
 //
 // **Idempotent, because the controller asserts on every start** rather than creating once at

internal/broker/jetstream_test.go

@@ -3,6 +3,8 @@ package broker
 import (
 	"testing"
 
+	"github.com/nats-io/nats.go"
+
 	"github.com/novox/mesh-controller/internal/testbus"
 )
 
@@ -66,3 +68,32 @@ func TestAgainstARealServer(t *testing.T) {
 		}
 	})
 }
+
+// A connection says what it is in the server's list (novox/hq issue 327): the process's name, unless the
+// caller names this one; and a lent connection's Close leaves its owner's open.
+func TestAConnectionIsNamedAndALentOneIsNotClosed(t *testing.T) {
+	url := testbus.URL(t)
+	was := ConnectionName
+	ConnectionName = "mesh-controller verb conditions"
+	defer func() { ConnectionName = was }()
+	named, err := Dial(url)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer named.Close()
+	if got := named.Conn().Opts.Name; got != "mesh-controller verb conditions" {
+		t.Errorf("named %q", got)
+	}
+	lease, err := Dial(url, nats.Name("mesh-controller serving lease"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer lease.Close()
+	if got := lease.Conn().Opts.Name; got != "mesh-controller serving lease" {
+		t.Errorf("a name the caller gave became %q", got)
+	}
+	Borrow(named).Close()
+	if !named.Conn().IsConnected() {
+		t.Error("closing a lent connection closed its owner's")
+	}
+}

internal/catalogue/agent_account_test.go

@@ -0,0 +1,157 @@
+package catalogue
+
+import (
+	"strings"
+	"testing"
+)
+
+// The account agents run as (novox/hq ADR 0266): a module names it as a machine fact — the agent account
+// where the node names one, the operator's otherwise — and asks the node-engine to judge it never to become
+// root only where it is the agents' own.
+
+func TestTheAgentAccountFactFallsBackToTheOperatorAndIsNeverRootOnlyWhenItsOwn(t *testing.T) {
+	facts := machineFacts(Resolution{Node: "anchor", Account: "ops"}, nil, "")
+	if facts["agent-account"] != "ops" || facts["agent-home"] != "/home/ops" || facts["agent-root"] != "" {
+		t.Errorf("with no agent account named, agents run as the operator: %v", facts)
+	}
+	facts = machineFacts(Resolution{Node: "anchor", Account: "ops", AccountHome: "/srv/ops"}, nil, "")
+	if facts["agent-home"] != "/srv/ops" {
+		t.Errorf("the operator's stated home is the agent's home when they are one account: %v", facts)
+	}
+	facts = machineFacts(Resolution{Node: "anchor", Account: "ops", AgentAccount: "agent"}, nil, "")
+	if facts["agent-account"] != "agent" || facts["agent-home"] != "/home/agent" || facts["agent-root"] != RootNever {
+		t.Errorf("a named agent account is the agents', never root: %v", facts)
+	}
+	if facts["account"] != "ops" {
+		t.Errorf("the operator account is still the operator's: %v", facts)
+	}
+	facts = machineFacts(Resolution{Node: "anchor", AgentAccount: "agent", AgentAccountHome: "/var/lib/agent"}, nil, "")
+	if facts["agent-home"] != "/var/lib/agent" || facts["agent-root"] != RootNever {
+		t.Errorf("an agent account with a stated home on a machine with no operator: %v", facts)
+	}
+	if _, has := machineFacts(Resolution{Node: "anchor"}, nil, "")["agent-account"]; has {
+		t.Error("a machine with no account at all names an agent account")
+	}
+}
+
+// The agent's module, in the shape the catalogue's declares it: the account, never root where it is its
+// own; its directory under that home, owned by it.
+const agentModule = `{"module": "agent", "version": "1", "resources": [
+  {"id": "account", "type": "user", "name": "${machine:agent-account}", "root": "${machine:agent-root}"},
+  {"id": "home", "type": "directory", "path": "${machine:agent-home}/.agent", "mode": "0700",
+   "owner": "${machine:agent-account}"}
+]}`
+
+func TestTheAgentAccountIsDeclaredNeverRootOnlyToAnEngineThatJudgesIt(t *testing.T) {
+	m, err := ParseManifest([]byte(agentModule))
+	if err != nil {
+		t.Fatal(err)
+	}
+	compose := func(r Resolution, with Rendering) (user, home map[string]any) {
+		t.Helper()
+		r.Node, r.Modules = "anchor", []Manifest{m}
+		out, err := r.Declaration(with)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return fileNamed(out, "agent.account"), fileNamed(out, "agent.home")
+	}
+
+	user, home := compose(Resolution{Account: "ops", AgentAccount: "agent"}, Rendering{JudgesRoot: true})
+	if user["name"] != "agent" || user[RootField] != RootNever {
+		t.Errorf("an engine that judges root is sent the agent account never to become root: %v", user)
+	}
+	if home["path"] != "/home/agent/.agent" || home["owner"] != "agent" {
+		t.Errorf("the agent's directory is under its own home, its own: %v", home)
+	}
+
+	user, _ = compose(Resolution{Account: "ops", AgentAccount: "agent"}, Rendering{})
+	if _, sent := user[RootField]; sent || user["name"] != "agent" {
+		t.Errorf("an older engine, which parses strictly, is sent root: %v", user)
+	}
+
+	user, home = compose(Resolution{Account: "ops"}, Rendering{JudgesRoot: true})
+	if _, sent := user[RootField]; sent || user["name"] != "ops" {
+		t.Errorf("where agents run as the operator, root asserts nothing and is not sent: %v", user)
+	}
+	if home["path"] != "/home/ops/.agent" || home["owner"] != "ops" {
+		t.Errorf("with no agent account, the agent's directory is the operator's: %v", home)
+	}
+}
+
+func TestTheRuntimeIsToldTheAgentAccount(t *testing.T) {
+	with := Rendering{ArtifactStore: "anchor.internal:5101",
+		Needed: map[string]map[string]string{RuntimeModule: {"broker": "sealed-credential"}}}
+	envOf := func(r Resolution) map[string]string {
+		t.Helper()
+		r.Node, r.Modules = "anchor", []Manifest{aToolsModule(t, "nftables", "tools/index.js"), theRuntime(t)}
+		out, err := r.Declaration(with)
+		if err != nil {
+			t.Fatal(err)
+		}
+		process := fileNamed(out, RuntimeModule+"."+RuntimeProcessID())
+		if process == nil {
+			t.Fatal("no runtime process was composed")
+		}
+		return process["env"].(map[string]string)
+	}
+	env := envOf(Resolution{Account: "ops", AgentAccount: "agent"})
+	if env[RuntimeAgentAccount] != "agent" || env[RuntimeAgentHome] != "/home/agent" || env[RuntimeOperatorAccount] != "ops" {
+		t.Errorf("the runtime is not told whom agents run as: %v", env)
+	}
+	env = envOf(Resolution{Account: "ops"})
+	if env[RuntimeAgentAccount] != "ops" || env[RuntimeAgentHome] != "/home/ops" {
+		t.Errorf("with no agent account, agents run as the operator: %v", env)
+	}
+	env = envOf(Resolution{})
+	if _, set := env[RuntimeAgentAccount]; set {
+		t.Errorf("a machine with no account names an agent account: %v", env)
+	}
+	if problems := bundleEnvProblems("x", Artifact{Name: "b", Kind: ArtifactBundle, Loads: []string{"x"},
+		Env: map[string]string{RuntimeAgentAccount: "me"}}); len(problems) == 0 {
+		t.Error("a bundle may tell the runtime whom agents run as")
+	}
+}
+
+// No placement and no access at the machine's own system or the mesh's state, however it is spelled (novox/hq
+// ADR 0266); a module's own place elsewhere is taken.
+func TestAPlacementOrAnAccessAtTheMachinesOwnIsRefused(t *testing.T) {
+	m := Manifest{Module: "notes", Resources: []map[string]any{{"id": "data", "type": "directory"}},
+		Accesses: []Access{{ID: "media"}}}
+	for _, path := range []string{"/", "/etc", "/etc/sudoers.d", "/usr/bin", "/root", "/var/lib", "/home",
+		"/var/lib/mesh/x", "/var/lib/mesh-host", "/srv/../etc", "/proc/1", "/dev"} {
+		layers := []Layer{{From: "laptop", Values: map[string]any{PlacesSetting: map[string]any{"data": path}}}}
+		if _, err := Places(m, layers); err == nil {
+			t.Errorf("a place at %s was taken", path)
+		}
+		layers = []Layer{{From: "laptop", Values: map[string]any{AccessesSetting: map[string]any{"media": path}}}}
+		if _, err := AccessPlaces(m, layers); err == nil {
+			t.Errorf("an access at %s was taken", path)
+		}
+	}
+	for _, path := range []string{"/srv/notes", "/mnt/plex/data", "/storage/media", "/home/restic", "/var/lib/notes/data"} {
+		layers := []Layer{{From: "laptop", Values: map[string]any{PlacesSetting: map[string]any{"data": path}}}}
+		if got, err := Places(m, layers); err != nil || got["data"].Path != path {
+			t.Errorf("a place at %s: %v %v", path, got, err)
+		}
+	}
+}
+
+// A line break or a NUL in any string of any setting is refused, at any depth; PEM blocks alone may hold lines.
+func TestASettingHoldsOneLine(t *testing.T) {
+	m := Manifest{Module: "mailu"}
+	for _, v := range []any{"a\nDEBUG=1", "a\rb", "a\x00b", map[string]any{"k": []any{"ok", "x\ny"}},
+		map[string]any{"k\nx": "v"}} {
+		if err := JudgeSettings(m, []Layer{{From: "home", Values: map[string]any{"v": v}}}, false); err == nil ||
+			!strings.Contains(err.Error(), "line break") {
+			t.Errorf("%q: %v", v, err)
+		}
+	}
+	pem := "-----BEGIN CERTIFICATE-----\nMIIBeDCCAR2gAwIBAgIQ\n-----END CERTIFICATE-----\n"
+	if err := JudgeSettings(m, []Layer{{From: "home", Values: map[string]any{"root": pem}}}, false); err != nil {
+		t.Errorf("a PEM block: %v", err)
+	}
+	if err := JudgeSettings(m, []Layer{{From: "home", Values: map[string]any{"root": pem + "PATH=/tmp evil\n"}}}, false); err == nil {
+		t.Error("a PEM block with a line of something else after it was taken")
+	}
+}

internal/catalogue/build.go

@@ -399,7 +399,7 @@ func versionOf(digest string) string {
 // telling the runtime what it is, which is the mesh's to say (novox/hq ADR 0192).
 var bundleEnvWords = map[string]bool{
 	RuntimeToolModules: true, RuntimeBrokerFile: true, RuntimeOperatorAccount: true,
-	RuntimeOperatorHome: true, RuntimeToolEnv: true,
+	RuntimeOperatorHome: true, RuntimeToolEnv: true, RuntimeAgentAccount: true, RuntimeAgentHome: true,
 }
 
 // bundleEnvProblems says what is wrong with what a bundle says it is given (novox/hq ADR 0192):

internal/catalogue/declaration.go

@@ -241,6 +241,31 @@ type Rendering struct {
 	// refuses a field it does not know, whole — so to it the field is not sent, and what it runs is
 	// judged by liveness alone.
 	ReadsHealth bool
+
+	// JudgesRoot says this machine's node-engine judges a user's declared `root` (novox/hq ADR 0266: its
+	// statement's contract is link.RootContract or later). To an older, strict engine the field is not
+	// sent, and the account it names is not judged — which the self-check says, as not judged.
+	JudgesRoot bool
+}
+
+// RootField is a user resource's field saying the account must never become root without a person
+// (novox/hq ADR 0266).
+const RootField = "root"
+
+// rootInto composes a user's `root` for the node-engine: taken away when it asserts nothing (empty — a
+// machine where agents run as the operator) or when the engine is older than the field and parses
+// strictly; kept as "never" otherwise.
+func rootInto(resource map[string]any, with Rendering) {
+	if resource["type"] != "user" {
+		return
+	}
+	value, has := resource[RootField]
+	if !has {
+		return
+	}
+	if s, _ := value.(string); s == "" || !with.JudgesRoot {
+		delete(resource, RootField)
+	}
 }
 
 // machinePort is where a module's port lives on this machine, or the port itself when the mesh has
@@ -980,6 +1005,9 @@ func (r Resolution) compose(with Rendering, owner map[string]string,
 			// How it is ready, in the node-engine's words: its endpoint as the port this machine
 			// published it on — or not sent at all to an engine older than the field (ADR 0240).
 			healthInto(copied, m, with)
+			// And a user's `root` (novox/hq ADR 0266): sent only when it asserts something, to an engine
+			// that judges it.
+			rootInto(copied, with)
 			// The account's environment and every module's shell code, where this module holds the
 			// seat that places them (novox/hq ADR 0203, ADR 0204). Gathered from every module on
 			// the node, as the jails are, and **last of every placeholder pass**: shell code is a

internal/catalogue/machine_into_files.go

@@ -78,9 +78,47 @@ func machineFacts(r Resolution, names map[string]string, meshRange string) map[s
 		out["account"] = r.Account
 		out["account-home"] = accountHomeOf(r.Account, r.AccountHome)
 	}
+	// The account agents run as here, and whether it must never become root (novox/hq ADR 0266). The agent
+	// account where the node names one; the operator account otherwise, so a module writing the agent's
+	// home names one fact on every machine. `agent-root` is "never" only for an account of the agents' own:
+	// the user resource naming it then asks the node-engine to judge it, and on a machine where agents run
+	// as the operator it is empty, asserting nothing — the operator's account may become root there.
+	if agent, home := r.agentAccount(); agent != "" {
+		out["agent-account"] = agent
+		out["agent-home"] = home
+		out["agent-root"] = ""
+		if r.AgentAccount != "" {
+			out["agent-root"] = RootNever
+		}
+	}
 	return out
 }
 
+// RootNever is what a user resource's `root` says of an account that must never become root without a
+// person (novox/hq ADR 0266); the node-engine judges it.
+const RootNever = "never"
+
+// agentAccount is the account agents run as on this machine and its home: the agent account when the node
+// names one (novox/hq ADR 0266), else the operator account; empty when neither is known.
+func (r Resolution) agentAccount() (string, string) {
+	if r.AgentAccount != "" {
+		return r.AgentAccount, agentHomeOf(r.AgentAccount, r.AgentAccountHome)
+	}
+	if r.Account != "" {
+		return r.Account, accountHomeOf(r.Account, r.AccountHome)
+	}
+	return "", ""
+}
+
+// agentHomeOf is where the agent account's home is: what was stored, or /home/<account>. Never /root: the
+// agent account is never root.
+func agentHomeOf(account, home string) string {
+	if home != "" {
+		return home
+	}
+	return "/home/" + account
+}
+
 // accountHomeOf is where an account's home is: what was stored, or the derived default — /root for
 // root, /home/<account> otherwise. The one place the default is written, so a fact and the store
 // cannot disagree about it.
@@ -105,8 +143,10 @@ func machineInto(resource map[string]any, facts map[string]string, module string
 	// (novox/hq to-be 29), the same reason its content names ${machine:address}. And the name a
 	// `user` shape sets the login shell of, and the user a user-scoped unit or a process runs as:
 	// the shell module makes the operator's account its holder's login shell, and the desktop's
-	// watchers run as that account (novox/hq ADR 0176, ADR 0177) — neither can name the person.
-	for _, field := range []string{"path", "owner", "content", "name", "user"} {
+	// watchers run as that account (novox/hq ADR 0176, ADR 0177) — neither can name the person. And a
+	// user's `root`: the agent's module declares the account agents run as with ${machine:agent-root},
+	// "never" only where that account is the agents' own (novox/hq ADR 0266).
+	for _, field := range []string{"path", "owner", "content", "name", "user", "root"} {
 		s, ok := resource[field].(string)
 		if !ok {
 			continue

internal/catalogue/placement.go

@@ -2,6 +2,7 @@ package catalogue
 
 import (
 	"fmt"
+	"path/filepath"
 	"regexp"
 	"sort"
 	"strings"
@@ -44,6 +45,33 @@ type Placement struct {
 
 var ownerShape = regexp.MustCompile(`^[0-9]+:[0-9]+$`)
 
+// systemTrees are where no placement and no access may be: the machine's own system, and the node-engine's
+// and the tool runner's state (novox/hq ADR 0266). A placed directory is created and chowned by the
+// node-engine as root, and an access is mounted into a container: a place at /etc, owned by an account a
+// caller names, hands that account the machine. Refused at or below each of these.
+var systemTrees = []string{"/etc", "/usr", "/boot", "/root", "/proc", "/sys", "/dev", "/run", "/bin", "/sbin",
+	"/lib", "/lib64", "/var/lib/mesh", "/var/lib/mesh-host", "/var/lib/mesh-bus-conf"}
+
+// systemRoots are directories a placement may be below but never be: each holds the whole machine's, or
+// every module's or every person's, directories.
+var systemRoots = []string{"/", "/var", "/var/lib", "/home", "/mnt", "/srv", "/opt", "/storage", "/data", "/tmp", "/var/tmp"}
+
+// systemPath says why a path is the machine's own and no placement's, or "".
+func systemPath(path string) string {
+	clean := filepath.Clean(path)
+	for _, root := range systemRoots {
+		if clean == root {
+			return clean + " is a whole tree of the machine's"
+		}
+	}
+	for _, tree := range systemTrees {
+		if clean == tree || strings.HasPrefix(clean, tree+"/") {
+			return clean + " is in " + tree + ", the machine's own or the mesh's state"
+		}
+	}
+	return ""
+}
+
 // accessRef is how a module names one of its accesses: ${access:<id>}.
 var accessRef = regexp.MustCompile(`\$\{access:([a-z0-9][a-z0-9-]*)\}`)
 
@@ -103,7 +131,11 @@ func Places(m Manifest, layers []Layer) (map[string]Placement, error) {
 			if !strings.HasPrefix(p.Path, "/") {
 				return nil, fmt.Errorf("%s places %q at %q, which is not an absolute path", m.Module, id, p.Path)
 			}
-			p.Path = strings.TrimRight(p.Path, "/")
+			p.Path = filepath.Clean(p.Path)
+			if why := systemPath(p.Path); why != "" {
+				return nil, fmt.Errorf("%s places %q at %s: %s, and the node-engine would create and own it as "+
+					"root (novox/hq ADR 0266)", m.Module, id, p.Path, why)
+			}
 			out[id] = p
 		}
 	}
@@ -147,7 +179,12 @@ func AccessPlaces(m Manifest, layers []Layer) (map[string]string, error) {
 				return nil, fmt.Errorf("%s places the access %q at %v, which is not an absolute path",
 					m.Module, id, body)
 			}
-			out[id] = strings.TrimRight(path, "/")
+			path = filepath.Clean(path)
+			if why := systemPath(path); why != "" {
+				return nil, fmt.Errorf("%s places the access %q at %s: %s, and an access is mounted into the "+
+					"module's container (novox/hq ADR 0266)", m.Module, id, path, why)
+			}
+			out[id] = path
 		}
 	}
 	if len(out) == 0 {

internal/catalogue/resolve.go

@@ -32,6 +32,11 @@ type Node struct {
 	// to-be 29). What a home-scoped file is owned by and what ${machine:account} resolves to.
 	Account     string
 	AccountHome string
+	// AgentAccount is the login agents run as here when it is not the operator's, AgentAccountHome its
+	// home when not derived (novox/hq ADR 0266). What ${machine:agent-account} resolves to; empty means
+	// agents run as the operator account.
+	AgentAccount     string
+	AgentAccountHome string
 }
 
 // World is what the rest of the mesh already has.
@@ -134,6 +139,10 @@ type Resolution struct {
 	// here without a store lookup.
 	Account     string
 	AccountHome string
+	// AgentAccount and AgentAccountHome are the account agents run as here when it is not the
+	// operator's, and its home (novox/hq ADR 0266); empty when agents run as the operator account.
+	AgentAccount     string
+	AgentAccountHome string
 	// Capabilities are the machine's, as its profile reported them, carried from the node so a
 	// contribution placed only where the machine has something (`if-capability`, novox/hq ADR 0255)
 	// is decided here without a store lookup.
@@ -703,7 +712,8 @@ func Resolve(catalogue map[string]Manifest, assigned []string, node Node, world
 	}
 
 	resolution := Resolution{Node: node.Name, At: node.At, PublicDomain: node.PublicDomain,
-		Account: node.Account, AccountHome: node.AccountHome, Capabilities: node.Capabilities,
+		Account: node.Account, AccountHome: node.AccountHome, AgentAccount: node.AgentAccount,
+		AgentAccountHome: node.AgentAccountHome, Capabilities: node.Capabilities,
 		Because: because, Needs: needs, Unhostable: unhostable, Kept: kept}
 	for _, n := range providersFirst(order, catalogue) {
 		resolution.Modules = append(resolution.Modules, catalogue[n])

internal/catalogue/runtime.go

@@ -83,6 +83,11 @@ const (
 	RuntimeBrokerFile      = "MESH_BROKER_FILE"
 	RuntimeOperatorAccount = "MESH_OPERATOR_ACCOUNT"
 	RuntimeOperatorHome    = "MESH_OPERATOR_HOME"
+	// RuntimeAgentAccount and RuntimeAgentHome are the account agents run as on the machine and its home
+	// (novox/hq ADR 0266): the agent account where the node names one, the operator account otherwise.
+	// The agent's module writes the agent's home from them; absent where neither account is known.
+	RuntimeAgentAccount = "MESH_AGENT_ACCOUNT"
+	RuntimeAgentHome    = "MESH_AGENT_HOME"
 	// RuntimeToolEnv is every served module's composed environment, as JSON (novox/hq ADR 0192):
 	// {"<module>": {"<word>": "<value>"}}. The runtime takes it at start, removes it from its own
 	// environment and hands each module's words to that module's bundles alone. In the unit, so a
@@ -215,6 +220,10 @@ func (r Resolution) runtimeProcess(with Rendering) (map[string]any, error) {
 		env[RuntimeOperatorHome] = accountHomeOf(r.Account, r.AccountHome)
 		process["user"] = r.Account
 	}
+	if agent, home := r.agentAccount(); agent != "" {
+		env[RuntimeAgentAccount] = agent
+		env[RuntimeAgentHome] = home
+	}
 	// Routed through the artifact store as this network reaches it now, like everything the mesh
 	// built; refused with the same words when there is no store to route through.
 	if err := artifactsInto(process, RuntimeModule, with); err != nil {

internal/catalogue/settings.go

@@ -209,6 +209,68 @@ func deepCopy(in map[string]any) map[string]any {
 	return out
 }
 
+// settingsHoldOneLine refuses a line break or a NUL in any string of any setting, for every module, at any
+// depth: a key or a value, in an object or a list (novox/hq ADR 0266). A value is substituted into env and
+// configuration files the node-engine writes as root (an app's .env, a logind drop-in), and a line break
+// there is a directive of the caller's own; a NUL ends a string early wherever C reads it. Judged where a
+// setting is kept and again where it is composed, so a stored value with one costs its module its place
+// and says which key. One shape is let through: PEM blocks alone (a certificate authority's root handed to a
+// provider), whose lines are base64 between BEGIN and END. Anything else that must hold lines is the
+// module's own file, not a setting.
+func settingsHoldOneLine(module string, layers []Layer) error {
+	for _, layer := range layers {
+		for _, key := range sortedKeysAny(layer.Values) {
+			if at := lineBreakIn(layer.Values[key], key); at != "" {
+				return fmt.Errorf("%s: the setting %s in %q holds a line break or a NUL, which a file it is written "+
+					"into would read as a directive of its own (novox/hq ADR 0266); a setting is one line",
+					module, at, layer.From)
+			}
+		}
+	}
+	return nil
+}
+
+// pemShape is the one value with lines a setting may hold: PEM blocks and nothing else — a certificate
+// authority's root the operator hands a provider is one. Its lines are base64 between BEGIN and END: no
+// space, quote, dot or underscore, so no path, option or command — at most a padded line an env file would
+// read as an empty assignment, which names no program.
+var pemShape = regexp.MustCompile(`^(-----BEGIN [A-Z0-9 ]+-----\n([A-Za-z0-9+/]{1,76}={0,2}\n)+-----END [A-Z0-9 ]+-----\n?)+$`)
+
+// lineBreakIn is the path of the first string under v holding \n, \r or NUL, or "".
+func lineBreakIn(v any, at string) string {
+	switch t := v.(type) {
+	case string:
+		if strings.ContainsAny(t, "\n\r\x00") && !pemShape.MatchString(t) {
+			return at
+		}
+	case map[string]any:
+		for _, k := range sortedKeysAny(t) {
+			if strings.ContainsAny(k, "\n\r\x00") {
+				return at + "." + strings.ToValidUTF8(strings.NewReplacer("\n", "\\n", "\r", "\\r", "\x00", "\\0").Replace(k), "?")
+			}
+			if found := lineBreakIn(t[k], at+"."+k); found != "" {
+				return found
+			}
+		}
+	case []any:
+		for i, e := range t {
+			if found := lineBreakIn(e, fmt.Sprintf("%s[%d]", at, i)); found != "" {
+				return found
+			}
+		}
+	}
+	return ""
+}
+
+func sortedKeysAny(m map[string]any) []string {
+	out := make([]string, 0, len(m))
+	for k := range m {
+		out = append(out, k)
+	}
+	sort.Strings(out)
+	return out
+}
+
 // UnusedSettings names settings that reach nothing.
 //
 // Somebody who sets a key on a module with nothing mergeable, or misspells one, has changed
@@ -405,6 +467,9 @@ var networkName = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9_.-]*$`)
 // refused where it is stored (SetSettings, with UnusedSettings) and said where a plan is read,
 // and never costs a module its place.
 func JudgeSettings(m Manifest, layers []Layer, adopted bool) error {
+	if err := settingsHoldOneLine(m.Module, layers); err != nil {
+		return err
+	}
 	// With no layers too: a definition may ask for a setting nobody made — an access placed by
 	// nobody, a file's ${setting:…} nothing sets — and that is the same statement, missing.
 	if _, err := GivenPorts(m, layers); err != nil {

internal/catalogue/verbs.go

@@ -237,9 +237,9 @@ var ControllerVerbs = []Verb{
 			"node":   "the machine that runs the module",
 			"module": "the module's name",
 		}, []string{"node", "module"})},
-	{Name: "token", Description: "Issue a one-time token for a machine to join with. Give the public half of the " +
-		"tunnel key the machine made (`nox-mesh-host key`): the machine is given its address and made a peer of " +
-		"the hub, and joins through the tunnel. The token is shown once, in the answer.",
+	{Name: "token", Description: "Refused through a verb since novox/hq ADR 0266: the one-time token a machine " +
+		"joins with is answered to its caller, and whoever may call a verb includes agents. Issue it at the " +
+		"controller's terminal: `mesh-controller token issue --new <name> --overlay-key <public half>`.",
 		Input: schema(map[string]string{
 			"node":        "a machine the mesh already has a record for",
 			"new":         "or the name of a machine to create the record for",
@@ -267,10 +267,14 @@ var ControllerVerbs = []Verb{
 			"list": "\"preferences\": every module's preferences — key, default and why — and the value on each " +
 				"machine it is assigned to with where it comes from; module and node narrow it (novox/hq ADR 0262)",
 		}, nil, "clear", "replace", "history")},
-	{Name: "command", Description: "Run one command line of the controller's own, as you would type it at its " +
-		"shell — `node account g14 jochen`, `node show ace`, `module list` — and answer what it printed. The " +
-		"generic verb beside the named ones (novox/hq ADR 0154): everything the binary can do, without a verb " +
-		"per command. Any node may call any tool (ADR 0175), so nothing is held back here.",
+	{Name: "command", Description: "Run one reading command line of the controller's own, as you would type it at " +
+		"its shell — `node show ace`, `module list`, `plans`, `conditions show <key>` — and answer what it " +
+		"printed. The generic verb beside the named ones (novox/hq ADR 0154), and since ADR 0266 it only reads: " +
+		"status, version, help, seats, healers, hand-acts, durations, collection, images, artifacts, data, builds, " +
+		"queue, plan, plans (not stop/close/go), doctor (not run), conditions list/show/history, node list/show, " +
+		"module list, settings show/preferences, retire list, cleanup list, delivery plan/walks, bus, mirrors (not " +
+		"--record/--confirm). What writes has its named verb; what sets a key, issues a credential or a token, or " +
+		"accepts, recovers or exports a secret is the controller's terminal's alone.",
 		Input: schema(map[string]string{
 			"command": "the command line, as the controller's binary takes it; quotes group a word with spaces",
 		}, []string{"command"})},

internal/facts/facts.go

@@ -131,6 +131,10 @@ type Machine struct {
 	// home is when that is not the derived one.
 	Account     string `json:"account,omitempty"`
 	AccountHome string `json:"account-home,omitempty"`
+	// AgentAccount is the account agents run as there when it is not the operator's (a pseudonym), and
+	// AgentAccountHome its home when not derived (novox/hq ADR 0266).
+	AgentAccount     string `json:"agent-account,omitempty"`
+	AgentAccountHome string `json:"agent-account-home,omitempty"`
 	// PublicDomain is the domain it answers for, its labels replaced.
 	PublicDomain string `json:"public-domain,omitempty"`
 	// Assigned is every module assigned there.

internal/inventory/agent_account_test.go

@@ -0,0 +1,93 @@
+package inventory
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"testing"
+)
+
+// The agent account (novox/hq ADR 0266): recorded and read back with every node, its home derived when
+// not stated, cleared by an empty name — and refused when it is root, the operator's own account, or no
+// login at all, because each of those would say agents have an account of their own while they do not.
+func TestAgentAccountIsRecordedAndRefusedWhereItWouldNotConfine(t *testing.T) {
+	inv := ForTest(t)
+	ctx := context.Background()
+	if _, err := inv.AddNode(ctx, "anchor"); err != nil {
+		t.Fatal(err)
+	}
+	if err := inv.SetAccount(ctx, "anchor", "operator", ""); err != nil {
+		t.Fatal(err)
+	}
+
+	n, err := inv.NodeByName(ctx, "anchor")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n.AgentAccount != "" || n.AgentHome() != "" {
+		t.Fatalf("a node that names none has agent account %q, home %q", n.AgentAccount, n.AgentHome())
+	}
+
+	if err := inv.SetAgentAccount(ctx, "anchor", "agent", ""); err != nil {
+		t.Fatal(err)
+	}
+	n, _ = inv.NodeByName(ctx, "anchor")
+	if n.AgentAccount != "agent" || n.AgentHome() != "/home/agent" {
+		t.Fatalf("agent account %q, home %q; want agent, /home/agent", n.AgentAccount, n.AgentHome())
+	}
+	all, err := inv.Nodes(ctx)
+	if err != nil || len(all) != 1 || all[0].AgentAccount != "agent" {
+		t.Fatalf("the listing does not carry the agent account: %+v %v", all, err)
+	}
+
+	if err := inv.SetAgentAccount(ctx, "anchor", "agent", "/srv/agent"); err != nil {
+		t.Fatal(err)
+	}
+	if n, _ = inv.NodeByName(ctx, "anchor"); n.AgentHome() != "/srv/agent" {
+		t.Fatalf("the stated home is %q", n.AgentHome())
+	}
+
+	for _, c := range []struct{ account, home, says string }{
+		{"root", "", "may not run as root"},
+		{"operator", "", "operator account"},
+		{"Agent", "", "not a login name"},
+		{"9agent", "", "not a login name"},
+		{"agent", "relative", "absolute"},
+		{"postgres", "", "service account"},
+		{"systemd-network", "", "service account"},
+		{"showcase", "", "service account"},
+		{"", "/home/x", "without an agent account"},
+	} {
+		err := inv.SetAgentAccount(ctx, "anchor", c.account, c.home)
+		if err == nil || !strings.Contains(err.Error(), c.says) {
+			t.Errorf("%q %q: %v; want a refusal saying %q", c.account, c.home, err, c.says)
+		}
+	}
+	if n, _ = inv.NodeByName(ctx, "anchor"); n.AgentAccount != "agent" {
+		t.Fatalf("a refusal changed the record: %q", n.AgentAccount)
+	}
+
+	// The other direction: the operator account may not be named as the agent account either.
+	if err := inv.SetAccount(ctx, "anchor", "agent", ""); err == nil || !strings.Contains(err.Error(), "agent account") {
+		t.Fatalf("the operator account named as the agent account: %v; want a refusal", err)
+	}
+	if n, _ = inv.NodeByName(ctx, "anchor"); n.Account != "operator" {
+		t.Fatalf("a refusal changed the operator account: %q", n.Account)
+	}
+
+	if err := inv.SetAgentAccount(ctx, "anchor", "", ""); err != nil {
+		t.Fatal(err)
+	}
+	if err := inv.SetAccount(ctx, "anchor", "agent", ""); err != nil {
+		t.Fatalf("with the agent account cleared, the name is free: %v", err)
+	}
+	if err := inv.SetAccount(ctx, "anchor", "operator", ""); err != nil {
+		t.Fatal(err)
+	}
+	if n, _ = inv.NodeByName(ctx, "anchor"); n.AgentAccount != "" || n.AgentAccountHome != "" {
+		t.Fatalf("clearing left %q %q", n.AgentAccount, n.AgentAccountHome)
+	}
+	if err := inv.SetAgentAccount(ctx, "nowhere", "agent", ""); !errors.Is(err, ErrNoSuchNode) {
+		t.Fatalf("an unknown node: %v", err)
+	}
+}

internal/inventory/health.go

@@ -31,6 +31,9 @@ type ResourceHealth struct {
 	// Account is the account whose own service manager runs it, or the account a resource of kind account
 	// is (novox/hq ADR 0254).
 	Account string `json:"account,omitempty"`
+	// Root is "never" on an account verdict that judged whether the account can become root without a
+	// person (novox/hq ADR 0266).
+	Root string `json:"root,omitempty"`
 }
 
 // NodeHealth is a machine's newest statement, as kept.

internal/inventory/migrations/0083-a-node-names-the-account-its-agents-run-as.sql

@@ -0,0 +1,13 @@
+-- A node names the account its agents run as (novox/hq ADR 0266).
+--
+-- On the control node every agent session ran as the operator's account, which may become root without
+-- a password: any agent there could become root without a person. The decision is an account of the
+-- agents' own, without sudo, beside the operator's, who keeps theirs. Stated by the operator at the
+-- controller's terminal, like the operator account (migration 0036), and never by a verb or a setting,
+-- so no agent can change which account it is.
+--
+-- Empty rather than null, as the operator account is: empty is a real state, "agents run as the
+-- operator's account here" — a workstation's today. The home is stored only when it is not
+-- /home/<account>; empty means derive it.
+alter table node add column agent_account text not null default '';
+alter table node add column agent_account_home text not null default '';

internal/inventory/nodes.go

@@ -9,6 +9,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"regexp"
 	"sort"
 	"strings"
 	"time"
@@ -69,6 +70,14 @@ type Node struct {
 	Account     string
 	AccountHome string
 
+	// AgentAccount is the login agents run as on this machine when it is not the operator's — `agent`
+	// on the control node (novox/hq ADR 0266): an account of their own, without sudo, so no agent there
+	// can become root without a person. Empty means agents run as the operator account. Stated at the
+	// controller's terminal only, never by a verb or a setting. AgentAccountHome is its home when not
+	// /home/<account>; empty means derive it.
+	AgentAccount     string
+	AgentAccountHome string
+
 	// HostVersion is the version of the host this machine reported running (novox/hq 04-ISSUES/087).
 	// Empty when it has not said since the mesh began keeping it — which is not the same as running
 	// no host, so nothing derives "behind" from an empty one.
@@ -91,6 +100,17 @@ func (n Node) Home() string {
 	}
 }
 
+// AgentHome is the agent account's home, derived when not stored; empty when no agent account is named.
+func (n Node) AgentHome() string {
+	if n.AgentAccount == "" {
+		return ""
+	}
+	if n.AgentAccountHome != "" {
+		return n.AgentAccountHome
+	}
+	return "/home/" + n.AgentAccount
+}
+
 // Silent is how long since this node was last heard from, and whether it ever was.
 func (n Node) Silent() (time.Duration, bool) {
 	if n.LastSeen.IsZero() {
@@ -147,14 +167,14 @@ func (i *Inventory) AddNodeAs(ctx context.Context, name string, adopted bool) (N
 // nodeColumns and scanNode are the one reading of a node row, so every way of finding a node
 // says whether it is adopted.
 const nodeColumns = `id, name, created, last_seen, adopted, adopted_since, account, account_home,
-	host_version`
+	agent_account, agent_account_home, host_version`
 
 func scanNode(row pgx.Row) (Node, error) {
 	var n Node
 	var seen, since *time.Time
 	var host *string
 	if err := row.Scan(&n.ID, &n.Name, &n.Created, &seen, &n.Adopted, &since,
-		&n.Account, &n.AccountHome, &host); err != nil {
+		&n.Account, &n.AccountHome, &n.AgentAccount, &n.AgentAccountHome, &host); err != nil {
 		return Node{}, err
 	}
 	if host != nil {
@@ -172,7 +192,23 @@ func scanNode(row pgx.Row) (Node, error) {
 // SetAccount records the operator account on a node — its human login — and optionally where that
 // account's home is (novox/hq to-be 29). An empty home means the mesh derives it. Clearing the
 // account (empty name) is allowed: a machine may stop having a known operator.
+//
+// **Never the node's agent account** (novox/hq ADR 0266): the operator account may become root, and the
+// agent account exists so agents cannot; naming the one as the other gives agents root. Refused here as
+// SetAgentAccount refuses the other direction.
 func (i *Inventory) SetAccount(ctx context.Context, node, account, home string) error {
+	account = strings.TrimSpace(account)
+	if account != "" {
+		n, err := i.NodeByName(ctx, node)
+		if err != nil {
+			return err
+		}
+		if n.AgentAccount != "" && n.AgentAccount == account {
+			return fmt.Errorf("%s is %s's agent account: the operator account may become root, and agents run as "+
+				"%s so that they cannot (novox/hq ADR 0266); clear the agent account first "+
+				"(node agent-account %s --clear) if the operator is to log in as it", account, node, account, node)
+		}
+	}
 	tag, err := i.store.Pool().Exec(ctx,
 		`update node set account = $1, account_home = $2 where name = $3`, account, home, node)
 	if err != nil {
@@ -184,6 +220,86 @@ func (i *Inventory) SetAccount(ctx context.Context, node, account, home string)
 	return nil
 }
 
+// loginName is what a login may be called: what useradd accepts by default, lower case, a letter or
+// an underscore first.
+var loginName = regexp.MustCompile(`^[a-z_][a-z0-9_-]{0,31}$`)
+
+// SetAgentAccount records the account agents run as on a node, and optionally its home (novox/hq ADR
+// 0266). An empty account clears it: agents run as the operator account again.
+//
+// **Refused, rather than recorded and judged later:** root, which is the very thing the account exists
+// to keep agents from; the node's operator account, which may become root without a password and is
+// what agents ran as before — naming it here would say the agents have an account of their own while
+// they do not; and a name no machine would accept as a login.
+func (i *Inventory) SetAgentAccount(ctx context.Context, node, account, home string) error {
+	account, home = strings.TrimSpace(account), strings.TrimSpace(home)
+	if account == "" && home != "" {
+		return errors.New("a home without an agent account says nothing; name the account too")
+	}
+	if account != "" {
+		if err := AgentAccountRefusal(account, home); err != nil {
+			return err
+		}
+		n, err := i.NodeByName(ctx, node)
+		if err != nil {
+			return err
+		}
+		if n.Account != "" && n.Account == account {
+			return fmt.Errorf("%s is %s's operator account: agents would run as the operator, who may become "+
+				"root; clear the agent account instead (node agent-account %s --clear)", account, node, node)
+		}
+	}
+	tag, err := i.store.Pool().Exec(ctx,
+		`update node set agent_account = $1, agent_account_home = $2 where name = $3`, account, home, node)
+	if err != nil {
+		return err
+	}
+	if tag.RowsAffected() == 0 {
+		return fmt.Errorf("%w: %s", ErrNoSuchNode, node)
+	}
+	return nil
+}
+
+// serviceAccounts are the system and service accounts a machine of the mesh has, or a module of the
+// catalogue declares (showcase, and the accounts ADR 0259 gives the router and the channels). The controller
+// cannot read a machine's user database, so this list is the controller's half; the node-engine's half is
+// refusing to take an existing account below the first login uid as one that must never become root.
+var serviceAccounts = map[string]bool{
+	"root": true, "bin": true, "daemon": true, "sys": true, "adm": true, "nobody": true, "mail": true,
+	"ftp": true, "http": true, "www-data": true, "git": true, "sshd": true, "dbus": true, "polkitd": true,
+	"postgres": true, "docker": true, "nats": true, "redis": true, "uuidd": true, "dnsmasq": true,
+	"avahi": true, "rtkit": true, "colord": true, "geoclue": true, "tss": true, "alpm": true, "usbmux": true,
+	"showcase": true, "messenger": true, "telegram": true,
+}
+
+// serviceAccount says whether a name is a system or service account: one of the list, or a name of
+// systemd's own (systemd-…).
+func serviceAccount(name string) bool {
+	return serviceAccounts[name] || strings.HasPrefix(name, "systemd-")
+}
+
+// AgentAccountRefusal is why an agent account cannot be named, or nil: root, a malformed login, or a
+// home that is not an absolute path.
+func AgentAccountRefusal(account, home string) error {
+	if account == "root" {
+		return errors.New("agents may not run as root: the agent account exists to keep them from it " +
+			"(novox/hq ADR 0266)")
+	}
+	if !loginName.MatchString(account) {
+		return fmt.Errorf("%q is not a login name: lower case letters, digits, _ and -, a letter or _ first, "+
+			"at most 32", account)
+	}
+	if serviceAccount(account) {
+		return fmt.Errorf("%q is a system or service account a machine or a module already has: the agent "+
+			"account is one the mesh creates for agents alone, which nothing else runs as or owns files as "+
+			"(novox/hq ADR 0266); name a new one, such as agent", account)
+	}
+	if home != "" && !strings.HasPrefix(home, "/") {
+		return fmt.Errorf("the agent account's home %q is not an absolute path", home)
+	}
+	return nil
+}
+
 // Nodes are every node record, oldest first.
 func (i *Inventory) Nodes(ctx context.Context) ([]Node, error) {
 	rows, err := i.store.Pool().Query(ctx,

internal/link/builds_nats.go

@@ -47,6 +47,12 @@ func BuildsOverNATSOn(address, seat string) (Builders, error) {
 	return &natsBuilds{js: js, owned: true, seat: seat}, nil
 }
 
+// BuildsOn is the asking side on a connection the caller holds, which Close leaves open: the serving
+// controller asks on its own rather than dialling one per build (novox/hq issue 327).
+func BuildsOn(js *broker.JetStream, seat string) Builders {
+	return &natsBuilds{js: js, seat: seat}
+}
+
 // role is the seat asked: what the asker was made for, or the current build role for one made
 // without saying (a test building the struct by hand).
 func (b *natsBuilds) role() string {

internal/link/calls.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"log"
 	"regexp"
+	"runtime/debug"
 	"sort"
 	"strconv"
 	"strings"
@@ -575,6 +576,19 @@ func (l *CallLog) serveCallWithin(seat, verb string, args json.RawMessage, reply
 	done := make(chan outcome, 1)
 	go func() {
 		var body []byte
+		// **A handler that panics is an answer, not a dead controller.** A verb answered in the serving
+		// process (novox/hq issue 327: conditions, hand-acts, queue, dead-letters) runs on this goroutine,
+		// where a panic would take every other call and the controller with it.
+		defer func() {
+			if p := recover(); p != nil {
+				if logger != nil {
+					logger.Printf("%s.%s: call %s panicked: %v\n%s", seat, verb, c.ID, p, debug.Stack())
+				}
+				body, _ = json.Marshal(map[string]any{"error": fmt.Sprintf("%s failed inside the controller and "+
+					"answered nothing: %v. It is in the controller's log", verb, p)})
+				done <- outcome{body, true}
+			}
+		}()
 		result, err := handle(ctx, args)
 		failed := err != nil
 		if errors.Is(err, ErrHandingOver) {

internal/link/calls_test.go

@@ -11,6 +11,10 @@ import (
 	"sync"
 	"testing"
 	"time"
+
+	"github.com/nats-io/nats.go"
+
+	"github.com/novox/mesh-controller/internal/testbus"
 )
 
 // answers collects what a call answered, and fails a second answer: the bus permits one.
@@ -223,3 +227,29 @@ func TestAJoinTokenIsShownToItsCallerAndNotKept(t *testing.T) {
 		}
 	}
 }
+
+// A verb whose handler panics answers an error, and the controller serves the next call (review of
+// novox/hq issue 327: read verbs are answered in the serving process now).
+func TestAHandlerThatPanicsAnswersAnError(t *testing.T) {
+	conn, err := nats.Connect(testbus.URL(t))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	stop, err := OverNATS{Conn: conn}.ServeSeatTools("panicky", map[string]ToolHandler{
+		"boom": func(context.Context, json.RawMessage) (any, error) { panic("nil map") },
+		"fine": func(context.Context, json.RawMessage) (any, error) { return "ok", nil },
+	}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer stop()
+	answer, err := AskMeshSeatTool(context.Background(), conn, "panicky", "boom", map[string]any{}, 5*time.Second)
+	if err != nil || !strings.Contains(answer.Error, "failed inside the controller") {
+		t.Fatalf("a panic answered %+v (%v)", answer, err)
+	}
+	answer, err = AskMeshSeatTool(context.Background(), conn, "panicky", "fine", map[string]any{}, 5*time.Second)
+	if err != nil || answer.Error != "" {
+		t.Fatalf("the call after a panic answered %+v (%v)", answer, err)
+	}
+}

internal/link/protocol.go

@@ -420,6 +420,20 @@ const LivenessContract = 1
 // because an older one parses strictly and would refuse the whole declaration for it.
 const ReadinessContract = 2
 
+// RootContract is the statement of an engine that also judges a user's declared `root` (novox/hq ADR 0266):
+// whether an account declared never to become root without a person can — uid 0, a group that grants root,
+// a sudo rule, a secret of the mesh it may read. Only to such an engine is the field sent: an older one
+// parses strictly and would refuse the whole declaration for it.
+const RootContract = 3
+
+// ReasonRoot starts the reason of an account verdict that found a way to root (ADR 0266); the node-engine's
+// own words (mesh-host internal/accounts ReasonRoot).
+const ReasonRoot = "can become root without a person"
+
+// RootNever is the value of a user's `root`, and of a verdict's Root, that the account must never become
+// root without a person (ADR 0266).
+const RootNever = "never"
+
 // Health is one statement of a machine's long-running resources (to-be 48 §4): in every report, as the
 // event HealthSubject between reports on each change, and again every minute while one is not healthy.
 // The node-engine's own (mesh-host internal/link Health); a test on each side holds the field names.
@@ -542,6 +556,10 @@ type ResourceHealth struct {
 	// manager, and the account itself for a resource of kind KindAccount (novox/hq ADR 0254). Empty from an
 	// engine older than that, and for anything the machine's own manager or runtime runs.
 	Account string `json:"account,omitempty"`
+	// Root is "never" on a verdict of kind KindAccount whose account is declared never to become root
+	// without a person (novox/hq ADR 0266): the engine judged that too, and a healthy verdict says it cannot.
+	// Empty from an engine older than RootContract, and on every other verdict.
+	Root string `json:"root,omitempty"`
 }
 
 // HealthSaid is the health event's body: the machine and its statement. The machine is read from the

vendor/github.com/novox/mesh-host/internal/declaration/declaration.go

@@ -383,8 +383,25 @@ type User struct {
 	// has it not. On the account rather than on the unit, because it is the account's: two units of
 	// one account cannot disagree about it, and undeclaring one of them must not stop the other.
 	Linger *bool `json:"linger,omitempty"`
+
+	// Root says whether this account may become root without a person (novox/hq ADR 0266). "never"
+	// is the agents' own account: the login an agent session runs as on a machine where it must not
+	// reach root by itself. Empty asserts nothing, as Shell's does.
+	//
+	// **A statement the engine judges, never one it acts on.** The apply gives an account it creates
+	// no password, no sudo rule and no group beyond those declared, as it always has, and takes none
+	// away from one it finds: a sudo rule or a group granted by hand is a person's to remove, and a
+	// declaration that silently stripped them would be the mesh deciding what a person's machine
+	// grants. What "never" adds is the look: on every look the engine reads whether the account can
+	// become root by itself — by its uid, a group that grants root, any sudo rule, or a secret the mesh
+	// placed that it can read — and says it unhealthy while it can (internal/accounts), so the
+	// controller can tell a machine where it holds from one where it does not.
+	Root string `json:"root,omitempty"`
 }
 
+// RootNever is the one value Root takes besides empty: the account never becomes root without a person.
+const RootNever = "never"
+
 // Network is a named network on this machine.
 //
 // **A name and nothing else.** Not a driver, a subnet or a gateway: each of those is something a
@@ -478,6 +495,9 @@ func (u *User) validate(where string, _ bool) []string {
 	if u.Home != "" && !strings.HasPrefix(u.Home, "/") {
 		problems = append(problems, where+": a home directory is an absolute path")
 	}
+	if u.Root != "" && u.Root != RootNever {
+		problems = append(problems, fmt.Sprintf("%s: root is %q or absent, and %q is neither", where, RootNever, u.Root))
+	}
 	return problems
 }
 

vendor/modules.txt

@@ -75,7 +75,7 @@ github.com/nats-io/nkeys
 # github.com/nats-io/nuid v1.0.1
 ## explicit
 github.com/nats-io/nuid
-# github.com/novox/mesh-host v0.0.0 => git.novox.be/novox/mesh-host v0.0.0-20261007162834-56e2ebec4bac
+# github.com/novox/mesh-host v0.0.0 => git.novox.be/novox/mesh-host v0.0.0-20261008191932-c74cf16b755e
 ## explicit; go 1.26.0
 github.com/novox/mesh-host/internal/declaration
 github.com/novox/mesh-host/validate
@@ -133,4 +133,4 @@ golang.org/x/text/width
 # golang.org/x/time v0.15.0
 ## explicit; go 1.25.0
 golang.org/x/time/rate
-# github.com/novox/mesh-host => git.novox.be/novox/mesh-host v0.0.0-20261007162834-56e2ebec4bac
+# github.com/novox/mesh-host => git.novox.be/novox/mesh-host v0.0.0-20261008191932-c74cf16b755e