Merge pull request 'Name the account agents run as on a node, and say whether it can become root (hq ADR 0266)' (#164) from feat/a-node-names-the-account-its-agents-run-as into main

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/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/doctor.go

@@ -121,6 +121,11 @@ var probeRegistry = []probe{
 	{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_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/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/nodes.go

@@ -100,6 +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;
@@ -107,7 +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])
 	}
 }
 
@@ -178,6 +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"
 
@@ -592,6 +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

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",

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/seatverbs.go

@@ -55,6 +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.
@@ -249,9 +252,14 @@ func (a *verbArguments) commandLine() ([]string, error) {
 		// settings verb is where what a verb may not set is refused, and one route is one set of words.
 		// The command refuses places and accesses through any verb as well; this says so before it runs.
 		if argv[0] == "settings" && slices.ContainsFunc(argv[1:], func(w string) bool { return w == "set" || w == "clear" }) {
-			return nil, errors.New("settings are set and cleared through the settings verb, not the generic " +
-				"command; and places and accesses only at the controller's terminal (novox/hq issue 339). " +
-				"Nothing was done")
+			return nil, &heldAtTheTerminal{msg: "settings are set and cleared through the settings verb, not the " +
+				"generic command; and places and accesses only at the controller's terminal (novox/hq issue 339). " +
+				"Nothing was done"}
+		}
+		// 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.
@@ -1071,7 +1079,8 @@ 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
@@ -1332,3 +1341,131 @@ 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

@@ -271,7 +271,6 @@ var accountedFlags = map[string]map[string]string{
 	"builds": {"n": "=limit"},
 	"plans":  {"n": "=limit", "what-if": "=repository"},
 	// 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"
@@ -108,11 +109,14 @@ 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)
+		}
 	}
 }
 
@@ -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 show dnsmasq '{"a": "b c"}' --node ace`})
 	if err != nil || len(argv) != 6 || argv[3] != `{"a": "b c"}` {
 		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)
+	}
+}

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 v0.0.0-20261009103656-1c61b72f354d

go.sum

@@ -4,6 +4,12 @@ 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 v0.0.0-20261009081005-b28d7bbcbff4 h1:f4rBnKSemuN0Z9dTtRJMigIGfEs6ltFPOILJGHGab74=
+git.novox.be/novox/mesh-host v0.0.0-20261009081005-b28d7bbcbff4/go.mod h1:72ZATZjxMLaJfWdvlSDJrygIoBzCmKIjCDMhEXxVzTo=
+git.novox.be/novox/mesh-host v0.0.0-20261009101157-2673e7a2c95e h1:H7eVqDILL6e9cMbWSLHTbCqu9ZxDOmyeQhUmWl9QBV0=
+git.novox.be/novox/mesh-host v0.0.0-20261009101157-2673e7a2c95e/go.mod h1:72ZATZjxMLaJfWdvlSDJrygIoBzCmKIjCDMhEXxVzTo=
+git.novox.be/novox/mesh-host v0.0.0-20261009103656-1c61b72f354d h1:IrmJ+lz21n+eSqKrmXREtR/7raUCBJ+fZvs+BNhuXVI=
+git.novox.be/novox/mesh-host v0.0.0-20261009103656-1c61b72f354d/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/catalogue/agent_account_test.go

@@ -0,0 +1,119 @@
+package catalogue
+
+import (
+	"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": "${machine:agent-account}", "home": "${machine:agent-home}",
+   "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 || user["home"] != "/home/agent" {
+		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", AgentAccountHome: "/srv/agent"}, Rendering{JudgesRoot: true})
+	if user["home"] != "/srv/agent" {
+		t.Errorf("an agent account named with a home of its own is made there: %v", user)
+	}
+
+	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")
+	}
+}

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
@@ -981,6 +1006,9 @@ 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 +143,12 @@ 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 ${machine:agent-root},
+	// "never" only where that account is the agents' own (novox/hq ADR 0266), and its `home`, so an account
+	// the operator named with a home of its own is made there (${machine:agent-home}); the node-engine reads a
+	// user's home only when it creates the account, so an existing one is never moved.
+	for _, field := range []string{"path", "owner", "content", "name", "user", "root", "home"} {
 		s, ok := resource[field].(string)
 		if !ok {
 			continue

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/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/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.
@@ -550,6 +564,10 @@ 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

@@ -198,6 +198,12 @@ type File struct {
 	// by looking rather than by knowing which field won.
 	Sealed string `json:"sealed,omitempty"`
 
+	// Trusted is the catalogue's word on whether the settings this file's content took are trusted (novox/hq
+	// issue 339). It is the controller's to act on, and a controller takes it out before it sends a declaration.
+	// Accepted here, and nothing is done with it, so that a controller that passes it on — an older one, or one
+	// rolled back to — never costs a node its whole declaration. Not part of the file's digest.
+	Trusted *bool `json:"trusted,omitempty"`
+
 	// Secrets are sealed values put into Content where it says `${secret:name}`.
 	//
 	// **The one place a secret and a configuration meet, and it happens on the machine.** A
@@ -383,8 +389,25 @@ 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 +501,9 @@ 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 v0.0.0-20261009103656-1c61b72f354d
 ## 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 v0.0.0-20261009103656-1c61b72f354d