diff --git a/modules/mesh-vault/cmd/mesh-vault/ledgers.go b/modules/mesh-vault/cmd/mesh-vault/ledgers.go
new file mode 100644
index 00000000..287019f1
--- /dev/null
+++ b/modules/mesh-vault/cmd/mesh-vault/ledgers.go
@@ -0,0 +1,69 @@
+package main
+
+// The ledger accounts of a machine and the tool runner's own secret `ledgers` (novox/hq ADR 0597 §9, design 25 § 12.4,
+// issue 1966 V1 and V2). Nothing here is the custody ledger of ledger.go (ADR 0085): this file is about the bus account
+// of kind ledger, one per module assignment that asks for a ledger.
+//
+// The tool runner of a machine holds its machine's ledger accounts together as its own secret `ledgers`
+// (`own/<node>/node-tools/ledgers`): a JSON map of module to credential, `{}` when there is none, so its composition
+// never refuses a secret the vault did not make. The vault makes it as `{}` for every machine whose tool runner is
+// wanted, and rewrites it on each ledger account minted or retired, saying `secret-changed` once per rewrite.
+
+import (
+	"encoding/json"
+	"sort"
+
+	"git.novox.be/novox/mesh-sdk/go/buscompose"
+)
+
+// toolRunnerModule is the module whose own secret `ledgers` is: the tool runner (mesh-tools node-tools).
+const toolRunnerModule = "node-tools"
+
+// ledgersSecret is the vault's name of node's `ledgers`.
+func ledgersSecret(node string) (string, error) {
+	return OwnSecret(node, toolRunnerModule, buscompose.LedgersSecret)
+}
+
+// toolRunnerNodes are the machines whose tool runner is wanted, sorted.
+func (v *Vault) toolRunnerNodes() []string {
+	v.minting.mu.Lock()
+	defer v.minting.mu.Unlock()
+	var out []string
+	for _, w := range v.minting.wants {
+		if w.Kind == buscompose.KindNodeTools {
+			out = append(out, w.Node)
+		}
+	}
+	sort.Strings(out)
+	return out
+}
+
+// LedgersPass makes `ledgers` as `{}` on every machine whose tool runner is wanted and for which the vault holds none,
+// at the vault's minute pass (and when the tool runner's want is heard).
+func (v *Vault) LedgersPass() {
+	for _, node := range v.toolRunnerNodes() {
+		v.ensureLedgers(node)
+	}
+}
+
+// ensureLedgers keeps node's `ledgers` as `{}` when the vault holds none: a held one is never touched here.
+func (v *Vault) ensureLedgers(node string) {
+	secret, err := ledgersSecret(node)
+	if err != nil {
+		v.log("%s's ledgers are not made: %v", node, err)
+		return
+	}
+	_, held, err := v.Store.Read(secret)
+	if err != nil || held {
+		if err != nil {
+			v.log("%s is not read, so its ledgers are not made: %v", secret, err)
+		}
+		return
+	}
+	empty, _ := json.Marshal(map[string]json.RawMessage{})
+	if _, err := v.keepLocked(secret, string(empty), "the vault", "", OriginMade, keepOptions{neverReplace: true}); err != nil {
+		v.log("%s is not made, tried again at the next pass: %v", secret, err)
+		return
+	}
+	v.log("made %s as {}: no ledger account is held for its machine yet", secret)
+}
diff --git a/modules/mesh-vault/cmd/mesh-vault/ledgers_test.go b/modules/mesh-vault/cmd/mesh-vault/ledgers_test.go
new file mode 100644
index 00000000..ec8e424c
--- /dev/null
+++ b/modules/mesh-vault/cmd/mesh-vault/ledgers_test.go
@@ -0,0 +1,61 @@
+package main
+
+import (
+	"encoding/json"
+	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/buscompose"
+	"git.novox.be/novox/mesh-sdk/go/seal"
+)
+
+// Ledger accounts and the tool runner's own secret `ledgers` (novox/hq ADR 0597 §9, issue 1966). Not the custody
+// ledger of ledger.go (ADR 0085), which is another thing.
+
+// nodeToolsWant is the wanted account of a machine's tool runner, as the grants part writes it.
+func nodeToolsWant(node string) buscompose.WantedAccount {
+	w := aWant("node-tools")
+	w.Kind, w.Node, w.User = buscompose.KindNodeTools, node, node+".node-tools"
+	return w
+}
+
+// ledgerWant is the wanted ledger account of a module on a machine.
+func ledgerWant(node, module string) buscompose.WantedAccount {
+	w := aWant(module)
+	w.Kind, w.Node, w.User, w.Claims = buscompose.KindLedger, node, "ledger."+node+"."+module, nil
+	return w
+}
+
+// ledgersOf is what the vault's `own` answers the machine as node-tools' `ledgers`: the map of module to credential,
+// and whether the secret is there at all.
+func ledgersOf(t *testing.T, v testVault, priv string) (map[string]json.RawMessage, bool) {
+	t.Helper()
+	own, err := v.OwnOfNode("node.ace")
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, o := range own.Own {
+		if o.Module == "node-tools" && o.Name == buscompose.LedgersSecret {
+			value, err := seal.Open(o.Sealed, priv)
+			if err != nil {
+				t.Fatal(err)
+			}
+			got := map[string]json.RawMessage{}
+			if err := json.Unmarshal([]byte(value), &got); err != nil {
+				t.Fatalf("ledgers is not a JSON map: %v", err)
+			}
+			return got, true
+		}
+	}
+	return nil, false
+}
+
+// changesOf counts the secret-changed events said for name since the first of events.
+func changesOf(v testVault, since int, name string) int {
+	n := 0
+	for _, e := range v.bus.events[since:] {
+		if e["event"] == ChangedEvent && e["name"] == name {
+			n++
+		}
+	}
+	return n
+}
diff --git a/modules/mesh-vault/cmd/mesh-vault/main.go b/modules/mesh-vault/cmd/mesh-vault/main.go
index e4e06e00..3333b3c0 100644
--- a/modules/mesh-vault/cmd/mesh-vault/main.go
+++ b/modules/mesh-vault/cmd/mesh-vault/main.go
@@ -350,6 +350,7 @@ func main() {
 				}
 				env.Vault.HashOwed()
 				env.Vault.MintOwed()
+				env.Vault.LedgersPass()
 				env.Vault.RetirePass()
 				env.Vault.RotationPass()
 				env.Vault.LoginsPass()
diff --git a/modules/mesh-vault/cmd/mesh-vault/mint.go b/modules/mesh-vault/cmd/mesh-vault/mint.go
index 3b20a47e..21ed60cb 100644
--- a/modules/mesh-vault/cmd/mesh-vault/mint.go
+++ b/modules/mesh-vault/cmd/mesh-vault/mint.go
@@ -193,6 +193,9 @@ func (v *Vault) WantHeard(user string, raw []byte, deleted bool) {
 	v.minting.wants[user] = w
 	v.minting.mu.Unlock()
 	v.wantBack(user)
+	if w.Kind == buscompose.KindNodeTools {
+		v.ensureLedgers(w.Node)
+	}
 	if _, err := v.mintWanted(w, "the grants part's want of "+user); err != nil {
 		v.log("%s is not minted: %v", user, err)
 	}
diff --git a/modules/mesh-vault/cmd/mesh-vault/mint_test.go b/modules/mesh-vault/cmd/mesh-vault/mint_test.go
index 8ca556f6..edd36ba1 100644
--- a/modules/mesh-vault/cmd/mesh-vault/mint_test.go
+++ b/modules/mesh-vault/cmd/mesh-vault/mint_test.go
@@ -99,6 +99,36 @@ func TestTheVaultMintsAWantedAccountOnceAndNothingItHolds(t *testing.T) {
 	if st := v.MintState(); len(st.HeldBack) != 0 || len(st.Minted) != 1 {
 		t.Errorf("vault_status says %+v: an adopted user is not held back, one account minted", st)
 	}
+	t.Run("ledgers", func(t *testing.T) {
+		for _, c := range []struct {
+			name string
+			run  func(t *testing.T, v testVault, priv string)
+		}{
+			// 1966/AC24 (issue 1966 V1): a machine carrying node-tools, with no ledger account, has `ledgers` as {}.
+			{"an empty ledgers on a machine with node-tools", func(t *testing.T, v testVault, priv string) {
+				if _, ok := ledgersOf(t, v, priv); ok {
+					t.Fatal("ledgers is there before node-tools is wanted")
+				}
+				w := nodeToolsWant("ace")
+				v.WantHeard(w.User, wantRaw(t, w), false)
+				before := len(v.bus.events)
+				v.LedgersPass()
+				got, ok := ledgersOf(t, v, priv)
+				if !ok || len(got) != 0 {
+					t.Fatalf("ledgers is %v (held %v), want {}", got, ok)
+				}
+				v.LedgersPass()
+				if n := changesOf(v, before, "own/ace/node-tools/ledgers"); n != 0 {
+					t.Errorf("a second pass said secret-changed %d times for a value that did not change", n)
+				}
+			}},
+		} {
+			t.Run(c.name, func(t *testing.T) {
+				v, _, priv := mintingVault(t)
+				c.run(t, v, priv)
+			})
+		}
+	})
 }
 
 // 774/AC8, after research 072's gap "vault mints after the lease": the vault is the one issuer, so a wanted account is