diff --git a/.gitignore b/.gitignore
index cc5b132..21b8ded 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,17 +1,16 @@
 # secrets
-.env*
+.env
+.env.*
 !.env.example
-*.key
-*.pem
 
-# deps/build
+# dependencies / build output
 node_modules/
 dist/
 
-# generated evidence
+# runtime artifacts
 outputs/
-
-# misc
 *.log
+
+# OS / editor
 .DS_Store
 __MACOSX/
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..86026d9
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,15 @@
+# Changelog
+
+## 0.2.0 (VaultMesh-grade artifact)
+
+- Safety boundary: `--dry-run` plans + `vmc apply` execution
+- Per-server lockfiles with `--force`
+- Receipts:
+  - canonical hashing (BLAKE3 + SHA256)
+  - `prev_blake3` chaining and `HEAD.json`
+  - optional operator signatures (Ed25519) without altering canonical hashes
+- Verification:
+  - `vmc verify receipt ...`
+  - `vmc verify chain ...`
+- Merkle receipts:
+  - `vmc merkle receipts` outputs a root commitment file
diff --git a/README.md b/README.md
index 996e833..bf0ca4c 100644
--- a/README.md
+++ b/README.md
@@ -1,14 +1,87 @@
 # vm-cloud
 
-Hetzner CLI + MCP tooling for VM ops and research notes.
+Hetzner Cloud operator CLI (`vmc`) with audit-ready receipts, plan/apply safety, and a tamper-evident local ledger.
 
 ## Quick start
 
-- npm install
-- ./bin/vmc servers list
-- ./bin/vmc snapshot servers
-- ./bin/vmc research new "Title"
+1) Install deps
 
-## Env
+```bash
+npm install
+```
 
-Set HCLOUD_TOKEN in ~/.env or ./.env.
+2) Configure Hetzner token
+
+Create `~/.env` (recommended) or a project `.env` with:
+
+```bash
+HCLOUD_TOKEN=xxx
+```
+
+3) Run
+
+```bash
+# dev (runs TS directly)
+npm run dev -- --help
+
+# or
+./bin/vmc --help
+```
+
+## Commands
+
+### Read-only
+
+```bash
+vmc servers list
+vmc snapshot servers
+vmc research new "Hetzner Baseline YYYY-MM-DD"
+vmc research append --from outputs/hetzner/servers-*.json
+```
+
+### Mutations (safe)
+
+All mutations:
+- resolve server by id/name (exact first, partial only when unambiguous)
+- require confirmation (or `--yes`)
+- write a receipt to `outputs/receipts/`
+- acquire a per-server lock (`~/.cache/vm-cloud/locks/<id>.lock`) to prevent concurrent ops
+
+#### Plan (dry-run)
+
+```bash
+vmc servers labels <name|id> env=prod owner=ops --dry-run
+# => outputs/plans/plan-*.json with SHA256+BLAKE3
+```
+
+#### Apply
+
+```bash
+vmc apply --plan outputs/plans/plan-*.json --yes --reason "change ticket / intent"
+```
+
+### Ledger + verification
+
+```bash
+vmc verify receipt outputs/receipts/<file>.json --head --plan --sig
+vmc verify chain --head --sig
+```
+
+### Signing
+
+```bash
+vmc keygen
+vmc sign receipt outputs/receipts/<file>.json
+```
+
+### Merkle receipts
+
+```bash
+vmc merkle receipts
+# => outputs/ledger/merkle-*.json (root over receipt blake3 chain)
+```
+
+## Safety notes
+
+- Never commit `.env` or `outputs/` or `node_modules/` (see `.gitignore`).
+- Rotate any leaked tokens immediately.
diff --git a/UPGRADE_PATH.md b/UPGRADE_PATH.md
new file mode 100644
index 0000000..8cdb316
--- /dev/null
+++ b/UPGRADE_PATH.md
@@ -0,0 +1,71 @@
+# vm-cloud Upgrade Path (VaultMesh)
+
+This repo is designed to evolve into a verifiable operator subsystem: **actions → receipts → ledger → merkle → anchors**.
+
+## Current state (this artifact)
+
+- Per-server lock files (`~/.cache/vm-cloud/locks/<serverId>.lock`) with `--force`
+- Receipts written to `outputs/receipts/` with:
+  - canonical hashing (`blake3 + sha256`)
+  - `prev_blake3` chaining
+  - `HEAD.json` updated on every receipt
+- Plan/apply boundary:
+  - `--dry-run` emits a plan to `outputs/plans/`
+  - `vmc apply --plan ...` executes and links the plan hashes into the receipt
+- Operator signing (Ed25519):
+  - `vmc keygen`
+  - `vmc sign receipt <receipt>`
+  - `vmc verify receipt <receipt> --sig`
+  - `vmc verify chain --sig`
+- Merkle commitment:
+  - `vmc merkle receipts` writes `outputs/ledger/merkle-*.json`
+
+## Next steps (recommended)
+
+### 1) CI gate: “ledger must verify”
+
+In CI, after tests:
+
+```bash
+npm run build
+node dist/cli.js verify chain --head
+```
+
+Optionally require signatures:
+
+```bash
+node dist/cli.js verify chain --sig --head
+```
+
+### 2) Anchoring the Merkle root
+
+The merkle root file is your commitment point. Anchor it using your preferred substrate:
+
+- **btc-anchor**: commit root into an OP_RETURN / inscription scheme (policy-dependent)
+- **eth-anchor**: store root in a contract/event log
+- **rfc3161-anchor**: timestamp the root using an RFC3161 TSA
+
+The anchoring step should store:
+- `root`
+- `created_at`
+- `leaf_count`
+- `head_blake3`
+- a signature over the above (operator key)
+
+### 3) Multi-operator keys + rotation
+
+- Add a `key_id` (KID) and embed it in receipts
+- Allow multiple trusted public keys for verification
+- Add `vmc keys list` and `vmc keys trust <pub>` for distributed ops
+
+### 4) MCP plan/apply flow
+
+Expose “plan” and “apply” as MCP tools so an agent can:
+- generate a plan (dry-run)
+- have a human approve/sign the plan
+- apply it and produce a linked receipt
+
+### 5) Drift + policy checks
+
+- Add `vmc policy check` that evaluates server labels, naming, and network posture
+- Make policy checks emit signed attestations into the same ledger
diff --git a/bin/vmc b/bin/vmc
index 8da36b1..2a79de3 100755
--- a/bin/vmc
+++ b/bin/vmc
@@ -1,4 +1,10 @@
 #!/usr/bin/env bash
 set -euo pipefail
-cd "$(dirname "$0")/.."
-exec npx -y tsx src/cli.ts "$@"
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+
+if [[ -f "$ROOT/dist/cli.js" ]]; then
+  exec node "$ROOT/dist/cli.js" "$@"
+else
+  exec npx -y tsx "$ROOT/src/cli.ts" "$@"
+fi
diff --git a/package-lock.json b/package-lock.json
index 983831e..14bf42c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -9,11 +9,8 @@
       "version": "0.0.1",
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.0.0",
-        "@noble/ed25519": "^2.1.0",
-        "@noble/hashes": "^1.4.0",
         "commander": "^12.0.0",
-        "dotenv": "^16.0.0",
-        "json-canonicalize": "^1.0.6"
+        "dotenv": "^16.0.0"
       },
       "bin": {
         "vmc": "bin/vmc"
@@ -517,27 +514,6 @@
         }
       }
     },
-    "node_modules/@noble/ed25519": {
-      "version": "2.3.0",
-      "resolved": "https://registry.npmjs.org/@noble/ed25519/-/ed25519-2.3.0.tgz",
-      "integrity": "sha512-M7dvXL2B92/M7dw9+gzuydL8qn/jiqNHaoR3Q+cb1q1GHV7uwE17WCyFMG+Y+TZb5izcaXk5TdJRrDUxHXL78A==",
-      "license": "MIT",
-      "funding": {
-        "url": "https://paulmillr.com/funding/"
-      }
-    },
-    "node_modules/@noble/hashes": {
-      "version": "1.8.0",
-      "resolved": "https://registry.npmjs.org/@noble/hashes/-/hashes-1.8.0.tgz",
-      "integrity": "sha512-jCs9ldd7NwzpgXDIf6P3+NrHh9/sD6CQdxHyjQI+h/6rDNo88ypBxxz45UDuZHz9r3tNz7N/VInSVoVdtXEI4A==",
-      "license": "MIT",
-      "engines": {
-        "node": "^14.21.3 || >=16"
-      },
-      "funding": {
-        "url": "https://paulmillr.com/funding/"
-      }
-    },
     "node_modules/@types/node": {
       "version": "20.19.27",
       "resolved": "https://registry.npmjs.org/@types/node/-/node-20.19.27.tgz",
@@ -1219,12 +1195,6 @@
         "url": "https://github.com/sponsors/panva"
       }
     },
-    "node_modules/json-canonicalize": {
-      "version": "1.2.0",
-      "resolved": "https://registry.npmjs.org/json-canonicalize/-/json-canonicalize-1.2.0.tgz",
-      "integrity": "sha512-TTdjBvqrqJKSADlEsY5rWbx8/1tOrVlTR/aSLU8N2VSInCTffP0p+byYB8Es+OmL4ZOeEftjUdvV+eJeSzJC/Q==",
-      "license": "MIT"
-    },
     "node_modules/json-schema-traverse": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-1.0.0.tgz",
diff --git a/package.json b/package.json
index 78be5ff..95c1e69 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "vm-cloud",
-  "version": "0.0.1",
+  "version": "0.2.0",
   "description": "Hetzner ops + research documentation CLI",
   "type": "module",
   "bin": {
@@ -10,15 +10,15 @@
     "dev": "tsx src/cli.ts",
     "build": "tsc",
     "start": "node dist/cli.js",
-    "mcp": "tsx src/index.ts"
+    "mcp": "tsx src/index.ts",
+    "verify": "tsx src/cli.ts verify chain --head"
   },
   "dependencies": {
-    "@noble/ed25519": "^2.1.0",
     "@modelcontextprotocol/sdk": "^1.0.0",
-    "@noble/hashes": "^1.4.0",
     "commander": "^12.0.0",
     "dotenv": "^16.0.0",
-    "json-canonicalize": "^1.0.6"
+    "@noble/hashes": "^1.4.0",
+    "@noble/ed25519": "^2.1.0"
   },
   "devDependencies": {
     "@types/node": "^20.0.0",
diff --git a/src/cli.ts b/src/cli.ts
index 41ccbef..2bea770 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -1,22 +1,28 @@
 import { Command } from "commander";
 import { requireHcloudToken } from "./lib/env.js";
 import { HcloudClient } from "./lib/hcloud.js";
+
 import { serversList } from "./commands/servers.list.js";
 import { serversAction } from "./commands/servers.action.js";
 import { serversLabels } from "./commands/servers.labels.js";
 import { applyPlan } from "./commands/apply.js";
+
+import { snapshotServers } from "./commands/snapshot.js";
+
+import { researchNew } from "./commands/research.new.js";
+import { researchAppend } from "./commands/research.append.js";
+
 import { keygen } from "./commands/keygen.js";
 import { signReceipt } from "./commands/sign.receipt.js";
 import { verifyReceipt } from "./commands/verify.receipt.js";
-import { snapshotServers } from "./commands/snapshot.js";
-import { researchNew } from "./commands/research.new.js";
-import { researchAppend } from "./commands/research.append.js";
+import { verifyChain } from "./commands/verify.chain.js";
+import { merkleReceipts } from "./commands/merkle.receipts.js";
 
 const program = new Command();
 program
   .name("vmc")
   .description("vm-cloud: Hetzner ops + research documentation")
-  .version("0.0.1");
+  .version("0.2.0");
 
 const servers = program.command("servers").description("Server operations");
 
@@ -28,142 +34,105 @@ servers
     await serversList(client);
   });
 
-servers
-  .command("reboot")
-  .description("Reboot a server by name or id")
-  .argument("<nameOrId>", "Server name or id")
-  .option("--yes", "Confirm the action without prompting")
-  .option("--reason <text>", "Reason for the action (optional)")
-  .option("--force", "Break an active server lock")
-  .option("--allow-partial", "Allow partial match when using --yes")
-  .option("--dry-run", "Plan only; do not call Hetzner")
-  .option("--sign", "Sign the receipt after mutation")
-  .option("--require-sig", "Fail if signing fails or key is missing")
-  .action(
-    async (
-      nameOrId: string,
-      opts: {
-        yes?: boolean;
-        reason?: string;
-        force?: boolean;
-        allowPartial?: boolean;
-        dryRun?: boolean;
-        sign?: boolean;
-        requireSig?: boolean;
-      }
-    ) => {
-      const client = new HcloudClient(requireHcloudToken());
-      await serversAction(client, nameOrId, "reboot", opts);
+function addMutationFlags(cmd: Command) {
+  return cmd
+    .option("--yes", "Confirm the action without prompting")
+    .option("--reason <text>", "Reason for the action (required with --yes)")
+    .option("--force", "Break an active server lock")
+    .option("--allow-partial", "Allow partial match when using --yes")
+    .option("--dry-run", "Plan only; do not call Hetzner")
+    .option("--sign", "If an operator key exists, sign the resulting receipt");
+}
+
+addMutationFlags(
+  servers
+    .command("reboot")
+    .description("Reboot a server by name or id")
+    .argument("<nameOrId>", "Server name or id")
+).action(
+  async (
+    nameOrId: string,
+    opts: {
+      yes?: boolean;
+      reason?: string;
+      force?: boolean;
+      allowPartial?: boolean;
+      dryRun?: boolean;
+      sign?: boolean;
     }
-  );
+  ) => {
+    const client = new HcloudClient(requireHcloudToken());
+    await serversAction(client, nameOrId, "reboot", opts);
+  }
+);
 
-servers
-  .command("poweroff")
-  .description("Power off a server by name or id")
-  .argument("<nameOrId>", "Server name or id")
-  .option("--yes", "Confirm the action without prompting")
-  .option("--reason <text>", "Reason for the action (optional)")
-  .option("--force", "Break an active server lock")
-  .option("--allow-partial", "Allow partial match when using --yes")
-  .option("--dry-run", "Plan only; do not call Hetzner")
-  .option("--sign", "Sign the receipt after mutation")
-  .option("--require-sig", "Fail if signing fails or key is missing")
-  .action(
-    async (
-      nameOrId: string,
-      opts: {
-        yes?: boolean;
-        reason?: string;
-        force?: boolean;
-        allowPartial?: boolean;
-        dryRun?: boolean;
-        sign?: boolean;
-        requireSig?: boolean;
-      }
-    ) => {
-      const client = new HcloudClient(requireHcloudToken());
-      await serversAction(client, nameOrId, "poweroff", opts);
+addMutationFlags(
+  servers
+    .command("poweroff")
+    .description("Power off a server by name or id")
+    .argument("<nameOrId>", "Server name or id")
+).action(
+  async (
+    nameOrId: string,
+    opts: {
+      yes?: boolean;
+      reason?: string;
+      force?: boolean;
+      allowPartial?: boolean;
+      dryRun?: boolean;
+      sign?: boolean;
     }
-  );
+  ) => {
+    const client = new HcloudClient(requireHcloudToken());
+    await serversAction(client, nameOrId, "poweroff", opts);
+  }
+);
 
-servers
-  .command("poweron")
-  .description("Power on a server by name or id")
-  .argument("<nameOrId>", "Server name or id")
-  .option("--yes", "Confirm the action without prompting")
-  .option("--reason <text>", "Reason for the action (optional)")
-  .option("--force", "Break an active server lock")
-  .option("--allow-partial", "Allow partial match when using --yes")
-  .option("--dry-run", "Plan only; do not call Hetzner")
-  .option("--sign", "Sign the receipt after mutation")
-  .option("--require-sig", "Fail if signing fails or key is missing")
-  .action(
-    async (
-      nameOrId: string,
-      opts: {
-        yes?: boolean;
-        reason?: string;
-        force?: boolean;
-        allowPartial?: boolean;
-        dryRun?: boolean;
-        sign?: boolean;
-        requireSig?: boolean;
-      }
-    ) => {
-      const client = new HcloudClient(requireHcloudToken());
-      await serversAction(client, nameOrId, "poweron", opts);
+addMutationFlags(
+  servers
+    .command("poweron")
+    .description("Power on a server by name or id")
+    .argument("<nameOrId>", "Server name or id")
+).action(
+  async (
+    nameOrId: string,
+    opts: {
+      yes?: boolean;
+      reason?: string;
+      force?: boolean;
+      allowPartial?: boolean;
+      dryRun?: boolean;
+      sign?: boolean;
     }
-  );
+  ) => {
+    const client = new HcloudClient(requireHcloudToken());
+    await serversAction(client, nameOrId, "poweron", opts);
+  }
+);
 
-servers
-  .command("labels")
-  .description("Set labels on a server by name or id")
-  .argument("<nameOrId>", "Server name or id")
-  .argument("<labels...>", "Label pairs in key=value form")
-  .option("--yes", "Confirm the action without prompting")
-  .option("--reason <text>", "Reason for the action (optional)")
-  .option("--force", "Break an active server lock")
-  .option("--allow-partial", "Allow partial match when using --yes")
-  .option("--dry-run", "Plan only; do not call Hetzner")
-  .option("--sign", "Sign the receipt after mutation")
-  .option("--require-sig", "Fail if signing fails or key is missing")
-  .action(
-    async (
-      nameOrId: string,
-      labels: string[],
-      opts: {
-        yes?: boolean;
-        reason?: string;
-        force?: boolean;
-        allowPartial?: boolean;
-        dryRun?: boolean;
-        sign?: boolean;
-        requireSig?: boolean;
-      }
-    ) => {
-      const client = new HcloudClient(requireHcloudToken());
-      await serversLabels(client, nameOrId, labels, opts);
+addMutationFlags(
+  servers
+    .command("labels")
+    .description("Set labels on a server by name or id")
+    .argument("<nameOrId>", "Server name or id")
+    .argument("<labels...>", "Label pairs in key=value form")
+).action(
+  async (
+    nameOrId: string,
+    labels: string[],
+    opts: {
+      yes?: boolean;
+      reason?: string;
+      force?: boolean;
+      allowPartial?: boolean;
+      dryRun?: boolean;
+      sign?: boolean;
     }
-  );
-
-program
-  .command("keygen")
-  .description("Generate an Ed25519 operator keypair")
-  .option("--force", "Overwrite existing keypair")
-  .action(async (opts: { force?: boolean }) => {
-    await keygen(opts);
-  });
-
-const sign = program.command("sign").description("Signing tools");
-
-sign
-  .command("receipt")
-  .description("Sign a receipt with the operator key")
-  .argument("<path>", "Receipt JSON path")
-  .option("--force", "Overwrite existing signature fields")
-  .action(async (p: string, opts: { force?: boolean }) => {
-    await signReceipt(p, opts);
-  });
+  ) => {
+    const client = new HcloudClient(requireHcloudToken());
+    await serversLabels(client, nameOrId, labels, opts);
+  }
+);
 
 program
   .command("apply")
@@ -173,28 +142,24 @@ program
   .option("--reason <text>", "Reason for the action (required with --yes)")
   .option("--force", "Break an active server lock")
   .option("--allow-partial", "Allow partial match when using --yes")
-  .option("--sign", "Sign the receipt after mutation")
-  .option("--require-sig", "Fail if signing fails or key is missing")
+  .option("--sign", "If an operator key exists, sign the resulting receipt")
   .action(
-    async (
-      opts: {
-        plan: string;
-        yes?: boolean;
-        reason?: string;
-        force?: boolean;
-        allowPartial?: boolean;
-        sign?: boolean;
-        requireSig?: boolean;
-      }
-    ) => {
+    async (opts: {
+      plan: string;
+      yes?: boolean;
+      reason?: string;
+      force?: boolean;
+      allowPartial?: boolean;
+      sign?: boolean;
+    }) => {
       const client = new HcloudClient(requireHcloudToken());
       await applyPlan(client, opts.plan, opts);
     }
   );
 
-program
-  .command("snapshot")
-  .description("Write snapshots to outputs/")
+const snapshot = program.command("snapshot").description("Write snapshots to outputs/");
+
+snapshot
   .command("servers")
   .description("Snapshot Hetzner servers JSON")
   .action(async () => {
@@ -221,20 +186,55 @@ research
     researchAppend(opts.from, opts.note);
   });
 
+program
+  .command("keygen")
+  .description("Generate an Ed25519 operator keypair")
+  .option("--force", "Overwrite existing keypair")
+  .action(async (opts: { force?: boolean }) => {
+    await keygen(opts);
+  });
+
+const sign = program.command("sign").description("Signing tools");
+
+sign
+  .command("receipt")
+  .description("Sign a receipt with the operator key")
+  .argument("<path>", "Receipt JSON path")
+  .option("--force", "Overwrite existing signature fields")
+  .action(async (p: string, opts: { force?: boolean }) => {
+    await signReceipt(p, opts);
+  });
+
 const verify = program.command("verify").description("Verification tools");
 
 verify
   .command("receipt")
   .description("Verify a receipt file and optional plan/head linkage")
   .argument("<path>", "Receipt JSON path")
-  .option("--head", "If receipt matches HEAD.file, validate HEAD.blake3 too")
+  .option("--head", "Assert this receipt is the current HEAD and validate HEAD.blake3")
   .option("--plan", "If receipt references a plan file, verify its hashes too")
   .option("--sig", "Verify the Ed25519 signature on the receipt")
-  .action(
-    async (p: string, opts: { head?: boolean; plan?: boolean; sig?: boolean }) => {
-      await verifyReceipt(p, opts);
-    }
-  );
+  .action(async (p: string, opts: { head?: boolean; plan?: boolean; sig?: boolean }) => {
+    await verifyReceipt(p, opts);
+  });
+
+verify
+  .command("chain")
+  .description("Verify the receipt chain via prev_blake3 pointers (from HEAD back)")
+  .option("--head", "Ensure HEAD.file exists")
+  .option("--sig", "Require and verify Ed25519 signatures on every receipt")
+  .action(async (opts: { head?: boolean; sig?: boolean }) => {
+    await verifyChain(opts);
+  });
+
+const merkle = program.command("merkle").description("Merkle tools");
+
+merkle
+  .command("receipts")
+  .description("Compute a Merkle root over the receipt chain (genesis->HEAD)")
+  .action(() => {
+    merkleReceipts();
+  });
 
 program.parseAsync(process.argv).catch((err) => {
   console.error(err?.message ?? err);
diff --git a/src/commands/apply.ts b/src/commands/apply.ts
index c782108..a185241 100644
--- a/src/commands/apply.ts
+++ b/src/commands/apply.ts
@@ -2,49 +2,17 @@ import fs from "node:fs";
 import path from "node:path";
 import { HcloudClient } from "../lib/hcloud.js";
 import { requireConfirmation } from "../lib/confirm.js";
-import { readPrivateKey } from "../lib/keys.js";
 import { acquireServerLock } from "../lib/lock.js";
 import { hashBlake3Hex, hashSha256Hex } from "../lib/hash.js";
-import {
-  readPlan,
-  resolvePlanPath,
-  type PlanAction,
-  type PlanMatch,
-  type ServerPlan
-} from "../lib/plan.js";
+import { readPlan, resolvePlanPath, validatePlan, type ServerPlan } from "../lib/plan.js";
 import { writeReceipt } from "../lib/receipt.js";
-import { signReceiptFile } from "../lib/signature.js";
+import { maybeAutoSignReceipt } from "../lib/signing.js";
 
-const ACTIONS: PlanAction[] = ["poweron", "poweroff", "reboot", "labels"];
-const MATCHES: PlanMatch[] = ["id", "exact", "partial"];
-
-function planError(message: string): never {
-  const err = new Error(message);
-  (err as { exitCode?: number }).exitCode = 4;
-  throw err;
-}
-
-function validatePlan(plan: ServerPlan) {
-  if (plan.plan_version !== "1") {
-    planError(`Unsupported plan_version: ${String(plan.plan_version)}`);
-  }
-  if (!plan.created_at || Number.isNaN(Date.parse(plan.created_at))) {
-    planError("Plan created_at is missing or invalid.");
-  }
-  if (!ACTIONS.includes(plan.action)) {
-    planError(`Unsupported action: ${String(plan.action)}`);
-  }
-  if (!plan.server || typeof plan.server.id !== "number" || !plan.server.name) {
-    planError("Plan server id/name is missing or invalid.");
-  }
-  if (!MATCHES.includes(plan.match)) {
-    planError(`Unsupported match type: ${String(plan.match)}`);
-  }
-  if (!plan.request?.method || !plan.request?.path) {
-    planError("Plan request method/path is missing.");
-  }
-  if (plan.applied !== false) {
-    planError("Plan must have applied=false.");
+function mustExist(p: string, label: string) {
+  if (!fs.existsSync(p)) {
+    const err = new Error(`${label} not found: ${p}`);
+    (err as { exitCode?: number }).exitCode = 2;
+    throw err;
   }
 }
 
@@ -57,84 +25,66 @@ export async function applyPlan(
     force?: boolean;
     allowPartial?: boolean;
     sign?: boolean;
-    requireSig?: boolean;
   } = {}
 ) {
   const absPlan = resolvePlanPath(planPath);
-  if (!fs.existsSync(absPlan)) {
-    throw new Error(`Plan not found: ${absPlan}`);
-  }
+  mustExist(absPlan, "Plan");
 
   const plan = readPlan(absPlan);
-  const plan_sha256 = hashSha256Hex(plan);
-  const plan_blake3 = hashBlake3Hex(plan);
   validatePlan(plan);
 
+  const plan_sha256 = hashSha256Hex(plan);
+  const plan_blake3 = hashBlake3Hex(plan);
+  const plan_file = path.relative(process.cwd(), absPlan) || absPlan;
+
   if (plan.match === "partial" && opts.yes && !opts.allowPartial) {
-    planError("Plan was created from a partial match. Use --allow-partial.");
+    const err = new Error(
+      `Plan match is partial. Use --allow-partial to proceed.`
+    );
+    (err as { exitCode?: number }).exitCode = 4;
+    throw err;
   }
 
   const reasonRaw = opts.reason?.trim();
-  if (opts.yes && !reasonRaw) {
-    const err = new Error("Reason is required when using --yes.");
+  if (opts.yes && !reasonRaw && !plan.reason) {
+    const err = new Error("Reason is required when using --yes (or set plan.reason).");
     (err as { exitCode?: number }).exitCode = 2;
     throw err;
   }
 
-  const expectedPath =
-    plan.action === "labels"
-      ? `/servers/${plan.server.id}`
-      : `/servers/${plan.server.id}/actions/${plan.action}`;
-  const expectedMethod = plan.action === "labels" ? "PUT" : "POST";
-  if (plan.request.path !== expectedPath || plan.request.method !== expectedMethod) {
-    planError("Plan request does not match the expected action path/method.");
-  }
-
-  if (plan.action === "labels") {
-    const body = plan.request.body as { labels?: Record<string, string> } | undefined;
-    if (!body?.labels || typeof body.labels !== "object") {
-      planError("Plan labels body is missing or invalid.");
-    }
-  }
-
+  // Ensure target still exists.
   const servers = await client.listServers();
   const server = servers.find((s) => s.id === plan.server.id);
   if (!server) {
-    planError(`Server id ${plan.server.id} not found.`);
-  }
-  if (server.name !== plan.server.name) {
-    planError(
-      `Server name mismatch for id ${plan.server.id}: expected ${plan.server.name}, got ${server.name}`
-    );
-  }
-
-  if (opts.requireSig) {
-    try {
-      readPrivateKey();
-    } catch (err) {
-      const msg = err instanceof Error ? err.message : String(err);
-      const requireErr = new Error(`Signing key required: ${msg}`);
-      (requireErr as { exitCode?: number }).exitCode = 7;
-      throw requireErr;
-    }
+    const err = new Error(`No server found with id ${plan.server.id}`);
+    (err as { exitCode?: number }).exitCode = 3;
+    throw err;
   }
 
   const lock = acquireServerLock(server.id, { force: opts.force });
-  const plan_file = path.relative(process.cwd(), absPlan) || absPlan;
   try {
     const reason = reasonRaw || plan.reason || "unspecified";
+
     await requireConfirmation({
       action: plan.action,
-      server: { id: server.id, name: server.name, ip: server.public_net?.ipv4?.ip },
+      server: {
+        id: server.id,
+        name: server.name,
+        ip: server.public_net?.ipv4?.ip
+      },
       reason,
       yes: opts.yes,
       match: plan.match
     });
 
-    let response;
+    let response:
+      | Awaited<ReturnType<HcloudClient["powerAction"]>>
+      | Awaited<ReturnType<HcloudClient["updateServerLabels"]>>;
+
     if (plan.action === "labels") {
-      const body = plan.request.body as { labels: Record<string, string> };
-      response = await client.updateServerLabels(server.id, body.labels);
+      const body = (plan.request.body ?? {}) as { labels?: Record<string, string> };
+      const labels = body.labels ?? {};
+      response = await client.updateServerLabels(server.id, labels);
     } else {
       response = await client.powerAction(server.id, plan.action);
     }
@@ -142,12 +92,12 @@ export async function applyPlan(
     const receipt = writeReceipt({
       action: plan.action,
       reason,
-      server: { id: server.id, name: server.name, ip: server.public_net?.ipv4?.ip },
-      request: {
-        method: plan.request.method,
-        path: plan.request.path,
-        body: plan.request.body
+      server: {
+        id: server.id,
+        name: server.name,
+        ip: server.public_net?.ipv4?.ip
       },
+      request: plan.request,
       response: {
         status: response.status,
         ok: response.ok,
@@ -164,20 +114,8 @@ export async function applyPlan(
       );
     }
 
-    const mustSign = Boolean(opts.sign || opts.requireSig);
-    if (mustSign) {
-      try {
-        const signed = await signReceiptFile(receipt.file);
-        console.log(`Signed: ${signed.file} signer_kid=${signed.signer_kid}`);
-      } catch (err) {
-        const msg = err instanceof Error ? err.message : String(err);
-        if (opts.requireSig) {
-          const signErr = new Error(`Receipt signing failed: ${msg}`);
-          (signErr as { exitCode?: number }).exitCode = 7;
-          throw signErr;
-        }
-        console.warn(`WARN: receipt signing failed: ${msg}`);
-      }
+    if (opts.sign) {
+      await maybeAutoSignReceipt(receipt.file);
     }
 
     console.log(
diff --git a/src/commands/keygen.ts b/src/commands/keygen.ts
index 79ef459..7c786d5 100644
--- a/src/commands/keygen.ts
+++ b/src/commands/keygen.ts
@@ -1,8 +1,10 @@
-import { generateKeypair } from "../lib/keys.js";
+import { generateKeypair, keyPaths } from "../lib/keys.js";
 
 export async function keygen(opts: { force?: boolean } = {}) {
-  const { privateKeyPath, publicKeyPath, publicKey } = await generateKeypair(opts);
-  console.log(`Private key: ${privateKeyPath}`);
-  console.log(`Public key: ${publicKeyPath}`);
-  console.log(`Public key (hex): ${publicKey}`);
+  const paths = keyPaths();
+  const res = await generateKeypair({ force: opts.force });
+  console.log(`Key directory: ${paths.dir}`);
+  console.log(`Public key: ${res.pub_path}`);
+  console.log(`Public hex: ${res.pub_hex}`);
+  console.log(`Private key: ${res.priv_path} (keep secret)`);
 }
diff --git a/src/commands/merkle.receipts.ts b/src/commands/merkle.receipts.ts
new file mode 100644
index 0000000..5ed094e
--- /dev/null
+++ b/src/commands/merkle.receipts.ts
@@ -0,0 +1,65 @@
+import fs from "node:fs";
+import path from "node:path";
+import { nowStamp, ensureDir } from "../lib/report.js";
+import { readHead, receiptsDir } from "../lib/ledger.js";
+import { merkleRootBlake3 } from "../lib/merkle.js";
+
+type ReceiptEnv = { blake3?: string; prev_blake3?: string | null };
+
+export function merkleReceipts() {
+  const head = readHead();
+  if (!head) {
+    const err = new Error("HEAD.json not found or invalid");
+    (err as { exitCode?: number }).exitCode = 2;
+    throw err;
+  }
+
+  const dir = receiptsDir();
+  const files = fs
+    .readdirSync(dir)
+    .filter((f) => f.endsWith(".json") && f !== "HEAD.json")
+    .map((f) => path.join(dir, f));
+
+  const map = new Map<string, ReceiptEnv>();
+  for (const f of files) {
+    try {
+      const raw = fs.readFileSync(f, "utf8");
+      const env = JSON.parse(raw) as ReceiptEnv;
+      if (env.blake3) map.set(env.blake3, env);
+    } catch {
+      // ignore
+    }
+  }
+
+  // Walk prev pointers from head to genesis.
+  const chain: string[] = [];
+  let cur: string | null = head.blake3;
+  while (cur) {
+    const env = map.get(cur);
+    if (!env) break;
+    chain.push(cur);
+    cur = env.prev_blake3 ?? null;
+  }
+
+  const leaves = chain.slice().reverse(); // genesis -> head
+  const root = merkleRootBlake3(leaves);
+
+  const { stamp } = nowStamp();
+  const outDir = path.join(process.cwd(), "outputs", "ledger");
+  ensureDir(outDir);
+  const outFile = path.join(outDir, `merkle-${stamp}.json`);
+
+  const payload = {
+    created_at: new Date().toISOString(),
+    alg: "blake3",
+    leaf_count: leaves.length,
+    head_blake3: head.blake3,
+    root,
+    leaves
+  };
+
+  fs.writeFileSync(outFile, JSON.stringify(payload, null, 2), "utf8");
+  console.log(`Merkle root: ${root}`);
+  console.log(`Leaves: ${leaves.length}`);
+  console.log(`Wrote: ${outFile}`);
+}
diff --git a/src/commands/servers.action.ts b/src/commands/servers.action.ts
index 25edc32..8e1cf40 100644
--- a/src/commands/servers.action.ts
+++ b/src/commands/servers.action.ts
@@ -1,11 +1,10 @@
 import { HcloudClient } from "../lib/hcloud.js";
 import { requireConfirmation } from "../lib/confirm.js";
-import { readPrivateKey } from "../lib/keys.js";
 import { acquireServerLock } from "../lib/lock.js";
 import { writePlan } from "../lib/plan.js";
 import { writeReceipt } from "../lib/receipt.js";
-import { signReceiptFile } from "../lib/signature.js";
 import { resolveServer } from "../lib/resolve.js";
+import { maybeAutoSignReceipt } from "../lib/signing.js";
 
 export async function serversAction(
   client: HcloudClient,
@@ -18,38 +17,21 @@ export async function serversAction(
     allowPartial?: boolean;
     dryRun?: boolean;
     sign?: boolean;
-    requireSig?: boolean;
   } = {}
 ) {
   const { server, match } = await resolveServer(client, input);
+
   if (match === "partial") {
     console.warn(
       `Partial match: "${input}" resolved to ${server.name} (${server.id})`
     );
   }
 
-  if (match === "partial" && opts.yes && !opts.allowPartial) {
-    const err = new Error(
-      `Partial match for "${input}". Use --allow-partial to proceed.`
-    );
-    (err as { exitCode?: number }).exitCode = 4;
-    throw err;
-  }
-
   const reasonRaw = opts.reason?.trim();
-  if (!opts.dryRun && opts.yes && !reasonRaw) {
-    const err = new Error("Reason is required when using --yes.");
-    (err as { exitCode?: number }).exitCode = 2;
-    throw err;
-  }
 
-  const path = `/servers/${server.id}/actions/${action}`;
+  // Plan-only mode (no locks, no confirmation, no API calls)
+  const reqPath = `/servers/${server.id}/actions/${action}`;
   if (opts.dryRun) {
-    if (opts.sign || opts.requireSig) {
-      const err = new Error("Cannot sign receipts during --dry-run.");
-      (err as { exitCode?: number }).exitCode = 2;
-      throw err;
-    }
     const plan = {
       plan_version: "1",
       created_at: new Date().toISOString(),
@@ -60,40 +42,41 @@ export async function serversAction(
         ip: server.public_net?.ipv4?.ip
       },
       match,
-      request: { method: "POST", path },
+      request: { method: "POST", path: reqPath },
       reason: reasonRaw,
       applied: false
     } as const;
+
     const { file, sha256, blake3 } = writePlan(plan);
     console.log(`Resolved: ${server.name} (id=${server.id}) match=${match}`);
-    console.log(`Request: POST ${path}`);
+    console.log(`Request: POST ${reqPath}`);
     console.log(`Plan: ${file}`);
     console.log(`BLAKE3: ${blake3}`);
     console.log(`SHA256: ${sha256}`);
     return plan;
   }
 
-  if (opts.requireSig) {
-    try {
-      readPrivateKey();
-    } catch (err) {
-      const msg = err instanceof Error ? err.message : String(err);
-      const requireErr = new Error(`Signing key required: ${msg}`);
-      (requireErr as { exitCode?: number }).exitCode = 7;
-      throw requireErr;
-    }
+  if (match === "partial" && opts.yes && !opts.allowPartial) {
+    const err = new Error(
+      `Partial match for "${input}". Use --allow-partial to proceed.`
+    );
+    (err as { exitCode?: number }).exitCode = 4;
+    throw err;
+  }
+
+  if (opts.yes && !reasonRaw) {
+    const err = new Error("Reason is required when using --yes.");
+    (err as { exitCode?: number }).exitCode = 2;
+    throw err;
   }
 
   const lock = acquireServerLock(server.id, { force: opts.force });
   try {
     const reason = reasonRaw || "unspecified";
+
     await requireConfirmation({
       action,
-      server: {
-        id: server.id,
-        name: server.name,
-        ip: server.public_net?.ipv4?.ip
-      },
+      server: { id: server.id, name: server.name, ip: server.public_net?.ipv4?.ip },
       reason,
       yes: opts.yes,
       match
@@ -103,12 +86,8 @@ export async function serversAction(
     const receipt = writeReceipt({
       action,
       reason,
-      server: {
-        id: server.id,
-        name: server.name,
-        ip: server.public_net?.ipv4?.ip
-      },
-      request: { method: "POST", path },
+      server: { id: server.id, name: server.name, ip: server.public_net?.ipv4?.ip },
+      request: { method: "POST", path: reqPath },
       response: {
         status: response.status,
         ok: response.ok,
@@ -118,28 +97,16 @@ export async function serversAction(
       lock: { file: lock.file, started_at: lock.info.started_at, force: opts.force }
     });
 
+    if (opts.sign) {
+      await maybeAutoSignReceipt(receipt.file);
+    }
+
     if (!response.ok) {
       throw new Error(
         `Hetzner API error ${response.status}. Receipt: ${receipt.file}`
       );
     }
 
-    const mustSign = Boolean(opts.sign || opts.requireSig);
-    if (mustSign) {
-      try {
-        const signed = await signReceiptFile(receipt.file);
-        console.log(`Signed: ${signed.file} signer_kid=${signed.signer_kid}`);
-      } catch (err) {
-        const msg = err instanceof Error ? err.message : String(err);
-        if (opts.requireSig) {
-          const signErr = new Error(`Receipt signing failed: ${msg}`);
-          (signErr as { exitCode?: number }).exitCode = 7;
-          throw signErr;
-        }
-        console.warn(`WARN: receipt signing failed: ${msg}`);
-      }
-    }
-
     console.log(
       `OK ${action} ${server.name} (id=${server.id}) receipt=${receipt.file} blake3=${receipt.blake3} sha256=${receipt.sha256}`
     );
diff --git a/src/commands/servers.labels.ts b/src/commands/servers.labels.ts
index ab1d05d..fdc6259 100644
--- a/src/commands/servers.labels.ts
+++ b/src/commands/servers.labels.ts
@@ -1,27 +1,26 @@
 import { HcloudClient } from "../lib/hcloud.js";
 import { requireConfirmation } from "../lib/confirm.js";
-import { readPrivateKey } from "../lib/keys.js";
 import { acquireServerLock } from "../lib/lock.js";
 import { writePlan } from "../lib/plan.js";
 import { writeReceipt } from "../lib/receipt.js";
-import { signReceiptFile } from "../lib/signature.js";
 import { resolveServer } from "../lib/resolve.js";
+import { maybeAutoSignReceipt } from "../lib/signing.js";
 
 function parseLabels(args: string[]) {
-  if (!args.length) {
-    throw new Error("At least one label in key=value form is required");
-  }
-
   const labels: Record<string, string> = {};
-  for (const raw of args) {
-    const idx = raw.indexOf("=");
-    if (idx <= 0 || idx === raw.length - 1) {
-      throw new Error(`Invalid label "${raw}". Use key=value`);
+  for (const a of args) {
+    const idx = a.indexOf("=");
+    if (idx <= 0 || idx === a.length - 1) {
+      const err = new Error(`Invalid label "${a}". Use key=value.`);
+      (err as { exitCode?: number }).exitCode = 2;
+      throw err;
     }
-    const key = raw.slice(0, idx).trim();
-    const value = raw.slice(idx + 1).trim();
+    const key = a.slice(0, idx).trim();
+    const value = a.slice(idx + 1).trim();
     if (!key || !value) {
-      throw new Error(`Invalid label "${raw}". Use key=value`);
+      const err = new Error(`Invalid label "${a}". Use key=value.`);
+      (err as { exitCode?: number }).exitCode = 2;
+      throw err;
     }
     labels[key] = value;
   }
@@ -39,41 +38,23 @@ export async function serversLabels(
     allowPartial?: boolean;
     dryRun?: boolean;
     sign?: boolean;
-    requireSig?: boolean;
   } = {}
 ) {
   const { server, match } = await resolveServer(client, input);
+
   if (match === "partial") {
     console.warn(
       `Partial match: "${input}" resolved to ${server.name} (${server.id})`
     );
   }
 
-  if (match === "partial" && opts.yes && !opts.allowPartial) {
-    const err = new Error(
-      `Partial match for "${input}". Use --allow-partial to proceed.`
-    );
-    (err as { exitCode?: number }).exitCode = 4;
-    throw err;
-  }
-
   const reasonRaw = opts.reason?.trim();
-  if (!opts.dryRun && opts.yes && !reasonRaw) {
-    const err = new Error("Reason is required when using --yes.");
-    (err as { exitCode?: number }).exitCode = 2;
-    throw err;
-  }
-
   const labels = parseLabels(args);
   const next = { ...(server.labels ?? {}), ...labels };
-  const path = `/servers/${server.id}`;
+  const reqPath = `/servers/${server.id}`;
 
+  // Plan-only mode
   if (opts.dryRun) {
-    if (opts.sign || opts.requireSig) {
-      const err = new Error("Cannot sign receipts during --dry-run.");
-      (err as { exitCode?: number }).exitCode = 2;
-      throw err;
-    }
     const plan = {
       plan_version: "1",
       created_at: new Date().toISOString(),
@@ -84,13 +65,14 @@ export async function serversLabels(
         ip: server.public_net?.ipv4?.ip
       },
       match,
-      request: { method: "PUT", path, body: { labels: next } },
+      request: { method: "PUT", path: reqPath, body: { labels: next } },
       reason: reasonRaw,
       applied: false
     } as const;
+
     const { file, sha256, blake3 } = writePlan(plan);
     console.log(`Resolved: ${server.name} (id=${server.id}) match=${match}`);
-    console.log(`Request: PUT ${path}`);
+    console.log(`Request: PUT ${reqPath}`);
     console.log(JSON.stringify({ labels: next }, null, 2));
     console.log(`Plan: ${file}`);
     console.log(`BLAKE3: ${blake3}`);
@@ -98,27 +80,27 @@ export async function serversLabels(
     return plan;
   }
 
-  if (opts.requireSig) {
-    try {
-      readPrivateKey();
-    } catch (err) {
-      const msg = err instanceof Error ? err.message : String(err);
-      const requireErr = new Error(`Signing key required: ${msg}`);
-      (requireErr as { exitCode?: number }).exitCode = 7;
-      throw requireErr;
-    }
+  if (match === "partial" && opts.yes && !opts.allowPartial) {
+    const err = new Error(
+      `Partial match for "${input}". Use --allow-partial to proceed.`
+    );
+    (err as { exitCode?: number }).exitCode = 4;
+    throw err;
+  }
+
+  if (opts.yes && !reasonRaw) {
+    const err = new Error("Reason is required when using --yes.");
+    (err as { exitCode?: number }).exitCode = 2;
+    throw err;
   }
 
   const lock = acquireServerLock(server.id, { force: opts.force });
   try {
     const reason = reasonRaw || "unspecified";
+
     await requireConfirmation({
       action: "labels",
-      server: {
-        id: server.id,
-        name: server.name,
-        ip: server.public_net?.ipv4?.ip
-      },
+      server: { id: server.id, name: server.name, ip: server.public_net?.ipv4?.ip },
       reason,
       yes: opts.yes,
       match
@@ -128,12 +110,8 @@ export async function serversLabels(
     const receipt = writeReceipt({
       action: "labels",
       reason,
-      server: {
-        id: server.id,
-        name: server.name,
-        ip: server.public_net?.ipv4?.ip
-      },
-      request: { method: "PUT", path, body: { labels: next } },
+      server: { id: server.id, name: server.name, ip: server.public_net?.ipv4?.ip },
+      request: { method: "PUT", path: reqPath, body: { labels: next } },
       response: {
         status: response.status,
         ok: response.ok,
@@ -143,28 +121,16 @@ export async function serversLabels(
       lock: { file: lock.file, started_at: lock.info.started_at, force: opts.force }
     });
 
+    if (opts.sign) {
+      await maybeAutoSignReceipt(receipt.file);
+    }
+
     if (!response.ok) {
       throw new Error(
         `Hetzner API error ${response.status}. Receipt: ${receipt.file}`
       );
     }
 
-    const mustSign = Boolean(opts.sign || opts.requireSig);
-    if (mustSign) {
-      try {
-        const signed = await signReceiptFile(receipt.file);
-        console.log(`Signed: ${signed.file} signer_kid=${signed.signer_kid}`);
-      } catch (err) {
-        const msg = err instanceof Error ? err.message : String(err);
-        if (opts.requireSig) {
-          const signErr = new Error(`Receipt signing failed: ${msg}`);
-          (signErr as { exitCode?: number }).exitCode = 7;
-          throw signErr;
-        }
-        console.warn(`WARN: receipt signing failed: ${msg}`);
-      }
-    }
-
     console.log(
       `OK labels ${server.name} (id=${server.id}) receipt=${receipt.file} blake3=${receipt.blake3} sha256=${receipt.sha256}`
     );
diff --git a/src/commands/sign.receipt.ts b/src/commands/sign.receipt.ts
index c5c0566..a5cbaa2 100644
--- a/src/commands/sign.receipt.ts
+++ b/src/commands/sign.receipt.ts
@@ -1,12 +1,8 @@
-import { signReceiptFile } from "../lib/signature.js";
+import { signReceiptFile } from "../lib/signing.js";
 
-export async function signReceipt(
-  receiptPath: string,
-  opts: { force?: boolean } = {}
-) {
-  const signed = await signReceiptFile(receiptPath, opts);
-  console.log("OK receipt signed");
-  console.log(`file: ${signed.file}`);
-  console.log(`signer_pub: ${signed.signer_pub}`);
-  console.log(`signer_kid: ${signed.signer_kid}`);
+export async function signReceipt(path: string, opts: { force?: boolean } = {}) {
+  const res = await signReceiptFile(path, { force: opts.force });
+  console.log(`Signed: ${path}`);
+  console.log(`signer_pub: ${res.signer_pub}`);
+  console.log(`signature: ${res.signature}`);
 }
diff --git a/src/commands/verify.chain.ts b/src/commands/verify.chain.ts
new file mode 100644
index 0000000..af4c4a2
--- /dev/null
+++ b/src/commands/verify.chain.ts
@@ -0,0 +1,111 @@
+import fs from "node:fs";
+import path from "node:path";
+import { hashBlake3Hex, hashSha256Hex } from "../lib/hash.js";
+import { readHead, receiptsDir } from "../lib/ledger.js";
+import { verifyMessage } from "../lib/keys.js";
+
+type ReceiptEnvelope = Record<string, unknown> & {
+  blake3?: string;
+  sha256?: string;
+  prev_blake3?: string | null;
+
+  sig_alg?: string;
+  signer_pub?: string;
+  signature?: string;
+};
+
+function stripForHash(env: ReceiptEnvelope) {
+  const {
+    hash_alg: _hash_alg,
+    blake3: _blake3,
+    sha256: _sha256,
+    sig_alg: _sig_alg,
+    signer_pub: _signer_pub,
+    signature: _signature,
+    signed_at: _signed_at,
+    ...body
+  } = env as Record<string, unknown> as any;
+  return body;
+}
+
+export async function verifyChain(opts: { sig?: boolean; head?: boolean } = {}) {
+  const head = readHead();
+  if (!head) {
+    const err = new Error("HEAD.json not found or invalid");
+    (err as { exitCode?: number }).exitCode = 2;
+    throw err;
+  }
+
+  const dir = receiptsDir();
+  if (!fs.existsSync(dir)) {
+    const err = new Error(`Receipts dir not found: ${dir}`);
+    (err as { exitCode?: number }).exitCode = 2;
+    throw err;
+  }
+
+  const files = fs
+    .readdirSync(dir)
+    .filter((f) => f.endsWith(".json") && f !== "HEAD.json")
+    .map((f) => path.join(dir, f));
+
+  const map = new Map<string, { file: string; env: ReceiptEnvelope }>();
+  for (const f of files) {
+    try {
+      const raw = fs.readFileSync(f, "utf8");
+      const env = JSON.parse(raw) as ReceiptEnvelope;
+      const b3 = String(env.blake3 ?? "");
+      if (b3) map.set(b3, { file: f, env });
+    } catch {
+      // ignore unreadable receipts
+    }
+  }
+
+  const failures: string[] = [];
+  let cur: string | null = head.blake3;
+  let count = 0;
+
+  while (cur) {
+    const item = map.get(cur);
+    if (!item) {
+      failures.push(`missing receipt for blake3=${cur}`);
+      break;
+    }
+
+    const { env, file } = item;
+    const body = stripForHash(env);
+    const b3_calc = hashBlake3Hex(body);
+    const sha_calc = hashSha256Hex(body);
+
+    if (env.blake3 !== b3_calc) failures.push(`blake3 mismatch: ${path.basename(file)}`);
+    if (env.sha256 !== sha_calc) failures.push(`sha256 mismatch: ${path.basename(file)}`);
+
+    if (opts.sig) {
+      if (env.sig_alg !== "ed25519" || !env.signature || !env.signer_pub) {
+        failures.push(`missing signature fields: ${path.basename(file)}`);
+      } else {
+        const msg = new TextEncoder().encode(String(env.blake3 ?? ""));
+        const ok = await verifyMessage(msg, String(env.signature), String(env.signer_pub));
+        if (!ok) failures.push(`bad signature: ${path.basename(file)}`);
+      }
+    }
+
+    count += 1;
+    cur = env.prev_blake3 ? String(env.prev_blake3) : null;
+  }
+
+  if (opts.head) {
+    // HEAD.file should exist and match the head hash.
+    const headFileAbs = path.resolve(head.file);
+    if (!fs.existsSync(headFileAbs)) {
+      failures.push(`HEAD.file missing: ${head.file}`);
+    }
+  }
+
+  if (failures.length) {
+    const err = new Error("Ledger chain verification failed:\n- " + failures.join("\n- "));
+    (err as { exitCode?: number }).exitCode = 5;
+    throw err;
+  }
+
+  console.log(`OK chain receipts=${count} head=${head.blake3}`);
+}
diff --git a/src/commands/verify.receipt.ts b/src/commands/verify.receipt.ts
index 69dd217..f2e7e40 100644
--- a/src/commands/verify.receipt.ts
+++ b/src/commands/verify.receipt.ts
@@ -2,37 +2,7 @@ import fs from "node:fs";
 import path from "node:path";
 import { hashBlake3Hex, hashSha256Hex } from "../lib/hash.js";
 import { readHead } from "../lib/ledger.js";
-import { keyIdFromPublicHex, verifyMessage } from "../lib/keys.js";
-
-type ReceiptEnvelope = {
-  receipt_version: "1";
-  created_at: string;
-  cwd: string;
-  user: string;
-  hostname: string;
-  argv: string[];
-  reason: string;
-  lock_file: string | null;
-  lock_started_at: string | null;
-  force: boolean;
-  plan_file: string | null;
-  plan_sha256: string | null;
-  plan_blake3: string | null;
-  target: { id: number; name: string; ip?: string | null };
-  request: unknown;
-  response: unknown;
-  prev_blake3: string | null;
-  hash_alg: "blake3+sha256";
-  blake3: string;
-  sha256: string;
-  sig_alg?: "ed25519";
-  signer_pub?: string;
-  signer_kid?: string;
-  signed_at?: string;
-  signature?: string;
-};
-
-type ReceiptBody = Omit<ReceiptEnvelope, "hash_alg" | "blake3" | "sha256">;
+import { verifyMessage } from "../lib/keys.js";
 
 function mustExist(p: string, label: string) {
   if (!fs.existsSync(p)) {
@@ -42,16 +12,31 @@ function mustExist(p: string, label: string) {
   }
 }
 
-function stripHashes(env: ReceiptEnvelope): ReceiptBody {
+type ReceiptEnvelope = Record<string, unknown> & {
+  hash_alg?: string;
+  blake3?: string;
+  sha256?: string;
+  prev_blake3?: string | null;
+
+  plan_file?: string | null;
+  plan_sha256?: string | null;
+  plan_blake3?: string | null;
+
+  sig_alg?: string;
+  signer_pub?: string;
+  signature?: string;
+  signed_at?: string;
+};
+
+function stripForHash(env: ReceiptEnvelope) {
   const {
     hash_alg: _hash_alg,
     blake3: _blake3,
     sha256: _sha256,
     sig_alg: _sig_alg,
     signer_pub: _signer_pub,
-    signer_kid: _signer_kid,
-    signed_at: _signed_at,
     signature: _signature,
+    signed_at: _signed_at,
     ...body
   } = env;
   return body;
@@ -65,95 +50,69 @@ export async function verifyReceipt(
   mustExist(abs, "Receipt");
 
   const raw = fs.readFileSync(abs, "utf8");
-  let env: ReceiptEnvelope;
-  try {
-    env = JSON.parse(raw) as ReceiptEnvelope;
-  } catch {
-    const err = new Error("Receipt is not valid JSON");
-    (err as { exitCode?: number }).exitCode = 2;
-    throw err;
-  }
-
-  if (env.hash_alg !== "blake3+sha256" || !env.blake3 || !env.sha256) {
-    const err = new Error(
-      "Receipt missing required hash fields (hash_alg/blake3/sha256)"
-    );
-    (err as { exitCode?: number }).exitCode = 2;
-    throw err;
-  }
-
-  const body = stripHashes(env);
-  const blake3 = hashBlake3Hex(body);
-  const sha256 = hashSha256Hex(body);
+  const env = JSON.parse(raw) as ReceiptEnvelope;
 
   const failures: string[] = [];
-  if (blake3 !== env.blake3) {
-    failures.push(`BLAKE3 mismatch (expected ${env.blake3}, got ${blake3})`);
-  }
-  if (sha256 !== env.sha256) {
-    failures.push(`SHA256 mismatch (expected ${env.sha256}, got ${sha256})`);
+
+  if (env.hash_alg !== "blake3+sha256") {
+    failures.push(`hash_alg mismatch (got ${String(env.hash_alg)})`);
   }
 
-  if (opts.plan && env.plan_file) {
-    const planAbs = path.isAbsolute(env.plan_file)
-      ? env.plan_file
-      : path.join(process.cwd(), env.plan_file);
-    try {
-      mustExist(planAbs, "Plan file referenced by receipt");
-      const planRaw = fs.readFileSync(planAbs, "utf8");
-      const planObj = JSON.parse(planRaw) as unknown;
-      const planSha = hashSha256Hex(planObj);
-      const planB3 = hashBlake3Hex(planObj);
-      if (!env.plan_sha256 || !env.plan_blake3) {
-        failures.push("Receipt is missing plan hash fields");
+  const body = stripForHash(env);
+  const blake3_calc = hashBlake3Hex(body);
+  const sha256_calc = hashSha256Hex(body);
+
+  if (env.blake3 !== blake3_calc) failures.push("blake3 mismatch");
+  if (env.sha256 !== sha256_calc) failures.push("sha256 mismatch");
+
+  if (opts.plan) {
+    const planFile = env.plan_file ? String(env.plan_file) : "";
+    const planSha = env.plan_sha256 ? String(env.plan_sha256) : "";
+    const planBlake = env.plan_blake3 ? String(env.plan_blake3) : "";
+
+    if (!planFile) {
+      failures.push("receipt has no plan_file");
+    } else {
+      const planAbs = path.resolve(planFile);
+      if (!fs.existsSync(planAbs)) {
+        failures.push(`plan file not found: ${planFile}`);
       } else {
-        if (env.plan_sha256 !== planSha) {
-          failures.push(
-            `Plan SHA256 mismatch (expected ${env.plan_sha256}, got ${planSha})`
-          );
-        }
-        if (env.plan_blake3 !== planB3) {
-          failures.push(
-            `Plan BLAKE3 mismatch (expected ${env.plan_blake3}, got ${planB3})`
-          );
+        try {
+          const planRaw = fs.readFileSync(planAbs, "utf8");
+          const plan = JSON.parse(planRaw) as unknown;
+          const sha = hashSha256Hex(plan);
+          const b3 = hashBlake3Hex(plan);
+          if (planSha && sha !== planSha) failures.push("plan_sha256 mismatch");
+          if (planBlake && b3 !== planBlake) failures.push("plan_blake3 mismatch");
+        } catch (e) {
+          failures.push(`failed to read/parse plan: ${(e as Error).message}`);
         }
       }
-    } catch (err) {
-      const msg = err instanceof Error ? err.message : String(err);
-      failures.push(msg);
     }
   }
 
   if (opts.head) {
     const head = readHead();
     if (!head) {
-      failures.push("HEAD.json missing");
+      failures.push("HEAD.json not found or invalid");
     } else {
       const rel = path.relative(process.cwd(), abs) || abs;
-      if (head.file === rel && head.blake3 !== env.blake3) {
-        failures.push(
-          `HEAD blake3 mismatch (HEAD=${head.blake3}, receipt=${env.blake3})`
-        );
+      if (head.file !== rel) {
+        failures.push(`receipt is not HEAD.file (HEAD.file=${head.file})`);
+      }
+      if (head.blake3 !== env.blake3) {
+        failures.push("HEAD.blake3 mismatch");
       }
     }
   }
 
   if (opts.sig) {
-    if (!env.signature || !env.signer_pub || env.sig_alg !== "ed25519") {
-      const err = new Error("Receipt signature fields missing or invalid");
-      (err as { exitCode?: number }).exitCode = 2;
-      throw err;
-    }
-    const msg = new TextEncoder().encode(env.blake3);
-    const ok = await verifyMessage(msg, env.signature, env.signer_pub);
-    if (!ok) failures.push("Signature verification failed");
-    if (env.signer_kid) {
-      const kid = keyIdFromPublicHex(env.signer_pub);
-      if (env.signer_kid !== kid) {
-        failures.push(
-          `Signer key id mismatch (expected ${env.signer_kid}, got ${kid})`
-        );
-      }
+    if (env.sig_alg !== "ed25519" || !env.signature || !env.signer_pub) {
+      failures.push("signature fields missing (need sig_alg, signer_pub, signature)");
+    } else {
+      const msg = new TextEncoder().encode(String(env.blake3 ?? ""));
+      const ok = await verifyMessage(msg, String(env.signature), String(env.signer_pub));
+      if (!ok) failures.push("signature verification failed");
     }
   }
 
@@ -163,10 +122,8 @@ export async function verifyReceipt(
     throw err;
   }
 
-  console.log("OK receipt verified");
-  console.log(`file: ${abs}`);
-  console.log(`blake3: ${env.blake3}`);
-  console.log(`sha256: ${env.sha256}`);
-  if (env.prev_blake3) console.log(`prev_blake3: ${env.prev_blake3}`);
-  if (env.plan_file) console.log(`plan: ${env.plan_file}`);
+  console.log(`OK receipt ${receiptPath}`);
+  console.log(`blake3=${env.blake3}`);
+  console.log(`sha256=${env.sha256}`);
+  if (opts.sig && env.signature) console.log(`sig=ok signer_pub=${env.signer_pub}`);
 }
diff --git a/src/lib/hash.ts b/src/lib/hash.ts
index d33cc3f..3c1395a 100644
--- a/src/lib/hash.ts
+++ b/src/lib/hash.ts
@@ -1,17 +1,59 @@
+import crypto from "node:crypto";
 import { blake3 } from "@noble/hashes/blake3";
-import { sha256 } from "@noble/hashes/sha256";
-import { bytesToHex } from "@noble/hashes/utils";
-import { canonicalize } from "json-canonicalize";
+import { bytesToHex, utf8ToBytes } from "@noble/hashes/utils";
 
-export function canonicalBytes(obj: unknown): Uint8Array {
-  const json = canonicalize(obj);
-  return new TextEncoder().encode(json);
+type Json =
+  | null
+  | boolean
+  | number
+  | string
+  | Json[]
+  | { [k: string]: Json };
+
+/**
+ * Deterministic JSON normalization: recursively sorts object keys and removes
+ * `undefined` so hashing is stable across runs.
+ *
+ * Note: this is *not* a full RFC 8785 implementation, but it is stable for the
+ * structures we emit (plain JSON objects).
+ */
+export function canonicalize(value: unknown): Json {
+  if (value === null) return null;
+
+  const t = typeof value;
+  if (t === "string" || t === "number" || t === "boolean") return value as Json;
+
+  if (Array.isArray(value)) {
+    return value.map((v) => canonicalize(v)) as Json;
+  }
+
+  if (t === "object") {
+    const obj = value as Record<string, unknown>;
+    const out: Record<string, Json> = {};
+    for (const k of Object.keys(obj).sort()) {
+      const v = obj[k];
+      if (v === undefined) continue;
+      out[k] = canonicalize(v);
+    }
+    return out;
+  }
+
+  // functions / symbols / bigint should never appear in our receipts/plans
+  return String(value) as unknown as Json;
 }
 
-export function hashBlake3Hex(obj: unknown): string {
-  return bytesToHex(blake3(canonicalBytes(obj)));
+export function canonicalJson(value: unknown): string {
+  return JSON.stringify(canonicalize(value));
 }
 
-export function hashSha256Hex(obj: unknown): string {
-  return bytesToHex(sha256(canonicalBytes(obj)));
+export function hashSha256Hex(value: unknown): string {
+  return crypto
+    .createHash("sha256")
+    .update(canonicalJson(value), "utf8")
+    .digest("hex");
+}
+
+export function hashBlake3Hex(value: unknown): string {
+  const bytes = utf8ToBytes(canonicalJson(value));
+  return bytesToHex(blake3(bytes));
 }
diff --git a/src/lib/keys.ts b/src/lib/keys.ts
index 991ae5c..efc6bde 100644
--- a/src/lib/keys.ts
+++ b/src/lib/keys.ts
@@ -2,7 +2,6 @@ import fs from "node:fs";
 import os from "node:os";
 import path from "node:path";
 import { getPublicKey, sign, verify, utils, etc } from "@noble/ed25519";
-import { blake3 } from "@noble/hashes/blake3";
 import { sha512 } from "@noble/hashes/sha512";
 import { bytesToHex, hexToBytes } from "@noble/hashes/utils";
 
@@ -10,6 +9,7 @@ const KEY_DIR = path.join(os.homedir(), ".config", "vm-cloud", "keys");
 const PRIV_PATH = path.join(KEY_DIR, "operator_ed25519.key");
 const PUB_PATH = path.join(KEY_DIR, "operator_ed25519.pub");
 
+// noble/ed25519 requires a SHA-512 implementation to be wired.
 if (!etc.sha512Sync) {
   etc.sha512Sync = (...messages) => sha512(etc.concatBytes(...messages));
 }
@@ -19,34 +19,26 @@ function ensureKeyDir() {
 }
 
 export function keyPaths() {
-  return { dir: KEY_DIR, privateKey: PRIV_PATH, publicKey: PUB_PATH };
+  return { dir: KEY_DIR, priv: PRIV_PATH, pub: PUB_PATH };
 }
 
-export function readPrivateKey(): Uint8Array {
-  if (!fs.existsSync(PRIV_PATH)) {
-    const err = new Error(`Private key not found: ${PRIV_PATH}`);
-    (err as { exitCode?: number }).exitCode = 2;
-    throw err;
-  }
-  const hex = fs.readFileSync(PRIV_PATH, "utf8").trim();
-  return hexToBytes(hex);
+export function hasKeypair(): boolean {
+  return fs.existsSync(PRIV_PATH) && fs.existsSync(PUB_PATH);
 }
 
-export function readPublicKey(): Uint8Array {
-  if (!fs.existsSync(PUB_PATH)) {
-    const err = new Error(`Public key not found: ${PUB_PATH}`);
-    (err as { exitCode?: number }).exitCode = 2;
-    throw err;
-  }
-  const hex = fs.readFileSync(PUB_PATH, "utf8").trim();
-  return hexToBytes(hex);
+export function readPublicKeyHex(): string {
+  return fs.readFileSync(PUB_PATH, "utf8").trim();
+}
+
+export function readPrivateKeyHex(): string {
+  return fs.readFileSync(PRIV_PATH, "utf8").trim();
 }
 
 export async function generateKeypair(opts: { force?: boolean } = {}) {
   ensureKeyDir();
   if (!opts.force && (fs.existsSync(PRIV_PATH) || fs.existsSync(PUB_PATH))) {
     const err = new Error(
-      `Key already exists. Use --force to overwrite: ${PRIV_PATH}`
+      `Keypair already exists. Use --force to overwrite: ${PUB_PATH}`
     );
     (err as { exitCode?: number }).exitCode = 2;
     throw err;
@@ -58,33 +50,24 @@ export async function generateKeypair(opts: { force?: boolean } = {}) {
   fs.writeFileSync(PRIV_PATH, bytesToHex(priv), { mode: 0o600 });
   fs.writeFileSync(PUB_PATH, bytesToHex(pub), { mode: 0o644 });
 
-  return {
-    privateKeyPath: PRIV_PATH,
-    publicKeyPath: PUB_PATH,
-    publicKey: bytesToHex(pub)
-  };
+  return { priv_path: PRIV_PATH, pub_path: PUB_PATH, pub_hex: bytesToHex(pub) };
 }
 
-export function keyIdFromPublicHex(publicKeyHex: string) {
-  const pub = hexToBytes(publicKeyHex);
-  return bytesToHex(blake3(pub));
-}
-
-export async function signMessage(message: Uint8Array) {
-  const priv = readPrivateKey();
-  const pub = await getPublicKey(priv);
-  const signature = await sign(message, priv);
-  const publicKey = bytesToHex(pub);
-  const signerKid = keyIdFromPublicHex(publicKey);
-  return { signature: bytesToHex(signature), publicKey, signerKid };
+export async function signMessage(
+  message: Uint8Array,
+  privHex?: string
+): Promise<string> {
+  const priv = hexToBytes(privHex ?? readPrivateKeyHex());
+  const sig = await sign(message, priv);
+  return bytesToHex(sig);
 }
 
 export async function verifyMessage(
   message: Uint8Array,
-  signatureHex: string,
-  publicKeyHex: string
-) {
-  const signature = hexToBytes(signatureHex);
-  const publicKey = hexToBytes(publicKeyHex);
-  return verify(signature, message, publicKey);
+  sigHex: string,
+  pubHex?: string
+): Promise<boolean> {
+  const sig = hexToBytes(sigHex);
+  const pub = hexToBytes(pubHex ?? readPublicKeyHex());
+  return verify(sig, message, pub);
 }
diff --git a/src/lib/ledger.ts b/src/lib/ledger.ts
index 3760971..e42b404 100644
--- a/src/lib/ledger.ts
+++ b/src/lib/ledger.ts
@@ -2,7 +2,7 @@ import fs from "node:fs";
 import path from "node:path";
 import { ensureDir } from "./report.js";
 
-function receiptsDir() {
+export function receiptsDir() {
   return path.join(process.cwd(), "outputs", "receipts");
 }
 
@@ -12,28 +12,22 @@ function headPath() {
 
 export type ReceiptHead = { blake3: string; file: string; created_at: string };
 
+export function writeHead(head: ReceiptHead) {
+  ensureDir(receiptsDir());
+  fs.writeFileSync(headPath(), JSON.stringify(head, null, 2), "utf8");
+}
+
 export function readHead(): ReceiptHead | null {
   try {
     const raw = fs.readFileSync(headPath(), "utf8");
-    const data = JSON.parse(raw) as ReceiptHead;
+    const data = JSON.parse(raw) as Partial<ReceiptHead>;
     if (!data?.blake3 || !data?.file || !data?.created_at) return null;
-    return data;
+    return data as ReceiptHead;
   } catch {
     return null;
   }
 }
 
 export function readPrevReceiptHash(): string | null {
-  try {
-    const raw = fs.readFileSync(headPath(), "utf8");
-    const data = JSON.parse(raw) as { blake3?: string };
-    return typeof data.blake3 === "string" ? data.blake3 : null;
-  } catch {
-    return null;
-  }
-}
-
-export function writeHead(next: { blake3: string; file: string; created_at: string }) {
-  ensureDir(receiptsDir());
-  fs.writeFileSync(headPath(), JSON.stringify(next, null, 2), { mode: 0o600 });
+  return readHead()?.blake3 ?? null;
 }
diff --git a/src/lib/merkle.ts b/src/lib/merkle.ts
new file mode 100644
index 0000000..0ebd64c
--- /dev/null
+++ b/src/lib/merkle.ts
@@ -0,0 +1,24 @@
+import { blake3 } from "@noble/hashes/blake3";
+import { bytesToHex, concatBytes, hexToBytes } from "@noble/hashes/utils";
+
+export function merkleRootBlake3(leavesHex: string[]): string {
+  if (!leavesHex.length) {
+    const err = new Error("No leaves provided for merkle root");
+    (err as { exitCode?: number }).exitCode = 2;
+    throw err;
+  }
+
+  let level = leavesHex.map((h) => hexToBytes(h));
+
+  while (level.length > 1) {
+    const next: Uint8Array[] = [];
+    for (let i = 0; i < level.length; i += 2) {
+      const left = level[i];
+      const right = i + 1 < level.length ? level[i + 1] : left; // duplicate last
+      next.push(blake3(concatBytes(left, right)));
+    }
+    level = next;
+  }
+
+  return bytesToHex(level[0]);
+}
diff --git a/src/lib/plan.ts b/src/lib/plan.ts
index 0e718e8..04234e8 100644
--- a/src/lib/plan.ts
+++ b/src/lib/plan.ts
@@ -1,7 +1,7 @@
 import fs from "node:fs";
 import path from "node:path";
-import { hashBlake3Hex, hashSha256Hex } from "./hash.js";
 import { ensureDir, nowStamp } from "./report.js";
+import { hashBlake3Hex, hashSha256Hex } from "./hash.js";
 
 export type PlanAction = "poweron" | "poweroff" | "reboot" | "labels";
 export type PlanMatch = "id" | "exact" | "partial";
@@ -17,25 +17,41 @@ export type ServerPlan = {
   applied: false;
 };
 
-export function resolvePlanPath(planPath: string) {
-  return path.isAbsolute(planPath) ? planPath : path.join(process.cwd(), planPath);
-}
-
-export function writePlan(plan: ServerPlan) {
+export function writePlan(plan: ServerPlan): {
+  file: string;
+  sha256: string;
+  blake3: string;
+} {
   const { stamp } = nowStamp();
   const dir = path.join(process.cwd(), "outputs", "plans");
-  const name = `plan-${stamp}-${plan.action}-${plan.server.id}.json`;
   ensureDir(dir);
+  const name = `plan-${stamp}-${plan.action}-${plan.server.id}.json`;
   const file = path.join(dir, name);
-  const json = JSON.stringify(plan, null, 2);
-  fs.writeFileSync(file, json, "utf8");
+  fs.writeFileSync(file, JSON.stringify(plan, null, 2), "utf8");
   const sha256 = hashSha256Hex(plan);
   const blake3 = hashBlake3Hex(plan);
   return { file, sha256, blake3 };
 }
 
 export function readPlan(planPath: string): ServerPlan {
-  const abs = resolvePlanPath(planPath);
-  const raw = fs.readFileSync(abs, "utf8");
-  return JSON.parse(raw) as ServerPlan;
+  const raw = fs.readFileSync(planPath, "utf8");
+  const data = JSON.parse(raw) as unknown;
+  validatePlan(data);
+  return data;
+}
+
+export function validatePlan(plan: unknown): asserts plan is ServerPlan {
+  const p = plan as Partial<ServerPlan>;
+  if (!p || typeof p !== "object") throw new Error("Invalid plan (not an object)");
+  if (p.plan_version !== "1") throw new Error("Invalid plan_version");
+  if (!p.created_at) throw new Error("Invalid created_at");
+  if (!p.action) throw new Error("Invalid action");
+  if (!p.server?.id || !p.server?.name) throw new Error("Invalid server");
+  if (!p.match) throw new Error("Invalid match");
+  if (!p.request?.method || !p.request?.path) throw new Error("Invalid request");
+  if (p.applied !== false) throw new Error("Plan.applied must be false");
+}
+
+export function resolvePlanPath(p: string) {
+  return path.resolve(p);
 }
diff --git a/src/lib/receipt.ts b/src/lib/receipt.ts
index 1f4d22c..668d44e 100644
--- a/src/lib/receipt.ts
+++ b/src/lib/receipt.ts
@@ -14,8 +14,8 @@ type ReceiptRequest = {
 type ReceiptResponse = {
   status: number;
   ok: boolean;
-  data?: unknown;
-  raw?: string;
+  data: unknown;
+  raw: string;
 };
 
 type ReceiptInput = {
@@ -36,22 +36,34 @@ type ReceiptBody = {
   hostname: string;
   argv: string[];
   reason: string;
+
   lock_file: string | null;
   lock_started_at: string | null;
   force: boolean;
+
   plan_file: string | null;
   plan_sha256: string | null;
   plan_blake3: string | null;
+
   target: { id: number; name: string; ip?: string | null };
+
   request: ReceiptRequest;
   response: ReceiptResponse;
+
   prev_blake3: string | null;
 };
 
-type ReceiptEnvelope = ReceiptBody & {
+export type ReceiptEnvelope = ReceiptBody & {
   hash_alg: "blake3+sha256";
   blake3: string;
   sha256: string;
+
+  // Optional signing metadata. These fields are NOT included in the canonical
+  // receipt hash (verification strips them before hashing).
+  sig_alg?: "ed25519";
+  signer_pub?: string;
+  signature?: string;
+  signed_at?: string;
 };
 
 function fileStamp(d = new Date()) {
@@ -64,51 +76,59 @@ function fileStamp(d = new Date()) {
   return `${yyyy}${mm}${dd}-${hh}${mi}${ss}`;
 }
 
-export function writeReceipt(input: ReceiptInput) {
+export function writeReceipt(input: ReceiptInput): {
+  file: string;
+  sha256: string;
+  blake3: string;
+} {
   const dir = path.join(process.cwd(), "outputs", "receipts");
   ensureDir(dir);
 
-  const file = path.join(
-    dir,
-    `${fileStamp()}-${input.action}-${input.server.id}.json`
-  );
-
   const created_at = new Date().toISOString();
   const prev_blake3 = readPrevReceiptHash();
+
   const body: ReceiptBody = {
     receipt_version: "1",
     created_at,
     cwd: process.cwd(),
     user: process.env.USER ?? process.env.LOGNAME ?? "unknown",
     hostname: os.hostname(),
-    argv: process.argv,
+    argv: process.argv.slice(),
     reason: input.reason || "unspecified",
+
     lock_file: input.lock?.file ?? null,
     lock_started_at: input.lock?.started_at ?? null,
     force: Boolean(input.lock?.force),
+
     plan_file: input.plan?.file ?? null,
     plan_sha256: input.plan?.sha256 ?? null,
     plan_blake3: input.plan?.blake3 ?? null,
+
     target: {
       id: input.server.id,
       name: input.server.name,
       ip: input.server.ip ?? null
     },
+
     request: input.request,
     response: input.response,
+
     prev_blake3
   };
 
   const blake3 = hashBlake3Hex(body);
   const sha256 = hashSha256Hex(body);
-  const envelope: ReceiptEnvelope = {
+
+  const env: ReceiptEnvelope = {
     ...body,
     hash_alg: "blake3+sha256",
     blake3,
     sha256
   };
 
-  fs.writeFileSync(file, JSON.stringify(envelope, null, 2), "utf8");
+  const file = path.join(dir, `${fileStamp()}-${input.action}-${input.server.id}.json`);
+  fs.writeFileSync(file, JSON.stringify(env, null, 2), "utf8");
+
   const relFile = path.relative(process.cwd(), file) || file;
   writeHead({ blake3, file: relFile, created_at });
 
diff --git a/src/lib/signature.ts b/src/lib/signature.ts
deleted file mode 100644
index 89b907d..0000000
--- a/src/lib/signature.ts
+++ /dev/null
@@ -1,63 +0,0 @@
-import fs from "node:fs";
-import path from "node:path";
-import { signMessage } from "./keys.js";
-
-type ReceiptEnvelope = {
-  blake3: string;
-  sig_alg?: string;
-  signer_pub?: string;
-  signer_kid?: string;
-  signed_at?: string;
-  signature?: string;
-};
-
-export async function signReceiptFile(
-  receiptPath: string,
-  opts: { force?: boolean } = {}
-) {
-  const abs = path.resolve(receiptPath);
-  if (!fs.existsSync(abs)) {
-    const err = new Error(`Receipt not found: ${abs}`);
-    (err as { exitCode?: number }).exitCode = 2;
-    throw err;
-  }
-
-  const raw = fs.readFileSync(abs, "utf8");
-  let env: ReceiptEnvelope;
-  try {
-    env = JSON.parse(raw) as ReceiptEnvelope;
-  } catch {
-    const err = new Error("Receipt is not valid JSON");
-    (err as { exitCode?: number }).exitCode = 2;
-    throw err;
-  }
-
-  if (!env.blake3) {
-    const err = new Error("Receipt missing blake3 field");
-    (err as { exitCode?: number }).exitCode = 2;
-    throw err;
-  }
-
-  if ((env.signature || env.signer_pub) && !opts.force) {
-    const err = new Error("Receipt already signed. Use --force to overwrite.");
-    (err as { exitCode?: number }).exitCode = 2;
-    throw err;
-  }
-
-  const msg = new TextEncoder().encode(env.blake3);
-  const { signature, publicKey, signerKid } = await signMessage(msg);
-  const signedAt = new Date().toISOString();
-
-  const next = {
-    ...env,
-    sig_alg: "ed25519",
-    signer_pub: publicKey,
-    signer_kid: signerKid,
-    signed_at: signedAt,
-    signature
-  };
-
-  fs.writeFileSync(abs, JSON.stringify(next, null, 2), "utf8");
-
-  return { file: abs, signer_pub: publicKey, signer_kid: signerKid, signed_at: signedAt, signature };
-}
diff --git a/src/lib/signing.ts b/src/lib/signing.ts
new file mode 100644
index 0000000..06b2aa9
--- /dev/null
+++ b/src/lib/signing.ts
@@ -0,0 +1,58 @@
+import fs from "node:fs";
+import path from "node:path";
+import { hasKeypair, readPublicKeyHex, signMessage } from "./keys.js";
+
+export async function signReceiptFile(
+  receiptPath: string,
+  opts: { force?: boolean } = {}
+) {
+  const abs = path.resolve(receiptPath);
+  const raw = fs.readFileSync(abs, "utf8");
+  const env = JSON.parse(raw) as Record<string, unknown>;
+
+  const blake3 = String(env["blake3"] ?? "");
+  if (!blake3) {
+    const err = new Error("Receipt missing blake3 field");
+    (err as { exitCode?: number }).exitCode = 2;
+    throw err;
+  }
+
+  const hasSig =
+    Boolean(env["signature"]) || Boolean(env["signer_pub"]) || Boolean(env["sig_alg"]);
+  if (hasSig && !opts.force) {
+    const err = new Error("Receipt already has signature fields (use --force to overwrite)");
+    (err as { exitCode?: number }).exitCode = 2;
+    throw err;
+  }
+
+  if (!hasKeypair()) {
+    const err = new Error("No operator keypair found. Run: vmc keygen");
+    (err as { exitCode?: number }).exitCode = 2;
+    throw err;
+  }
+
+  const msg = new TextEncoder().encode(blake3);
+  const signature = await signMessage(msg);
+  const signer_pub = readPublicKeyHex();
+
+  env["sig_alg"] = "ed25519";
+  env["signer_pub"] = signer_pub;
+  env["signature"] = signature;
+  env["signed_at"] = new Date().toISOString();
+
+  fs.writeFileSync(abs, JSON.stringify(env, null, 2), "utf8");
+  return { signature, signer_pub };
+}
+
+/**
+ * Best-effort auto-sign: if keys exist and the receipt is unsigned, sign it.
+ * Never throws (returns null on failure).
+ */
+export async function maybeAutoSignReceipt(receiptPath: string) {
+  if (!hasKeypair()) return null;
+  try {
+    return await signReceiptFile(receiptPath, { force: false });
+  } catch {
+    return null;
+  }
+}