diff --git a/runtime/tests/runtime-signing.test.mjs b/runtime/tests/runtime-signing.test.mjs
index df6c058..f63b788 100644
--- a/runtime/tests/runtime-signing.test.mjs
+++ b/runtime/tests/runtime-signing.test.mjs
@@ -145,6 +145,68 @@ test("boot fails fast without keys unless DEV_AUTO_KEYS=1", async () => {
   assert.match(`${res.stderr}${res.stdout}`, /fatal signer misconfiguration|Missing required env var/);
 });
 
+
+
+test("same key material derives the same kid across restarts", async () => {
+  const keys = makeKeys();
+  const env = {
+    RECEIPT_SIGNING_PRIVATE_KEY_PEM_B64: keys.privatePemB64,
+    RECEIPT_SIGNING_PUBLIC_KEY_B64: keys.publicRaw32B64,
+    RECEIPT_SIGNER_ID: "runtime.commandlayer.eth",
+  };
+  const a = await startServer(env);
+  const b = await startServer(env);
+  try {
+    const ha = await (await fetch(`${a.base}/health`)).json();
+    const hb = await (await fetch(`${b.base}/health`)).json();
+    assert.equal(ha.kid, keys.kid);
+    assert.equal(hb.kid, keys.kid);
+    assert.equal(ha.kid, hb.kid);
+  } finally {
+    await stop(a.proc);
+    await stop(b.proc);
+  }
+});
+
+test("boot rejects mismatched public/private signer key material", async () => {
+  const a = makeKeys();
+  const b = makeKeys();
+  const res = spawnSync(process.execPath, ["server.mjs"], {
+    cwd: process.cwd(),
+    env: {
+      ...process.env,
+      HOST: "127.0.0.1",
+      PORT: "0",
+      RECEIPT_SIGNING_PRIVATE_KEY_PEM_B64: a.privatePemB64,
+      RECEIPT_SIGNING_PUBLIC_KEY_B64: b.publicRaw32B64,
+      RECEIPT_SIGNER_ID: "runtime.commandlayer.eth",
+      DEV_AUTO_KEYS: "0",
+    },
+    encoding: "utf8",
+    timeout: 4000,
+  });
+  assert.notEqual(res.status, 0);
+  assert.match(`${res.stderr}${res.stdout}`, /keypair: private\/public key mismatch/);
+});
+
+test("boot rejects missing signer id in persistent signer mode", async () => {
+  const keys = makeKeys();
+  const res = spawnSync(process.execPath, ["server.mjs"], {
+    cwd: process.cwd(),
+    env: {
+      ...process.env,
+      HOST: "127.0.0.1",
+      PORT: "0",
+      RECEIPT_SIGNING_PRIVATE_KEY_PEM_B64: keys.privatePemB64,
+      RECEIPT_SIGNING_PUBLIC_KEY_B64: keys.publicRaw32B64,
+      DEV_AUTO_KEYS: "0",
+    },
+    encoding: "utf8",
+    timeout: 4000,
+  });
+  assert.notEqual(res.status, 0);
+  assert.match(`${res.stderr}${res.stdout}`, /RECEIPT_SIGNER_ID must be non-empty|Missing required env var/);
+});
 test("makeReceipt production path emits signed receipts with runtime kid and canonical fields", async () => {
   const keys = makeKeys();
   const srv = await startServer({
diff --git a/scripts/print-ens-records.mjs b/scripts/print-ens-records.mjs
new file mode 100644
index 0000000..195f467
--- /dev/null
+++ b/scripts/print-ens-records.mjs
@@ -0,0 +1,39 @@
+#!/usr/bin/env node
+import crypto from "node:crypto";
+
+const CANONICAL = "json.sorted_keys.v1";
+
+function decodeB64Strict(value) {
+  const cleaned0 = String(value || "").replace(/\s+/g, "");
+  if (!cleaned0) return null;
+  let cleaned = cleaned0.replace(/-/g, "+").replace(/_/g, "/");
+  const pad = cleaned.length % 4;
+  if (pad) cleaned += "=".repeat(4 - pad);
+  const out = Buffer.from(cleaned, "base64");
+  if (!out.length) return null;
+  return out;
+}
+
+function deriveKidFromRaw32(raw32) {
+  return crypto.createHash("sha256").update(raw32).digest("base64url").slice(0, 16);
+}
+
+const pubB64 = String(process.env.RECEIPT_SIGNING_PUBLIC_KEY_B64 || "").trim();
+const signerId = String(process.env.RECEIPT_SIGNER_ID || "").trim();
+
+if (!signerId) {
+  console.error("Missing RECEIPT_SIGNER_ID");
+  process.exit(1);
+}
+
+const raw = decodeB64Strict(pubB64);
+if (!raw || raw.length !== 32) {
+  console.error("RECEIPT_SIGNING_PUBLIC_KEY_B64 must decode to 32-byte Ed25519 public key");
+  process.exit(1);
+}
+
+const kid = deriveKidFromRaw32(raw);
+console.log(`cl.sig.pub=ed25519:${raw.toString("base64")}`);
+console.log(`cl.sig.kid=${kid}`);
+console.log(`cl.sig.canonical=${CANONICAL}`);
+console.log(`cl.receipt.signer=${signerId}`);
diff --git a/server.mjs b/server.mjs
index b833fee..b68ac6c 100644
--- a/server.mjs
+++ b/server.mjs
@@ -111,6 +111,7 @@ const ENABLED_VERBS = (
   .filter(Boolean);
 
 const DEV_AUTO_KEYS = envFlag("DEV_AUTO_KEYS");
+const PERSISTENT_CANONICAL_METHOD = "json.sorted_keys.v1";
 
 function envAnySource(...names) {
   for (const n of names) {
@@ -369,6 +370,22 @@ function assertBootConfigOrThrow() {
   if (missing.length) throw new Error(`Missing required env var(s): ${missing.join(", ")}`);
 }
 
+
+function requirePersistentSignerInvariantsOrThrow() {
+  if (runtimeConfig.canonicalMethod !== PERSISTENT_CANONICAL_METHOD) {
+    throw new Error(`canonicalization must be ${PERSISTENT_CANONICAL_METHOD}`);
+  }
+  if (!runtimeConfig.signerId || !String(runtimeConfig.signerId).trim()) {
+    throw new Error("RECEIPT_SIGNER_ID must be non-empty");
+  }
+}
+
+function assertKeypairMatches(privatePem, publicPem) {
+  const probe = Buffer.from("commandlayer-runtime-signer-probe");
+  const sig = crypto.sign(null, probe, crypto.createPrivateKey({ key: privatePem, format: "pem" }));
+  const ok = crypto.verify(null, probe, crypto.createPublicKey({ key: publicPem, format: "pem" }), sig);
+  if (!ok) throw new Error("private/public key mismatch");
+}
 function validatePublicKeyPem(pem) {
   if (!pem) return { ok: false, reason: "missing public key" };
   try {
@@ -435,7 +452,7 @@ function maybeEnableDevAutoKeys() {
   runtimeConfig.kid = deriveKidFromRaw32(raw32);
   runtimeConfig.signerSource = "dev_auto_keys";
 
-  console.warn("DEV_AUTO_KEYS=1 enabled; generated in-memory temporary Ed25519 keypair.");
+  console.warn("[boot] DEV MODE: DEV_AUTO_KEYS=1 enabled; generated in-memory temporary Ed25519 keypair.");
   console.warn(`TEMP PRIVATE KEY PEM (set RECEIPT_SIGNING_PRIVATE_KEY_PEM): ${escapedOneLinePem(activeSigner.privateKeyPem)}`);
   console.warn(`TEMP PUBLIC RAW32 B64 (set RECEIPT_SIGNING_PUBLIC_KEY_B64): ${activeSigner.publicKeyRaw32B64}`);
   printEnsTxtValues({
@@ -449,6 +466,14 @@ function maybeEnableDevAutoKeys() {
 function initializeSignerConfigOrThrow() {
   signerBootState.errors = [];
 
+  if (!DEV_AUTO_KEYS) {
+    try {
+      requirePersistentSignerInvariantsOrThrow();
+    } catch (e) {
+      signerBootState.errors.push(String(e?.message || e));
+    }
+  }
+
   try {
     assertBootConfigOrThrow();
   } catch (e) {
@@ -479,6 +504,14 @@ function initializeSignerConfigOrThrow() {
     maybeEnableDevAutoKeys();
   }
 
+  if (activeSigner.privateKeyPem && activeSigner.publicKeyPem) {
+    try {
+      assertKeypairMatches(activeSigner.privateKeyPem, activeSigner.publicKeyPem);
+    } catch (e) {
+      signerBootState.errors.push(`keypair: ${e?.message || e}`);
+    }
+  }
+
   if (activeSigner.privateKeyPem && activeSigner.publicKeyPem && activeSigner.source === "dev_auto_keys") {
     signerBootState.errors = [];
   }
@@ -500,8 +533,9 @@ function initializeSignerConfigOrThrow() {
     }
   }
 
+  const bootMode = DEV_AUTO_KEYS ? "DEV MODE" : "PERSISTENT SIGNER MODE";
   console.log(
-    `[boot] signer_ok=${signerBootState.ok} signer_source=${activeSigner.source} kid=${runtimeConfig.kid} fp=${
+    `[boot] ${bootMode} signer_ok=${signerBootState.ok} signer_source=${activeSigner.source} signer_id=${runtimeConfig.signerId || "n/a"} canonicalization=${runtimeConfig.canonicalMethod} kid=${runtimeConfig.kid} fp=${
       activeSigner.publicKeyFingerprint || "n/a"
     }`
   );