diff --git a/docs/specs/renewal-stamp-v1.md b/docs/specs/renewal-stamp-v1.md
new file mode 100644
index 000000000..9681ad437
--- /dev/null
+++ b/docs/specs/renewal-stamp-v1.md
@@ -0,0 +1,55 @@
+# Renewal stamp v1 wire contract
+
+This file records the exact v1 signed-stamp representation pinned by fixture commit `377c0cd9269c982bb2e71b60a51bc77367718031`, based on main `d63d4c44ef274d24f67a7f889379226e4769e261`. The selected architecture is the Bobbie-reviewed design `1635acfc1c4d9f965a58101eb5f8a0dcb45f39ef0996225021597157ac757a53`. This specification freezes the wire contract only; it does not implement runtime renewal behavior.
+
+## Renewal lease authority
+
+A renewal lease is an existing owner-authorized UCAN/CACAO delegation. This specification does **not** define a new lease serialization, lease signature format, or a real signed lease vector. Its exact control capability is:
+
+- Ability: `tinycloud.delegation/renew`
+- Resource: `urn:cid:<canonical original delegation CID>`
+
+The CIDs named `originalCid` and `leaseCid` in the known-answer fixture are generated from synthetic DAG-CBOR placeholder artifacts. They test stamp encoding and the non-null root link only; they are not signed UCAN/CACAO delegation records and do not freeze the lease's actual bytes.
+
+## Signed stamp bytes
+
+The signed byte sequence is the deterministic DAG-CBOR encoding of exactly this two-entry map:
+
+```text
+{
+  "domain": "tinycloud/node/renewal-stamp/v1",
+  "unsigned": {
+    "type": "TinyCloudRenewalStamp",
+    "version": 1,
+    "originalCid": <canonical CID string>,
+    "leaseCid": <canonical CID string>,
+    "leaseGeneration": <unsigned integer>,
+    "previousStampCid": <canonical CID string>,
+    "nodeDid": <DID string>,
+    "renewerEpoch": <unsigned integer>,
+    "newEnd": <RFC3339 UTC string>
+  }
+}
+```
+
+`previousStampCid` is non-null. The first stamp sets it to that lease's CID. `leaseGeneration` records the issuance generation; it is not a use-time equality check. `renewerEpoch` is the current renewer identity epoch. `newEnd` is serialized as a UTC RFC3339 string. The domain value has no NUL terminator; there is no additional domain prefix outside the encoded map.
+
+Encode with the repository's deterministic `serde_ipld_dagcbor` representation. The detached Ed25519 signature is over the exact encoded bytes above; it is not embedded in those bytes. The stamp CID is CIDv1 with raw codec `0x55` and Blake3-256 over those exact bytes; the detached signature is excluded from the CID input.
+
+Derive the renewer signing seed from the node's `StaticSecret` with the exact context bytes `tinycloud/node/renewer/v1`, using `StaticSecret::derive_key` (Blake3-256 of the static secret followed by the context). This is distinct from the node's identity-key context and storage-key generation.
+
+## Pinned vector
+
+The synthetic fixture is `tinycloud-node-server/tests/fixtures/renewal-stamp-v1.json`; its assertions are in `tinycloud-node-server/tests/renewal_stamp_v1_vectors.rs`. The fixture's fixed master-secret bytes (`42` repeated 32 times) are public test data only.
+
+- Original placeholder CID: `bafkr4ifaiwrq52xkndrm7jbwqvywq3tkilydyxrj24oofckit6ink7f6hy`
+- Lease placeholder CID and first `previousStampCid`: `bafkr4iaiwsgu3x5bvuigtms3hrlhrwpshbv5lxar5oj7uhh5dfg2sbcl4q`
+- Stamp CID: `bafkr4ibtywvyzwld56wljgytygpis2dddualt6h6b343e52rzmsegyw5nq`
+- Signer public key (hex): `49fd44f3fe8930b0e89f61c51333195578deacaf22105a78f647d8c05afc7c5d`
+- Detached signature (hex): `34caf6cc60615a4c0d4f4e934c0263dde1c17fdd5becfa0f693337987b0250f0b430d7fe4518db41a882cc26ee979603736b883798fb83bbc95fb61af077020d`
+
+Exact canonical DAG-CBOR bytes (hex):
+
+```text
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
+```
diff --git a/tinycloud-node-server/tests/fixtures/renewal-stamp-v1.json b/tinycloud-node-server/tests/fixtures/renewal-stamp-v1.json
new file mode 100644
index 000000000..98519aac3
--- /dev/null
+++ b/tinycloud-node-server/tests/fixtures/renewal-stamp-v1.json
@@ -0,0 +1,34 @@
+{
+  "schema": "tinycloud/node/renewal-stamp-vector/v1",
+  "renewAbility": "tinycloud.delegation/renew",
+  "renewResourcePrefix": "urn:cid:",
+  "renewerKeyContext": "tinycloud/node/renewer/v1",
+  "stampDomain": "tinycloud/node/renewal-stamp/v1",
+  "testOnlyMasterSecretHex": "4242424242424242424242424242424242424242424242424242424242424242",
+  "originalArtifact": {
+    "type": "RenewalVectorOriginalDelegation",
+    "version": 1
+  },
+  "leaseArtifact": {
+    "type": "RenewalVectorLease",
+    "version": 1
+  },
+  "stamp": {
+    "domain": "tinycloud/node/renewal-stamp/v1",
+    "unsigned": {
+      "type": "TinyCloudRenewalStamp",
+      "version": 1,
+      "originalCid": "bafkr4ifaiwrq52xkndrm7jbwqvywq3tkilydyxrj24oofckit6ink7f6hy",
+      "leaseCid": "bafkr4iaiwsgu3x5bvuigtms3hrlhrwpshbv5lxar5oj7uhh5dfg2sbcl4q",
+      "leaseGeneration": 3,
+      "previousStampCid": "bafkr4iaiwsgu3x5bvuigtms3hrlhrwpshbv5lxar5oj7uhh5dfg2sbcl4q",
+      "nodeDid": "did:key:z6MkpXveUyjpCDe6P83rNYqAZmoTc9qopJ6GBuRQRotz3zF7",
+      "renewerEpoch": 7,
+      "newEnd": "2030-01-02T03:04:05Z"
+    }
+  },
+  "canonicalDagCborHex": "a266646f6d61696e781f74696e79636c6f75642f6e6f64652f72656e6577616c2d7374616d702f763168756e7369676e6564a964747970657554696e79436c6f756452656e6577616c5374616d70666e6577456e6474323033302d30312d30325430333a30343a30355a676e6f646544696478386469643a6b65793a7a364d6b7058766555796a7043446536503833724e5971415a6d6f546339716f704a364742755251526f747a337a46376776657273696f6e01686c65617365436964783b6261666b7234696169777367753378356276756967746d733368726c6872777073686276356c786172356f6a3775686835646667327362636c34716b6f726967696e616c436964783b6261666b7234696661697772713532786b6e64726d376a6277717679777133746b696c79647978726a32346f6f66636b697436696e6b37663668796c72656e6577657245706f6368076f6c6561736547656e65726174696f6e037070726576696f75735374616d70436964783b6261666b7234696169777367753378356276756967746d733368726c6872777073686276356c786172356f6a3775686835646667327362636c3471",
+  "stampCid": "bafkr4ibtywvyzwld56wljgytygpis2dddualt6h6b343e52rzmsegyw5nq",
+  "signerPublicKeyHex": "49fd44f3fe8930b0e89f61c51333195578deacaf22105a78f647d8c05afc7c5d",
+  "signatureHex": "34caf6cc60615a4c0d4f4e934c0263dde1c17fdd5becfa0f693337987b0250f0b430d7fe4518db41a882cc26ee979603736b883798fb83bbc95fb61af077020d"
+}
diff --git a/tinycloud-node-server/tests/renewal_stamp_v1_vectors.rs b/tinycloud-node-server/tests/renewal_stamp_v1_vectors.rs
new file mode 100644
index 000000000..b24d03a4c
--- /dev/null
+++ b/tinycloud-node-server/tests/renewal_stamp_v1_vectors.rs
@@ -0,0 +1,89 @@
+//! Contract-only known-answer vector for the v1 renewal stamp.
+//!
+//! The fixture pins canonical DAG-CBOR bytes, the raw-Blake3 CID, and the
+//! detached Ed25519 signature before runtime implementation. Its fixed master
+//! seed is synthetic and public; it is not a production key.
+
+use ed25519_dalek::{Signer, SigningKey, Verifier, VerifyingKey};
+use serde_json::{json, Value};
+use tinycloud_core::{hash::hash, keys::StaticSecret};
+
+fn raw_blake3_cid(bytes: &[u8]) -> String {
+    hash(bytes).to_cid(0x55).to_string()
+}
+
+fn dag_cbor(value: &Value) -> Vec<u8> {
+    serde_ipld_dagcbor::to_vec(value).expect("test vector DAG-CBOR serializes")
+}
+
+fn decode_hex(value: &Value) -> Vec<u8> {
+    hex::decode(value.as_str().expect("hex string")).expect("valid fixture hex")
+}
+
+#[test]
+fn renewal_stamp_v1_matches_pinned_bytes_cid_and_signature() {
+    let fixture: Value = serde_json::from_str(include_str!("fixtures/renewal-stamp-v1.json"))
+        .expect("renewal vector JSON parses");
+    let key_context = fixture["renewerKeyContext"].as_str().unwrap().as_bytes();
+    let domain = fixture["stampDomain"].as_str().unwrap();
+    let master_secret = decode_hex(&fixture["testOnlyMasterSecretHex"]);
+    let node_secret = StaticSecret::new(master_secret).expect("32-byte test seed");
+    let signing_seed: [u8; 32] = node_secret
+        .derive_key(key_context)
+        .try_into()
+        .expect("fixed-length derivation");
+    let signer = SigningKey::from_bytes(&signing_seed);
+
+    let original_cid = raw_blake3_cid(&dag_cbor(&fixture["originalArtifact"]));
+    let lease_cid = raw_blake3_cid(&dag_cbor(&fixture["leaseArtifact"]));
+    let resource = format!(
+        "{}{}",
+        fixture["renewResourcePrefix"].as_str().unwrap(),
+        original_cid
+    );
+
+    assert_eq!(fixture["renewAbility"], "tinycloud.delegation/renew");
+    assert_eq!(
+        fixture["renewResourcePrefix"], "urn:cid:",
+        "the control capability targets the canonical original CID"
+    );
+    assert_eq!(resource, format!("urn:cid:{original_cid}"));
+
+    let stamp = &fixture["stamp"];
+    assert_eq!(stamp["domain"], domain);
+    assert_eq!(stamp["unsigned"]["type"], "TinyCloudRenewalStamp");
+    assert_eq!(stamp["unsigned"]["version"], 1);
+    assert_eq!(stamp["unsigned"]["originalCid"], original_cid);
+    assert_eq!(stamp["unsigned"]["leaseCid"], lease_cid);
+    assert_eq!(stamp["unsigned"]["previousStampCid"], lease_cid);
+    assert_eq!(stamp["unsigned"]["nodeDid"], node_secret.node_did());
+    assert_eq!(stamp["unsigned"]["leaseGeneration"], 3);
+    assert_eq!(stamp["unsigned"]["renewerEpoch"], 7);
+    assert_eq!(stamp["unsigned"]["newEnd"], "2030-01-02T03:04:05Z");
+
+    let bytes = dag_cbor(stamp);
+    assert_eq!(hex::encode(&bytes), fixture["canonicalDagCborHex"]);
+    assert_eq!(raw_blake3_cid(&bytes), fixture["stampCid"]);
+    assert_eq!(
+        hex::encode(signer.verifying_key().to_bytes()),
+        fixture["signerPublicKeyHex"]
+    );
+
+    let signature_bytes = signer.sign(&bytes).to_bytes();
+    assert_eq!(hex::encode(signature_bytes), fixture["signatureHex"]);
+    let signature = ed25519_dalek::Signature::from_slice(&decode_hex(&fixture["signatureHex"]))
+        .expect("64-byte Ed25519 signature");
+    let verifying_key = VerifyingKey::from_bytes(&signer.verifying_key().to_bytes())
+        .expect("derived public key is valid");
+    verifying_key
+        .verify(&bytes, &signature)
+        .expect("pinned detached signature verifies over exact DAG-CBOR bytes");
+
+    let decoded: Value =
+        serde_ipld_dagcbor::from_slice(&bytes).expect("canonical DAG-CBOR decodes");
+    assert_eq!(
+        dag_cbor(&decoded),
+        bytes,
+        "DAG-CBOR re-encoding is byte-identical"
+    );
+}