diff --git a/docs/architecture/rfcs/typescript-control-plane-migration-v0.md b/docs/architecture/rfcs/typescript-control-plane-migration-v0.md
index 7191f79bc7..b69aee08fc 100644
--- a/docs/architecture/rfcs/typescript-control-plane-migration-v0.md
+++ b/docs/architecture/rfcs/typescript-control-plane-migration-v0.md
@@ -1151,6 +1151,18 @@ debit. This closes the demonstrated T3 consumer gap, not D1–D3, provider
 promotion, or the remaining Python transaction adapters. See the
 [operating contract](../../quota-allocation.md#receipt-backed-settlement-progress).
 
+**Canonical claim contention.** The TS claim command now retries a conclusive
+provider revision CAS rejection at most twice, using the same operation and
+lease keys. Every attempt rereads the receipt and complete authority and
+revalidates source registration, Todo eligibility, acceptance and lease scopes.
+An explicit provider revision or transfer grant stays pinned; ambiguous writes
+retain existing receipt recovery. Independent claims can both finish while
+same-Todo or overlapping-scope claims still admit one owner. This adopts the
+shared-authority conflict contract at the canonical writer; it does not reserve
+recommendations, change local writer serialization, or qualify sustained
+multi-host throughput. CLI claim callers inherit the behavior; no frontend or
+Lark action contract changes.
+
 **Long-history transport boundary.** Replan history still has one TS decision
 owner. Small requests retain the inline codec; larger complete fact snapshots
 travel through a private, digest-bound local file reference. The same reducer
diff --git a/docs/architecture/rfcs/typescript-control-plane-migration-v0.zh-CN.md b/docs/architecture/rfcs/typescript-control-plane-migration-v0.zh-CN.md
index 14e75dafe0..579f50f5af 100644
--- a/docs/architecture/rfcs/typescript-control-plane-migration-v0.zh-CN.md
+++ b/docs/architecture/rfcs/typescript-control-plane-migration-v0.zh-CN.md
@@ -838,6 +838,8 @@ T3/D1 reader，未完成全部 Todo writer、retention/compaction 或 promotion
 
 配额准入与结算消费者现在从统一 Todo reader 读取完整来源，在显示压缩前解析显式 Todo 选择。它删除直接追加 Markdown 候选的路径，保留 promote 前的事件适配；promote 后权威为空或不可读都不能复活展示行。结算进度由现有 TS 回执链归约，Python 负责完整身份命令及 JSON/Markdown 展示。现有幂等 writer 可补齐缺失的 spend 回执而不再次扣款。这关闭已复现的 T3 消费者缺口，不代表 D1–D3、provider promotion 或剩余 Python 事务适配已完成。操作语义见[结算进度契约](../../quota-allocation.md#receipt-backed-settlement-progress)。
 
+**Canonical claim 争抢。** TS claim 命令现在对明确的 provider revision CAS 拒绝最多重试两次，保持同一 operation 与 lease key；每次重新读取回执和完整权威，复核来源注册、Todo 资格、acceptance 和 lease 写范围。显式 provider revision 或 transfer grant 保持固定，写入结果不明确时沿用回执恢复。独立认领可以同时完成，同 Todo 或重叠写范围仍只接受一方。这让 canonical writer 采用 shared-authority 冲突契约，不预留推荐项、不改变本机 writer 串行化，也不证明持续多主机吞吐。CLI claim 调用方继承该行为，frontend／Lark 动作契约不变。
+
 **长历史传输边界。** Replan 历史仍由一个 TS owner 决策。小请求保留 inline
 codec；较大的完整事实快照通过私有临时文件和摘要绑定的引用传递。同一 reducer
 校验全部记录、agent 作用域内的 ACK 及重试身份；RPC 预算和展示窗口都不允许截断
diff --git a/loopx/control_plane/coordination/todo_claim.ts b/loopx/control_plane/coordination/todo_claim.ts
index a906a1c2b8..a024eb6160 100644
--- a/loopx/control_plane/coordination/todo_claim.ts
+++ b/loopx/control_plane/coordination/todo_claim.ts
@@ -330,6 +330,23 @@ export async function executeCoordinationTodoClaim(
   store: AuthorityStore,
   rawInput: CoordinationTodoClaimInput,
   authoritySourcesCurrent: AuthoritySourceCheck = uncheckedAuthoritySource,
+): Promise<CoordinationTodoClaimResult> {
+  // Retry only a conclusive provider CAS rejection. Each attempt rereads the
+  // original receipt and the complete head, then rechecks source authorization,
+  // claim ownership, acceptance and lease/write-scope exclusion. Pinned revisions
+  // (including handoff grants) must return to their caller for a fresh observation.
+  for (let attempt = 0; ; attempt++) {
+    const result = await executeClaimAttempt(store, rawInput, authoritySourcesCurrent);
+    if (attempt >= 2 || rawInput.expected_provider_revision !== undefined ||
+        rawInput.transfer_grant !== undefined || result.status !== "conflict" ||
+        result.conflict_kind !== "provider_revision_mismatch") return result;
+  }
+}
+
+async function executeClaimAttempt(
+  store: AuthorityStore,
+  rawInput: CoordinationTodoClaimInput,
+  authoritySourcesCurrent: AuthoritySourceCheck,
 ): Promise<CoordinationTodoClaimResult> {
   let input: CoordinationTodoClaimInput;
   try {
diff --git a/tests/control_plane_ts/authority_store_conformance.ts b/tests/control_plane_ts/authority_store_conformance.ts
index 8a2e382e2e..557e8eddf5 100644
--- a/tests/control_plane_ts/authority_store_conformance.ts
+++ b/tests/control_plane_ts/authority_store_conformance.ts
@@ -1,3 +1,4 @@
+import {registerClaimContentionConformance} from "./claim_contention_conformance.ts";
 import {registerMonitorGateScopeConformance} from "./monitor_gate_scope_conformance.ts";
 import {projectCoordinationSource, SOURCE_PROJECTION_REQUEST_SCHEMA} from "../../loopx/control_plane/coordination/source_projection.ts";
 import {registerCanonicalSnapshotConformance} from "./canonical_snapshot_conformance.ts";
@@ -290,6 +291,7 @@ export function registerAuthorityStoreConformance(
   registerLeaseAcquisitionConformance(providerName, factory);
   registerCommandObservationConformance(providerName, factory);
   registerClaimAcquisitionProofConformance(providerName, factory);
+  registerClaimContentionConformance(providerName, factory);
   registerAuthorityScanConformance(providerName, factory);
   registerOwnershipObservationConformance(providerName, factory);
   registerSuccessionReadConformance(providerName, factory);
@@ -1398,7 +1400,7 @@ export function registerAuthorityStoreConformance(
       assert.deepEqual(afterIdempotent.head, loaded.head);
       assert.equal((await store.readReceipt("claim-and-acquire-idempotent")).status, "found");
     });
-    test(`${providerName} conformance: competing ownership transactions cannot split claim and lease (${native ? "native" : "v0"})`, async (t) => {
+    test(`${providerName} conformance: competing ownership revalidates the winning claim and lease (${native ? "native" : "v0"})`, async (t) => {
       const {store, contender} = await factory(t);
       const goalId = "goal-competing-ownership";
       const projection = {
@@ -1435,8 +1437,9 @@ export function registerAuthorityStoreConformance(
       ]));
       assert.deepEqual(
         results.map((result) => result.status).sort(),
-        ["applied", "conflict"],
+        ["applied", "failed"],
       );
+      assert.equal(results.find(result => result.status === "failed")?.reason_code, "claim_owner_mismatch");
       const winnerIndex = results.findIndex((result) => result.status === "applied");
       assert.notEqual(winnerIndex, -1);
       const winner = winnerIndex === 0 ? "agent-a" : "agent-b";
@@ -1543,7 +1546,7 @@ export function registerAuthorityStoreConformance(
       assert.deepEqual(await store.loadAuthority(), transferred);
     });
     for (const fault of ["lease_replaced", "lost_response"] as const) {
-      test(`${providerName} conformance: hard-lease claim ${fault} (${native ? "native" : "v0"})`, async (t) => {
+      test(`${providerName} conformance: hard-lease claim revalidation ${fault} (${native ? "native" : "v0"})`, async (t) => {
         const {store, contender} = await factory(t);
         const goalId = "goal-claim";
         const projection = {...todoClaimProjection(goalId, native), handoff_mode: "hard_lease"};
@@ -1596,7 +1599,8 @@ export function registerAuthorityStoreConformance(
           },
         };
         const result = await executeCoordinationTodoClaim(intercepted, request);
-        assert.equal(result.status, fault === "lease_replaced" ? "conflict" : "recovered");
+        assert.equal(result.status, fault === "lease_replaced" ? "failed" : "recovered");
+        if (fault === "lease_replaced") assert.equal(result.reason_code, "handoff_mode_requires_lease");
         assert.equal((await store.readReceipt(request.operation_id)).status,
           fault === "lease_replaced" ? "missing" : "found");
         const after = await store.loadAuthority();
diff --git a/tests/control_plane_ts/claim_contention_conformance.ts b/tests/control_plane_ts/claim_contention_conformance.ts
new file mode 100644
index 0000000000..9df0b71c7d
--- /dev/null
+++ b/tests/control_plane_ts/claim_contention_conformance.ts
@@ -0,0 +1,120 @@
+/** Exercise command retries through real provider CAS, with deterministic races. */
+import assert from "node:assert/strict";
+import test from "node:test";
+import type {JsonObject} from "../../loopx/control_plane/effect_program.ts";
+import {configureGoalAcceptance} from "../../loopx/control_plane/goals/acceptance_authority.ts";
+import type {AuthorityStore, AuthorityStoreCommit} from "../../loopx/control_plane/coordination/authority_store.ts";
+import {executeCoordinationTodoClaim as claim} from "../../loopx/control_plane/coordination/todo_claim.ts";
+import {authorityProjectionFixture} from "./authority_projection_fixture.ts";
+import type {AuthorityStoreConformanceFactory} from "./authority_store_conformance.ts";
+
+function beforeCommit(store: AuthorityStore, before: (input: AuthorityStoreCommit) => Promise<void>): AuthorityStore {
+  return new Proxy(store, {get(target, key) {
+    if (key === "commitAuthority") return async (input: AuthorityStoreCommit) => {
+      await before(input);
+      return target.commitAuthority(input);
+    };
+    const value = Reflect.get(target, key);
+    return typeof value === "function" ? value.bind(target) : value;
+  }});
+}
+
+export function registerClaimContentionConformance(provider: string, factory: AuthorityStoreConformanceFactory) {
+  async function setup(t: test.TestContext, overlap = false) {
+    const {store, contender} = await factory(t);
+    const todos = ["todo_one", "todo_two"].map(todo_id => ({todo_id, role: "agent", status: "open",
+      done: false, archive_state: "active", task_class: "advancement_task", text: "Synthetic work",
+      claimed_by: null, required_write_scopes: [overlap ? "shared/**" : `${todo_id}/**`]}));
+    assert.equal((await store.commitAuthority({operation_id: "seed", expected_provider_revision: null,
+      next_projection: authorityProjectionFixture("goal-a", todos, [], "native", {handoff_mode: "hard_lease"}),
+      events: [], receipts: []})).status, "applied");
+    const requests = ["agent-a", "agent-b"].map((agent, i) => ({goal_id: "goal-a", todo_id: todos[i].todo_id,
+      claimed_by: agent, actor_agent_id: agent, expected_role: "agent", registered_agents: ["agent-a", "agent-b"],
+      operation_id: `claim-${agent}`, lease_request: {idempotency_key: `execution-${agent}`, expected_version: 0, ttl_seconds: 600},
+      dry_run: false, now: new Date("2026-09-30T10:00:00Z")}));
+    return {store, contender, requests};
+  }
+
+  for (const scenario of ["independent", "same-todo", "overlap"] as const) {
+    test(`${provider} claim contention: ${scenario} revalidates the latest head`, async t => {
+      const {store, contender, requests} = await setup(t, scenario === "overlap");
+      if (scenario === "same-todo") requests[1].todo_id = requests[0].todo_id;
+      let arrivals = 0;
+      let release!: () => void;
+      const barrier = new Promise<void>(resolve => { release = resolve; });
+      const stores = [store, contender].map(value => beforeCommit(value, async () => {
+        if (++arrivals === 2) release();
+        await barrier;
+      }));
+      const results = await Promise.all(requests.map((request, i) => claim(stores[i], request)));
+      assert.equal(results.filter(r => r.status === "applied").length, scenario === "independent" ? 2 : 1,
+        JSON.stringify(results));
+      if (scenario !== "independent") {
+        const loser = results.findIndex(r => r.status !== "applied");
+        assert.equal(results[loser].status, "failed", JSON.stringify(results[loser]));
+        assert.equal(results[loser].reason_code, scenario === "same-todo" ? "claim_owner_mismatch" : "write_scope_conflict");
+        assert.equal((await store.readReceipt(requests[loser].operation_id)).status, "missing");
+      }
+      for (let i = 0; i < results.length; i++) if (results[i].status === "applied") {
+        const receipt = await store.readReceipt(requests[i].operation_id);
+        assert.equal(receipt.status, "found");
+        assert.equal((await claim(stores[i], requests[i])).status, "replayed");
+        assert.deepEqual(await store.readReceipt(requests[i].operation_id), receipt);
+      }
+      assert.equal(arrivals, scenario === "independent" ? 3 : 2);
+      const final = await store.loadAuthority();
+      if (final.status !== "loaded") throw new Error("missing final authority");
+      const winners = requests.filter((_, i) => results[i].status === "applied");
+      assert.equal((final.head.leases as JsonObject[]).length, winners.length);
+      for (const winner of winners) {
+        assert.equal((final.head.todos as JsonObject[]).find(todo => todo.todo_id === winner.todo_id)?.claimed_by,
+          winner.claimed_by, "rebasing an independent claim must retain the previous winner");
+      }
+    });
+  }
+
+  test(`${provider} claim contention: newly required acceptance is rechecked`, async t => {
+    const {store, contender, requests} = await setup(t);
+    let commits = 0;
+    const wrapped = beforeCommit(store, async () => {
+      commits++;
+      const current = await contender.loadAuthority();
+      if (current.status !== "loaded") throw new Error("missing fixture");
+      assert.equal((await configureGoalAcceptance(contender, {
+        goal_id: "goal-a", actor_agent_id: null, operation_id: "require-acceptance",
+        expected_provider_revision: current.provider_revision,
+        document: {scope: {kind: "all_advancement"}, objective: "Validate the accepted work", non_goals: [],
+          criteria: [{id: "outcome", description: "Validation passes", validation_argv: ["python", "-V"]}],
+          bindings: []},
+      })).status, "applied");
+    });
+    const result = await claim(wrapped, requests[0]);
+    assert.equal(commits, 1);
+    assert.equal(result.status, "failed");
+    assert.equal((result.goal_acceptance_guard as JsonObject).allowed, false);
+    assert.equal((await store.readReceipt(requests[0].operation_id)).status, "missing");
+  });
+
+  for (const scenario of ["pinned", "source-change", "exhausted"] as const) {
+    test(`${provider} claim contention: ${scenario} stops without a claim receipt`, async t => {
+      const {store, contender, requests} = await setup(t);
+      const initial = await store.loadAuthority();
+      assert.equal(initial.status, "loaded");
+      if (initial.status !== "loaded") throw new Error("missing fixture");
+      let commits = 0;
+      const wrapped = beforeCommit(store, async () => {
+        const current = await contender.loadAuthority();
+        if (current.status !== "loaded") throw new Error("missing fixture");
+        assert.equal((await contender.commitAuthority({operation_id: `peer-${++commits}`,
+          expected_provider_revision: current.provider_revision, next_projection: current.head,
+          events: [], receipts: []})).status, "applied");
+      });
+      const result = await claim(wrapped, {...requests[0], ...(scenario === "pinned"
+        ? {expected_provider_revision: initial.provider_revision} : {})},
+        async () => scenario !== "source-change" || commits === 0);
+      assert.equal(commits, scenario === "exhausted" ? 3 : 1);
+      assert.equal(result.status, scenario === "source-change" ? "failed" : "conflict", JSON.stringify(result));
+      assert.equal((await store.readReceipt(requests[0].operation_id)).status, "missing");
+    });
+  }
+}