Speed up task claim hot path

apps/mcp-server/src/tools/task.ts

@@ -5,7 +5,6 @@ import {
   classifyClaimAge,
   guardedClaimFile,
   listPlans,
-  liveFileContentionsForClaim,
 } from '@colony/core';
 import { claimPathRejectionMessage } from '@colony/storage';
 import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
@@ -396,12 +395,6 @@ export function register(server: McpServer, ctx: ToolContext): void {
         );
       }
       const previous = store.storage.getClaim(task_id, normalizedFilePath);
-      const liveContentions = liveFileContentionsForClaim(store, {
-        task_id,
-        session_id,
-        file_path: normalizedFilePath,
-        assume_requester_live: true,
-      });
       const guarded = guardedClaimFile(store, {
         task_id,
         session_id,
@@ -453,8 +446,8 @@ export function register(server: McpServer, ctx: ToolContext): void {
         file_path: normalizedFilePath,
         claim_status: guarded.status,
         claim_task_id: guarded.claim_task_id ?? task_id,
-        warning: liveContentions[0] ?? null,
-        live_file_contentions: liveContentions,
+        warning: null,
+        live_file_contentions: [],
         overlap: previousClaim?.overlap ?? 'none',
         previous_claim: previousClaim,
       });

apps/mcp-server/test/task-threads.test.ts

@@ -97,6 +97,27 @@ describe('task threads — file claims', () => {
     expect(claim?.metadata).toContain('"file_path":"src/viewer.tsx"');
   });
 
+  it('keeps uncontended task_claim_file calls under the hot-path budget', async () => {
+    const repoRoot = mkdtempSync(join(dir, 'repo-'));
+    mkdirSync(join(repoRoot, 'src'), { recursive: true });
+    const { task_id, sessionA } = seedTwoSessionTask(repoRoot);
+    const durations: number[] = [];
+
+    for (let i = 0; i < 40; i += 1) {
+      const started = performance.now();
+      const result = await call<{ live_file_contentions: unknown[] }>('task_claim_file', {
+        task_id,
+        session_id: sessionA,
+        file_path: `src/hot-path-${i}.ts`,
+      });
+      durations.push(performance.now() - started);
+      expect(result.live_file_contentions).toEqual([]);
+    }
+
+    const p95 = [...durations].sort((a, b) => a - b)[Math.floor(durations.length * 0.95)] ?? 0;
+    expect(p95).toBeLessThan(100);
+  });
+
   it('rejects pseudo task_claim_file paths with a pseudo-specific message', async () => {
     const { task_id, sessionA } = seedTwoSessionTask();
 

openspec/changes/agent-codex-speed-up-task-claim-file-2026-05-15-15-39/.openspec.yaml

@@ -0,0 +1,2 @@
+schema: spec-driven
+created: 2026-05-15

openspec/changes/agent-codex-speed-up-task-claim-file-2026-05-15-15-39/proposal.md

@@ -0,0 +1,23 @@
+## Why
+
+`task_claim_file` runs on the edit hot path. `colony gain` showed an average
+runtime above 3 seconds, and the MCP handler always performed the full live
+file contention scan even for ordinary uncontended claims where that payload is
+empty.
+
+## What Changes
+
+- Remove the unconditional live-contention scan from successful
+  `task_claim_file` responses.
+- Keep the guarded claim decision as the authority for blocking active owners,
+  stale claims, protected branches, and same-session refreshes.
+- Return the existing response shape with `warning: null` and
+  `live_file_contentions: []` for successful claims.
+
+## Impact
+
+- Cuts one repo-wide task/claim scan and OMX active-session read from the common
+  claim path.
+- Preserves existing hard-block behavior for active owners through
+  `guardedClaimFile`.
+- Adds a focused hot-path budget test for uncontended claim batches.

openspec/changes/agent-codex-speed-up-task-claim-file-2026-05-15-15-39/specs/speed-up-task-claim-file/spec.md

@@ -0,0 +1,22 @@
+## ADDED Requirements
+
+### Requirement: task_claim_file avoids live-contention scans on successful claims
+The `task_claim_file` MCP handler SHALL avoid the repo-wide live file
+contention scan when `guardedClaimFile` returns a successful claim status. For
+successful claims it SHALL preserve the response shape with `warning: null` and
+`live_file_contentions: []`. The guarded claim decision SHALL remain responsible
+for hard failures such as active owners, protected branch rejection, invalid
+paths, and takeover recommendations.
+
+#### Scenario: Uncontended claim returns compact success
+- **GIVEN** a task has no competing scoped claim for `file_path=F`
+- **WHEN** `task_claim_file` is called for `F`
+- **THEN** the claim succeeds
+- **AND** the response contains `warning: null`
+- **AND** the response contains `live_file_contentions: []`
+
+#### Scenario: Active owner still blocks
+- **GIVEN** another active session owns a scoped claim for `file_path=F`
+- **WHEN** `task_claim_file` is called for `F`
+- **THEN** the handler returns `CLAIM_HELD_BY_ACTIVE_OWNER`
+- **AND** no successful claim is recorded for the requester

openspec/changes/agent-codex-speed-up-task-claim-file-2026-05-15-15-39/tasks.md

@@ -0,0 +1,34 @@
+## Definition of Done
+
+This change is complete only when **all** of the following are true:
+
+- Every checkbox below is checked.
+- The agent branch reaches `MERGED` state on `origin` and the PR URL + state are recorded in the completion handoff.
+- If any step blocks (test failure, conflict, ambiguous result), append a `BLOCKED:` line under section 4 explaining the blocker and **STOP**. Do not tick remaining cleanup boxes; do not silently skip the cleanup pipeline.
+
+## Handoff
+
+- Handoff: change=`agent-codex-speed-up-task-claim-file-2026-05-15-15-39`; branch=`agent/codex/speed-up-task-claim-file-2026-05-15-15-39`; scope=`skip live-contention scan on successful task_claim_file`; action=`continue this sandbox or finish cleanup after a usage-limit/manual takeover`.
+- Copy prompt: Continue `agent-codex-speed-up-task-claim-file-2026-05-15-15-39` on branch `agent/codex/speed-up-task-claim-file-2026-05-15-15-39`. Work inside the existing sandbox, review `openspec/changes/agent-codex-speed-up-task-claim-file-2026-05-15-15-39/tasks.md`, continue from the current state instead of creating a new sandbox, and when the work is done run `gx branch finish --branch agent/codex/speed-up-task-claim-file-2026-05-15-15-39 --base main --via-pr --cleanup`.
+
+## 1. Specification
+
+- [x] 1.1 Finalize proposal scope and acceptance criteria for `agent-codex-speed-up-task-claim-file-2026-05-15-15-39`.
+- [x] 1.2 Define normative requirements in `specs/speed-up-task-claim-file/spec.md`.
+
+## 2. Implementation
+
+- [x] 2.1 Implement scoped behavior changes.
+- [x] 2.2 Add/update focused regression coverage.
+
+## 3. Verification
+
+- [x] 3.1 Run targeted project verification commands.
+- [x] 3.2 Run `openspec validate agent-codex-speed-up-task-claim-file-2026-05-15-15-39 --type change --strict`.
+- [x] 3.3 Run `openspec validate --specs`.
+
+## 4. Cleanup (mandatory; run before claiming completion)
+
+- [ ] 4.1 Run the cleanup pipeline: `gx branch finish --branch agent/<your-name>/<branch-slug> --base dev --via-pr --wait-for-merge --cleanup`. This handles commit -> push -> PR create -> merge wait -> worktree prune in one invocation.
+- [ ] 4.2 Record the PR URL and final merge state (`MERGED`) in the completion handoff.
+- [ ] 4.3 Confirm the sandbox worktree is gone (`git worktree list` no longer shows the agent path; `git branch -a` shows no surviving local/remote refs for the branch).