Agent Claim MCP Server

Agent Claim MCP

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Use Agent Claim MCP when multiple coding agents share one worktree and you need a tiny local coordination primitive before edits, not a full orchestration framework. It gives agents one job: claim paths, detect collisions, and release ownership so parallel work stops stomping the same files.

Agent Claim MCP is a local-first MCP server for Claude Code, Cursor, Cline, and other MCP clients that need file ownership coordination without queues, planners, or custom AGENTS.md conventions. The current release surface centers on three bounded actions only: claim normalized paths, inspect who owns them, and release by path or claim id with explicit conflict reporting across separate sessions.

Release status: @vk0/agent-claim-mcp@1.0.0 is live on npm, so the npx -y @vk0/agent-claim-mcp install path is now the truthful default for external users. Phase 5 external proof may be satisfied by either Official MCP Registry validation or a live Smithery listing, but the current proof state remains pending until one of those public artifacts is explicitly verified. Official MCP Registry validation is still pending, so do not describe the package as registry-accepted or marketplace-listed until a real registry or Smithery proof URL is cited.

Milestone truth: the product wedge stays narrow, 3 tools plus a local JSON ledger for shared-worktree collision prevention, not a broader orchestration platform.

Current next manual step: complete the pending human rerun and verification path for Official MCP Registry proof, then record the verdict from that run instead of assuming acceptance from npm availability.

Registry rerun quickstart

Current truthful state:

• npm 1.0.0 is live
• Official MCP Registry acceptance is still pending
• workflow 25282612113 did not complete the registry validation path
• the repo is now past the earlier NPM_TOKEN secret-fix step, but the registry proof still needs a human rerun plus verification before it can be treated as accepted

Exact rerun command:

gh run rerun 25282612113 --repo vk0dev/agent-claim-mcp

After the rerun, verify in this order:

1. confirm the rerun completed successfully in GitHub Actions
2. run npm run preflight:registry
3. follow docs/official-registry-validation-runbook.md
4. only then record registry acceptance as proven

Operator shortcut: use the runbook's Quick operator path for the exact rerun-to-verification order, and treat npm-live status as separate from registry-proof status.

Why / When to use

Choose this server when your workflow already has task routing, but still needs a simple lock-like primitive at edit time:

• two or more agents can touch the same repo in parallel
• you want collision detection before file edits, not after merge conflicts
• you want claims to expire automatically with TTLs
• you want a narrow primitive that another agent can understand from name + description alone
• you do not want a bundled rules engine, queue runner, or orchestration platform

Installation

The canonical external install path is now the published npm package:

{
  "mcpServers": {
    "agent-claim": {
      "command": "npx",
      "args": ["-y", "@vk0/agent-claim-mcp"]
    }
  }
}

Status note: npm install is live today, but Official MCP Registry validation and Smithery/other marketplace proof are still not established, so treat the package as npm-available first rather than marketplace-verified.

If you are developing from a local checkout instead of the published package, you can still point your MCP client at the built dist/server.js directly.

{
  "mcpServers": {
    "agent-claim": {
      "command": "node",
      "args": ["/absolute/path/to/agent-claim-mcp/dist/server.js"]
    }
  }
}

That second example is for local development only. On Windows, point your MCP client at the built dist/server.js path on your own machine instead of copying a POSIX path literally.

Build once before using the local path:

cd /Users/vkdev/projects/agent-claim-mcp
npm ci
npm run build

Claude Code

Add the stdio server to your Claude Code MCP config:

{
  "mcpServers": {
    "agent-claim": {
      "command": "npx",
      "args": ["-y", "@vk0/agent-claim-mcp"]
    }
  }
}

Claude Desktop

Claude Desktop uses ~/Library/Application Support/Claude/claude_desktop_config.json on macOS and %APPDATA%\Claude\claude_desktop_config.json on Windows:

{
  "mcpServers": {
    "agent-claim": {
      "command": "npx",
      "args": ["-y", "@vk0/agent-claim-mcp"]
    }
  }
}

After saving claude_desktop_config.json, fully restart Claude Desktop so it reloads the MCP server configuration.

Cursor

{
  "mcpServers": {
    "agent-claim": {
      "command": "npx",
      "args": ["-y", "@vk0/agent-claim-mcp"]
    }
  }
}

Cline

{
  "mcpServers": {
    "agent-claim": {
      "command": "npx",
      "args": ["-y", "@vk0/agent-claim-mcp"]
    }
  }
}

Limitations

This server is intentionally narrow and local-first. Install it when your agents share one filesystem view, not when you need distributed coordination.

• Claims live in a local ledger on disk, so they only coordinate sessions that can read and write the same worktree.
• It is not a hosted lock service, queue, or scheduler, and it does not replicate claims across machines by itself.
• TTL expiry is protective cleanup, not a substitute for higher-level task ownership or human review.
• Path normalization reduces shape mismatches, but agents still need to point at the same repo root or cwd for claims to line up.
• If your workflow needs cross-host coordination, central audit policy, or mandatory approvals, pair this server with a separate orchestration layer instead of stretching the claim ledger beyond its scope.

For a real multi-agent run before publishing, see DOGFOOD.md and the proof artifacts in docs/dogfood-report.md.

Tools

claim_files

Create or refresh a local file-claim entry so parallel agents can see ownership before editing and avoid stomping the same worktree paths during active tasks. Conflict responses are explicit, so overlapping claims across separate sessions do not stay implicit or in-memory only.

Input

{
  "agentId": "coder-a",
  "taskId": "task-123",
  "paths": ["src/foo.ts", "src/bar.ts"],
  "ttlSeconds": 3600,
  "note": "working on parser cleanup",
  "cwd": "/repo"
}

Output

{
  "ok": true,
  "claimed": ["/repo/src/bar.ts", "/repo/src/foo.ts"],
  "conflicts": [],
  "ledgerVersion": 1,
  "claimedUntil": "2026-05-03T16:00:00.000Z"
}

If any requested path is already claimed by another active owner, the tool returns ok: false and writes nothing.

release_claim

Remove an existing claim owned by the current agent so finished, paused, or reassigned work stops blocking other agents from safely editing the same paths.

Input

{
  "agentId": "coder-a",
  "paths": ["src/foo.ts"],
  "cwd": "/repo"
}

Output

{
  "ok": true,
  "released": ["/repo/src/foo.ts"],
  "missing": [],
  "ledgerVersion": 1
}

Only the current owner can release an active claim, whether you target it by claimId or by normalized paths, so cleanup works after real multi-agent runs and path-shape variants resolve consistently.

whose_claim

Read the local ledger and explain whether a file path is free or currently claimed, including owner, task, note, and expiry metadata for safe coordination across separate sessions sharing the same worktree.

Input

{
  "paths": ["src/foo.ts", "src/bar.ts"],
  "cwd": "/repo",
  "includeExpired": false
}

Output

{
  "results": [
    {
      "path": "/repo/src/bar.ts",
      "claimed": false
    },
    {
      "path": "/repo/src/foo.ts",
      "claimed": true,
      "ownerAgentId": "coder-a",
      "taskId": "task-123",
      "note": "working on parser cleanup",
      "expiresAt": "2026-05-03T16:00:00.000Z",
      "claimId": "2a08b70c-4203-44a2-b833-31592472de1e"
    }
  ],
  "ledgerVersion": 1
}

Real samples

1. coder-A claims foo.ts

{
  "tool": "claim_files",
  "arguments": {
    "agentId": "coder-A",
    "taskId": "task-42",
    "paths": ["src/foo.ts"],
    "note": "refactoring the claim parser",
    "cwd": "/repo"
  }
}

{
  "ok": true,
  "claimed": ["/repo/src/foo.ts"],
  "conflicts": [],
  "ledgerVersion": 1,
  "claimedUntil": "2026-05-03T16:00:00.000Z"
}

2. coder-B collides on the same file

{
  "tool": "claim_files",
  "arguments": {
    "agentId": "coder-B",
    "paths": ["src/foo.ts", "src/new.ts"],
    "cwd": "/repo"
  }
}

{
  "ok": false,
  "claimed": [],
  "conflicts": [
    {
      "path": "/repo/src/foo.ts",
      "ownerAgentId": "coder-A",
      "expiresAt": "2026-05-03T16:00:00.000Z"
    }
  ],
  "ledgerVersion": 1,
  "claimedUntil": "2026-05-03T16:00:00.000Z"
}

3. coder-A releases the file

{
  "tool": "release_claim",
  "arguments": {
    "agentId": "coder-A",
    "paths": ["src/foo.ts"],
    "cwd": "/repo"
  }
}

{
  "ok": true,
  "released": ["/repo/src/foo.ts"],
  "missing": [],
  "ledgerVersion": 1
}

Troubleshooting

claim_files returns ok: false

This means at least one requested path is already claimed by another active owner, so nothing new was written. Check the conflicts array for the exact overlapping normalized paths and the current ownerAgentId, then inspect the same paths with whose_claim before retrying.

{
  "tool": "whose_claim",
  "arguments": {
    "paths": ["src/foo.ts", "src/new.ts"],
    "cwd": "/repo"
  }
}

If one path collides, a mixed request is still all-or-nothing. Split the work or wait for the current owner to release the conflicting path.

release_claim with a claim id returns missing: ["..."]

That claim id was not active in the local ledger at release time. It may already be released, expired, or never existed on this machine. This is not treated as a partial success.

release_claim with paths returns released: []

If ok is still true but released is empty, the requested normalized paths did not match any active claim owned by the caller. The missing array tells you which normalized paths were not matched.

Use whose_claim first when you are unsure whether the path is free, owned by another agent, or already gone from the ledger.

Releasing someone else’s claim

Only the current owner can release an active claim. If another agent still owns the path, inspect it with whose_claim, coordinate with that owner, or wait for the TTL to expire.

Comparison

Choose Agent Claim MCP when you already have your own tasking layer and only need path ownership coordination.

Choose a broader orchestration project when you want one package to define agent rules, work queues, coordination policy, and higher-level execution flow.

FAQ

Pick claims when multiple agents intentionally share one checkout and one filesystem view — because they reuse the same node_modules, build artifacts, or a running dev server, or because the tasking layer already splits work by files rather than by branches. Branch-per-agent and worktree-per-agent prevent collisions by copying state and deferring conflicts to merge time; claims prevent collisions by declaring path ownership before the first edit, with no extra checkouts and no merge step. If your workflow already isolates each agent in its own branch or worktree, you may not need this server at all.

A claim is an advisory ownership record, not an enforced filesystem lock. Nothing physically prevents a misbehaving process from writing to a claimed path; enforcement is cooperative, which is exactly the contract MCP agents can follow: call claim_files before editing, respect ok: false, release when done. Worktree isolation is stronger but heavier — separate checkouts, duplicated state, and conflicts that only surface at merge. The two compose: use worktrees for long-lived parallel streams, and claims inside any single worktree that more than one agent touches.

Every claim carries a TTL (ttlSeconds, default 3600), and expired claims are pruned automatically on the next ledger read or write. That means a crashed, killed, or abandoned session can never block a path forever — the worst case is one TTL window. Expiry is protective cleanup, not task handoff: an agent still actively working should refresh its own claim (re-claim the same paths under the same agentId) instead of asking for a very long TTL up front.

claim_files is all-or-nothing. If any requested path is already owned by another active claim, the tool returns ok: false, writes nothing — including the non-conflicting paths in the same request — and lists each colliding normalized path with its current ownerAgentId and expiresAt in the conflicts array. There is no queueing, no retry, and no forced takeover. The calling agent decides what to do next: split the batch, inspect the owner with whose_claim, coordinate through its own tasking layer, or wait for release or TTL expiry.

Yes, as long as all clients run on the same machine as the same user. Each MCP client spawns its own server process, but every process converges on the same on-disk ledger with atomic temp-file-plus-rename writes, so a claim made from a Claude Code session is visible to a Cursor or Cline session immediately. The one thing agents must keep consistent is path shape: pass a cwd or absolute paths that resolve to the same repo root, so normalization lines up across clients.

All state lives in one local JSON ledger at ~/.agent-claim-mcp/ledger.json. There is no daemon, no background process, no network listener, no telemetry, and no cloud sync — the server only reads and writes that file when a tool is called. This is also the boundary of the product: claims coordinate sessions that share one filesystem view, and cross-host coordination is explicitly out of scope.

No. release_claim only removes active claims owned by the calling agentId, whether targeted by claimId or by normalized paths. If another agent still owns a path, your options are to inspect it with whose_claim, coordinate with that owner through your tasking layer, or wait for the TTL to expire. This keeps the primitive predictable: ownership changes only by explicit release or by expiry, never by a quiet takeover.

How it works

• claims are stored in a local JSON ledger at ~/.agent-claim-mcp/ledger.json
• paths are normalized to absolute paths so different agents cannot dodge collisions with relative path tricks or path-shape variants
• overlapping claims across separate sessions resolve through the same ledger instead of relying on in-memory coordination
• expired claims are pruned automatically on reads and writes
• writes use temp-file plus rename semantics for atomic updates

Development

npm ci
npm run build
npm test
npm run smoke

Packaging

The npm package is expected to ship at least:

• README.md
• server.json
• compiled dist/

Use this check before release:

npm pack --dry-run

Publish prerequisites

The expected publish path is the GitHub Actions release job that runs after a version tag push. For the unattended npm publish step to succeed, the workflow must receive a non-empty NODE_AUTH_TOKEN from the repo secret configured for npm publishing.

If NODE_AUTH_TOKEN is missing or empty in CI, the first npm publish attempt fails with ENEEDAUTH even when the package itself is ready. Before retrying a release, confirm the GitHub repository secret is present and mapped into the publish job rather than trying to re-run publish steps locally.

For the local proof path before tagging, run the short smoke checklist in docs/smoke-proof.md.

For the first post-publish external acceptance check, use the maintainer runbook in docs/official-registry-validation-runbook.md and the short recording template in docs/official-registry-validation-checklist.md.

License

MIT