hatchet-mcp

An MCP server that lets AI agents observe and operate Hatchet workflows — status, runs, logs, workers, and metrics, plus trigger / cancel / replay.

Why: Hatchet has a great API but no MCP. This wraps it so agents (Claude Code / Desktop, etc.) can see and act on workflow state.

Install

Add this to your Claude Code / Claude Desktop MCP config:

{
  "mcpServers": {
    "hatchet": {
      "command": "npx",
      "args": ["-y", "hatchet-mcp"],
      "env": { "HATCHET_CLIENT_TOKEN": "<your-hatchet-api-token>" }
    }
  }
}

Get the token from the Hatchet dashboard → API tokens. The token is a JWT that encodes the server URL and tenant, so it's the only required setting.

Configuration

| Variable | Required | Description | | --- | --- | --- | | HATCHET_CLIENT_TOKEN | Yes | Hatchet API token (JWT). Encodes the server URL + tenant, so it's normally all you need. | | HATCHET_API_BASE | No | Override the API base URL. Self-hosters can point this at any Hatchet instance. | | HATCHET_TENANT_ID | No | Override the tenant id decoded from the token. |

Self-hosting? Set HATCHET_API_BASE to your own Hatchet instance and it works anywhere.

Tools

Observability (read-only)

| Tool | Description | | --- | --- | | whoami | Show the resolved Hatchet tenant + server URL and confirm the token works. | | list_workflows | List workflow definitions for the tenant. | | list_runs | List workflow runs (with an optional lookback window and filters). | | get_run | Get the full detail of one workflow run — status, tasks, errors. | | get_run_logs | Get log lines for a task by its external id. | | list_workers | List workers and their status. | | get_queue_metrics | Get task/queue metrics for the tenant (queue health). |

Actions (mutate live state)

| Tool | Description | | --- | --- | | trigger_workflow | Trigger a new workflow run by name with a JSON input payload. | | cancel_runs | Cancel one or more runs/tasks by external id. | | replay_runs | Replay/retry one or more runs/tasks by external id. |

Safety

The read tools (whoami, list_workflows, list_runs, get_run, get_run_logs, list_workers, get_queue_metrics) are non-destructive.

trigger_workflow, cancel_runs, and replay_runs mutate live state — their descriptions are prefixed MUTATES LIVE STATE so agents and users know they affect real runs.

The token grants full tenant access — treat it as a secret. Never commit it to source control.

Development

pnpm install
pnpm test    # vitest
pnpm build   # tsup -> dist/index.js

TypeScript / ESM, tested with vitest.

Status

v0.1.0 — all tools verified against Hatchet Cloud; works with self-hosted instances via HATCHET_API_BASE. trigger_workflow uses the stable /workflow-runs/trigger endpoint.