MCP Tools
Expose flows as Model Context Protocol tools. LLM agents can discover and call flowgen flows as tools over the MCP transport.
Configuration
The MCP server must be enabled in the worker config:
worker:
mcp_server:
enabled: true
port: 3001
path: /mcp/v1
credentials_path: /path/to/credentials.jsonIndividual flows register as MCP tools using the mcp_tool task:
- mcp_tool:
name: lookup_user
description: "Look up a user by ID."
input_schema:
type: object
properties:
user_id:
type: string
required:
- user_idFields
| Field | Type | Default | Description |
|---|---|---|---|
name | string | required | Tool name. Combined with the flow name as {flow_name}.{name} to form the full tool identifier. |
description | string | required | Human-readable description shown to LLMs for tool selection. |
input_schema | object | JSON Schema for the tool’s input parameters. | |
credentials_path | string | Path to credentials file for this tool. Overrides worker.mcp_server.credentials_path. | |
ack_timeout | duration | wait indefinitely | Max time to wait for flow completion before returning a timeout error to the MCP client. |
auth | object | Per-tool authentication config. When auth.required is true, requests must include a valid bearer token validated by the worker auth provider; the resolved user context is injected into event.meta.auth. | |
depends_on | list | Upstream task names. | |
retry | object | Retry configuration. |
The MCP server listens on the configured port and exposes registered tools over the MCP Streamable HTTP transport.
Output
Format: JSON
| Field | Type | Description |
|---|---|---|
arguments | object | Tool input parameters from the MCP tools/call request, structured per the configured input_schema. |