io.github.cyanheads/workflows-mcp-server

Official

by cyanheads · TypeScript

Store, query, and create YAML workflow playbooks for LLM agents.

Store, query, and generate YAML workflow playbooks for AI agent automation.

Topics

ai-agentsmcpmcp-serverworkflowworkflow-automationagent-automationmodel-context-protocolcyanheads

README.md12 KBView on GitHub

<div align="center"> <h1>@cyanheads/workflows-mcp-server</h1> <p><b>Store, query, and create YAML workflow playbooks for LLM agents via MCP. STDIO or Streamable HTTP.</b> <div>5 Tools</div> </p> </div> <div align="center">

</div> <div align="center">

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Tools

Five tools covering the full workflow library lifecycle — discovery, retrieval, creation, and deletion for both permanent and temporary workflows:

Tool	Description
`workflow_list`	List all permanent workflows in the index, with optional keyword, category, and tag filters.
`workflow_get`	Retrieve a complete workflow definition by name, with global instructions prepended.
`workflow_create`	Write a new permanent workflow YAML to the library.
`workflow_create_temp`	Write a temporary one-shot workflow, indexed but excluded from list results.
`workflow_delete`	Permanently remove a permanent workflow by name and optional version.

`workflow_list`

List permanent workflows from the in-memory index.

Optional keyword query filter (case-insensitive substring across workflow name and description)
Optional category filter (case-insensitive substring match)
Optional tag filter (AND match — all listed tags must be present)
Set includeTools: true to surface the unique server/tool pairs used across each workflow's steps
Temporary workflows are excluded; results sorted by name then version descending
Empty results echo the applied filters with a hint to broaden

`workflow_get`

Retrieve a complete workflow by name, including the global instructions document.

Semver-aware: omit version to get the highest available match; specify a version for an exact lookup
Returns the full workflow YAML structure with all steps and metadata
Injects the global_instructions.md content as globalInstructions — apply these when executing the workflow; null when the file is absent
Temporary workflows are accessible here even though excluded from workflow_list
Template placeholders ({{input.foo}}, {{steps.X.output.Y}}) are returned verbatim — the server never interpolates them

`workflow_create`

Write a new permanent workflow to the library.

Workflow stored at categories/<slugified-category>/<slugified-name>-<slugified-version>-workflow.yaml — one file per name@version, so multiple versions coexist
Rejects if name@version already exists — bump the version to create a new revision
Server stamps created_date and last_updated_date automatically
Index and snapshot rebuilt after write; filesystem watcher also fires (idempotent, debounced)

`workflow_create_temp`

Write a throwaway workflow to the temp/ directory.

No conflict check — temp workflows are intentionally ephemeral and overwriteable
Indexed and accessible via workflow_get but excluded from workflow_list results
Useful for one-shot plans, short-lived scaffolding, or session-specific orchestration steps

`workflow_delete`

Permanently remove a permanent workflow from the library.

Semver-aware: omit version to delete the highest available match; specify a version to target one exactly
Only permanent workflows can be deleted — temporary workflows are rejected (they expire on their own)
Irreversible: the file is removed and the workflow no longer appears in workflow_list or workflow_get

Features

Built on @cyanheads/mcp-ts-core:

Declarative tool definitions — single file per primitive, framework handles registration and validation
Unified error handling — handlers throw, framework catches, classifies, and formats
Pluggable auth: none, jwt, oauth
Swappable storage backends: in-memory, filesystem, Supabase, Cloudflare KV/R2/D1
Structured logging with optional OpenTelemetry tracing
STDIO and Streamable HTTP transports

Workflow library:

In-memory index keyed by name@version, built at startup from workflows-yaml/categories/ recursively
Semver-aware lookup — latest version returned when version is omitted
Filesystem watcher (Node.js fs.watch recursive) rebuilds the index on any add/change/remove; debounced to avoid thrash
YAML validated at index time — invalid files are skipped and logged, never crash the server
_index.json snapshot written on every rebuild for external tooling and debugging
Configurable WORKFLOWS_DIR, GLOBAL_INSTRUCTIONS_PATH, and debounce interval

Agent-friendly output:

workflow_get always includes globalInstructions alongside the workflow — no second call needed
Discriminated source field (permanent | temp) on every workflow_get response
Typed error contracts with structured reason codes (not_found, version_not_found, already_exists, temp_not_allowed, index_unavailable) so callers can branch on error type rather than parsing messages
workflow_list with includeTools: true surfaces all MCP server/tool dependencies at a glance

Getting started

No API keys required. The server reads from a local workflows-yaml/ directory by default.

Add the following to your MCP client configuration file:

json

{
  "mcpServers": {
    "workflows-mcp-server": {
      "type": "stdio",
      "command": "bunx",
      "args": ["@cyanheads/workflows-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "WORKFLOWS_DIR": "/absolute/path/to/your/workflows-yaml"
      }
    }
  }
}

Or with npx (no Bun required):

json

{
  "mcpServers": {
    "workflows-mcp-server": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@cyanheads/workflows-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "WORKFLOWS_DIR": "/absolute/path/to/your/workflows-yaml"
      }
    }
  }
}

Or with Docker:

json

{
  "mcpServers": {
    "workflows-mcp-server": {
      "type": "stdio",
      "command": "docker",
      "args": [
        "run", "-i", "--rm",
        "-e", "MCP_TRANSPORT_TYPE=stdio",
        "-v", "/absolute/path/to/your/workflows-yaml:/workflows-yaml",
        "-e", "WORKFLOWS_DIR=/workflows-yaml",
        "ghcr.io/cyanheads/workflows-mcp-server:latest"
      ]
    }
  }
}

For Streamable HTTP, set the transport and start the server:

MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 bun run start:http
# Server listens at http://localhost:3010/mcp

Seed workflows

The repository ships a workflows-yaml/ directory with example workflows organized under categories/. These are ready to use as a starting point. The workflows-yaml/global_instructions.md file contains instructions the server prepends to every workflow_get response — edit it to set global guidance for your agent.

Prerequisites

Bun v1.3.2 or higher (or Node.js v24+).
A local directory containing YAML workflow files (or use the bundled workflows-yaml/ seed).

Installation

Clone the repository:

git clone https://github.com/cyanheads/workflows-mcp-server.git

Navigate into the directory:

cd workflows-mcp-server

Install dependencies:

bun install

Configure environment:

cp .env.example .env
# edit .env if needed — most settings have defaults

Configuration

Variable	Description	Default
`WORKFLOWS_DIR`	Absolute or relative path to the workflows root directory.	`./workflows-yaml`
`GLOBAL_INSTRUCTIONS_PATH`	Path to the global instructions markdown file. Derives from `WORKFLOWS_DIR` when not set.	`<WORKFLOWS_DIR>/global_instructions.md`
`WATCHER_DEBOUNCE_MS`	Milliseconds to debounce filesystem change events before rebuilding the index.	`500`
`MCP_TRANSPORT_TYPE`	Transport: `stdio` or `http`.	`stdio`
`MCP_HTTP_PORT`	Port for HTTP server.	`3010`
`MCP_AUTH_MODE`	Auth mode: `none`, `jwt`, or `oauth`.	`none`
`MCP_LOG_LEVEL`	Log level (RFC 5424).	`info`
`OTEL_ENABLED`	Enable OpenTelemetry instrumentation (spans, metrics, completion logs).	`false`

See .env.example for the full list of optional overrides.

Running the server

Local development

Build and run:

# One-time build
bun run rebuild

# Run the built server
bun run start:stdio
# or
bun run start:http

Run checks and tests:

bun run devcheck   # Lint, format, typecheck, security
bun run test       # Vitest test suite
bun run lint:mcp   # Validate MCP definitions against spec

Docker

docker build -t workflows-mcp-server .
docker run --rm \
  -v /path/to/workflows-yaml:/workflows-yaml \
  -e WORKFLOWS_DIR=/workflows-yaml \
  -p 3010:3010 \
  workflows-mcp-server

The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/workflows-mcp-server. OpenTelemetry peer dependencies are installed by default — build with --build-arg OTEL_ENABLED=false to omit them.

Project structure

Directory	Purpose
`src/index.ts`	`createApp()` entry point — registers tools and inits the workflow index service.
`src/config/`	Server-specific environment variable parsing and validation with Zod.
`src/mcp-server/tools/`	Tool definitions (`*.tool.ts`).
`src/services/workflow-index/`	`WorkflowIndexService` — YAML parsing, index build, watcher, semver lookup, write helpers.
`tests/`	Unit and integration tests mirroring `src/`.
`workflows-yaml/`	Seed workflow library — `categories/` for permanent workflows, `temp/` for throwaway ones, `global_instructions.md` for agent-global guidance.

Development guide

See CLAUDE.md for development guidelines and architectural rules. The short version:

Handlers throw, framework catches — no try/catch in tool logic
Use ctx.log for request-scoped logging
Register new tools via the barrel in src/mcp-server/tools/definitions/index.ts
Filesystem operations go through WorkflowIndexService, not directly in tool handlers

Contributing

Issues and pull requests are welcome. Run checks and tests before submitting:

bun run devcheck
bun run test

License

Apache-2.0 — see LICENSE for details.

Install

Configuration

Environment variables

WORKFLOWS_DIRdefault ./workflows-yaml

Absolute or relative path to the workflows root directory.

GLOBAL_INSTRUCTIONS_PATH

Path to the global instructions markdown file. Derives from WORKFLOWS_DIR when not set.

WATCHER_DEBOUNCE_MSdefault 500

Milliseconds to debounce filesystem change events before rebuilding the index.

MCP_LOG_LEVELdefault info

Sets the minimum log level for output (e.g., 'debug', 'info', 'warn').

MCP_HTTP_HOSTdefault 127.0.0.1

The hostname for the HTTP server.

MCP_HTTP_PORTdefault 3010

The port to run the HTTP server on.

MCP_HTTP_ENDPOINT_PATHdefault /mcp

The endpoint path for the MCP server.

MCP_AUTH_MODEdefault none

Authentication mode to use: 'none', 'jwt', or 'oauth'.

claude_desktop_config.json

{
  "mcpServers": {
    "workflows-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@cyanheads/workflows-mcp-server@0.2.0",
        "run",
        "start:stdio"
      ],
      "env": {
        "WORKFLOWS_DIR": "./workflows-yaml",
        "GLOBAL_INSTRUCTIONS_PATH": "<YOUR_GLOBAL_INSTRUCTIONS_PATH>",
        "WATCHER_DEBOUNCE_MS": "500",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}