QMCP - Model Context Protocol Server

A spec-aligned Model Context Protocol (MCP) server built with FastAPI.

Features

• ✅ Tool Discovery - List available tools via /v1/tools

• ✅ Tool Invocation - Execute tools via /v1/tools/{name}

• ✅ Invocation History - Audit trail via /v1/invocations

• ✅ Human-in-the-Loop - Request human input via /v1/human/*

• ✅ Persistence - SQLite with SQLModel/aiosqlite

• ✅ Python Client - qmcp.client.MCPClient for workflows

• ✅ Metaflow Examples - Ready-to-use flow templates

• ✅ Agent Framework - SQLModel schemas + mixins for agent types/topologies

• ✅ PydanticAI Integration - Create agents from QMCP models with full audit trail

• ✅ Structured Logging - JSON logs with structlog

• ✅ Request Tracing - Correlation IDs across requests

• ✅ Metrics - Prometheus-compatible /metrics endpoint

• ✅ CLI Interface - Manage via qmcp command

Quick Start

# Install dependencies
uv sync

# Start the server
uv run qmcp serve

# Or with development reload
uv run qmcp serve --reload

See quickstart.md for a copy-paste walkthrough.

Adoption and Onboarding

Adoption checklist:

• Decide how the server is hosted (local, container, or VM) and who can reach it.

• Set QMCP_HOST, QMCP_PORT, and QMCP_DATABASE_URL for your environment.

• Standardize X-Correlation-ID values for audit trails across clients.

• Decide how humans submit HITL responses (UI or API).

• Wire /metrics into your monitoring stack.

Onboarding path:

1. uv sync --all-extras

2. Run the end-to-end tutorial below.

3. uv run qmcp serve for local exploration.

End-to-End Tutorial (HITL approval workflow)

This tutorial mirrors the end-to-end test tests/test_hitl.py::TestHITLWorkflow::test_complete_approval_workflow.

Copy and paste:

uv sync --all-extras
uv run pytest tests/test_hitl.py::TestHITLWorkflow::test_complete_approval_workflow -v

Client Library

from qmcp.client import MCPClient

with MCPClient(base_url="http://localhost:3333") as client:
    # List tools
    tools = client.list_tools()

    # Invoke a tool
    result = client.invoke_tool("echo", {"message": "Hello!"})
    print(result.result)

    # Human-in-the-loop
    request = client.create_human_request(
        request_id="approval-001",
        request_type="approval",
        prompt="Approve deployment?",
        options=["approve", "reject"]
    )
    response = client.wait_for_response("approval-001", timeout=3600)

See docs/client.md for full API documentation.

CLI Commands

# Start the server
qmcp serve [--host HOST] [--port PORT] [--reload]

# Start the server for Docker-based flows
qmcp cookbook serve [--host 0.0.0.0] [--port PORT] [--reload]

# List registered tools
qmcp tools list

# Show configuration
qmcp info

# Run a cookbook flow in Docker
qmcp cookbook simple-plan --goal "Deploy a web service"

# Start the server + run a cookbook flow (unified dev)
qmcp cookbook dev simple-plan --goal "Deploy a web service"

# Run a cookbook flow via the generic runner
qmcp cookbook run simple-plan --goal "Deploy a web service"

# Run other cookbook recipes (flow args are passed through)
qmcp cookbook run approved-deploy --service "api-gateway" --environment "staging"
qmcp cookbook dev local-qc-gauntlet --change-summary "Add audit fields" --target-area "metrics, logging"

# Run a cookbook flow in Docker explicitly
qmcp cookbook docker simple-plan --goal "Deploy a web service"

# If the qmcp shim cannot be installed (Windows)
uv run --no-sync python -m qmcp cookbook run simple-plan --goal "Deploy a web service"

# Run tests with auto setup/teardown
qmcp test [-v] [--coverage] [TEST_PATH]

Cookbook flows run in Docker and require Docker Desktop (Linux engine). Add --no-sync to skip syncing flow dependencies if the image is already built.

API Endpoints

Built-in Tools

• echo - Echo input back (for testing)

• planner - Create execution plans

• executor - Execute approved plans

• reviewer - Review and assess results

Development

# Install dev dependencies
uv sync --all-extras

# Run tests (with auto cleanup)
uv run qmcp test -v

# Run tests with coverage
uv run qmcp test --coverage

# Run linter
uv run ruff check .

Architecture

See docs/architecture.md for the full architectural overview.

The system follows a three-plane architecture:

1. Client/Orchestration - Metaflow workflows (MCP client)

2. MCP Server - FastAPI service (this project)

3. Execution/Storage - Tools and database

Documentation

• Quickstart - Copy-paste setup and validation

• Overview - What and why

• Architecture - How and constraints

• Tools - Tool capabilities

• Client Library - Python client API

• Human-in-the-Loop - HITL guide

• Agent Framework - Agent schemas and mixins

• PydanticAI Integration - Agent runtime integration

• Deployment - Production deployment guide

• Contributing - Development guidelines

• Roadmap - Development phases

Example Flows

See examples/flows/ for Metaflow integration examples:

• simple_plan.py - Basic tool invocation

• approved_deploy.py - HITL approval workflow

• local_agent_chain.py - Local LLM plan -> review -> refine with SQLModel artifacts

• local_qc_gauntlet.py - Local LLM QC checklist/task/gate builder

• local_release_notes.py - Local LLM release notes and doc update suggestions

For local LLM flows, install extras with uv sync --extra flows. Start uv run qmcp serve --host 0.0.0.0 when --use-mcp True to enable MCP calls from Docker-based flows. On Windows, prefer running flows in a Linux container to avoid platform-specific Metaflow dependencies.

Docker runner (recommended on Windows):

docker compose -f docker-compose.flows.yml build
docker compose -f docker-compose.flows.yml run --rm flow-runner \
  examples/flows/local_agent_chain.py run --use-mcp True --goal "..."

Set MCP_URL and LLM_BASE_URL (or pass --mcp-url / --llm-base-url) when running in Docker, e.g. http://host.docker.internal:3333.

License

MIT