Contraption Company MCP

An MCP (Model Context Protocol) server for Contraption Company essay, built on Chroma Cloud.

How to Install

Contraption Company MCP is available as a hosted MCP server with no authentication.

How to configure in common clients

{
  "mcpServers": {
    "contraption-company": {
      "url": "https://mcp.contraption.co"
    }
  }
}

{
  "servers": {
    "contraption-company": {
      "type": "http",
      "url": "https://mcp.contraption.co"
    }
  }
}

[mcp_servers.contraption-company]
command = "npx"
args = ["mcp-remote", "--transport", "http", "https://mcp.contraption.co"]

claude mcp add --transport http contraption-company https://mcp.contraption.co

from openai import OpenAI

client = OpenAI()

response = client.responses.create(
    model="gpt-5",
    input="List the newest Contraption Company blog posts.",
    tools=[
        {
            "type": "mcp",
            "server_label": "contraption-company",
            "server_url": "https://mcp.contraption.co",
            "require_approval": "never",
        }
    ],
)
print(response)

Features

• Semantic Search: Hybrid search with Voyage contextualized embeddings + sparse Splade vectors
• Automatic Indexing: Syncs with the blog API on startup and via scheduled polling
• Full Content Access: Uses Ghost Admin API to index all published posts and pages, including members-only posts
• Fast Performance: Powered by FastAPI and Chroma Cloud
• Background Updates: Polls Ghost every few minutes for new, updated, or deleted posts and pages
• Query Logging: Records searches in a dedicated Chroma collection for analysis
• Docker Ready: Includes Dockerfile for easy deployment
• Well Tested: Comprehensive test suite with pytest

Run Locally

1. Clone and install:

git clone <repository>
cd mcp
uv sync --all-extras

2. Configure environment:

cp .env.example .env
# Edit .env with your credentials

3. Run the server:

./run.sh
# Or: uv run python -m src.main

Docker

# Build
docker build -t contraption-mcp .

# Run
docker run -p 8000:8000 --env-file .env contraption-mcp

# Or use docker-compose
docker-compose up

Configuration

Running locally requires credentials for external services:

• Ghost Admin API Key: From your Ghost Admin panel (Settings > Integrations)
• Chroma Cloud Credentials: Tenant ID, Database, and API key from Chroma Cloud
• Chroma Query Collection (optional): Set CHROMA_QUERY_COLLECTION to override the default queries collection
• Voyage API Key: Required to generate contextualized embeddings
• Ghost Blog URL: Your Ghost blog's URL
• Polling Interval (optional): Set POLL_INTERVAL_SECONDS to override the default 5 minute sync cadence

MCP Tools

• fetch(id=None, url=None, method="GET", headers=None, body=None): Fetch a single post or page via the MCP fetch contract using the canonical URL as the identifier. Provide either the id returned by list_posts/search (which is the canonical URL) or a url; Ghost slugs and shorthand schemes are also accepted but responses always resolve to full URLs.
• list_posts(sort_by, page, limit): List posts with pagination, returning canonical URLs as identifiers
• search(query, limit): Semantic search across posts and pages that emits canonical URLs for result IDs

API Endpoints

• GET /: Server info (redirects to GitHub repo for non-MCP requests)
• GET /health: Health check
• GET /debug/search: Debug search endpoint (see /debug/docs for Swagger UI)
• /mcp/*: MCP protocol endpoints

Background Sync

The server polls the Ghost Admin API every 5 minutes to detect new, updated, or deleted posts and pages. Adjust the cadence by setting the POLL_INTERVAL_SECONDS environment variable.

Development

# Install dev dependencies
make dev

# Run tests
make test

# Lint and format
make format lint

# Run all checks
make check

License

MIT