Contextator

Give your AI agent your documentation.

Contextator is a self-hosted documentation server that speaks the Model Context Protocol. You point it at the places your documentation actually lives — a folder on the server, a git repository, a zip someone sent you, an Obsidian vault, a Notion workspace — and each project becomes its own URL that Claude Code, Cursor, Claude Desktop and any other MCP client can search — meaning and exact wording at once:

http://localhost:3444/mcp/my-project

Ask your agent “how do we rotate the signing key?” and it searches your documentation, quotes the right paragraph and tells you which file it came from.

No repository clone needed — this pulls the published image, contextator/contextator:

mkdir contextator && cd contextator
curl -fsSLO https://raw.githubusercontent.com/Contextator/Contextator/main/docker-compose.yml
curl -fsSLO https://raw.githubusercontent.com/Contextator/Contextator/main/.env.example
cp .env.example .env
docker compose up -d

Then open http://localhost:3444/ and create your first project. The whole walkthrough is in Quick Start — about ten minutes from nothing to an agent answering questions.

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What makes it different

• One URL per project, fully isolated. A client connected to /mcp/billing can never see /mcp/mobile. Separate documents, separate embeddings, separate everything.
• Many sources per project. A local directory and two git repositories and an uploaded vault and a Notion workspace — merged into one searchable endpoint, each under its own name.
• Open or closed, per project. A new project is token required by default — creating it mints a first token, shown once — and can be opened or switched to account required from its own page. Open means anyone who can reach the endpoint reads everything indexed there; token required needs a bearer token, a credential for the endpoint rather than an account; account required checks the project’s own memberships through OAuth 2.1 on every request. See Security.
• Accounts, not a shared password. Everyone signs in as themselves; root and admin reach every project, and a member reaches only the ones you add it to, as a viewer or an editor. See Accounts and Permissions.
• 100 % local by default. Embeddings run on your CPU. No API key, no account with anyone else, nothing leaves the machine. Switch to OpenAI embeddings with two environment variables if you prefer.
• Multilingual. The default model covers 100 languages including Turkish. Ask in the language the answer is written in: matching across languages is a measured limit of the model, not a switch.
• One container. PostgreSQL and the application ship in a single image. There is no database to install and no migration to run.
• More than Markdown. Markdown, MDX and plain text are indexed as they are; HTML, Word, CSV and PDF are converted to Markdown at the edge, and an OpenAPI or Swagger specification becomes one document per operation. There is no OCR, so a scanned PDF is refused by name rather than half-indexed.
• Incremental. Files are hashed; a re-index only re-embeds what actually changed.
• Works with old and new clients. Both MCP transports are served on the same URL, so clients pick whichever they support without any configuration.

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Start here

Sources

Going deeper

Indexing · Embedding Models · Content Types · Push Webhooks · Admin API · Accounts and Permissions · Security · Backup and Data · FAQ

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Contextator is free software under the GNU AGPL v3 or later — run it, change it, share it; a modified version you let others reach over a network owes them its source. A commercial licence is available if those terms do not fit.