minirag

A self-hostable RAG system with no signup and no cost by default. Drop in your notes, specs, and docs; they get chunked and embedded locally; retrieve them through an MCP server your AI tools can call. Ships with an evaluation harness so retrieval quality is measured, not guessed.

Quick start

cp .env.example .env
docker compose up
# api:  http://localhost:3000/health

No API key needed — embeddings run locally.

Related MCP server: RAG-MCP

Try it now (without Docker)

pnpm install
pnpm ingest ./sample-context   # dry-run: parse + chunk + report by doctype

Ingest your context

Point the CLI at any file or folder and pass --write:

pnpm ingest /path/to/your/notes --write

Subfolder names become doctypes automatically (spec/file.md → doctype spec), or pass --doctype <name> explicitly. Re-running on the same content is idempotent — it won't duplicate chunks.

How it works

files → chunk → embed → Postgres+pgvector → search → MCP tools → your AI client
                                    ↑
                             eval harness (measures retrieval quality)

Your context is organized by doctype (meeting-notes, spec, codebase, …) — folder names map to doctypes automatically, so retrieval can filter by type.

Stack

TypeScript end to end. Postgres + pgvector, local embeddings (Transformers.js, bge-small-en-v1.5), Fastify API, MCP server. All free, all self-hostable, one language.

Swapping the embedder

Local (default) is free and requires no signup. OpenAI/Voyage are opt-in behind the same Embedder interface, for higher quality at the cost of an API key:

1. Set EMBEDDER=openai (or voyage) and the matching API key in .env.

2. The vector dimension changes with the model, so old chunks won't match the new one — there's no automated migration, clear and re-ingest:

   docker compose exec db psql -U minirag -d minirag -c "TRUNCATE chunks, documents RESTART IDENTITY CASCADE;"
   pnpm ingest /path/to/your/notes --write

3. Re-run pnpm eval run to confirm quality didn't regress.

The embedder id is stored per chunk; retrieval checks it against the active embedder at query time and refuses to mix models rather than silently corrupting search.

Status

Core pipeline (ingest, retrieve, eval, MCP) is complete and verified — see the docs/ for the full picture.

Docs

Using with Claude Code

Procedural guides live as skills in .claude/skills/ (ingest, retrieve, eval) and are invoked on demand when a task matches. See docs/architecture.md for the architecture boundaries and working conventions.

MCP Server

Register the minirag MCP server with Claude Code:

claude mcp add-json minirag '{
  "command": "pnpm",
  "args": ["-C", "/path/to/minirag", "--filter", "@minirag/mcp", "start"],
  "env": {
    "DATABASE_URL": "postgresql://minirag:minirag@localhost:5432/minirag",
    "EMBEDDER": "local",
    "EMBEDDER_MODEL": "bge-small-en-v1.5",
    "EMBEDDER_DIM": "384"
  }
}' --scope project

This writes a project-scoped .mcp.json at the repo root. It bakes in your absolute repo path, so it's gitignored, not committed — each teammate runs the command above to generate their own. ~/.config/claude/mcp.json is not read by current Claude Code versions — there's no cwd field in the schema, so -C /path/to/minirag pins pnpm's working directory instead. After adding, run claude (or /mcp → reconnect) to approve and connect the server. See .mcp.example.json for the shape of the generated file.

See docs/mcp-client-setup.md for detailed setup instructions.

/minirag Command

Use the /minirag slash command to search the vector store and get grounded answers with citations:

/minirag how do I configure the embedder?
/minirag [spec] architecture decisions
/minirag [meeting-notes] who attended the sync?

The command calls the MCP search_context tool and returns answers grounded in retrieved chunks with source citations.

Contributing

• pnpm lint && pnpm typecheck and pnpm eval run (fixture corpus, metrics must not regress) before opening a PR.

• If you changed chunking/embedder/rerank, include the before/after eval delta in the PR.

• To add a doctype: add its chunking strategy in packages/core (see docs/architecture.md), then add golden cases in packages/eval/golden/<name>.yaml.

• See docs/architecture.md for module boundaries: core depends on nothing internal; ingest/retrieve never import each other; api and mcp are the only entry points and never reimplement retrieval logic; eval tests the real MCP tools.

License

MIT — see LICENSE.

minirag depends on third-party open-source packages — almost all permissively licensed (MIT, Apache-2.0, ISC, BSD), with one exception: a prebuilt libvips binary (LGPL-3.0-or-later, transitively pulled in via the embedding library's image-handling dependency, never invoked by minirag's own text-only pipeline) — and, at runtime, downloads pretrained embedding model weights from Hugging Face (bge-small-en-v1.5 by default, MIT-licensed; all-MiniLM-L6-v2 as an alternative, Apache-2.0-licensed). Neither model's weights are vendored in this repo. See NOTICE for the attribution list and THIRD_PARTY_LICENSES.md for full third-party license text, including why the LGPL dependency doesn't affect this project's own MIT license.