midas-memory-mcp (TypeScript) — experimental

A TypeScript port of Midas: local-first, source-traceable memory for AI agents over MCP — no LLM and no network at ingest or query.

Status: experimental. The Python server (pip install "midas-memory[mcp,local]") is the reference implementation with semantic ONNX embeddings, NLI-gated belief revision, and the full eval harness behind it. This port covers the core for Node-first setups.

Why it exists

Most MCP clients live in the Node ecosystem. This package gives them a zero-Python install:

npx midas-memory-mcp        # or: npm i -g midas-memory-mcp && midas-mcp

{
  "mcpServers": {
    "midas": {
      "command": "npx",
      "args": ["-y", "midas-memory-mcp"],
      "env": { "MIDAS_MCP_DB": "/home/you/.midas/memory.sqlite3" }
    }
  }
}

Parity with the Python server

• Same SQLite schema and float32 blob encoding — a TS server and a Python server can point at the same DB file and share one live memory (both probe SQLite's data_version and refresh on other connections' writes). Verified bidirectionally in tests.
• Bit-comparable hashing embedder (md5 token hashing, identical sign/index math) — vectors written by one runtime are recalled semantically by the other. Parity is pinned by a fixture generated from the Python implementation.
• Same tool surface — remember, capture (policy-gated, no LLM), recall (source-traceable), build_context (lean dated lines + "Today is" anchor), inspect_memory, check_memory_use (provenance guard), forget, forget_matching (dry-run + audit), forget_all, maintain, stats, memory_policy — plus the same env knobs (MIDAS_MCP_DB, MIDAS_MCP_MAX_RECORDS, MIDAS_MCP_MIN_IMPORTANCE, MIDAS_MCP_NAMESPACE, MIDAS_MCP_ACTOR, MIDAS_MCP_SUPERSEDE) and the same injected agent policy text.
• Same shipping behaviour — relevance × importance × recency ranking, the measured-safe scale-free parsimony floor (minRelevanceRatio 0.3), BM25+RRF hybrid (cached index), typed belief revision with supersession chains, no-LLM importance scoring, selective forgetting with durable-tier protection.

Not ported (yet)

• Semantic ONNX embeddings (bge / multilingual) — the default embedder here is the offline hashing one (lexical-ish). For real semantic recall today, run the Python server; both can share the same DB.
• Local NLI contradiction gating, the cross-encoder reranker, and the eval harness.

Requirements

Node >= 22.5 (uses the built-in node:sqlite; you may see its experimental warning on stderr).

npm test   # builds + runs the suite, including the Python-parity fixture

MIT — same license, same repo, same PRIVACY.md posture: everything stays on your machine.