mcp-memory-rs MCP server

mcp-memory-rs

Local-first MCP memory server in pure Rust. Persistent, versioned, queryable memory for AI agents — owned by the user, not by a platform.

State lives on your disk as plain JSON categories backed by SQLite (FTS5). Every write is versioned and backed up. A fleet of devices syncs through an optional HTTP endpoint with merkle manifests and optimistic concurrency. No cloud account, no embedding service, no network dependency in the default mode.

Why

Agent memory tied to a vendor dies with the vendor session. This server keeps the agent's long-lived state — identity, projects, infrastructure notes, per-device workflows — in files you can read, grep, diff, and back up yourself. Any MCP client (Claude Code, Codex, or anything speaking MCP stdio) gets the same memory; swapping the model does not lose the state.

Design choices that follow from that:

Sync is a separate, explicit step — never a hidden dependency.

• Local-first: the stdio server works fully offline against local storage.

database can be rebuilt from the files; the files are the truth.

• Plain storage: one JSON file per category plus a SQLite index. The

backup first. memoryhistory and memorycompact manage the tail.

• Versioning by default: every write keeps history; deletes create a

concurrent agents into explicit conflicts.

• Concurrency-safe writes: expected_hash turns clobbering races between

memorysearchsemantic adds an optional TF-IDF hybrid. No model downloads.

• Zero ML in the core: full-text search is SQLite FTS5 with BM25;

The pair: for corpus recall (chunked documents, BM25 retrieval,

original-text injection) see the companion server

mcp-vl-msa-rs. This server holds

the curated agent state; that one holds the queryable corpus.

flowchart LR
    A["AI agent<br/>(any MCP client)"]
    A -->|"curated state<br/>read / write / sync"| M["mcp-memory-rs<br/><i>the notebook</i>"]
    A -->|"corpus recall<br/>index / search / fetch"| V["mcp-vl-msa-rs<br/><i>the library</i>"]
    M --- D1[("JSON categories<br/>SQLite FTS5")]
    V --- D2[("tantivy BM25<br/>collections")]

Install

Prebuilt binary (recommended) — download the archive for your platform from the latest release, extract, and point your MCP client at the binary:

tar xzf mcp-memory-rs-x86_64-unknown-linux-gnu.tar.gz
install -m755 mcp-memory-rs-*/mcp-memory-rs ~/.local/bin/

Prebuilt targets (Linux + Android): x8664-unknown-linux-gnu, x8664-unknown-linux-musl, aarch64-unknown-linux-gnu, aarch64-unknown-linux-musl (edge / ARM / Termux), aarch64-linux-android.

macOS: no prebuilt binary is shipped (it would need Apple code-signing). Install from source instead — cargo install compiles it on your Mac in one command, no signing needed:

cargo install --git https://github.com/DioNanos/mcp-memory-rs --locked

--locked uses the committed Cargo.lock (reproducible build).

Quick start

cargo build --release

# stdio MCP server, offline mode (default)
./target/release/mcp-memory-rs

Claude Code (~/.claude.json) or any MCP client:

Shortened. The full README is on GitHub.