repo-mem: Open-Source MCP Server Adds Persistent Team Memory to Claude Code

What repo-mem does

repo-mem is an MCP server that adds persistent, shared memory to Claude Code sessions. It addresses the problem of session isolation in team environments where one developer's debugging insights disappear after their session ends, leaving other team members starting blind when working on related code.

Technical implementation

The solution stores observations in per-user SQLite databases inside the Git repository itself. It uses FTS5 for full-text search across all team members' databases. Claude Code hooks automatically capture commits, deploys, and test runs. A session start hook injects recent team activity (approximately 200 tokens).

Architecture details

• MCP server with 8 tools (search, save, get, timeline, etc.)
• 3 Claude Code hooks (PostToolUse, Stop, SessionStart)
• SQLite + FTS5 for search (no vector database, no external services)
• Per-user database files committed to Git (typically < 1MB each)
• Token-efficient design: index returns ~50 tokens per result, with full details loaded on demand

Setup and scale

Setup is done with npx repo-mem init. The creators report running it with 4,000+ observations on a monorepo. The MCP server is approximately 900 lines of JavaScript, and the hooks are about 170 lines each. The hooks contain no AI calls—they use purely rule-based extraction.

The project is MIT licensed and available on GitHub at https://github.com/timosieber/repo-mem. The Reddit discussion explores how this approach compares to vector-based memory systems.