Local MCP memory server that gives AI agents editable Markdown memory
brain.md, by Mi4uu, is a local-first knowledge management system and MCP server that provides persistent project context for AI coding assistants. It stores notes as structured Markdown so agents can retrieve and update decisions across sessions, using semantic search and direct file edits to keep project state accessible. The app includes on-device indexing and permissions controls, targeting developers, researchers, and power users who need private, persistent agent memory during development workflows.
It exposes a programmatic toolkit so agents can act on your vault
The app implements an MCP server that provides 16 tools and two resources so external agents can inspect, query, and modify local files programmatically. Agents can run context-aware retrieval from a vector index and turn results into new or edited Markdown notes. That capability makes a personal vault actionable, letting agents perform targeted edits, create decision entries, and surface relevant timeline items as part of an automated workflow.
Embeddings and search run without cloud dependencies, preserving local control
The app ships a bundled WASM ONNX embedding model, bge-small-en-v1.5, and uses LanceDB as its vector store so vectorization and retrieval occur on-device rather than via external APIs. Per-folder permissions let users restrict which directories agents may access. These elements keep core processing local and remove cloud telemetry or external service dependence for primary search and retrieval.
Integrates with developer toolchains but assumes technical setup
The app is distributed as a single Bun binary for macOS, Linux, and Windows and supports Obsidian-style Markdown features such as Wikilinks, embeds, and frontmatter. It also records edits to a Git history so changes are versioned and reversible. Connecting an AI requires an MCP-compatible client, which places the tool squarely within developer workflows rather than casual note-taking environments.
A practical local-memory choice for technical users, with a setup trade-off
brain.md is a practical option for technically minded users who need an on-device, editable memory layer for MCP agents, because it separates current decisions from historical timelines and stores that material in standard Markdown. Expect a setup and configuration step: the app assumes familiarity with developer tooling and agent clients. This makes it well suited to integration-focused workflows rather than casual personal note use.
