OpenMemBrain

OpenMembrane

OpenMembrane is the intelligent membrane for AI coding memory. It autonomously reads and learns from your coding sessions — you never have to tell it what to save. It selectively absorbs project knowledge, blocks secrets, filters noise, resolves conflicts, and persists only what matters.

No manual effort. No data leaves your machine unless you choose it. Safe, private, and trustworthy by design.

Table of Contents

• Installation

• Configuring Your AI Tool

  • Claude Desktop
  • Claude Code
  • VS Code / GitHub Copilot
  • Cursor
  • OpenCode

• Automatic Memory Capture

• Environment Variables

• MCP Tools

• Architecture

• Diagnostics And Errors

• Static Fallback Files

• Development

• Documentation

• Zero-effort — learns from sessions automatically, no commands or prompts needed

• Secure by default — secrets are detected and rejected before they ever reach storage

• Self-managing — deduplicates, resolves conflicts, and filters noise on its own

• Local-first — all memory stays on your machine; optional EU/CH-hosted cloud sync

• Tool-agnostic — works with any AI coding tool via MCP (Claude, Copilot, Cursor, OpenCode, and more)

Installation

Install and run the MCP server with npx (requires Node.js >= 18):

npx openmembrane

Or install globally:

npm install -g openmembrane
openmembrane

No cloud accounts required. All memory is stored locally.

Configuring Your AI Tool

OpenMembrane runs as an MCP server over stdio. Add it to your AI tool's MCP configuration:

Claude Desktop

Edit claude_desktop_config.json:

{
  "mcpServers": {
    "openmembrane": {
      "command": "npx",
      "args": ["openmembrane"]
    }
  }
}

Claude Code

claude mcp add openmembrane -- npx openmembrane

VS Code / GitHub Copilot

Add to .vscode/mcp.json in your project:

{
  "servers": {
    "openmembrane": {
      "command": "npx",
      "args": ["openmembrane"]
    }
  }
}

Cursor

Add to .cursor/mcp.json in your project:

{
  "mcpServers": {
    "openmembrane": {
      "command": "npx",
      "args": ["openmembrane"]
    }
  }
}

OpenCode

Add to ~/.config/opencode/opencode.json:

{
  "mcp": {
    "openmembrane": {
      "type": "local",
      "command": ["npx", "-y", "openmembrane"]
    }
  }
}

See .opencode/INSTALL.md for detailed setup including global instructions and development-from-source configuration.

Automatic Memory Capture

Adding the MCP server gives your AI tool access to OpenMembrane's tools. To ensure the AI uses them automatically — loading project memory at session start and saving durable knowledge as it's discovered — add a global instruction file.

Create ~/.config/openmembrane/instructions.md with instructions for the AI to:

• Call get_project_rules, get_relevant_context, and list_memory_candidates at the start of each session.
• Call remember proactively when durable knowledge is discovered, providing structured content and a type (e.g., coding_rule, known_gotcha, architecture_decision). No API key needed.

Then wire the file into your tool's global configuration:

Platform	Global instruction mechanism
OpenCode	"instructions": ["~/.config/openmembrane/instructions.md"] in ~/.config/opencode/opencode.json
Claude Code	Append to ~/.claude/CLAUDE.md
Cursor	Add to Rules for AI in Cursor Settings
VS Code / Copilot	Create ~/.copilot/instructions/openmembrane.instructions.md with applyTo: "**"

See the platform-specific setup guides in docs/setup/ for detailed instructions.

Alternatively, run export_static_memory_files in any project to generate per-project instruction files (AGENTS.md, CLAUDE.md, etc.) that include both usage instructions and stored memories.

Environment Variables

By default, local memory is stored in .openmembrane under the current working directory. Override this with:

• OPENMEMBRANE_HOME: directory for local JSON memory stores.
• OPENMEMBRANE_PROJECT_ID: default project id when a tool call does not pass projectId.

MCP Tools

• remember — save structured memory directly. Provide content, type, and optional scope/tags. No API key needed. Supports single and batch mode.
• propose_memory_from_session — submit a session transcript or summary for server-side LLM extraction. Requires a configured extractor. Useful for automation adapters.
• get_project_rules — retrieve project rules and conventions for the current scope.
• get_relevant_context — find memories relevant to a natural language query.
• search_memory — search saved memories by query, scope, type, or tags.
• list_memory_candidates — list pending memory candidates awaiting approval.
• approve_memory_candidate — approve a pending candidate to save it as memory.
• approve_all_candidates — approve all pending candidates at once.
• reject_memory_candidate — reject a pending candidate with an optional reason.
• reject_all_candidates — reject all pending candidates at once.
• update_memory — update the content, type, scope, or tags of a saved memory.
• supersede_memory — mark a memory as superseded, optionally linking a replacement.
• review_stale_memories — list memories older than a threshold (default: 6 months).
• export_static_memory_files — generate static instruction files (AGENTS.md, CLAUDE.md, etc.).
• get_diagnostics — retrieve diagnostic events filtered by severity or code.
• list_audit_log — retrieve recent audit events.

Architecture

OpenMembrane supports two paths for saving memory:

1. remember (primary): The AI tool calls remember directly with structured content and type. No server-side LLM needed. Memories go through the full pipeline (secret detection, policy filtering, deduplication) and are auto-saved.

2. propose_memory_from_session (secondary): An adapter or AI tool submits a full session transcript for server-side LLM extraction. Requires a configured extractor (OpenAI or compatible provider).

remember tool                          propose_memory_from_session
  |                                      |
  v                                      v
processStructured()                    SessionIngestor
  |                                      -> SecretDetector redaction
  v                                      -> MemoryExtractor interface
MemoryClassifier                         -> MemoryClassifier
  -> PolicyEngine                        -> PolicyEngine
  -> Deduplicator                        -> Deduplicator
  -> ConflictDetector                    -> ConflictDetector
  -> ActionRecommender                   -> ActionRecommender
  -> MemoryStore or PendingCandidateStore

Package responsibilities:

• packages/core: domain types, extraction interface, policy checks, classification, deduplication, conflict detection, and pipeline orchestration.
• packages/storage: local JSON persistence for saved memory, pending approvals, and audit events.
• packages/exporters: static fallback file generation for AI tools that read project instruction files.
• packages/shared: small runtime helpers for IDs, time, and result types.
• apps/mcp-server: local MCP server exposing saved memory and approval workflows to AI tools.

Provider-specific LLM calls are intentionally kept out of the core. The boundary is:

interface MemoryExtractor {
  extract(input: SessionInput): Promise<MemoryCandidate[]>;
}

The MockMemoryExtractor is used for deterministic testing. The LlmMemoryExtractor supports OpenAI and any compatible API endpoint (via baseUrl).

Diagnostics And Errors

OpenMembrane distinguishes audit history from diagnostics:

• Audit events describe normal memory activity, such as session ingestion, candidate extraction, saved memory, queued candidates, and rejected candidates.
• Diagnostics describe operational problems, such as validation errors, missing candidates, invalid local JSON stores, unsafe approval attempts, and export failures.

MCP tools return safe user-facing error payloads with a diagnosticId. The detailed diagnostic can be inspected through get_diagnostics without exposing raw transcripts or secrets.

Static Fallback Files

Static exporters can generate:

• AGENTS.md
• CLAUDE.md
• .github/copilot-instructions.md
• .cursor/rules/openmembrane.mdc
• docs/ai/project-memory.md

These files are compatibility fallbacks for tools that cannot retrieve memory through MCP. By default, exporters omit confidential memories because these files may be committed to source control. Callers must explicitly opt in to include confidential memory.

Development

git clone https://github.com/mohamadalhusseinie/openmembrane.git
cd openmembrane
npm install

Run the MCP server locally (from source via tsx):

npm run mcp:stdio

Run tests and type checking:

npm test          # vitest
npm run typecheck # tsc --noEmit
npm run check     # both

Build the publishable bundle:

npm run build

Documentation

• Architecture — pipeline design, type schemas, MCP tool surface, package dependencies
• Security and Privacy — secret handling, data storage rules, LLM usage policy
• Product Vision — product thesis, UX workflow, memory quality criteria
• Roadmap — phased delivery plan from local MVP to hosted mode
• Contributing — setup, development workflow, PR guidelines