memex: trusted engineering context for agentic software engineering

Open-source MCP server and hook service that keeps Claude Code and Codex engineering context current as the code changes, and holds edits whose evidence changed.

memex.stifler.in

A daemon, hook service and MCP server that turn commits and file changes into structured engineering knowledge and deliver it to agents with freshness and provenance preserved, without making memex a source of personal memory or raw session state.

memex builds a bitemporal knowledge graph of your repository (modules, symbols, decisions, problems, evidence, and code evolution). In v1 it also hooks into Claude Code and Codex: each session starts with the right context, each edit is checked against the current code, and the agent is told exactly what changed.

Where memex lives

Evaluation record in BENCHMARK.md, release history in CHANGELOG.md, reporting process in SECURITY.md, and how to work on it in CONTRIBUTING.md.

https://github.com/user-attachments/assets/b14e3185-ea36-4ae5-bd18-2d34e6bf7be4

memex v1 in 60 seconds. If the player does not load, download the video.

Live context (v1)

Coding agents work from a snapshot of the code. A teammate pushes, another agent edits a file, a branch moves, and the agent keeps acting on what it read earlier. v1 keeps that snapshot current, inside Claude Code and Codex:

uv tool install memex-mcp          # installs the `memex` command
cd your-repo
memex v1 doctor                    # what is set up, what is missing, what to do next
memex v1 install claude            # hooks in .claude/settings.json; global settings untouched
memex v1 install codex --neo4j-uri bolt://localhost:7687   # optional, for Codex

memex needs a Neo4j 5 server you already run (Docker is not required). Hooks go only into the checkout's own project configuration, and memex never asks for or stores your client credentials. Full guide, host recipes and rollback: docs/v1/25_ONBOARDING.md.

flowchart LR
    A[Your repository<br/>files + git] --> B[memex watcher<br/>tree-sitter + Gemini]
    B --> C[Neo4j graph<br/>bitemporal facts]
    C --> D[memex core<br/>ContextPacket selection]
    D --> H[Hook service<br/>session start · edit checks · resume notice]
    D --> E[Hermes MemoryProvider<br/>automatic read-only prefetch]
    D --> F[MCP tools<br/>explicit lookup]
    H --> G[Claude Code / Codex]
    E --> G
    F --> G

    style B fill:#cfe8ff,stroke:#0066cc,color:#000
    style C fill:#fff4cf,stroke:#cc9900,color:#000
    style H fill:#d4f5d4,stroke:#2d8f2d,color:#000

Install

Via Claude Code marketplace

/plugin marketplace add STiFLeR7/claude-plugins
/plugin install memex-mcp@stifler-marketplace

Restart your Claude Code session.

The first start after installing or upgrading downloads memex's Python dependencies (about 40 seconds), which can exceed Claude Code's MCP connect timeout once. Warm it up first, then restart:

npx -y stifler-memex-mcp --help     # one-time download; later starts take a few seconds

If Claude Code still shows a connection timeout, open /mcp and reconnect memex. If a tool says memex cannot reach Neo4j, start Neo4j (for example docker start memex-neo4j); the tools recover without a restart.

Manual

docker compose -f docker/docker-compose.yml up -d
cat > .env <<EOF
NEO4J_URI=bolt://localhost:7687
NEO4J_USER=neo4j
NEO4J_PASSWORD=memex-local
GEMINI_API_KEY=your-key-here
EOF
npx stifler-memex-mcp init --repo .
npx stifler-memex-mcp watch --repo .
npx stifler-memex-mcp serve --repo .

Hermes integration

The Hermes integration is read-only. Hermes retains personal memory, raw session state, and execution state. memex supplies repository engineering context through a bounded ContextPacket; it does not ingest Hermes state.db, transcripts, prompts, or tool results.

Add the memex provider to Hermes' profile configuration:

memory:
  provider: memex
plugins:
  memex:
    repo_path: /absolute/path/to/repository
    prefetch_timeout_seconds: 7
    max_items: 8
    max_chars: 12000

If Hermes is not installed, use the same context selector through the MCP get_engineering_context tool. Both paths share the protocol-neutral memex core and fail open when retrieval is unavailable.

Self-hosted team deployment

For a shared team setup (one Neo4j + one memex-server, auth on by default, Neo4j's ports never exposed to the host):

bash docker/bootstrap-team-env.sh
docker compose -f docker/docker-compose.team.yml up -d

See docker/TEAM-DEPLOY.md for the full flow, capturing the initial admin key, and the down -v footgun to avoid.

At a glance

The lifecycle

flowchart TD
    Init[memex init<br/>extract baseline] --> Watch[memex watch<br/>daemon + git hooks]
    Watch -->|commit| Extract[tree-sitter extract<br/>symbols, imports, lockfile]
    Extract --> Synth[Gemini Flash<br/>diff → Decision nodes]
    Synth --> Write[Graphiti add_episode<br/>+ post-hoc bitemporal SET]
    Write --> Decay[Scheduler<br/>nightly confidence decay]
    Decay -->|stale edges| Archive[expired_at = now]

    Serve[memex serve<br/>MCP stdio/HTTP] -.->|reads| Write
    Agent[AI agent] -->|14 MCP tools| Serve
    Serve -->|record_decision / record_problem| Write

    Cluster[memex cluster<br/>Leiden over hybrid edges] -.->|every N commits| Write

    style Init fill:#e8f4ff,color:#000
    style Watch fill:#fff4cf,color:#000
    style Synth fill:#ffe0cc,color:#000
    style Serve fill:#d4f5d4,color:#000

MCP tools

14 tools: eight read, four write, two analytic.

Read

Write

Bitemporal confidence

Confidence is not a stored number that mutates. It is computed at query time from base_confidence, validation status, time since last reinforcement, and access count.

flowchart LR
    Edge[Edge created<br/>base_confidence] --> Q{Validated by<br/>a human?}
    Q -->|yes| Slow[Slow regime<br/>half-life ~139d]
    Q -->|no| Fast[Fast regime<br/>stale at exactly 30d]
    Slow --> Score[Composite score<br/>conf × recency × rehearsal]
    Fast --> Score
    Score -->|below floor| Stale[get_stale_context surfaces it]
    Score -->|access| Bump[last_reinforced_at updated]
    Bump --> Score

    style Slow fill:#d4f5d4,color:#000
    style Fast fill:#ffd4d4,color:#000

Hierarchical clusters

memex cluster runs hierarchical Leiden over a hybrid edge graph:

Measure Your Savings

memex tracks token reduction metrics and human review actions locally in a SQLite database (~/.config/memex/telemetry.db).

You can query your savings at any time using the CLI:

memex stats

Or view the raw JSON payload:

memex stats --json

Or target a specific repository scope:

memex stats --repo /path/to/repo

This returns an aggregation of:

• Period Summaries: Calls, tokens returned, naive tokens (size of files requested), tokens saved, and token reduction percentage across today, last 7 days, last 30 days, and lifetime.
• Top Tools: The most valuable tools sorted by total tokens saved.
• Agent Clients: Active agents (Claude Code, Gemini CLI, Cursor, Codex) and their token saving distribution.
• Validation Health: Total validated, unvalidated, and corroborated nodes, along with the elapsed days since the last review.

The same statistics are exposed via the HTTP MCP transport:

GET /stats?repo=/path/to/repo
Authorization: Bearer <your-key>

Connect your agent

{
  "mcpServers": {
    "memex": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "stifler-memex-mcp", "serve", "--repo", "."]
    }
  }
}

{
  "mcpServers": {
    "memex": {
      "command": "npx",
      "args": ["-y", "stifler-memex-mcp", "serve", "--repo", "."]
    }
  }
}

{
  "mcpServers": {
    "memex": {
      "command": "npx",
      "args": ["-y", "stifler-memex-mcp", "serve", "--repo", "."]
    }
  }
}

[mcp_servers.memex]
command = "npx"
args = ["-y", "stifler-memex-mcp", "serve", "--repo", "."]

memex memory-tool serve --repo .                     # in-process
memex memory-tool serve --repo . --transport http    # FastAPI on :7464

from memex.memory_tool import MemexAsyncMemoryTool
memory_tool = MemexAsyncMemoryTool(repo_root=".")
client.beta.messages.run_tools(..., tools=[memory_tool])

Operating principles

When to use memex

Project structure

memex/
├── memex/
│   ├── extractor/        tree-sitter + lockfile parsers
│   ├── graph/            Neo4j writes, confidence, archive, cluster engine
│   ├── synthesizer/      Gemini Flash → Decision nodes
│   ├── mcp_server/       14 MCP tools (read + write + analytic)
│   ├── memory_tool/      Anthropic memory_20250818 adapter
│   ├── watcher/          daemon + git hooks
│   └── cli.py            init / watch / serve / review / graph / cluster
├── tests/                unit, integration, and objective evaluation suites
├── docker/               Neo4j compose
├── npm/                  npx wrapper (publishes as stifler-memex-mcp)
└── Dockerfile            introspection-only image for MCP directory sandboxes

Commands

License

MIT. See LICENSE.

Author

Hill Patel (@STiFLeR7)

Core Contributors & Maintainers

• Hill Patel (@STiFLeR7), architect and maintainer
• Nirvaan Lagishetty (@Nirvaan05), lead contributor and maintainer

Contributing

Open an issue or PR. uv sync --all-extras installs the development toolchain. Run uv run pytest -m "not integration" for the offline suite and uv run ruff check . before opening a PR. Version bumps must update pyproject.toml, npm/package.json, server.json, and the team Docker image tag together.

Release history is in CHANGELOG.md. The v1 design and evaluation records are under docs/v1/, and the v0.9 architecture under docs/architecture/v0.9/.

Vannevar Bush, 1945: "Consider a future device for individual use, which is a sort of mechanized private file and library. It needs a name, and to coin one at random, memex will do."