ContextOS is an MCP server that gives AI coding agents persistent memory across sessions. Stop re-explaining your codebase every morning.
ContextOS injects your workspace context into every Claude Code session automatically. The agent knows the state of your project before you type a word.
Tell ContextOS about decisions, gotchas, todos, and notes during your session. It stores them with tags, importance scores, and timestamps.
When Claude Code connects, ContextOS assembles the current workspace context and injects it via the MCP initialize handshake. No tool call needed.
Use the recall tool for deeper digs. Vector search plus BM25, merged with Reciprocal Rank Fusion and reranked by recency and importance.
No cloud, no API keys, no telemetry. One binary.
all-MiniLM-L6-v2 ships inside the binary. No API key required. Also supports Ollama and OpenAI if you prefer.
Vector search + BM25 keyword search, merged via Reciprocal Rank Fusion, reranked by recency and importance.
Context injected on every MCP initialize. The agent knows your workspace before the first message.
One database per repo root, stored at ~/.contextos/. Nothing leaves your machine.
Current branch, recent commits, and uncommitted file count are included in the injected context automatically.
Windows, Linux, macOS Intel and Apple Silicon. No .NET install required. 118 MB, one file.
The installer downloads the right binary, registers it with Claude Code, and runs a selftest to confirm everything works.
curl -fsSL https://raw.githubusercontent.com/
aftabkh4n/contextos/main/install.sh | bash
Then open Claude Code in any git repo and ask: "What was I working on?"
Apache 2.0 · Built by Aftab Bashir