Pensieve author Ted Haley describes building a local index of code, documents, and agent sessions so coding agents query via MCP instead of iterative grep/read loops. Product page benchmarks (author-run) cite ~43% fewer tool calls and ~18% lower lookup cost versus grep-heavy workflows; independent reproduction not cited on the thread.
Pensieve targets Apple Silicon Macs, uses local embeddings (Qwen3-Embedding-0.6B per third-party coverage), SQLite storage, and integrates with Claude Code, Cursor, Codex, and other MCP clients via pensieve mcp or HTTP.