SELECTOOLS: Multi-agent graphs, tool calling, RAG, 50 evaluators, PII redaction. All in one pip install.

Releasing v0.20.1 of selectools, an open-source (Apache-2.0) Python framework for AI agent systems. Supports OpenAI, Anthropic, Gemini, and Ollama. pip install selectools The technical hook: how interrupts work after a human pause LangGraph's interrupt() mechanism re-executes the entire node body on resume. This is by-design and falls out of LangGraph's checkpoint-replay model. The official guidance is to make pre-interrupt side effects idempotent, place expensive work after the interrupt() call, or split side effects into a separate downstream node. It works, but every node that needs human input has to be structured around the resume semantics. It's a leaky abstraction. Selectools uses Python generators instead. The node yields an InterruptRequest. The graph resumes at the exact yield point via generator.send(). Expensive work runs exactly once, with no idempotency contortions required. async def review_node(state): analysis = await expensive_llm_analysis(state.data["draft"]) # runs