Best alternatives to OpenSmith in 2026

When you're building an app powered by an LLM, something eventually goes wrong in a way that's hard to debug — a bad response, an unexpected cost spike, a chain of tool calls that went sideways. Tracing tools let you replay exactly what happened, but most of them are cloud services that require sending your application's data to someone else's servers. OpenSmith does the same job entirely on your own machine. It's a free, open-source (MIT) Python tracing and observability tool for LLM pipelines, storing traces in a local SQLite database by default (with optional PostgreSQL). It offers decorators and context managers plus automatic patching for OpenAI, Anthropic, and LiteLLM calls, integrates with vector databases like Qdrant, ChromaDB, and Pinecone, and provides both a local web interface (port 7823) and a CLI for inspection, filtering, and export.