Best Open Source Alternatives to LangSmith

3 open-source tools that can replace LangSmith. Compare tech stacks, licenses and stars below.

MCPNOASSERTION

Open-source LLM app development platform for building AI workflows, RAG pipelines, and agents.

153k·LLM Ops·Open source

Alternative to

NOASSERTION

Open-source observability and policy enforcement for AI agent harnesses, capturing runs and blocking risky tool calls.

3.2k·LLM Ops·Open source

Alternative to

MCPApache-2.0

Self-hosted control plane for OpenClaw and Hermes AI-agent fleets on Docker/Kubernetes with REST, CLI, and MCP.

50·LLM Ops·Open source

Alternative to