Alternatives. What could replace LangSmith?
Direct substitutes
HeliconeLLM observability platform: logging, costs, latency, prompt/completion analysis, evaluations, caching. Proxy gateway or native integration. Open-source and managed cloud. Since March 2026: maintenance mode (acquired by Mintlify).
LangChainMIT open-source framework for building LLM apps: Python/JavaScript abstractions, 100+ LLM/tool integrations, RAG, autonomous agents, and LangGraph for agent orchestration.
LlamaIndexData-oriented framework for RAG, indexing, and LLM apps.
OpenAI APIAI model API for chat, generation, agents, embeddings, and tools.
pgvectorPostgreSQL extension for storing and searching embeddings.
PineconeManaged vector database for semantic search and RAG.