A library for building stateful, multi-agent applications with LLMs, built on top of LangChain. Provides fine-grained control over agent loops.

An AI gateway and observability platform that tracks every LLM request. It provides the monitoring, caching, and debugging tools needed to manage production AI agents.

An AI development platform for building, testing, and managing LLM-powered applications. It provides tools for prompt engineering, semantic search, and model evaluation.

The enterprise-grade stack for evaluating and testing AI applications. It provides the tools needed to track performance, run automated evals, and manage datasets for production-ready AI.

A professional prompt engineering IDE that provides tools for managing, testing, and optimizing LLM prompts. It features version control, dataset management, and automated evaluation for production AI engineering.

A comprehensive platform for monitoring, testing, and debugging AI agents in production. It provides deep observability into agent behavior, tool usage, and cost, ensuring reliable autonomous workflows.

A CLI tool and library for testing and evaluating LLM outputs. It allows developers to run systematic benchmarks across different prompts and models to ensure quality and prevent regressions.

An open-source observability and analytics platform for LLM applications. It provides detailed tracing, evaluation, and cost tracking to help teams improve their AI features and agentic workflows.

A platform for managing and tracking LLM requests. It acts as a middleware between your code and the LLM API, providing a dashboard for prompt versioning, logging, and evaluation.

An open-source AI observability platform specifically designed for LLMs and RAG. It provides tools for tracing, evaluation, and troubleshooting to ensure that AI applications are performing as expected in production.

A collaborative platform for building, monitoring, and evaluating AI agents. Literal AI provides a unified workspace for teams to track agent performance, manage prompts, and iterate on agentic workflows together.

A comprehensive open-source LLMOps platform for monitoring, evaluating, and optimizing AI agents. LangWatch provides detailed tracing, automated evaluations, and agent simulation testing to ensure production reliability.

An open-source collaboration platform for AI engineers and domain experts to build high-quality datasets for LLM fine-tuning and evaluation. Argilla focuses on human-in-the-loop workflows to ensure data excellence.

A comprehensive platform for LLM evaluation, observability, and guardrailing. Galileo provides tools for systematic testing of LLM applications across the entire development lifecycle, from prompt engineering to production monitoring.

A specialized framework for evaluating Retrieval Augmented Generation (RAG) pipelines. It offers automated metrics for measuring faithfulness, answer relevance, and context precision without requiring ground-truth labels.

A lightweight prompt engineering library that treats prompts as functions. It provides automated versioning, monitoring, and visualization tools, including 'Ell Studio' for local prompt version control and performance tracking.

An innovative AI toolkit designed to help teams build, iterate, and deploy reliable AI agents. It features a web-hosted IDE for natural language programming and one-click API deployment for high-quality language model applications.

A dev-first open-source infrastructure designed to build, manage, and run autonomous AI agents at scale. It features a robust tool-belt, concurrent agent execution, and enterprise-grade observability for agentic operations.

An end-to-end prompt engineering and AI quality platform. Maxim AI provides professional-grade infrastructure for experimentation, evaluation, simulation, and production monitoring of LLM applications.

An open-source platform for orchestrating and managing multi-agent workforces. It provides a unified workspace for defining agent roles, connecting data sources via RAG, and monitoring autonomous execution at scale.

An AI observability and governance platform designed for the entire model lifecycle. It features 'LangKit' for real-time monitoring of LLM quality, security, and performance, providing automated guardrails for production agents.

Best AI LLM Observability Tools 2026: LangSmith vs Langfuse vs Arize Phoenix

Master AI Automation 2026 and Generative Engine Optimization. Comparing LangSmith, Langfuse, and Arize Phoenix for LLM monitoring, evaluation, and tracing.