Alternatives to LangWatch

Open-source LLM observability: trace agents, manage prompts, and run evals on one MIT-licensed platform.

LangSmith is agent and LLM observability from the LangChain team: trace, monitor, evaluate, and deploy AI agents.

Open-source LLM observability and agent evaluation you can trace, self-host, and eval end to end.

Open-source AI evaluation and observability for LLMs, RAG apps, AI agents, and ML models.

Open-source LLM observability, evaluation, and cost tracking for teams shipping agentic AI

Open source AI engineering platform for agent and LLM tracing, evaluation, prompt management, and ML lifecycle work.

Laminar delivers open-source AI agent observability that auto-captures every LLM and tool call and surfaces failures with Signals.

Open-source Python library that turns vibe checks into reproducible evaluation loops for RAG pipelines and AI agents.

PandaProbe is open-source agent observability that traces runs, evaluates outcomes, and turns failures into validated fixes via its Repair

OpenJudge is an Apache 2.0 open-source AI evaluation framework shipping 50+ benchmark-validated graders for agents, LLMs, code, math, and multimodal models.

Maxim AI simulates, evaluates and observes AI agents — with Bifrost, its open-source LLM gateway, for routing and guardrails.

Open-source AI agent improvement: trace production runs, detect failures, investigate signals, verify fixes with evals.

Open-source Python framework that traces every AI agent span and scores runs with benchmarked, explainable LLM judges.

OpenLIT delivers OpenTelemetry-native LLM tracing, evals, guardrails, and prompt management you self-host free under Apache 2.0.

Open-source OpenTelemetry tracing, versioning, and sessions for Python LLM apps—bring your own backend.

Open-source benchmark that scores AI agents on real, multi-step software-company work tasks.

Open-source React components for rendering AI agent traces, tool calls and reasoning inside your own app.

Open-source collaboration layer that turns domain expertise into AI agent test suites

Agent evaluation platform that simulates voice and chat agents, traces production, and scores hallucinations before your customers hit them

AI quality workspace for LLM evaluation, production observability, red teaming, and governance

Fiddler AI is an enterprise control plane for agent observability, inline guardrails, and auditable AI governance.

Open-source prompt management with built-in LLM observability for cost, latency, and token usage

PromptLayer is the collaboration layer for AI engineering teams — a prompt CMS, eval harness, and agent observability stack in one dashboard.

ViDoRe Benchmark: an open visual document retrieval benchmark and ColPali model suite for enterprise RAG evaluation.

Edgee Team token observability puts every coding agent on a budget you set, with per-repo and per-PR attribution.

Agnost AI monitors production AI agents, clusters silent failures, and opens a fix for review.

Open-source toolkit for benchmarking vision-language models across 80+ multimodal tasks, with rankings published on the Open VLM Leaderboard.

Build custom RL environments in code and run agent evaluations with trace QA on every run

Slack-native continuous improvement for production AI agents: triage failures, isolate root causes, validate fixes before you ship.

OpenAI's December 2025 wet-lab evaluation where GPT-5 improved a real molecular cloning protocol 79-fold