Alternatives to LangSmith

Local, MIT-licensed token and cost observability for AI coding agents — reads the logs your agents already write.

Open-source LLM observability and agent evaluation you can trace, evaluate, and self-host for free.

Open-source LLM observability and agent evals: trace, evaluate, and improve production AI agents with MIT-licensed tooling.

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

Arize Phoenix is open-source LLM observability: trace agent steps, run evals, and self-host your traces.

Self-hosted layer that gives your AI coding agents shared memory, managed MCP tools, and cross-model audit.

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

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

Honeycomb Query Assistant turns plain-English questions into HQL against live production telemetry.

Galileo is an AI observability and eval engineering platform that turns offline evals into production guardrails for agents and RAG.

Developer observability platform that traces, replays, and debugs AI agent runs across OpenAI, CrewAI, Autogen and 400+ LLMs

Braintrust is an agent observability platform that traces AI runs, scores quality with evals, and surfaces production failure patterns.

Dash0 is OpenTelemetry-native observability where Agent0 investigates incidents, finds root cause, and opens fix PRs.

Galileo AI Evals turns offline evaluations into production guardrails that gate your AI agents in real time.

Arena AI ranks chat models, coding agents and fullstack builds on live head-to-head human votes.

Opik by Comet turns LLM traces into root-cause groupings, eval scores and code fixes so agent teams stop shipping the same bug twice

TruLens traces AI agent runs with OpenTelemetry-native evals, showing where an agent fails and where you can cut cost.

Athina AI is a collaborative AI development platform for managing prompts, running LLM evaluations, and monitoring production traces in one

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

Open-source AI coworker workspace that builds, schedules and ships agents to Slack or Telegram

Mastra is an open-source TypeScript agent framework for durable agents, typed workflows, and built-in evals.

PostHog is product analytics with session replay, feature flags, error tracking, and a context warehouse for you and your AI agents.

Open-source Python framework that replaces vibe checks with reproducible evaluation loops for RAG pipelines and AI agents.

Open-source AI observability for agent tracing, LLM-as-a-judge evals, and coding-agent cost tracking.

TruEra brings ML monitoring, LLM observability, and AI quality management into Snowflake for production model governance.

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

Raindrop traces, detects, and simulates fixes for silent AI agent failures in production before they reach your users.

AppWorld is a simulated-world benchmark for evaluating AI coding agents across 9 apps and 457 APIs.

Open-source agent observability that auto-captures every LLM and tool call and flags failures you never wrote a detector for.

Metoro is a Kubernetes observability and AI SRE agent that watches your cluster with eBPF and opens fix PRs for production issues.