Langfuse
93 · HealthyTracing, evaluation and prompt management for LLM applications and agents.
Tracing, evaluation and prompt management for LLM applications and agents.
Terminal coding agent that works with many model providers and can edit, run and test code in your repository.
Observability, evaluations and agent simulations for teams running LLM agents in production.
AI search and chat over your company's documents, with connectors for Slack, Google Drive, Confluence and more.
Studio for building LLM chatbots and agents, with knowledge bases and connectors for web chat, WhatsApp and other channels.
AI coding agent you can run yourself. Give it an issue and it edits code, runs commands and tests in a sandbox, then opens a pull request, with whichever LLM you choose.
Autonomous coding agent for VS Code and the command line that plans changes, edits files and runs commands with your approval.
Framework for customer-facing AI agents that follow explicit guidelines, so their answers stay consistent and on policy.
Visual builder for AI agents and RAG workflows, with a Python API.
Research agent that takes a GitHub issue and tries to fix it automatically with the language model of your choice.
Voice AI platform for building phone agents, with a visual workflow editor, telephony support and your choice of speech and LLM providers.
Proxy-based LLM observability that logs requests, costs and latency with one line of setup.
AI pair programmer in the terminal that edits code in your git repository and commits each change.
Drag-and-drop builder for LLM agents and chatflows.
The code for these is public, but the license is not an OSI open source license, or we have not verified it yet. Check the license notes on each project before relying on it.
Tracing and evaluation for LLM apps built on OpenTelemetry, with datasets and experiments.
Alternative to
Will it still be around?
Stable
Score 77/100
Can a business use it freely?
Free, no reselling
Elastic License 2.0 · source-available, not open source

A 25-seat team on LangSmith Plus pays about $975 a month. Phoenix on OpenTools costs $39 a month, setup included, so you save $936 a month, about $33,696 over three years.
Monthly cost
You save each month
$936/mo
96% less than today
Saving from month one
You save
List price checked 9 Oct 2026 · Source · Disclaimer
Stable · activity, bus factor and issue responsiveness, from GitHub
Score v2 · How it works
100/100
68/100
45/100
Free, no reselling
Elastic License 2.0 · Source-available, not open source
What you need to do
Free to self-host and use in your business, changes included. You may not sell it or offer it to others as a hosted service that competes with the vendor.
For Phoenix
Free to use and self-host, but you may not offer it to others as a hosted or managed service.
Elastic License 2.0 · Source-available, not open source. The code is public, but the license restricts how you can use it, usually by banning competing hosted services or capping production use. Not open source.
License text checked 2026-10-09 · Read it
Snapshot from 2026-10-09
Points for pull requests merged into Phoenix and reviews of them since 17 September 2026 (older history is still loading). Building something another user asked for earns more. 25 people have points on Phoenix in all.