Comet
Open-source platform for tracing LLM apps and agents, running evaluations, managing prompts and monitoring production use.
How the 8.0 was reached
- Quality of output8/10
Opik has 22,289 GitHub stars, active pushes and Apache-2.0 licence; 40+ evaluation metrics are vendor-stated only. github.com
- Ease of use7/10
60+ tracing integrations and an MCP server, with a free cloud plan needing no card; little independent usability evidence. comet.com
- Pricing value9/10
Free cloud plan with 25k spans/month, Pro at $19/month, and Apache-2.0 open source code free to self-host. comet.com
- API and integration quality8/10
SDK plus 60+ integrations and MCP server for Claude Code, Cursor, VS Code Copilot and Codex. comet.com
- Solves the problem it claims to solve8/10
Tracing, evaluation and optimizer features documented; strong GitHub adoption (22k stars) supports delivery of the observability claim. github.com
8.0/10 is the mean of the 5 criteria that apply. Scored on the five-criteria rubric v1, 29 September 2026. How scoring works
Pricing
- Self-host the same codebase as the hosted versions
- Agent tracing and analysis
- Test Suites and assertions
- Agent Playground
- Up to 10 team members
- 25k spans per month
- 60-day data retention
- Ollie coding harness trial
- Up to 50 team members
- 100k spans per month
- Customizable monthly span limits
- Customizable data retention periods
Key Features
- Agent tracing with 60+ integrations
- 40+ LLM-as-a-judge metrics for evaluation and hallucination detection, per the vendor
- Diagnostics that group recurring issues, find root causes and suggest fixes
- Agent Optimizer SDK for improving prompts and agents
- MCP server for Claude Code, Cursor, VS Code Copilot, Codex and opencode
Pros & Cons
Pros
- Apache-2.0 code can be self-hosted at no cost, with the same codebase as the hosted product
- Free cloud plan needs no credit card and allows 25k spans a month
- Pro tier at $19 a month is low for a team plan
- About 22k GitHub stars point to wide adoption
Cons
- The 40+ evaluation metrics are vendor-stated with no independent check
- Little independent evidence on how easy it is to use
- Free cloud retention is capped at 60 days
- Enterprise pricing is not published
A strong pick for developers who want LLM tracing and evals with a free, self-hostable option and cheap paid tiers. Teams that need independent proof of evaluation quality should test it against their own workloads first.
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