Langfuse
Langfuse is a strong default for teams that want tracing, prompt versioning and evaluations in one open-source tool, with the option to keep data on their own infrastructure. Teams that only want a hosted logging proxy with no SDK work, or that need guaranteed enterprise SSO without paying for add-ons, may find simpler or more bundled options.
Pros
- MIT-licensed core that can be self-hosted without usage limits
- Covers tracing, prompt management, evaluation and dashboards in one product
- Generous free cloud tier and unlimited users from the $29 Core plan
- OpenTelemetry support and SDKs for Python and JavaScript
Cons
- Usage above the included 100k units is billed extra, so busy apps pay more than the headline price
- Free tier keeps only 30 days of data and two users
- Enterprise SSO and RBAC require the $300 Teams add-on on Pro or the Enterprise plan