Langfuse

This release removes the unstable evaluation API endpoints, backfills saved evaluators, adds cost source visibility in trace cost breakdown tooltips, and introduces a preview 'Improved Message Rendering' feature with a normalized I/O parser; it also raises the playground output token limit ceiling to 65535 and fixes several evaluator, auth, and worker bugs. Because the unstable evaluation endpoints are removed, any integrations or scripts calling those API endpoints must be updated to use the current evaluation API.

Matters for: Teams that built automation or CI pipelines against Langfuse's evaluation API endpoints and teams running self-hosted Langfuse with ClickHouse-backed tracing.

Langfuse now lets you manage alerts for evaluators, filter observations with a dedicated filter builder, search the experiments table, and filter datasets by name instead of id; evaluator names are also disambiguated in filters and observation APIs now use a unified 'model' field instead of 'providedModelName'. Score filters for experiments and items are unified across levels, and dashboard widgets default to the measure's natural aggregation with a more reliable v4 read-path toggle.

Matters for: Teams running multiple evaluators and evaluation pipelines across many Langfuse projects who need alerting and filtering to manage evaluator output at scale.