Inngest vs Langfuse

Inngest

Langfuse

Inngest · 14 features

• AgentKit — Build AI agents as durable Inngest functions.
• Auto Retries — Configurable retries with exponential backoff.
• Concurrency Controls — Per-function and per-user concurrency limits.
• Cron Triggers — Scheduled functions via cron syntax.
• Debounce — Coalesce rapid-fire events into one execution.
• Dev Server — Local Inngest runtime for dev.
• Durable Steps — step.run, step.sleep, step.waitForEvent.
• Event System — Typed events with schemas.
• Fan Out / Batching — Process many events in parallel with batch control.
• Priority Lanes — Route premium customers to faster execution.
• Rate Limiting — Throttle events per key.
• Realtime — Stream function output to clients.
• Replay — Re-run past functions with new code.
• Self-Host — OSS runtime — run your own Inngest.

Langfuse · 16 features

• Annotation Queues — Human reviewers rate traces. Unlimited on Pro+.
• Dashboards — Aggregate metrics, cost, quality across projects.
• Datasets — Curate test sets from production traces. Run experiments.
• EU Cloud Region — GDPR-compliant hosting in EU.
• Evaluations — LLM-as-judge, manual scores, custom model-graded evaluators.
• LLM Cost Tracking — Automatic cost calculation per provider/model.
• OpenTelemetry Native — OTel SDK → Langfuse endpoint works out of box.
• Playground — Test prompts + models + variables live.
• Prompt Management — Version, tag, label prompts. Reference from code by label.
• Public API — Full REST API for ingest, query, prompt management.
• Python @observe decorator — One-line decorator to trace any function.
• Self-Hosting — Docker Compose + k8s Helm chart.
• Sessions — Group related traces (conversations, agent runs).
• Tracing — Capture every LLM call, tool call, nested span with inputs/outputs/cost.
• Users Tracking — Segment traces by user ID, track per-user cost.
• Webhooks — Subscribe to trace completion events.