Features
Real-time credit ledger with grants, rollovers, expiration
Feature entitlement gating (boolean and metered)
Subscription lifecycle management (upgrade, downgrade, proration)
Usage-based billing (per-unit, per-seat, credit-based)
Billing controls (spend caps, auto top-ups, usage alerts)
Flexible pricing (plans, variants, add-ons, tiers, graduated)
Sub-entity balances and plans
Webhooks and Slack/Discord notifications
Fail-open defaults for reliability
Observability via ClickHouse (usage history, charts, logs)
Plan versioning and grandfathering
Trial and auto top-up management
Minimal API: attach, check, track
Self-hostable open-source
Stripe as payment processor
Distributed tracing for LLM agents
Capture prompts, retrievals, tool calls, outputs
Human annotations on traces
Create datasets from traces
Run experiments to compare changes
OpenTelemetry-native instrumentation
Self-host locally, Docker, or Kubernetes
Cloud instances with free tier
Vendor agnostic: any model or framework
3M+ monthly downloads, 9k+ GitHub stars
