openmeter

OpenMeter is a real-time metering and billing engine that helps you track usage, enforce limits, manage subscriptions, and automate invoicing — all in one platform. Ingest events via a simple API, define meters with flexible aggregations, and connect usage data to billing, entitlements, and customer-facing dashboards.

Features

• Usage Metering — Ingest events in CloudEvents format, define meters with flexible aggregations (SUM, COUNT, AVG, MIN, MAX), and query usage in real time.
• Usage-Based Billing — Generate invoices from metered usage. Supports tiered, graduated, and flat-fee pricing with automated invoice lifecycle management.
• Usage Limits and Entitlements — Enforce usage quotas per feature with real-time balance tracking, boolean feature flags, and grace periods.
• Product Catalog — Define plans, add-ons, features, and rate cards. Manage subscriptions with mid-cycle changes, prorating, and alignment.
• Prepaid Credits — Support paid or promotional credit grants with priority-based burn-down and expiration.
• Customer Portal — Token-based self-service dashboards so your customers can see their own usage.
• Notifications — Webhook-based alerts with configurable rules and channels for usage thresholds and billing events.
• LLM Cost Tracking — First-class support for metering AI token usage and computing model-specific costs.

Getting Started

Cloud

The fastest way to start. Start for free and begin metering and billing in minutes — no infrastructure to manage.

Self-Hosted

Run OpenMeter locally with Docker Compose:

git clone git@github.com:openmeterio/openmeter.git
cd openmeter/quickstart
docker compose up -d

Then ingest your first event:

curl -X POST http://localhost:48888/api/v1/events \
  -H 'Content-Type: application/cloudevents+json' \
  --data-raw '{
    "specversion": "1.0",
    "type": "request",
    "id": "00001",
    "time": "2024-01-01T00:00:00.001Z",
    "source": "my-service",
    "subject": "customer-1",
    "data": { "method": "GET", "route": "/api/hello" }
  }'

Query your usage:

curl 'http://localhost:48888/api/v1/meters/api_requests_total/query?windowSize=HOUR' | jq

See the full quickstart guide for more details.

Deploy to Production

Deploy to Kubernetes using our Helm chart.

SDKs

Don't see your language? Use the OpenAPI spec directly or request an SDK.

Architecture

OpenMeter is built in Go with a stack optimized for high-volume event ingestion and real-time aggregation:

Community

We'd love to have you involved:

• Contributing — Start here if you want to contribute code.
• Code of Conduct — Our community guidelines.
• Blog — Product updates and engineering deep dives.

Development

Prerequisites: Nix and direnv are recommended. See CONTRIBUTING.md for detailed setup instructions.

make up       # Start dependencies (Postgres, Kafka, ClickHouse)
make server   # Run the API server with hot reload
make test     # Run tests
make lint     # Run linters

License

Licensed under Apache 2.0.