# OpenMeter Developer Portal

OpenMeter exposes a REST API for usage metering, billing, customers, subscriptions, entitlements, and integrations. Agents and new integrations should use API v3 by default. The domain-local OpenAPI document describes v3, and official TypeScript and Go v3 clients are available. Legacy v1 and v2 documentation remains available for existing OpenMeter Cloud and self-hosted integrations.

## Quickstart

Choose Konnect Metering & Billing for a managed environment, or run the Apache-2.0-licensed OpenMeter project locally. Managed API requests use a Bearer token. Keep API keys on the server and never expose them in browser code or source control. Self-hosted local development does not require an API key by default.

Send a CloudEvents-formatted usage event to the v3 events endpoint, then define a meter and query aggregated usage. The complete examples and typed request and response models are in the API v3 reference and client documentation.

## Developer resources

- [OpenMeter documentation](https://openmeter.io/docs)
- [Authentication and API keys](https://openmeter.io/developers#authentication)
- [Interactive API v3 reference](https://openmeter.io/docs/api/v3)
- [OpenAPI v3 YAML](https://openmeter.io/api/openapi.yaml)
- [Webhook documentation](https://openmeter.io/docs/integrations/notifications/webhooks)
- [TypeScript v3 client](https://www.npmjs.com/package/@openmeter/client)
- [Go v3 client](https://github.com/openmeterio/openmeter/tree/main/api/v3/client)
- [Legacy API and SDK compatibility](https://openmeter.io/docs/api)
- [Open source repository](https://github.com/openmeterio/openmeter)

## Sandbox and automation

Create a Kong Konnect account to evaluate the managed service, or use the open source project as an isolated local sandbox. OpenMeter publishes release artifacts and a container image for command-line and deployment workflows. No standalone OpenMeter MCP server is currently published; agents should use the v3 OpenAPI specification or a v3 client by default. Kong Konnect customers can also review the Konnect MCP documentation for platform-level automation.

## Errors and rate limits

OpenMeter REST errors use `application/problem+json` with a stable problem type, title, HTTP status, detail, and request instance. Limits vary by deployment and plan. Clients should inspect `RateLimit` and `RateLimit-Policy` when present, stop retrying until `Retry-After` on a 429 response has elapsed, and use exponential backoff with jitter for transient failures.