These guides cover the developer surface: API keys, webhook endpoints, the outbound email log, and rate limits. If you have not made your first request, start with the [Quickstart](/developers/quickstart).

## In this section

- [Modes and regions](/developers/modes-and-regions)
- [Create an API key](/developers/api-keys)
- [Rotate or revoke an API key](/developers/api-keys-rotate)
- [Create a webhook endpoint](/developers/webhooks)
- [Verify webhook signatures](/developers/webhooks-verify-signatures)
- [Replay and troubleshoot webhook deliveries](/developers/webhooks-replay-and-troubleshoot)
- [Email log](/developers/email-log)
- [Test data](/developers/test-data)
- [Rate limits](/developers/rate-limits)

For wire shapes see the [interactive reference](/reference) and the [API error codes](/api/errors).