Docs
Send usage events, meter them, and preview invoices.
Start here
- Product overview
What Passage does, and the six things it works with.
- Quickstart: send your first usage event
Create a key, send an event, count it with a meter, and read its usage.
API reference
- Authentication and API keys
Every /v1 request carries a bearer API key that reaches one account's data.
- Events
POST /v1/events records usage, up to 500 events per request.
- Meters
A meter turns events into a billable quantity.
- Usage and invoices
Read a meter's usage for a customer, and preview the month's invoice.
- CSV exports
POST /v1/exports returns the raw events in a date range as CSV.
Guides
- Idempotency and retries
Retry safely with an Idempotency-Key, backoff, and Retry-After.
- Rate limits
100 requests a second per account, and how to backfill without hitting it.
- Webhooks (legacy)
Legacy invoice webhooks (v0) were retired on 2026-06-30.
Links on this page
- https://passage.ink/docs/overview
- https://passage.ink/docs/quickstart
- https://passage.ink/docs/authentication
- https://passage.ink/docs/events
- https://passage.ink/docs/meters
- https://passage.ink/docs/usage-and-invoices
- https://passage.ink/docs/exports
- https://passage.ink/docs/idempotency
- https://passage.ink/docs/rate-limits
- https://passage.ink/docs/webhooks-legacy