generated: '2026-07-20'
method: searched
source: https://docs.processout.com/reference/getting-started-with-your-api
description: >-
  Cross-cutting request/response semantics for the ProcessOut API, harvested from the
  docs and derived from the OpenAPI. Cross-links errors/, lifecycle/, authentication/
  and rate-limits/.
authentication:
  style: http-basic
  detail: >-
    Project ID as username, secret API key as password. Sandbox uses a test-
    prefixed project ID and a key_sandbox_/key_test_ secret; production removes the
    prefix and uses a key_live_ secret. See authentication/processout-authentication.yml.
idempotency:
  supported: true
  mechanism: header
  header: Idempotency-Key
  description: >-
    Mutating operations accept an Idempotency-Key request header — a unique key to the
    request used for idempotency — so retries do not create duplicate resources. The
    header is declared across the create/mutate operations in the OpenAPI.
  source: openapi/processout-openapi.json
versioning:
  scheme: server-negotiated
  detail: >-
    The API root (GET https://api.processout.com/) advertises current_version and
    latest_version plus the list of available versions (1.0.0.0 - 1.3.0.1 observed).
  current: 1.3.0.1
error_envelope:
  format: processout-json
  fields: [success, error_type, message]
  detail: >-
    Errors return a JSON body with success:false, an error_type and a human-readable
    message. Payment declines are surfaced as a unified error/decline code on the
    transaction. See errors/processout-problem-types.yml and errors/processout-decline-codes.yml.
rate_limit_signaling:
  headers: [x-ratelimit, x-ratelimit-remaining]
  over_limit_status: 429
  detail: See rate-limits/processout-rate-limits.yml (GCRA, three independent limits).
webhooks:
  delivery: at-least-once
  ordering: not-guaranteed
  dedupe_required: true
  retries: at least 12 retries over 3 days with exponential backoff
  payload: '{ event_id, event_type } — fetch full event via GET /events/{event_id}.'
  detail: See asyncapi/processout-webhooks.yml.
resource_expansion:
  supported: true
  detail: >-
    The first level of sub-resources is expanded automatically on events/resources;
    deeper resources must be fetched. See docs/reference/expanding-resources.