Skip to main content
Explanation

Essentials

The foundations every integration needs, written once and linked from everywhere. Read these before you write much code, they're all short, and they'll save you grief. The UltraCart API is organized around REST and JSON: resource-oriented URLs, defined with the OpenAPI (Swagger) specification, with JSON for the request and response bodies wherever possible.

Getting started​

  • Authentication: OAuth 2.0 for multi-merchant apps, or a Simple Key for in-house automation.
  • OAuth 2.0 Guide: register a developer application and walk the full authorization-code flow to a Bearer access token.
  • Versioning: the X-UltraCart-Api-Version header, required on every request.
  • Download and install your SDK of choice, then review the samples to jump-start your project.

How requests and responses work​

  • Standard Responses: the success / error / metadata envelope shared by every endpoint.
  • Errors: HTTP status codes and the structured error object.
  • Object Identifiers: OIDs, their human-friendly companions, and how to set or clear them.
  • Expanding Objects: the _expand parameter for partial objects and leaner payloads.
  • Pagination: paging large result sets with _offset and result_set metadata.
  • Sorting: ordering results with the _sort parameter.
  • Date/Times: ISO-8601 everywhere.

Operating in production​

  • Rate Limiting: quotas, the leaky-bucket algorithm, and the no-concurrency rule.
  • Request IDs: the X-UltraCart-Request-Id header for tracing and support.
  • Webhooks: asynchronous event delivery instead of polling.

Once you know the essentials, head to the API Reference for the per-endpoint details.

Was this page helpful?