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Authentication

The public 511 transit endpoints are documented as requiring an api_key query parameter.

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Formats

Most transit endpoints support JSON and XML through an optional format parameter. Bulk GTFS downloads return zip files, and GTFS-Realtime feeds return protobuf payloads.

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Rate limits

As of the 511 transit page snapshot reviewed on March 25, 2026, the default token limit is documented as 60 requests per 3600 seconds.
That limit is low enough that any polling-heavy integration should assume aggressive caching is mandatory.

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Common errors

  • 401 Unauthorized for invalid API keys
  • 404 Not Found when an individual resource cannot be located
  • 500 Internal Server Error when the service cannot process the request

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Parameter casing mismatches

The public transit page and the transit PDF disagree on some parameter names.
  • stoptimetable is shown on the live page with lowercase operatorref, monitoringref, lineref, starttime, and endtime, while the PDF uses capitalized SIRI-style names
  • StopMonitoring uses stopcode on the public page, while the PDF shows stopCode
  • timetable uses lowercase includespecialservice and exceptiondate on the public page, while the PDF shows IncludeSpecialService and ExceptionDate
Treat the PDF as the best source for semantics and response structure, and the live public page as the best source for the exact request spelling when the two differ.