Changelog

This changelog highlights notable historical changes to the API Design Guide, such as revisions to naming conventions, error handling, and standard fields. It also logs the documentation migrations to Google API Improvement Proposals (AIPs).

2025-06

  • Redirected Design page Naming Convention to Google AIP.

2024-10

  • Redirected Design pages to Google AIPs, except for Directory Structure and Naming Conventions.

2021-12

  • Changed terminology Networked API to Network API for consistency with https://google.aip.dev/9.

2021-09

  • Document both Google API error format v1 and v2.

2021-04

  • Introduced visibility-based versioning.

  • Introduced API title to glossary.

2021-03

  • Added annotation for output only fields.

  • Update enum value guidance to always include an explicit _UNSPECIFIED value.

  • Add guidance on how to generate and parse resource names.

  • Add progress_percent to standard fields.

2021-02

  • Added guidance on proto3 optional primitive fields.

2021-01

  • Updated the Errors page to cover the latest improvement related to google.rpc.ErrorInfo and google.api.ErrorReason.

  • Added guidance on how to use oauth2l, curl, and System Parameters to troubleshoot errors with Google APIs.

  • Added 502 error code explanation to the Errors page. It is a network error instead of an API error.

2020-12

  • Package names should use singlar component names for global consistency. Package names must not use underscores.

2020-09

  • Cleaned up some field description requirements; changed some uses of "must" outside RFC 2119 to be RFC 2119 "should" directives.

  • Removed the bool deleted standard field, in favor of google.protobuf.Timestamp delete_time (which was already listed).

2020-07

  • Updated documentation.md to match https://google.aip.dev/192#formatting. Markdown tables and raw HTML must not be used in proto comments.

  • Added ErrorInfo for error handling.

  • Added Large Payloads for design patterns.

2020-04

  • Renamed Cloud APIs to Google Cloud APIs in glossary.
  • Introduced API and service as synonyms of API service.

2020-02

  • Updated versioning to add two versioning strategies (channel-based and release-based), remove guidance on point versions, and change how we refer to semantic versioning.

2020-01

  • Add data retention to design patterns.

2019-11

  • Add terminology Cloud APIs to glossary.
  • Recommend clients to retry only for UNAVAILABLE errors.

2019-06

  • Add "Bool vs Enum vs String" to design patterns.

2019-03

  • Add system parameters to standard fields.

2019-02

  • Add domain-scoped names to design patterns.

2018-03

  • Add streaming half-close semantics to design patterns.

2018-02

  • Add read_time to Standard Fields.

2018-01

  • Add schema reference for API Service Definition.

2017-12

  • Clarify API major version must be the last component of proto package name.

2017-11

  • Clarify why the Create method take an input resource.
  • Clarify collection IDs that don't have plural form, such as evidence and weather.
  • Add singleton resource to design patterns.
  • Clarify C# naming conventions for acronyms and versions.

2017-09

  • Add mime_type to standard fields.
  • Add expire_time to standard fields.
  • Add start_time and end_time to standard fields.

2017-02

  • Add "API endpoint" to glossary.
  • Add update_mask to standard fields.
  • Add a link to FieldMask to standard methods.
  • Mention that OpenAPI spec does not support unsigned integers.
  • Clarify that method names should use verbs in the imperative mood.