For any given API version, we will preserve:
  • Existing input parameters
  • Existing output parameters
However, we may do the following:
  • Add additional optional inputs
  • Add additional values to the output
  • Change conditions for specific error types
  • Add new variants to enum-like output values (for example, streaming event types)
Generally, if you are using the API as documented in this reference, we will not break your usage.

​
Version history

We always recommend using the latest API version whenever possible. Previous versions are considered deprecated and may be unavailable for new users.
  • 2023-06-01
    • New format for streaming server-sent events (SSE):
      • Completions are incremental. For example, " Hello", " my", " name", " is", " Claude." instead of " Hello", " Hello my", " Hello my name", " Hello my name is", " Hello my name is Claude.".
      • All events are named events, rather than data-only events.
      • Removed unnecessary data: [DONE] event.
    • Removed legacy exception and truncated values in responses.
  • 2023-01-01: Initial release.