Product Updates

Gemini API Interactions breaking changes (May 2026): outputs → steps, new response_format, and migration timeline

Google’s Gemini API Interactions endpoint is changing its response schema (outputs → steps), consolidating output format controls into response_format, and updating streaming event names, with a May 26 default flip and a June 8 legacy sunset.

By Authority AI Tools Editorial Team•2026-05-16•10 min read
Last reviewed: 2026-05-16
AATET
Authority AI Tools Editorial Team

Editorial Team

The Authority AI Tools editorial team maintains this directory using vendor documentation, dated source checks, product changelogs, and clearly identified hands-on observations where available.

Google published a migration guide for upcoming breaking changes to the Gemini API Interactions endpoint, including a response schema change from outputs to steps, plus a firm timeline for rollout. (https://ai.google.dev/gemini-api/docs/interactions-breaking-changes-may-2026)

1) Response schema: outputs → steps

Google says responses move from a flat outputs array to a structured steps array:

  • POST /interactions returns only output steps.
  • GET /interactions/{id} returns the full step timeline (including the initial user_input step).

(https://ai.google.dev/gemini-api/docs/interactions-breaking-changes-may-2026)

2) Output format changes: response_mime_type removed

Google says response_mime_type is removed and output control moves into a polymorphic response_format field.

The guide also notes that image output configuration previously under generation_config.image_config moves into a response_format entry with type: "image". (https://ai.google.dev/gemini-api/docs/interactions-breaking-changes-may-2026)

3) Streaming event names change

Google’s guide lists new server-sent-event types (e.g. interaction.created, interaction.completed, step.start, step.delta, step.stop) replacing older event names. (https://ai.google.dev/gemini-api/docs/interactions-breaking-changes-may-2026)

For streaming function calls, Google says function arguments arrive as partial JSON string deltas (arguments_delta), and clients must accumulate deltas to reconstruct full arguments. (https://ai.google.dev/gemini-api/docs/interactions-breaking-changes-may-2026)

Migration timeline (key dates)

The guide lists a staged rollout:

Sources

Free Resource

2026 AI Coding Tools Comparison Chart

Side-by-side comparison of features, pricing, and capabilities for every major AI coding tool.

No spam, unsubscribe anytime.

Frequently Asked Questions

What is Gemini API Interactions breaking changes (May 2026): outputs → steps, new response_format, and migration timeline?
Google’s Gemini API Interactions endpoint is changing its response schema (outputs → steps), consolidating output format controls into response_format, and updating streaming event names, with a May 26 default flip and a June 8 legacy sunset.

Related Articles

Product Updates

Cursor open-sources Mixture-of-Kittens, an MoE training megakernel

Cursor Research says its open-source Mixture-of-Kittens megakernel for GB300 NVL72 systems fuses MoE communication and computation and delivered a 1.41× end-to-end tokens-per-second gain in its production stack.

Read more →Product Updates

Cursor adds Google Workspace plugins for agents

Cursor’s August 3, 2026 changelog adds Google Workspace plugins that let coding agents read, write, and act across Drive, Gmail, Calendar, Docs, Sheets, and Chat.

Read more →Product Updates

Claude Code 2.1.224 adds self-hosted runners and cross-session messaging

Anthropic’s official Claude Code changelog update for August 7, 2026 adds self-hosted runners for web, mobile, and desktop sessions plus cross-session messaging and other workflow changes.

Read more →
← Back to Blog