2026-05-20 — Google I/O fallout dominates the day
🚨 Breaking
Gemini Interactions API v1beta is replacing its response schema. The outputs array becomes steps; response_mime_type is removed in favor of a unified response_format field. Hard timeline:
- Now: opt in via
Api-Revision: 2026-05-20request header to validate against the new schema - May 26: new schema becomes the default (6 days away)
- June 8: legacy schema removed entirely
Any code that reads outputs or writes response_mime_type will break no later than June 8. The opt-in header gives you a controlled migration window — use it.
Source: https://ai.google.dev/gemini-api/docs/interactions-breaking-changes-may-2026
🗑️ Dépréciations
Gemini 2.0 Flash and Gemini 2.0 Flash-Lite shut down June 1, 2026 — 12 days from now. Google's stated replacement is Gemini 2.5 Flash-Lite. If either model ID appears in your production config, this is your last full week to swap it.
Source: https://ai.google.dev/gemini-api/docs/pricing
💰 Pricing
Gemini 3.5 Flash prices at $1.50/M input · $9.00/M output — roughly 3× the cost of Gemini 3 Flash. In exchange: 76.2% on Terminal-Bench 2.1, 83.6% on MCP Atlas, and 4× faster throughput than other frontier models per Google's published figures.
Sources: https://finance.biggo.com/news/202605191936_Google_Gemini_3.5_Flash_launched_at_IO_2026 · https://blog.google/innovation-and-ai/technology/developers-tools/google-io-2026-developer-highlights/
🆕 Nouveautés
OpenAI GPT-5.4 + GPT-5.4 Pro are live for paying API customers. GPT-5.4 is available on both Chat Completions and Responses APIs. GPT-5.4 Pro (additional compute for harder reasoning) is Responses API only.
Source: https://developers.openai.com/api/docs/changelog
Gemini 3.5 Flash (GA, May 19) is Google's new primary agentic and coding model, outperforming Gemini 3.1 Pro on the above benchmarks. Available via Gemini API, AI Studio, Vertex AI, and Google Search AI Mode.
Anthropic acquires Stainless — the SDK compiler that generates official clients for Anthropic, OpenAI, Google, Meta, and Cloudflare — for at least $300M. No immediate API surface changes announced. Watch SDK changelogs as ownership transitions.
Source: https://asanify.com/blog/news/ai-sdk-consolidation-may-19-2026/
💡 Conseil du jour
Do this today: add Api-Revision: 2026-05-20 to your Gemini Interactions API calls and run your response-parsing code against the new steps schema. May 26 is 6 days out — if your parser breaks, you need that runway. Also grep your codebase for gemini-2.0-flash and gemini-2.0-flash-lite model IDs: June 1 shutdown is non-negotiable.