OpenAI ships GPT-5.5, Pro to API

// 45d agoMODEL RELEASE

OpenAI ships GPT-5.5, Pro to API

OpenAI’s April 23, 2026 changelog says GPT-5.5 is now available in the Chat Completions and Responses APIs, while GPT-5.5 Pro is available in the Responses API and Batch for harder problems that benefit from more compute. The release pushes the GPT-5 family forward with a 1M-token context window, image input, structured outputs, function calling, prompt caching, tool search, built-in computer use, hosted shell, apply patch, Skills, MCP, and web search support on GPT-5.5.

// ANALYSIS

This is a meaningful API upgrade, not just a naming bump: OpenAI is pairing a general-purpose flagship model with a more compute-heavy Pro tier and making the platform’s agentic tool stack feel much more first-class.

–GPT-5.5 lands in the core developer surfaces immediately: Chat Completions and Responses.
–GPT-5.5 Pro is positioned for tougher workloads and is explicitly available through Batch.
–The model stack leans hard into agent workflows, with tool search, computer use, hosted shell, apply patch, Skills, MCP, and web search support.
–The 1M-token context window makes this more interesting for long-horizon coding, analysis, and multi-document workflows than a standard model refresh.
–The release also clarifies product segmentation: GPT-5.5 is the default broad-use option, while Pro is the premium reasoning tier.

// TAGS

openaigpt-5.5gpt-5.5-proapiresponses-apichat-completionsbatchmodel-releasereasoningagents

DISCOVERED

45d ago

2026-04-24

PUBLISHED

45d ago

2026-04-24

RELEVANCE

10/ 10

AUTHOR

arabicalories

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OpenAI ships GPT-5.5, Pro to API