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OpenAI ships GPT-5.5, Pro to API
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HN · HACKER_NEWS// 6h 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

6h ago

2026-04-24

PUBLISHED

8h ago

2026-04-24

RELEVANCE

10/ 10

AUTHOR

arabicalories