
completions-api-bae55435·5 events·first seen Aliases: Completions API, Chat Completions API
OpenAI has made gpt-5.3-chat-latest available via the Chat Completions and Responses API, pointing to the GPT-5.3 Instant snapshot currently powering ChatGPT. This release gives API developers access to the same model version deployed in the consumer product. The update is a routine API availability expansion rather than a new model capability announcement.
OpenAI released GPT-5.4 and GPT-5.4 pro to the Chat Completions and Responses API, positioning them as frontier models for professional and compute-intensive work. The release bundles several infrastructure capabilities: tool search for deferred runtime tool loading to reduce token usage and improve latency, built-in computer use via screenshot-based UI interaction, a 1M token context window, and native Compaction support for long-running agent workflows. These additions collectively advance OpenAI's agentic API surface significantly. Note: as of the current canonical facts, GPT-5.5 is the current OpenAI flagship, making this a prior-generation release.
OpenAI released GPT-5.5 and GPT-5.5 Pro to the Chat Completions and Responses API, positioning them as frontier models for complex professional work and compute-intensive tasks respectively. GPT-5.5 supports a 1M token context window, image input, structured outputs, function calling, built-in computer use, hosted shell, MCP, web search, and Skills. Notable behavioral changes include reasoning effort defaulting to medium and extended-only prompt caching support.
OpenAI has added moderation scoring directly to the Responses API and Chat Completions API, allowing developers to receive moderation results for both inputs and outputs in a single API call. Previously, moderation required a separate API request. This reduces latency and integration complexity for applications that need content safety checks.
OpenAI has announced general availability of the GPT-4 API, alongside GPT-3.5 Turbo, DALL·E, and Whisper APIs. Concurrently, OpenAI is releasing a deprecation plan for older models in the Completions API, which are set to retire at the beginning of 2024. This marks a significant milestone in OpenAI's API product lifecycle, transitioning GPT-4 from limited access to broad developer availability.