OpenAI

let model = OpenAIModel("gpt-5.6-sol")          // Responses API
let chat  = OpenAIModel.chat("gpt-5.6-terra")   // chat completions wire

Key from OPENAI_API_KEY; base URL from OPENAI_BASE_URL or https://api.openai.com/v1. organization: and project: become the matching request headers.

Features

• Tools, structured output (JSON schema mode), vision, and streamed reasoning summaries (response.reasoning_summary_text.delta arrives as .reasoningDelta).
• URL citations surface as StreamPart.source and source-url parts in chat UIs.
• usage.cachedInputTokens reports prompt-cache hits.
• Built-in Responses tools have typed builders under OpenAIModel.Tools — webSearch, webSearchPreview, fileSearch(vectorStoreIds:), and codeInterpreter. Drop them in tools:; the calls and results stream back as provider-executed parts and citations as .source:

let result = try await generateText(
  model: OpenAIModel("gpt-5.6-sol"),
  prompt: "What happened in tech today?",
  tools: [OpenAIModel.Tools.webSearch()]
)
print(result.sources.map(\.url))

• Other Responses knobs (store, instructions, include, previous_response_id) pass through providerOptions, merged at the top level.

Models

Any id the API serves works. The library special-cases:

• Reasoning models — o1*, o3*, o4-mini*, and gpt-5* (except gpt-5-chat*): the reasoning parameter maps to reasoning.effort with an automatic detailed summary, and sampling knobs are dropped where those models reject them.
• gpt-5.1 through gpt-5.6 — accept temperature/topP again when reasoning effort is none.

Current lineup

Snapshot from July 2026; new ids work the day OpenAI ships them.

Beyond text