Skip to main content

​
Purpose

The openai package is a small client plus a few data structures for chat completions and streamed deltas.

​
Client construction

Create a client with: 
client := openai.NewClient(
    openai.WithBaseURL("https://your-provider.example/v1"),
    openai.WithAPIKey("your-api-key"),
    openai.WithHTTPClient(customHTTPClient),
)
Defaults:
  • base URL: https://api.openai.com/v1
  • request timeout on the default client: 5 minutes

​
Request methods

​
CreateChatCompletion

Sends a non-streaming POST request to: 
/chat/completions
It returns validation errors if model or messages are missing.

​
StreamChatCompletion

Also posts to /chat/completions, but forces stream=true, requests text/event-stream, and returns a channel of StreamEvent. Each StreamEvent can contain:
  • Data: a parsed response chunk
  • Done: true when [DONE] is received
  • Raw: the raw payload bytes
  • Error: a parse or scan error

​
Extra-field preservation

The package is intentionally tolerant of provider-specific fields.
  • ChatCompletionRequest.Extra is merged into outbound JSON.
  • Message.Extra, ToolCall.Extra, and ChatCompletionChoice.Extra preserve unknown inbound fields.
  • ChatCompletionResponse.Raw stores raw JSON fragments by top-level key.
That makes the package useful against OpenAI-compatible providers that add extra fields.

​
Stream accumulation

ChatCompletionAccumulator merges partial deltas into full choices. In particular, it:
  • concatenates text content
  • merges partial tool calls by index
  • stitches fragmented tool-call argument strings together
  • preserves extra fields and logprobs
  • preserves structured content when no text concatenation is possible
This is what loop.RunLoop relies on before executing tools.

​
Helper constructors

Use:
  • openai.SystemMessage(...)
  • openai.UserMessage(...)
  • openai.ToolMessage(...)
Use openai.MessageText(...) when you expect plain string content and want the helper’s type assertion behavior.

​
Error model

Non-2xx API responses return *openai.APIError, which includes:
  • StatusCode
  • Message
  • Body
That gives callers access to both a concise error string and the raw response body.