Request validation errors

inference.ValidateRequestFeatures is the common pre-codec gate. It validates feature combinations against the model’s declared capabilities.

Rules

The function rejects a transient-message count outside the message slice, a named tool choice whose name matches no declared tool, required tool choice with no tools, image blocks when Caps.AcceptsImages is false, invalid output schemas, duplicate tool names, the reserved structured-output tool name, structured output without Caps.StructuredOutput, and structured output with tools without Caps.StructuredOutputWithTools. It does not validate provider policy or wire JSON; those checks remain in each codec.

if err := inference.ValidateRequestFeatures(req); err != nil {
	var conflict *inference.StructuredOutputConflictError
	if errors.As(err, &conflict) {
		fmt.Println(conflict.Feature)
	}
	return err
}

Errors

Errors are InvalidTransientMessagesError, StructuredOutputConflictError, ImageInputUnsupportedError, StructuredOutputUnsupportedError, StructuredOutputWithToolsUnsupportedError, and SchemaValidationError. Model diagnostics are bounded; schema bytes, tool payloads, and raw model names beyond the documented bound are not retained.

Source and proof

• client.go
• structured_errors.go
• structured_result.go

Run go test ./....