wavetermdev/waveterm · error

model mismatch: chat has %s, chatOpts has %s

Error message

model mismatch: chat has %s, chatOpts has %s

What it means

RunOpenAIChatStep checks model compatibility with uctypes.AreModelsCompatible(chat.APIType, chat.Model, chatOpts.Config.Model) and returns "model mismatch" at openai-backend.go:484 when the chat's stored model is incompatible with the model in the request options. This prevents mixing history generated by one model into a request for an incompatible model.

Source

Thrown at pkg/aiusechat/openai/openai-backend.go:484

	chatOpts uctypes.WaveChatOpts,
	cont *uctypes.WaveContinueResponse,
) (*uctypes.WaveStopReason, []*OpenAIChatMessage, *uctypes.RateLimitInfo, error) {
	if sse == nil {
		return nil, nil, nil, errors.New("sse handler is nil")
	}

	// Get chat from store
	chat := chatstore.DefaultChatStore.Get(chatOpts.ChatId)
	if chat == nil {
		return nil, nil, nil, fmt.Errorf("chat not found: %s", chatOpts.ChatId)
	}

	// Validate that chatOpts.Config match the chat's stored configuration
	if chat.APIType != chatOpts.Config.APIType {
		return nil, nil, nil, fmt.Errorf("API type mismatch: chat has %s, chatOpts has %s", chat.APIType, chatOpts.Config.APIType)
	}
	if !uctypes.AreModelsCompatible(chat.APIType, chat.Model, chatOpts.Config.Model) {
		return nil, nil, nil, fmt.Errorf("model mismatch: chat has %s, chatOpts has %s", chat.Model, chatOpts.Config.Model)
	}
	if chat.APIVersion != chatOpts.Config.APIVersion {
		return nil, nil, nil, fmt.Errorf("API version mismatch: chat has %s, chatOpts has %s", chat.APIVersion, chatOpts.Config.APIVersion)
	}

	// Context with timeout if provided.
	if chatOpts.Config.TimeoutMs > 0 {
		var cancel context.CancelFunc
		ctx, cancel = context.WithTimeout(ctx, time.Duration(chatOpts.Config.TimeoutMs)*time.Millisecond)
		defer cancel()
	}

	// Validate continuation if provided
	if cont != nil {
		if !uctypes.AreModelsCompatible(chat.APIType, chatOpts.Config.Model, cont.Model) {
			return nil, nil, nil, fmt.Errorf("cannot continue with a different model, model:%q, cont-model:%q", chatOpts.Config.Model, cont.Model)
		}
	}

View on GitHub (pinned to a4447c1563)

Solutions

1. Set chatOpts.Config.Model from the chat's stored model (chat.Model) before stepping
2. Start a new chat when intentionally switching to a different model
3. Check uctypes.AreModelsCompatible to see whether the two models are considered compatible aliases (e.g. versioned variants) before assuming mismatch
4. If the model was deprecated, migrate the chat to the new compatible model name once, or recreate the chat

Example fix

// before
chatOpts.Config.Model = "gpt-4.1" // switched mid-chat
RunOpenAIChatStep(ctx, sse, chatOpts, nil)
// after
chat := chatstore.DefaultChatStore.Get(chatOpts.ChatId)
chatOpts.Config.Model = chat.Model // continue with the chat's model
RunOpenAIChatStep(ctx, sse, chatOpts, nil)

chat := chatstore.DefaultChatStore.Get(chatOpts.ChatId)
if chat != nil && !uctypes.AreModelsCompatible(chat.APIType, chat.Model, chatOpts.Config.Model) {
    chatOpts.Config.Model = chat.Model // or start a new chat with the new model
}

func modelCompatible(chatOpts uctypes.WaveChatOpts) bool {
    chat := chatstore.DefaultChatStore.Get(chatOpts.ChatId)
    return chat != nil && uctypes.AreModelsCompatible(chat.APIType, chat.Model, chatOpts.Config.Model)
}

if _, _, _, err := RunOpenAIChatStep(ctx, sse, chatOpts, nil); err != nil {
    if strings.HasPrefix(err.Error(), "model mismatch") {
        // either reset Config.Model to the chat's model or create a new chat
        return nil
    }
    return err
}

When it happens

Trigger: Calling RunOpenAIChatStep with Config.Model different (and not compatible per AreModelsCompatible) from the model the chat was created with — e.g. user switches model mid-conversation, or opts built from defaults rather than the chat record.

Common situations: Model upgraded/renamed server-side so old chats carry a retired model name; user changes model selection in the UI while continuing a conversation; config file defaults overriding the chat's model.

Related errors

• API type mismatch: chat has %s, chatOpts has %s
• cannot continue with a different model, model:%q, cont-model
• ai:model is required
• ai:endpoint is required
• wcloud endpoint not set

AI-assisted analysis of wavetermdev/waveterm@a4447c1563 (2026-09-01). Data as JSON: /api/errors/b090a3c3ff18d0b6. Report an issue: GitHub.