micro/go-micro · error

ai model is nil

Error message

ai model is nil

What it means

GenerateWithRetry validates its Model argument up front and returns this error immediately if m is nil, before any retry loop runs. It prevents a nil-pointer panic inside the retry/timeout machinery and surfaces the misconfiguration clearly.

Source

Thrown at ai/retry.go:147

}

// GeneratePolicy controls timeout and retry behavior for a model call.
type GeneratePolicy struct {
	Timeout     time.Duration
	MaxAttempts int
	Backoff     time.Duration
	// Jitter adds up to this duration of random delay to retry backoff.
	// It is opt-in so existing retry timing remains deterministic by default.
	Jitter time.Duration
}

// GenerateWithRetry calls m.Generate with per-attempt timeout and bounded retry.
func GenerateWithRetry(ctx context.Context, m Model, req *Request, policy GeneratePolicy, opts ...GenerateOption) (*Response, error) {
	if policy.MaxAttempts <= 0 {
		policy.MaxAttempts = 1
	}
	if m == nil {
		return nil, errors.New("ai model is nil")
	}

	var last error
	for attempt := 1; attempt <= policy.MaxAttempts; attempt++ {
		if err := ctx.Err(); err != nil {
			return nil, err
		}

		callCtx := ctx
		cancel := func() {}
		if policy.Timeout > 0 {
			callCtx, cancel = context.WithTimeout(ctx, policy.Timeout)
		}
		if info, ok := RunInfoFrom(callCtx); ok {
			info.Attempt = attempt
			info.MaxAttempts = policy.MaxAttempts
			callCtx = WithRunInfo(callCtx, info)
		}

View on GitHub (pinned to 24529f1404)

Solutions

1. Check the error from model/provider construction before calling GenerateWithRetry
2. Verify the model configuration is loaded (provider name, API key, model id) so the factory returns a non-nil Model
3. Add a nil check at the call site: if m == nil { return error before retrying }

Example fix

// before
model, _ := openai.New(cfg) // error ignored
resp, err := ai.GenerateWithRetry(ctx, model, req, policy)
// after
model, err := openai.New(cfg)
if err != nil {
    return err
}
if model == nil {
    return errors.New("model not configured")
}
resp, err := ai.GenerateWithRetry(ctx, model, req, policy)

if model == nil {
    return nil, errors.New("ai model not configured")
}
resp, err := ai.GenerateWithRetry(ctx, model, req, policy)

func modelReady(m ai.Model) bool { return m != nil }

resp, err := ai.GenerateWithRetry(ctx, model, req, policy)
if err != nil && strings.Contains(err.Error(), "ai model is nil") {
    return fmt.Errorf("model misconfigured: construction failed or config missing")
}

When it happens

Trigger: Calling ai.GenerateWithRetry with a nil Model — typically because model construction failed and the error was ignored, or a config lookup returned nil.

Common situations: Ignoring the error from provider/model factory functions; optional model config keys missing so the resolved model is nil; struct fields left zero because initialization is deferred or conditional.

Related errors

• flow: step %q has no Run function
• flow: step %d has an empty name
• agent: ResumeStreamAsk requires a checkpoint
• ErrStreamingUnsupported
• API error: nil response

AI-assisted analysis of micro/go-micro@24529f1404 (2026-09-01). Data as JSON: /api/errors/682fbe2a990a1d3d. Report an issue: GitHub.