# How to Debug Image Generation Failures and Handle Error Codes in awesome-gpt-image-2

> Debug image generation failures in awesome-gpt-image-2 by inspecting network responses and handling error codes like APIMART_RATE_LIMITED with statusForError().

- Repository: [苍何/awesome-gpt-image-2](https://github.com/freestylefly/awesome-gpt-image-2)
- Tags: how-to-guide
- Published: 2026-09-11

---

**To debug image generation failures in awesome-gpt-image-2, inspect the network response for the `error` and `retryAfterMs` fields, check server logs for the Apimart error code, and handle specific codes like `APIMART_RATE_LIMITED` (429) or `APIMART_BALANCE_REQUIRED` (500) by mapping them through the `statusForError()` function in [`api/generation/status.js`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/api/generation/status.js).**

The awesome-gpt-image-2 repository provides a robust image generation pipeline built on the Apimart API. When generation requests fail, the system returns structured error objects with custom codes that propagate from the backend client through to the frontend React components. Understanding how to debug these failures requires tracing the error flow through [`src/apimartClient.js`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/src/apimartClient.js), the API layer in `api/generation/`, and the UI components in `src/image25/`.

## Understanding the Error Handling Architecture

The error handling flow follows a three-tier architecture that transforms raw HTTP errors into user-friendly messages.

### The Apimart Client Layer

All image generation requests originate in **[`src/apimartClient.js`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/src/apimartClient.js)**, which wraps the Apimart API. When a request fails, the client creates a domain-specific `Error` instance using the `apimartErrorCode()` helper function. This error object contains:
- `code`: The specific error identifier (e.g., `APIMART_RATE_LIMITED`)
- `status`: The HTTP status from the upstream response
- `retryAfterMs`: Calculated delay before retrying rate-limited requests
- `upstreamMessage`: Original error message from Apimart

### API Layer Translation

Errors bubble up to the generation endpoints under `api/generation/*`. The **[`api/generation/status.js`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/api/generation/status.js)** file contains the critical `statusForError()` and `publicStatusErrorCode()` functions that map internal Apimart codes to appropriate HTTP status codes and public-facing error identifiers.

### Frontend Consumption

React components in **`src/image25/**/*.jsx`** (notably [`App.jsx`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/App.jsx)) consume these errors as JSON responses. When `ok: false` appears in the response payload, the UI displays contextual messages based on the `error` field and implements retry logic using the `retryAfterMs` value.

## Key Error Codes and Their Meanings

The following error codes are defined implicitly within the Apimart client and mapped to HTTP statuses in the API layer:

- **`APIMART_RATE_LIMITED`**: API quota exceeded; returns HTTP **429** with `retryAfterMs`
- **`APIMART_INVALID_TASK`**: Malformed or expired generation task; returns HTTP **400**
- **`APIMART_API_KEY_INVALID`**: Authentication failure; returns HTTP **500**
- **`APIMART_BALANCE_REQUIRED`**: Insufficient account credits; returns HTTP **500**
- **`APIMART_TASK_FAILED`**: Generic processing failure; returns HTTP **500**
- **`APIMART_POLL_ABORTED`**: Client-side timeout waiting for completion; returns HTTP **503**
- **`APIMART_GENERATION_FAILED`**: Fallback for unexpected errors; returns HTTP **500**

## Debugging Image Generation Failures Step by Step

When users report failed image generations, follow this systematic debugging workflow.

### Inspect Network Responses

Open browser DevTools and examine the response body from `/api/generation/*` endpoints. A typical error response follows this structure:

```json
{
  "ok": false,
  "error": "APIMART_RATE_LIMITED",
  "retryAfterMs": 7000
}

```

The `error` field contains the machine-readable code, while `retryAfterMs` indicates when to retry rate-limited requests.

### Check Server Logs

On the backend, errors are logged before being re-thrown to the API layer. Search logs for codes like `APIMART_BALANCE_REQUIRED` or `APIMART_TASK_FAILED`. The source of all errors is **[`src/apimartClient.js`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/src/apimartClient.js)**, where the original Apimart payload is wrapped with additional metadata.

### Validate Request Payloads

For errors like `APIMART_REQUEST_REJECTED` or `APIMART_BALANCE_REQUIRED`, verify the upstream payload fields. The `upstreamMessage` property in the error object captures the original Apimart error description, helping distinguish between content policy violations and payment issues.

### Verify Retry Logic

When encountering `APIMART_RATE_LIMITED`, confirm that your frontend respects the `retryAfterMs` value. The reference implementation in **[`src/image25/App.jsx`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/src/image25/App.jsx)** schedules automatic retries using this delay. If the delay is excessive, check your Apimart account quota settings.

## Handling Errors in the Frontend

Implement defensive polling logic that handles the specific error codes returned by the generation API.

```javascript
async function pollGeneration(id) {
  try {
    const res = await fetch(`/api/generation/status?id=${id}`);
    const data = await res.json();

    if (!data.ok) {
      switch (data.error) {
        case 'APIMART_RATE_LIMITED':
          console.warn(`Rate limited. Retrying in ${data.retryAfterMs}ms`);
          setTimeout(() => pollGeneration(id), data.retryAfterMs);
          break;
        case 'APIMART_BALANCE_REQUIRED':
          alert('Insufficient credits. Please top up your account.');
          break;
        case 'APIMART_INVALID_TASK':
          alert('Invalid task ID or parameters.');
          break;
        default:
          alert(`Generation failed: ${data.error}`);
      }
      return;
    }

    displayImage(data.imageUrl);
  } catch (e) {
    console.error('Network or unexpected error:', e);
  }
}

```

This implementation handles rate limiting with automatic retry, displays user-friendly messages for balance issues, and provides fallback error handling for edge cases.

## Server-Side Error Implementation

The backend constructs rich error objects that preserve context from the upstream API.

In **[`src/apimartClient.js`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/src/apimartClient.js)**, errors are instantiated with full metadata:

```javascript
if (!response.ok) {
  const payload = await response.json();
  const code = apimartErrorCode(response.status, payload);
  const error = new Error(code);
  
  error.code = error.message;
  error.status = response.status;
  error.retryAfterMs = retryAfterMilliseconds(
    response.headers?.get?.('retry-after')
  );
  error.upstreamMessage = String(payload?.error?.message || '');
  
  throw error;
}

```

The API layer then translates these internal errors in **[`api/generation/status.js`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/api/generation/status.js)**:

```javascript
function statusForError(error) {
  if (error?.code === 'APIMART_RATE_LIMITED') return 429;
  if (error?.code === 'APIMART_INVALID_TASK') return 400;
  if (error?.code === 'APIMART_API_KEY_INVALID' ||
      error?.code === 'APIMART_BALANCE_REQUIRED') return 500;
  return 500;
}

```

This mapping ensures that rate limits return proper 429 status codes for HTTP caching and retry-aware clients, while internal errors return 500 series codes.

## Summary

- **Trace errors through three layers**: The Apimart client ([`src/apimartClient.js`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/src/apimartClient.js)), API endpoints ([`api/generation/status.js`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/api/generation/status.js)), and React frontend ([`src/image25/App.jsx`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/src/image25/App.jsx)).
- **Handle `APIMART_RATE_LIMITED` with care**: Respect the `retryAfterMs` field to implement compliant backoff strategies.
- **Check `upstreamMessage` for root causes**: This field contains the original Apimart error description for debugging authentication or balance issues.
- **Map internal codes to HTTP statuses**: Use `statusForError()` to return appropriate status codes (429 for rate limits, 400 for invalid tasks).
- **Log before throwing**: Server logs in the client wrapper preserve the full error context before API layer transformation.

## Frequently Asked Questions

### What does the `APIMART_RATE_LIMITED` error code mean?

The `APIMART_RATE_LIMITED` code indicates that your request exceeded the Apimart API quota for your account. According to the source code in [`src/apimartClient.js`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/src/apimartClient.js), this error includes a `retryAfterMs` property calculated from the upstream `Retry-After` header. The API layer maps this to HTTP status **429**, and the frontend should wait the specified milliseconds before retrying the request.

### How do I distinguish between authentication errors and balance errors?

Both `APIMART_API_KEY_INVALID` and `APIMART_BALANCE_REQUIRED` return HTTP **500** status codes, but you can differentiate them by examining the `upstreamMessage` property in the error response. In [`src/apimartClient.js`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/src/apimartClient.js), this field is populated from `payload?.error?.message`, providing the specific reason from the Apimart API. Check your server logs for the exact code to determine whether to prompt users to check their API key or add credits.

### Where should I implement custom error handling for the frontend?

Implement custom error handling in the polling functions within **[`src/image25/App.jsx`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/src/image25/App.jsx)** or similar React components. The reference implementation checks the `ok` boolean in the JSON response, then switches on the `error` string to display contextual UI messages. For rate limiting specifically, use the `retryAfterMs` value to schedule automatic retries via `setTimeout()` rather than alerting the user.

### What if I receive an HTML error page instead of JSON?

If you receive a plain HTML error response instead of the expected JSON structure `{ ok: false, error: "..." }`, the request likely failed before reaching the Apimart client middleware. This typically indicates a server configuration issue, routing error, or unhandled exception in the API layer outside of the generation endpoints. Check that your request reaches `/api/generation/*` endpoints and that the `statusForError()` function in [`api/generation/status.js`](https://github.com/freestylefly/awesome-gpt-image-2/blob/main/api/generation/status.js) is properly wrapping all thrown exceptions.