# Google
export GOOGLE_API_KEY="..."
```

### 5. Handle Rate Limits

Use appropriate worker counts to avoid rate limits:

```typescript
await evaluatePrompt({
  dataset,
  messages: [{ role: "user", content: "{{input}}" }],
  model: "gpt-4o",
  taskWorkers: 5, // Limit parallel requests
});
```

## Troubleshooting

### API Key Not Found

```typescript
// Error: API key not found for provider

// Solution: Set environment variable
process.env.OPENAI_API_KEY = "sk-...";
```

### Model Not Supported

```typescript
// Error: Unsupported model ID

// Solution: Use custom implementation
class MyModel extends OpikBaseModel {
  // ... implementation
}
```

### Rate Limit Errors

```typescript
// Error: Rate limit exceeded

// Solution: Reduce worker count
await evaluatePrompt({
  dataset,
  messages: [{ role: "user", content: "{{input}}" }],
  model: "gpt-4o",
  taskWorkers: 3, // Reduce from default 10
});
```

## See Also

* [evaluatePrompt Function](/reference/typescript-sdk/evaluation/evaluatePrompt) - Using models with prompt evaluation
* [Metrics](/reference/typescript-sdk/evaluation/metrics) - Using models with LLM Judge metrics
* [Vercel AI SDK Documentation](https://sdk.vercel.ai/docs) - Full LanguageModel documentation