# Engines & locations

engines accepts the 8 ids below, several per request. Each engine is billed and returned separately. Engines come in two answer types: a product answer is what a real user sees in that AI product's interface; a model answer is what the model returns through its API with its own web search turned on.

| Engine id | Platform | Answer type | Cost per answer |
| --- | --- | --- | --- |
| `chatgpt` | ChatGPT | Product answer | 1 |
| `gemini` | Gemini | Product answer | 2 |
| `google-aio` | Google AI Overview | Product answer | 1 |
| `chatgpt-api` | ChatGPT API | Model answer | 1 |
| `gemini-api` | Gemini API | Model answer | 2 |
| `claude` | Claude | Model answer | 2 |
| `perplexity` | Perplexity | Model answer | 1 |
| `grok` | Grok | Model answer | 1 |

- Product answers: chatgpt, gemini, google-aio. Model answers: chatgpt-api, gemini-api, claude, perplexity, grok.
- chatgpt and chatgpt-api, gemini and gemini-api are separate engines. For the same question the product interface and the API can give different answers and citations, and KPIs and trends are counted separately. Use product answers to see what users actually see; use model answers for reproducible, model-by-model comparisons.
- When an engine is unavailable its answers fail; we never substitute the other answer type, so data under one engine id always means the same thing.
- location: ISO 3166-1 alpha-2 country code such as JP or US. Sets the region for search results and AI Overview. Default US.
- language: BCP 47 tag such as ja, zh-CN or en. Inferred from location by default.
- google-aio only answers when the results page shows an AI Overview; otherwise status is no_answer and nothing is charged.