# Billing & credits

You pay only for answers actually returned. Credits are held up front as prompt × engines × samples and settled when the request finishes. Credits are bought once and never expire.

| Call | Cost per answer |
| --- | --- |
| GEO data, standard engines (chatgpt, google-aio, chatgpt-api, perplexity, grok) | 1 |
| GEO data, premium engines (gemini, gemini-api, claude) | 2 |
| Index analysis (/v1/geo/index KPIs on each answer) | +1 |
| Cache hit | 0 |
| Engine timeout, failure or no answer | 0 |
| 503 engines_unavailable (every requested engine is unavailable) | 0 |
| /v1/geo/index/summary、/v1/jobs、/v1/account、/v1/status | 0 |

### Response headers

| Header | Meaning |
| --- | --- |
| `x-credits-used` | Credits actually charged for this request |
| `x-credits-remaining` | Balance after the charge |
| `x-cache` | hit, miss or partial (some answers hit) |

### Cache

Cache key is prompt + engine + location + language + sample index, kept 24 hours and shared across accounts. Pass fresh: true to skip the cache at the normal price.