> For the complete documentation index, see [llms.txt](https://docs.nexus.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nexus.xyz/api-reference/account/credit.md).

# POST /account/credit

Claim synthetic USDX credit.

`operationId`: `credit`

**Authentication:** `hmacAuth`.

Credit synthetic USDX to the authenticated account, up to a per-API-key daily allowance (default 500 USDX, resets at midnight UTC). `amount` is a decimal string; omit it to claim the full remaining daily allowance. Returns 429 with code `daily_limit_exceeded` once the allowance is used up, and 403 with code `credits_frozen` while crediting is administratively frozen. This is a **testnet-only** faucet: the credited USDX is synthetic and carries no real-world value. Mainnet has no synthetic credit — real-funds collateral arrives through the USDX bridge — so do not build a funding flow that assumes this operation exists on every network.

## Request body

Optional. [`CreditRequest`](/api-reference/guides/schemas.md#creditrequest) — `application/json`.

```json
{
  "amount": "500"
}
```

## Responses

| Status | Body                                                                | Meaning                                                                                                                                                                                                                                                                                                                                                                                                                  |
| ------ | ------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `200`  | [`CreditResponse`](/api-reference/guides/schemas.md#creditresponse) | Credit applied                                                                                                                                                                                                                                                                                                                                                                                                           |
| `401`  | — *(no schema declared)*                                            | —                                                                                                                                                                                                                                                                                                                                                                                                                        |
| `403`  | — *(no schema declared)*                                            | Refused. Either crediting is administratively frozen (`credits_frozen`), or a jurisdiction control refused the write (`US_RESTRICTED` / `GEO_UNRESOLVED` / `RESTRICTED_JURISDICTION`) — the latter are permanent for the caller's origin and must not be retried. Branch on `code`, which for the jurisdiction reasons equals the `x-nexus-block-reason` header. See “Jurisdiction restrictions” in the API description. |
| `429`  | — *(no schema declared)*                                            | Daily credit allowance exhausted (resets at midnight UTC)                                                                                                                                                                                                                                                                                                                                                                |

## Example

```bash
curl -X POST 'https://exchange.nexus.xyz/api/exchange/account/credit' \
  -H 'X-API-Key: nx_7f3a1b...' \
  -H 'X-Timestamp: 1776033911836' \
  -H 'X-Signature: <hmac-sha256>' \
  -H 'Content-Type: application/json'
```

***

<sub>Generated from</sub> <sub></sub><sub>`eng/apps/exchange/api/openapi.json`</sub> <sub></sub><sub>(spec</sub> <sub></sub><sub>`0.9.27`</sub><sub>). Do not edit by hand — regenerate with</sub> <sub></sub><sub>`python3 product/docs/tools/api-reference/generate.py`</sub><sub>. Hand-authored context lives in the Guides pages.</sub>


---

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