> 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/bridge/register-bridge-wallet.md).

# POST /api/v1/bridge/wallets

Register a withdrawal wallet.

`operationId`: `registerBridgeWallet`

**Authentication:** `hmacAuth`.

Register an ownership-proven wallet as the account's withdrawal sink. Submit the `address`, the `message` returned by `POST /api/v1/bridge/wallets/challenge` echoed back verbatim, and the EIP-191 signature over it.

The address recovered from the signature must equal `address`, and the account named in the challenge must be the authenticated account. The first verified wallet becomes the default. Idempotent: re-registering an address already registered to the account returns the existing record. Registering a *different* address while one is already registered is rejected with `409` / `wallet_already_registered`: an account holds one wallet in this cut and replacement is not supported, so the request is a rejection rather than an update.

Error codes: `invalid_address`, `invalid_challenge`, `challenge_expired`, `signature_mismatch` and `account_mismatch` on `400`; `wallet_already_registered` on `409`; `wallet_registration_unavailable` on `503` when the deployment has no challenge key configured.

## Request body

**Required.** [`RegisterBridgeWalletRequest`](/api-reference/guides/schemas.md#registerbridgewalletrequest) — `application/json`.

```json
{
  "address": "0x3178f4bC9A2B1e0d2Cf5eA1B7C4D6E8F0a2B4C6D",
  "message": "Nexus Exchange: register 0x3178f4bC9A2B1e0d2Cf5eA1B7C4D6E8F0a2B4C6D as the withdrawal wallet for account 0x7a1Fb3C5D7E9A1B3C5D7E9A1B3C5D7E9A1B3C5D7\nnonce: 9f2c1d84a6b03e57\nexpires: 1785772800000\ntag: 0x4d3c1a9f",
  "signature": "0xababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababab"
}
```

## Responses

| Status | Body                                                            | Meaning                                             |
| ------ | --------------------------------------------------------------- | --------------------------------------------------- |
| `200`  | [`BridgeWallet`](/api-reference/guides/schemas.md#bridgewallet) | The registered wallet (existing or newly verified). |
| `400`  | — *(no schema declared)*                                        | —                                                   |
| `401`  | — *(no schema declared)*                                        | —                                                   |
| `409`  | — *(no schema declared)*                                        | —                                                   |
| `429`  | — *(no schema declared)*                                        | —                                                   |
| `503`  | — *(no schema declared)*                                        | —                                                   |

## Example

```bash
curl -X POST 'https://exchange.nexus.xyz/api/exchange/api/v1/bridge/wallets' \
  -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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