---
title: "Add to the balance with USDC on Base (x402 v2)"
method: POST
path: "/wallet/topup/crypto"
tags: ["Balance"]
---

# Add to the balance with USDC on Base (x402 v2)

`POST /wallet/topup/crypto`

## Request

- Base URL: `https://api.phoenixlabs.space`
- URL: `https://api.phoenixlabs.space/wallet/topup/crypto`
- Auth: HTTP bearer

x402 v2 over HTTP. Without a PAYMENT-SIGNATURE header the answer is 402 with the payment terms in the PAYMENT-REQUIRED header (base64 JSON; also in the body as payment_required): exact scheme, USDC on Base (eip155:8453), paid to Phoenix Labs. Sign the EIP-3009 transfer and repeat the request with the base64 PaymentPayload in PAYMENT-SIGNATURE. A facilitator settles it (no gas needed from the payer), the transfer is confirmed on-chain, and the balance is credited 1 USDC = $1. The receipt comes back in PAYMENT-RESPONSE. $1 to $200. Refunds of unused USDC balance go back to the paying address in USDC.

## Headers

- `PAYMENT-SIGNATURE` string

## Request body

- object
  - `amount_cents` integer, required

## Response `200`

Paid and credited.

- object
  - `credited_cents` integer
  - `transaction` string
  - `explorer` string
  - `wallet` Wallet
    - `wallet_id` string
    - `balance_cents` integer
    - `spendable_cents` integer
    - `paused` boolean
    - `email` string: Only shown to the wallet key.
    - `agent_key` AgentKey
      - `id` string
      - `label` string
      - `limit_cents` integer
      - `spent_cents` integer
      - `remaining_cents` integer
      - `created_at` string
      - `last_used_at` string, nullable
      - `revoked` boolean

## Other responses

- `202`: Paid; waiting for the chain to confirm. The balance is credited when it does.
- `402`: Payment required (terms in PAYMENT-REQUIRED), or the payment was refused. Nothing was taken.
- `503`: USDC payments aren't switched on.

---

[API](https://skmtc.dev/phoenixlabs/apis/phoenix-labs-api.md) · [All operations](https://skmtc.dev/phoenixlabs/apis/phoenix-labs-api/llms.txt) · [OpenAPI document](https://skmtc.dev/phoenixlabs/apis/phoenix-labs-api/revisions/7648b94d8dd2?raw)