> ## Documentation Index
> Fetch the complete documentation index at: https://developers.circle.com/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Before reading these docs, install the relevant Circle Skill to get pre-loaded context — skills are LLM-optimized and cover architecture decisions, correct flows, and common pitfalls. In Claude Code: run /plugin marketplace add circlefin/skills then /plugin install circle-skills@circle. With Vercel Skills CLI: run npx skills add circlefin/skills. Available skills: use-usdc https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-usdc/SKILL.md (balances, transfers, approvals on EVM and Solana); EURC has no skill — see https://developers.circle.com/stablecoins/what-is-eurc.md; bridge-stablecoin https://github.com/circlefin/skills/blob/master/plugins/circle/skills/bridge-stablecoin/SKILL.md (crosschain transfers via CCTP, USDC, EURC, and third-party assets); use-arc https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-arc/SKILL.md (Arc chain config, contract deployment, USDC bridging — Arc docs: https://docs.arc.io/llms.txt); use-circle-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-circle-wallets/SKILL.md (choose wallet type); use-developer-controlled-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-developer-controlled-wallets/SKILL.md (custodial wallets for payouts and treasury); use-user-controlled-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-user-controlled-wallets/SKILL.md (embedded wallets with Web2 login); use-modular-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-modular-wallets/SKILL.md (smart contract wallets with passkeys and ERC-4337); use-gateway https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-gateway/SKILL.md (unified USDC balance, nanopayments); use-smart-contract-platform https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-smart-contract-platform/SKILL.md (deploy, interact, monitor contracts). Pair any skill with the Circle MCP server for live SDK signatures, contract addresses, and chain IDs: {"mcpServers":{"circle":{"url":"https://api.circle.com/v1/codegen/mcp"}}}.
> Read the product overview first. Each product has an overview explaining when and why to use it. Read it before quickstarts.
> Pick the right wallet type. Developer-controlled (you hold keys), user-controlled (end user holds keys via PIN/social login), or modular (smart contract wallets with passkeys). See https://developers.circle.com/wallets.md.
> Use CCTP V2 for crosschain transfers. CCTP natively transfers USDC and EURC via burn-and-mint, and supports permissionless wrapping of third-party assets via lock-and-mint. V1 is legacy; always use V2 unless V1 is specified or the chain requires it (Noble, Sui, and Aptos still require V1). Migration guide: https://developers.circle.com/cctp/migration-from-v1-to-v2.md.
> Use Bridge Kit for frontend bridging. Wraps CCTP with a simpler SDK for user-facing apps. Use CCTP directly for backend transfers.
> Gas Station vs Paymaster. Gas Station sponsors gas for Circle Wallet transactions. Paymaster lets users pay gas in USDC. Different use cases — read both overviews.
> Gateway Nanopayments for sub-cent payments. Gasless USDC micropayments down to $0.000001 via x402 and batched settlement. For pay-per-request APIs, AI agent payments, streaming.
> Look up USDC addresses per chain. Never hardcode — use https://developers.circle.com/stablecoins/usdc-contract-addresses.md.
> Prefer SDKs over raw API calls. Node.js and Python SDKs handle auth, retries, and errors.
> API key required. Bearer token in Authorization header. Testnet and mainnet use separate keys and may use different base URLs depending on the product.
> Set up webhooks when available. Most operations are async. Webhooks deliver transaction confirmations and state changes.
> When calling list endpoints, paginate using pageSize and pageAfter until no nextPageAfter cursor is returned—stopping at the first page silently misses records.
> Building an AI agent? Start with the Agent Stack—Circle CLI, agent wallets, and nanopayments built for autonomous use cases: https://developers.circle.com/agent-stack.md.

# Fund your digital asset account with a wire deposit

> Simulate a wire deposit and check your account balance using the Digital Asset Accounts API in sandbox

Walk through a basic integration flow: confirm your account, link a bank
account, get wire instructions, simulate a deposit, and verify the balance.

<Note>
  The Digital Asset Accounts API base URL is `https://api-sandbox.circle.com` for
  sandbox and `https://api.circle.com` for production. Set your API key in the
  `Authorization` header using the format `Bearer YOUR_API_KEY`. See
  [Sandbox environment](/digital-asset-accounts/references/testing-in-sandbox) and
  [Going to production](/digital-asset-accounts/references/going-to-production)
  for environment details.
</Note>

## Prerequisites

Before you begin, ensure that you've:

* Obtained an API key for Digital Asset Accounts from your Circle
  representative.
* Onboarded a business end user and recorded its `clientEntityId` and active
  `accountId`. See
  [Onboard customers](/digital-asset-accounts/quickstarts/onboard-customers).
* Run a device check for the end user and kept the `deviceId` it returned. The
  link-bank-account request in Step 2 requires the `deviceId` in `riskSignals`.
  See
  [Collect device risk signals](/end-user-onboarding/howtos/collect-device-risk-signals).
* (Recommended) Configured a
  [webhook subscription](/api-reference/webhook-endpoints#v2-notifications) for
  tracking asynchronous events.
* Checked whether Strong Customer Authentication (SCA) applies to your end
  users. Circle requires SCA for end users in the European Economic Area (EEA).
  See
  [Implement SCA](/digital-asset-accounts/howtos/strong-customer-authentication).
* Set up [mutual TLS (mTLS)](/circle-mint/set-up-mtls-authentication) for your
  entity's API traffic before going to production, if your entity operates in
  the EEA under the Markets in Crypto-Assets (MiCA) regulation.

## Step 1: Check your account balance

Confirm the account exists and check the starting balance:

```bash theme={null}
curl --request GET \
  --url https://api-sandbox.circle.com/v1/accounts/ACCOUNT_ID \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer YOUR_API_KEY'
```

Replace `ACCOUNT_ID` with your account ID and `YOUR_API_KEY` with your Bearer
token.

```json theme={null}
{
  "data": {
    "balances": [
      {
        "amount": "0.00",
        "currency": "USD"
      }
    ]
  }
}
```

## Step 2: Link a bank account

Link the end user's bank account. Circle uses it to match incoming wires and as
the destination for withdrawals.

```bash theme={null}
curl --request POST \
  --url https://api-sandbox.circle.com/v1/banks/wires \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
    "clientEntityId": "CLIENT_ENTITY_ID",
    "idempotencyKey": "RANDOM_UUID",
    "accountNumber": "123456789",
    "routingNumber": "021000021",
    "billingDetails": {
      "name": "Acme Corp",
      "line1": "100 Money Street",
      "city": "Boston",
      "district": "MA",
      "postalCode": "01234",
      "country": "US"
    },
    "bankAddress": {
      "bankName": "Chase Bank",
      "city": "New York",
      "country": "US"
    },
    "riskSignals": {
      "ipAddress": "END_USER_IP",
      "sessionId": "SESSION_ID",
      "deviceId": "DEVICE_ID"
    }
  }'
```

**Response**

```json theme={null}
{
  "data": {
    "id": "b8a025e7-d5e5-4e5a-8e35-2f3a7d1c9b4a",
    "status": "complete",
    "description": "CHASE BANK ****6789",
    "trackingRef": "CIR3XXXYYY"
  }
}
```

The response is trimmed to the fields this quickstart uses. Save the `id`: it's
the `WIRE_ID` you use in the next step. For end users in the EEA, this request
also needs SCA headers, and you can link an IBAN instead. See
[Wire deposits and withdrawals](/digital-asset-accounts/howtos/wire-deposits-and-withdrawals).

## Step 3: Get wire instructions

Retrieve the wire instructions for the linked bank account. Wire instructions
are the bank routing details your customer uses to send a wire transfer.

```bash theme={null}
curl --request GET \
  --url 'https://api-sandbox.circle.com/v1/banks/wires/WIRE_ID/instructions?accountId=ACCOUNT_ID' \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer YOUR_API_KEY'
```

The response includes a `trackingRef` that must be included in the wire
transfer:

```json theme={null}
{
  "data": {
    "trackingRef": "CIR3XXXYYY",
    "beneficiary": {
      "name": "Circle Internet Financial Inc",
      "address1": "99 High Street",
      "address2": "Boston, MA 02110"
    },
    "beneficiaryBank": {
      "name": "Silicon Valley Bank",
      "routingNumber": "121140399",
      "accountNumber": "1234567890",
      "currency": "USD",
      "country": "US"
    }
  }
}
```

## Step 4: Simulate a wire deposit

In sandbox, simulate a wire deposit using the mock payments endpoint. In
production, your customer sends a real wire transfer using the instructions from
step 3.

```bash theme={null}
curl --request POST \
  --url https://api-sandbox.circle.com/v1/mocks/payments/wire \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
    "trackingRef": "CIR3XXXYYY",
    "amount": {
      "amount": "10000.00",
      "currency": "USD"
    },
    "beneficiaryBank": {
      "accountNumber": "1234567890",
      "routingNumber": "121140399"
    }
  }'
```

The deposit starts in `pending` status (see
[Transaction states](/digital-asset-accounts/references/transaction-states)) and
settles instantly in sandbox:

```json theme={null}
{
  "data": {
    "trackingRef": "CIR3XXXYYY",
    "amount": {
      "amount": "10000.00",
      "currency": "USD"
    },
    "status": "pending"
  }
}
```

## Step 5: Verify the balance

After the deposit settles, check that the funds appear in your account:

```bash theme={null}
curl --request GET \
  --url https://api-sandbox.circle.com/v1/accounts/ACCOUNT_ID \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer YOUR_API_KEY'
```

The balance now reflects the deposited amount:

```json theme={null}
{
  "data": {
    "balances": [
      {
        "amount": "10000.00",
        "currency": "USD"
      }
    ]
  }
}
```

You now have a funded account in sandbox. See
[Account structure](/digital-asset-accounts/concepts/account-structure) to
understand how programs, accounts, and subaccounts relate.