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

# Initiate CCTP Bridge Transfer — POST /api/cctp/transfer

> POST /api/cctp/transfer — testnet/development flow: initiates a Circle CCTP bridge transfer of native USDC into Arc Testnet from the authenticated consumer's own FlareHQ-created Circle wallet.

<Warning>
  **Testnet/development flow.** This endpoint documents bridging into **Arc Testnet** (chain ID `5042002`, destination `Arc_Testnet`) for development and testing. FlareHQ production runs on **Arc Mainnet** (chain ID `5042`). Mainnet CCTP bridging is not claimed here — confirm the production bridging path with the operator.
</Warning>

Initiate a Cross-Chain Transfer Protocol (CCTP) bridge of **native USDC** into Arc Testnet (chain ID `5042002`). The transfer always originates from the signed-in consumer's own FlareHQ-created Circle developer-controlled wallet — never from a shared platform wallet and never from an address supplied in the request body. The route returns immediately with a `bridge_...` reference and runs the bridge in the background; poll [GET /api/cctp/transfer/status](/api-reference/cctp/status) with that reference to track progress.

Because this endpoint bridges from the caller's own wallet, authentication is **consumer-session based** (an `consumer_token` cookie), not an API key.

## Endpoint

```
POST https://flarehq.xyz/api/cctp/transfer
```

## Request

### Headers

| Header | Value |
| - | - |
| `Cookie` | `consumer_token=<JWT>` — required. Signed-in consumer session. The consumer's wallet must be a FlareHQ-created (Circle) wallet, not an external bring-your-own wallet. |
| `Content-Type` | `application/json` — required |

### Body Parameters

<ParamField body="fromChain" type="string" required>
  Source chain identifier. Must be one of the supported source chain IDs:

  * `"Arbitrum_Sepolia"` — Arbitrum Sepolia
  * `"Base_Sepolia"` — Base Sepolia
  * `"Optimism_Sepolia"` — Optimism Sepolia
  * `"Ethereum_Sepolia"` — Ethereum Sepolia
  * `"Polygon_Amoy_Testnet"` — Polygon Amoy

  The consumer's wallet is automatically provisioned on this chain the first time they bridge from it.
</ParamField>

<ParamField body="toChain" type="string" required>
  Destination chain identifier. Must be `"Arc_Testnet"` — Arc is the only destination this endpoint bridges into.
</ParamField>

<ParamField body="amount" type="string" required>
  USDC amount to bridge, as a decimal string (e.g. `"100.00"`). Pass the human-readable value, not raw atomic units.
</ParamField>

<ParamField body="recipient" type="string" required>
  The `0x...` Arc Testnet wallet address that will receive the minted USDC on the destination chain.
</ParamField>

## Response

<ResponseField name="success" type="boolean">
  `true` when the bridge transfer was initiated successfully.
</ResponseField>

<ResponseField name="status" type="string">
  Always `"pending"` on the initial response. Poll the status endpoint to track progress.
</ResponseField>

<ResponseField name="reference" type="string">
  Unique transfer identifier with the prefix `bridge_`. Pass it as the `reference` query parameter to [GET /api/cctp/transfer/status](/api-reference/cctp/status).

  Example: `"bridge_lx4m9q2t7w8k3p0ab5"`.
</ResponseField>

<ResponseField name="message" type="string">
  Human-readable instruction pointing at the status endpoint.

  Example: `"Bridge started — poll /api/cctp/transfer/status?reference=... to check progress."`
</ResponseField>

### Listing Supported Chains

A `GET` to the same path returns the current lists of supported source and destination chains without authenticating:

<ResponseField name="success" type="boolean">
  `true`.
</ResponseField>

<ResponseField name="sourceChains" type="array">
  Array of `{ id, label, testnet, circleBlockchain }` objects for every supported source chain.
</ResponseField>

<ResponseField name="destinationChains" type="array">
  Array of `{ id, label, testnet }` objects for every supported destination chain (always `Arc_Testnet`).
</ResponseField>

## Examples

<CodeGroup>
  ```bash cURL theme={null}
  curl -X POST https://flarehq.xyz/api/cctp/transfer \
    -H "Cookie: consumer_token=<your-session-jwt>" \
    -H "Content-Type: application/json" \
    -d '{
      "fromChain": "Ethereum_Sepolia",
      "toChain": "Arc_Testnet",
      "amount": "100.00",
      "recipient": "0xYourArcWalletAddress"
    }'
  ```

  ```js Node.js (fetch) theme={null}
  const res = await fetch('https://flarehq.xyz/api/cctp/transfer', {
    method: 'POST',
    headers: {
      Cookie: 'consumer_token=<your-session-jwt>',
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      fromChain: 'Arbitrum_Sepolia',
      toChain: 'Arc_Testnet',
      amount: '100.00',
      recipient: '0xYourArcWalletAddress',
    }),
  });

  const { success, reference, status } = await res.json();
  // Poll GET /api/cctp/transfer/status?reference=... with the reference
  ```
</CodeGroup>

### Success Response

```json theme={null}
{
  "success": true,
  "status": "pending",
  "reference": "bridge_lx4m9q2t7w8k3p0ab5",
  "message": "Bridge started — poll /api/cctp/transfer/status?reference=bridge_lx4m9q2t7w8k3p0ab5 to check progress."
}
```

### Chain Listing Response

```json theme={null}
{
  "success": true,
  "sourceChains": [
    { "id": "Arbitrum_Sepolia", "label": "Arbitrum Sepolia", "testnet": true, "circleBlockchain": "ARB-SEPOLIA" },
    { "id": "Base_Sepolia", "label": "Base Sepolia", "testnet": true, "circleBlockchain": "BASE-SEPOLIA" },
    { "id": "Optimism_Sepolia", "label": "Optimism Sepolia", "testnet": true, "circleBlockchain": "OP-SEPOLIA" },
    { "id": "Ethereum_Sepolia", "label": "Ethereum Sepolia", "testnet": true, "circleBlockchain": "ETH-SEPOLIA" },
    { "id": "Polygon_Amoy_Testnet", "label": "Polygon Amoy", "testnet": true, "circleBlockchain": "MATIC-AMOY" }
  ],
  "destinationChains": [
    { "id": "Arc_Testnet", "label": "Arc Testnet", "testnet": true }
  ]
}
```

### Error Responses

```json theme={null}
{
  "success": false,
  "error": "Sign in required to bridge funds."
}
```

```json theme={null}
{
  "success": false,
  "error": "Missing fields: fromChain, toChain, amount, recipient"
}
```

```json theme={null}
{
  "success": false,
  "error": "Unsupported source chain: SOL-DEVNET"
}
```

```json theme={null}
{
  "success": false,
  "error": "Bridging currently requires a FlareHQ-created wallet — external (bring-your-own) wallets can't be bridged from automatically."
}
```

## Notes

<Note>
  The bridge runs asynchronously and is **not** awaited inside the request — the HTTP response is returned as soon as the transfer is registered. Progress is tracked in process memory, so on a single-instance deployment the reference stays queryable until the transfer settles or the server restarts. If the server restarts before completion, the status endpoint reports the transfer as not found.
</Note>

<Warning>
  This endpoint only bridges **into** Arc. Moving USDC back out of Arc requires starting a new transfer with Arc as the source chain — reversing the same transfer is not possible.
</Warning>