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

# Bridging Integration Guide

> How to integrate the Relay API for bridging and onboarding

<Tip>
  New to Relay? Start with the [Quickstart Guide](/references/api/quickstart) and work your way through your first cross-chain transaction.
</Tip>

## Before you start

While not mandatory for integration, doing the following will improve the UX for your users considerably:

* **Verify user balance** - Ensure the user has sufficient funds for the bridge amount plus fees
* **Check chain support** - Confirm both origin and destination chains are supported
* **Validate quote** - Quotes are revalidated when being filled, keep your quotes as fresh as possible.
* **Handle errors** - Implement proper error handling for API requests and transaction failures

<Steps>
  <Step title="Get a Quote">
    ## Get a Quote

    Every action in Relay starts with a Quote, this includes bridging. The quote provides all necessary information including fees, transaction data, and execution steps. Use the [quote endpoint](/references/api/get-quote-v2) to request a bridge quote.

    <CodeGroup>
      ```bash Request theme={null}
      curl -X POST "https://api.relay.link/quote/v2" \
        -H "Content-Type: application/json" \
        -d '{
          "user": "0x03508bb71268bba25ecacc8f620e01866650532c",
          "originChainId": 1,
          "destinationChainId": 8453,
          "originCurrency": "0x0000000000000000000000000000000000000000",
          "destinationCurrency": "0x0000000000000000000000000000000000000000",
          "amount": "100000000000000000",
          "tradeType": "EXACT_INPUT"
        }'
      ```

      ```json Response expandable theme={null}
      {
        "steps": [
          {
            "id": "deposit",
            "action": "Confirm transaction in your wallet",
            "description": "Deposit funds for executing the bridge",
            "kind": "transaction",
            "requestId": "0x92b99e6e1ee1deeb9531b5ad7f87091b3d71254b3176de9e8b5f6c6d0bd3a331",
            "items": [
              {
                "status": "incomplete",
                "data": {
                  "from": "0x742d35Cc6634C0532925a3b8D9d4DB0a2D7DD5B3",
                  "to": "0xf70da97812cb96acdf810712aa562db8dfa3dbef",
                  "data": "0x00fad611",
                  "value": "100000000000000000",
                  "chainId": 1
                },
                "check": {
                  "endpoint": "/intents/status?requestId=0x92b99e6e1ee1deeb9531b5ad7f87091b3d71254b3176de9e8b5f6c6d0bd3a331",
                  "method": "GET"
                }
              }
            ]
          }
        ],
        "fees": {
          "gas": {
            "amount": "21000000000000000",
            "currency": "eth"
          },
          "relayer": {
            "amount": "5000000000000000",
            "currency": "eth"
          }
        },
        "details": {
          "operation": "bridge",
          "timeEstimate": 30,
          "currencyIn": {
            "currency": {
              "chainId": 1,
              "address": "0x0000000000000000000000000000000000000000",
              "symbol": "ETH",
              "name": "Ethereum",
              "decimals": 18
            },
            "amount": "100000000000000000"
          },
          "currencyOut": {
            "currency": {
              "chainId": 8453,
              "address": "0x0000000000000000000000000000000000000000",
              "symbol": "ETH",
              "name": "Ethereum",
              "decimals": 18
            },
            "amount": "95000000000000000"
          }
        }
      }
      ```
    </CodeGroup>

    You can learn more about quote request parameters and response data [here](/references/api/get-quote-v2).

    <Tip>
      To get a higher rate limit, you can [request an API key](/references/api/api-keys#how-to-get-an-api-key).
    </Tip>
  </Step>

  <Step title="Execute the Bridge">
    ## Execute the Bridge

    After receiving a bridge quote, execute it by processing each step in the response. The execution handles both the origin chain transaction and destination chain fulfillment.\
    \
    Learn more about step execution using the API [here](/references/api/api_core_concepts/step-execution).
  </Step>

  <Step title="Monitor Bridge Status">
    ## Monitor Bridge Status

    You can check the status of a bridge operation at any time using the [status endpoint](/references/api/get-intents-status-v3) with the `requestId` located inside each step object in your [quote response](/references/api/quickstart#request).

    <CodeGroup>
      ```bash Request theme={null}
      curl "https://api.relay.link/intents/status/v3?requestId=0xed42e2e48c56b06f8f384d66d5f3e6c450fc3a2c7cba19d92a01a649a31a0e94"
      ```

      ```json Response theme={null}
      {
        "status": "success",
        "inTxHashes": [
          "0xae0a66324f82bc54299663972b3a48c939af777ff795b13bd72e7755a6a68bb3"
        ],
        "txHashes": [
          "3exJVjCEMfqVCBN6FBCXPFp6JUmm91pBp9Mp5XWwkoBVAgcr6fM4kZyzdAhoRWtWAvVESMZPGA7G1CibTF8uxaMk"
        ],
        "updatedAt": 1769988962883,
        "originChainId": 8453,
        "destinationChainId": 792703809
      }
      ```
    </CodeGroup>

    <Tip>
      Poll this endpoint once per second. For a real-time status stream you can subscribe to Relay’s [**websocket server**](/references/api/api_guides/websockets).
    </Tip>

    Learn more about how to check the status of the fill [here](/references/api/api_core_concepts/step-execution#checking-the-fill-status).

    Learn more about the status lifecycle, see the [status lifecycle diagram](/references/api/quickstart#status-lifecycle).
  </Step>
</Steps>

## See Also

* [**App Fees**](/features/app-fees): Monetize your integration by adding a fee (in bps) to every quote.
* [**Deposit Addresses**](/features/deposit-addresses): Use Relay deposit addresses to unlock new chains and reduce wallet friction.
* [**Fee Sponsorship**](/features/fee-sponsorship): Sponsor fees for your users to reduce friction and improve the user experience.
* [**Handling Errors**](/references/api/api_core_concepts/handling-errors): Handle quote errors when using the Relay API.
* [**Relay Fees**](/references/api/api_core_concepts/fees): Understand the fees associated with using the Relay API.