Skip to main content

​
Overview

Application developers typically interact with Relay through the Relay API, which abstracts the settlement protocol entirely. However, understanding the protocol flow can help when debugging transactions or building advanced integrations. This page explains how the protocol surfaces in API responses and how to trace an order through the settlement flow.

​
Protocol Deposits via the API

When requesting a quote using the Relay API’s /quote/v2 endpoint, the response includes a protocol field when the order will be settled through the Relay Settlement protocol: 
{
  "steps": [...],
  "protocol": {
    "orderId": "0x1234...abcd",
    "depositChainId": 10,
    "paymentDetails": {
      "recipient": "0xDepositoryAddress...",
      "amount": "1000000",
      "token": "0xUSDCAddress..."
    }
  }
}
The key fields:
  • orderId — A unique identifier for this order, used to track it through the settlement flow
  • depositChainId — The chain where the user’s deposit will go
  • paymentDetails — The Depository address, token, and amount for the deposit
The protocol field only appears when the order uses the settlement protocol. Some routes may use alternative execution paths.

​
Tracing an Order

Once an order is submitted, you can trace it through the settlement flow:

​
1. Deposit Transaction

The user’s deposit transaction is a standard transfer to the Depository contract on the origin chain. You can find this on the origin chain’s block explorer.

​
2. Settlement on Relay Chain

After the solver fills the order, the Oracle attests the deposit and fill on the Relay Chain. These attestation transactions are visible on the Relay Chain Explorer.

​
3. Fill Transaction

The solver’s fill transaction is on the destination chain. This is the transaction that delivers the user’s requested action (transfer, swap, etc.).

​
When to Use Direct Protocol Integration

Most applications should use the Relay API. Consider direct protocol integration only if you need to:
  • Build custom deposit flows outside the standard API
  • Monitor settlement status at the protocol level
  • Implement custom order management
For direct integration details, see the Depository component documentation and contract references: