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

# Delta API Rust example

> End-to-end Rust example: call the Velora Delta API to quote a gasless 1 ETH → USDC intent via reqwest.

A minimal Rust program that calls `GET /v2/quote?mode=DELTA` and prints the recommended route's expected output and the `spender` from the returned `delta` block. Uses `reqwest` with `tokio`.

## File tree

```text theme={null}
my-app/
├─ Cargo.toml
└─ src/
   └─ main.rs
```

## Install

```bash theme={null}
cargo new my-app
cd my-app
cargo add reqwest --features json
cargo add tokio --features full
cargo add serde --features derive
```

## `src/main.rs`

```rust theme={null}
use serde::Deserialize;

#[derive(Deserialize, Debug)]
struct TokenAmount {
    amount: String,
}

#[derive(Deserialize, Debug)]
struct RouteStep {
    output: TokenAmount,
}

#[derive(Deserialize, Debug)]
struct Route {
    origin: RouteStep,
}

#[derive(Deserialize, Debug)]
struct DeltaPrice {
    route: Route,
    spender: String,
}

#[derive(Deserialize, Debug)]
struct QuoteResponse {
    delta: DeltaPrice,
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let params = [
        ("srcToken",     "0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE"), // ETH
        ("destToken",    "0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48"), // USDC
        ("amount",       "1000000000000000000"),                       // 1 ETH
        ("srcDecimals",  "18"),
        ("destDecimals", "6"),
        ("side",         "SELL"),
        ("chainId",      "1"),
        ("mode",         "DELTA"),
        ("userAddress",  "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"),
        ("partner",      "my-app-name"),
    ];

    let res = reqwest::Client::new()
        .get("https://api.velora.xyz/v2/quote")
        .query(&params)
        .send()
        .await?
        .error_for_status()?
        .json::<QuoteResponse>()
        .await?;

    println!("expected output: {}", res.delta.route.origin.output.amount);
    println!("spender:         {}", res.delta.spender);

    Ok(())
}
```

## Run it

```bash theme={null}
cargo run
```

You should see the recommended route's expected output (USDC, 6 decimals) and the `spender` address to approve before building the order.

## Next: build, sign, submit

Pass the unmodified `delta.route` into `POST /v2/delta/orders/build` (with `owner` set to the user address) to get EIP-712 typed data back as `{ toSign, orderHash }`. Sign `toSign` with an ERC-2098 compact signature, then `POST /v2/delta/orders` with `order` (the `toSign.value`), the `signature`, `chainId`, and your `partner`. Poll `GET /v2/delta/orders/{orderId}` for status. See [Delta → How it works](/delta/how-it-works).

<Warning>
  Pass `delta.route` **verbatim** to `/v2/delta/orders/build`. Reordering or re-encoding it will cause the build call to reject.
</Warning>

## Related pages

* [Delta overview](/delta/overview) — when to use Delta intents.
* [Delta → How it works](/delta/how-it-works) — quote → build → sign → auction → settle.
* [Delta API reference](/api-reference/delta/overview) — full parameter list.