Setup

npm install @solana/web3.js tweetnacl

[dependencies]
solana-sdk    = "1.18"
solana-client = "1.18"
base64        = "0.22"
bincode       = "1"
reqwest       = { version = "0.12", features = ["json"] }
serde_json    = "1"
tokio         = { version = "1", features = ["full"] }
chrono        = "0.4"

import { Connection, Keypair } from '@solana/web3.js';

const VANISH_URL  = 'https://core-api.vanish.trade';
const connection  = new Connection(process.env.SOLANA_RPC_URL!);
const userKeypair = Keypair.fromSecretKey(
  Uint8Array.from(JSON.parse(process.env.SOLANA_KEYPAIR!))
);

async function vanish(path: string, options?: RequestInit) {
  const res = await fetch(`${VANISH_URL}${path}`, {
    ...options,
    headers: {
      'Content-Type': 'application/json',
      'x-api-key': process.env.VANISH_API_KEY!,
      ...options?.headers,
    },
  });
  if (!res.ok) {
    throw new Error(`Vanish ${res.status}: ${await res.text()}`);
  }
  return res.json();
}

use reqwest::Client;
use solana_client::rpc_client::RpcClient;
use solana_sdk::signature::Keypair;
use serde_json::Value;

const VANISH_URL: &str = "https://core-api.vanish.trade";

// initialise once and pass through your application
let client   = Client::new();
let rpc      = RpcClient::new(std::env::var("SOLANA_RPC_URL").unwrap());
let api_key  = std::env::var("VANISH_API_KEY").unwrap();
let keypair_bytes: Vec<u8> = serde_json::from_str(
    &std::env::var("SOLANA_KEYPAIR").unwrap()
).unwrap();
let user_keypair = Keypair::from_bytes(&keypair_bytes).unwrap();

async fn vanish(
    client: &Client,
    api_key: &str,
    path: &str,
    body: Option<&Value>,
) -> Result<Value, reqwest::Error> {
    let mut req = client
        .request(
            if body.is_some() { reqwest::Method::POST } else { reqwest::Method::GET },
            format!("{}{}", VANISH_URL, path),
        )
        .header("x-api-key", api_key)
        .header("Content-Type", "application/json");

    if let Some(b) = body {
        req = req.json(b);
    }

    req.send().await?.json().await
}

import * as nacl from 'tweetnacl';

const TOS = "By signing, I hereby agree to Vanish's Terms of Service and agree to be bound by them (docs.vanish.trade/legal/TOS)";

function signMessage(details: string, keypair: Keypair): string {
  const message = [TOS, "", `Details: ${details}`].join('\n');
  const sig = nacl.sign.detached(new TextEncoder().encode(message), keypair.secretKey);
  return Buffer.from(sig).toString('base64');
}

use solana_sdk::signature::Signer;
use base64::{engine::general_purpose, Engine as _};

const TOS: &str = "By signing, I hereby agree to Vanish's Terms of Service and agree to be bound by them (docs.vanish.trade/legal/TOS)";

fn sign_message(details: &str, keypair: &Keypair) -> String {
    let message = format!("{TOS}\n\nDetails: {details}");
    let sig = keypair.sign_message(message.as_bytes());
    general_purpose::STANDARD.encode(sig.as_ref())
}

// Vanish signs the transaction; you submit it. Nothing to do on the Jito route.
async function broadcast(action: { transaction: string | null }) {
  if (!action.transaction) return;
  const txId = await connection.sendRawTransaction(
    Buffer.from(action.transaction, 'base64'), { maxRetries: 3 }
  );
  await connection.confirmTransaction(txId, 'confirmed');
  return txId;
}

// poll until the action reaches a terminal status
async function commit(path: '/commit' | '/borrow/commit', txId: string) {
  for (;;) {
    const res = await vanish(path, { method: 'POST', body: JSON.stringify({ tx_id: txId }) });
    if (res.status !== 'pending') return res;
    await new Promise((r) => setTimeout(r, 2000));
  }
}

use solana_sdk::transaction::VersionedTransaction;

// Vanish signs the transaction; you submit it. Nothing to do on the Jito route.
async fn broadcast(rpc: &RpcClient, action: &Value) -> Result<Option<String>, Box<dyn std::error::Error>> {
    let Some(encoded) = action["transaction"].as_str() else { return Ok(None) };
    let tx_bytes = general_purpose::STANDARD.decode(encoded)?;
    let tx: VersionedTransaction = bincode::deserialize(&tx_bytes)?;
    Ok(Some(rpc.send_and_confirm_transaction(&tx)?.to_string()))
}

// poll until the action reaches a terminal status
async fn commit(
    client: &Client, api_key: &str, path: &str, tx_id: &str,
) -> Result<Value, reqwest::Error> {
    loop {
        let res = vanish(client, api_key, path, Some(&serde_json::json!({ "tx_id": tx_id }))).await?;
        if res["status"] != "pending" {
            return Ok(res);
        }
        tokio::time::sleep(std::time::Duration::from_secs(2)).await;
    }
}