Swap via Fynd in minutes.
git clone https://github.com/propeller-heads/fynd.git
cd fyndexport TYCHO_API_KEY=your-api-key
export RUST_LOG=fynd=info
cargo run --release -- serveLast updated
npm install @kayibal/fynd-clientconst client = new FyndClient({
baseUrl: FYND_URL,
chainId: mainnet.id,
sender: account.address,
provider: viemProvider(publicClient, account.address),
fetchRevertReason: true,
});
// 1. Quote
const quote = await client.quote({
order: { tokenIn: WETH, tokenOut: USDC, amount: SELL_AMOUNT, side: 'sell', sender: account.address },
options: { encodingOptions: encodingOptions(0.005) },
});
console.log(`amount_out: ${quote.amountOut}`);
// 2. Approve if needed (checks on-chain allowance, skips if sufficient)
const approvalPayload = await client.approval({ token: WETH, amount: SELL_AMOUNT, checkAllowance: true });
if (approvalPayload !== null) {
const sig = await account.sign({ hash: approvalSigningHash(approvalPayload) });
await client.executeApproval({ tx: approvalPayload.tx, signature: sig });
}
// 3. Sign and execute swap
const payload = await client.swapPayload(quote);
const sig = await account.sign({ hash: swapSigningHash(payload) });
const settled = await (await client.executeSwap(assembleSignedSwap(payload, sig))).settle();
console.log(`settled: ${settled.settledAmount}, gas: ${settled.gasCost}`);cargo add fynd-clientlet client = FyndClientBuilder::new(FYND_URL, RPC_URL)
.with_sender(sender)
.build()
.await?;
// 1. Quote
let quote = client
.quote(QuoteParams::new(
Order::new(
Bytes::copy_from_slice(sell_token.as_slice()),
Bytes::copy_from_slice(buy_token.as_slice()),
BigUint::from(SELL_AMOUNT),
OrderSide::Sell,
Bytes::copy_from_slice(sender.as_slice()),
None,
),
QuoteOptions::default()
.with_timeout_ms(5_000)
.with_encoding_options(EncodingOptions::new(SLIPPAGE)),
))
.await?;
println!("amount_out: {}", quote.amount_out());
// 2. Approve if needed (checks on-chain allowance, skips if sufficient)
if let Some(approval_payload) = client
.approval(
&ApprovalParams::new(
Bytes::copy_from_slice(sell_token.as_slice()),
BigUint::from(SELL_AMOUNT),
true,
),
&SigningHints::default(),
)
.await?
{
let sig = signer.sign_hash(&approval_payload.signing_hash()).await?;
client
.execute_approval(SignedApproval::assemble(approval_payload, sig))
.await?
.await?;
}
// 3. Sign and execute swap
let payload = client.swap_payload(quote, &SigningHints::default()).await?;
let sig = signer.sign_hash(&payload.signing_hash()).await?;
let receipt = client
.execute_swap(SignedSwap::assemble(payload, sig), &ExecutionOptions::default())
.await?
.await?;
println!("gas: {}", receipt.gas_cost());# Wait until healthy
curl http://localhost:3000/v1/health
# → {"healthy":true,...}
# Request a quote — 1000 USDC → WETH
curl -X POST http://localhost:3000/v1/quote \
-H "Content-Type: application/json" \
-d '{
"orders": [
{
"token_in": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
"token_out": "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
"amount": "1000000000",
"side": "sell",
"sender": "0x0000000000000000000000000000000000000001"
}
],
"options": {
"timeout_ms": 5000,
"min_responses": 1
}
}'