Install the SDK, authenticate, and move your first cross-chain payment. Everything below works against the sandbox with test keys.
npm install @flowpay/sdkEvery request uses a bearer key scoped to an environment. Sandbox keys start with fp_test_ and settle on mirrored testnets with identical finality semantics.
export FLOWPAY_KEY="fp_live_9f2c…"Payments are idempotent. Pass an idempotency key to retry safely; the router picks the cheapest path that meets your finality target.
const payment = await flowpay.payments.create({
to: "ada@flowpay",
amount: "250.00",
currency: "USDC",
routing: "optimal",
});Subscribe to payment.settled and payment.failed. Every payload is signed with HMAC-SHA256 — verify before acting on it.
POST /webhooks/flowpay
x-flowpay-signature: t=1720…,v1=8a91…