Pay links API - Flashnet

A pay link stores payment terms for repeat Lightning checkout through Cash App. These endpoints are not in the OpenAPI spec; this page is the reference. See Pay links for the flow.

Endpoints

Management requires a server key; POST and DELETE require X-Idempotency-Key.

POST /v1/pay-links: 201 { payLink }.
GET /v1/pay-links: { payLinks }. limit defaults to 200, clamps to 1..1000; offset defaults to 0. Use includeDisabled=true to include disabled links.
GET /v1/pay-links/:id: { payLink }.
DELETE /v1/pay-links/:id: { ok: true }; disables the URL without cancelling existing orders.

Public GET /pay/:shortId serves HTML: mobile handoff or desktop navigation to /go?n=.... /go returns a mobile 302 to Cash App or desktop QR HTML. The same completed nonce reuses its order and invoice. These links do not extend invoice expiry. Onramp short URLs reuse one order and do not support /go.

Request body

destinationChain, destinationAsset: required. Assets: USDB, USDC, USDT, PathUSD. Chains: Spark, Solana, configured CCTP-forward destinations, excluding Hedera. The pair must have a configured lightning:BTC route.
recipientAddress: required destination address.
Exactly one of amountOut or amountFiatUsd; amount modes determine fees and delivery. amountOut is a positive integer string in destination smallest units representing whole cents; fractional cents return 400 invalid_request. amountFiatUsd is "1.00" to "50000.00".
Optional affiliateId: registered affiliate. Optional label: up to 255 characters, returned as webhook payLinkLabel.

Fiat-capped exact-out requires an eligible USD-stablecoin route, a positive partner-invoiced platform fee, and no app or affiliate fee plan. Other fiat links use exact-in.

Example

Create a link targeting 25 USDC on Base:

curl -X POST "https://orchestration.flashnet.xyz/v1/pay-links" \
  -H "Authorization: Bearer SERVER_KEY" \
  -H "Content-Type: application/json" \
  -H "X-Idempotency-Key: $(uuidgen)" \
  -d '{
    "destinationChain": "base",
    "destinationAsset": "USDC",
    "recipientAddress": "RECIPIENT_ADDRESS",
    "amountOut": "25000000",
    "label": "Coffee fund"
  }'

Replace SERVER_KEY with your fn_... key. Use a new X-Idempotency-Key for each operation and reuse it when retrying that same request. Amounts are integer strings in the asset’s smallest unit: "100000" is 0.001 BTC; "50000000" is 50 USDC on Base. Read each asset’s decimals from /routes.

Response excerpt:

{
  "payLink": {
    "id": "pl_01j7qn4a2b3c4d5e6f7g8h9j0k",
    "shortId": "k3f9x2",
    "destinationChain": "base",
    "destinationAsset": "USDC",
    "recipientAddress": "RECIPIENT_ADDRESS",
    "amountOut": "25000000",
    "label": "Coffee fund",
    "shortUrl": "https://orchestration.flashnet.xyz/pay/k3f9x2"
  }
}

Orders carry payLinkId and payLinkLabel in webhooks. History has no pay-link filter; query by recipientAddress and match webhook payLinkId.

​Endpoints

​Request body

​Example

Endpoints

Request body

Example