Cash App Payment API

Cash App does not publish a standalone public API for arbitrary third parties. The supported routes are Cash App Pay through Square’s Web Payments SDK for approved sellers, and a third-party orchestration API that adds hosted links, QR, webhooks, and Cash App routing through approved channel partners for categories Square will not underwrite.

Does Cash App have a public API?

Short answer: not a standalone one. Cash App is a consumer product owned by Block, the parent of Square. There is no open Cash App developer portal where any business can request keys and move money directly. Instead, Cash App acceptance reaches developers through two channels:

• Square’s APIs expose Cash App Pay as a payment method for approved Square sellers.
• Orchestration providers connect Cash App acceptance through approved channel partners and expose their own API, links, and webhooks — the route for digital and high-risk categories.

The integration routes

Route A — Cash App Pay via Square Web Payments SDK

If your category is accepted by Square, this is the canonical developer path. You load Square’s Web Payments SDK on the checkout page, render the Cash App Pay button, tokenize the buyer’s approval, and complete the charge with Square’s Payments API server-side. You subscribe to Square webhooks for payment lifecycle events. It is well-documented, PCI-friendly, and settles through Square.

Route B — Hosted payment links and webhooks (no SDK)

When you do not want to build a front-end checkout, you call an orchestration API to create a hosted payment link, redirect or message the buyer to it, and receive a webhook when the payment resolves. No card fields touch your servers. This is the fastest path to a first live Cash App payment and is how most Polapine integrations start.

Route C — Third-party orchestration API

The orchestration API generalizes Route B. One set of credentials lets you create payment links, route Cash App (plus crypto, Apple Pay, and Google Pay) through approved channel partners, attach order and campaign context, and consume a single unified webhook stream regardless of the underlying rail. It is the route used by digital goods, subscriptions, and approved high-risk verticals that cannot use Square directly.

Webhooks and payment status

Whatever route you choose, your integration is driven by payment-status events. Handle at least three states so fulfilment and reconciliation stay correct:

• completed — release the product, license, credit, or access.
• failed — surface a retry path; do not fulfil.
• pending — hold fulfilment until it resolves.

Persist both the provider transaction ID and your own order ID on every record so support and dispute handling can match a payment to an order. A representative orchestration webhook payload:

POST /your-endpoint/cash-app-webhook
{
  "event": "payment.completed",
  "invoice_id": "PD-10K3F9",
  "order_id": "your-internal-7741",
  "method": "cash_app",
  "amount": "49.00",
  "currency": "USD",
  "status": "completed",
  "provider_tx_id": "ch_3Nf...",
  "created_at": "2026-06-04T15:22:08Z"
}

Square Cash App Pay vs orchestration API

Example integration flow

1. Create a payment link via the API with your order ID, amount, and Cash App as the priority rail.
2. Deliver the link or QR to the buyer (redirect, email, chat, or invoice).
3. Receive the payment.completed webhook and verify its signature.
4. Re-fetch the transaction by ID to confirm status from the API.
5. Fulfil and store both IDs for reconciliation and support.

Polapine exposes exactly this flow. Start no-code with Cash App Checkout, then move to the Cash App + Crypto Payment Links API when you are ready to automate.

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