Documentation

Guides, references, and recipes for building on Flip.

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§ Start

What do you want to build?

→Accept payments online →Collect payments with invoices →Accept payments in person →Sell subscriptions →Offer usage-based pricing →Set up the customer portal →Set up your development environment →Build on Flip with AI →Browse integration quickstarts

§ Products

Products

Pick a product to find its guides, API reference, and sample applications.

§ Quickstart

Build your first Flip integration

Our most-followed guide takes you from zero to a working card charge with the Payment Element.

Install the Flip server SDK that matches your stack — Node, Python, Ruby, PHP, Go, Java, or .NET — and import it. Keep your secret key in a server-side environment variable so it never reaches the client. Most teams hold a separate test mode key for local development and route the production key through their secrets manager.

From the server, create a PaymentIntent for each checkout attempt. The PaymentIntent is the long-lived object that follows a payment across its full lifecycle — creation, authorization, capture, refund, or failure. Specify the amount in the smallest currency unit plus the currency code; Flip applies sensible defaults to everything else.

On the client, mount the Payment Element using the client secret that came back from your server. The Element renders a payment form that adapts to the customer's region and the methods you've enabled — cards, wallets, ACH, BNPL, stablecoins, and bank redirects all surface without extra code.

When the customer hits submit, fire flip.confirmPayment with a return URL. Flip walks them through any 3DS or redirect step required, then routes them back. On the server, subscribe to webhooks to update orders, kick off fulfillment, or trigger provisioning — webhooks are the source of truth for what actually happened.

shell · curlcopy

curl https://api.flip.com/v1/payment_intents \
  -u sk_test_xxx: \
  -d "amount=2000" \
  -d "currency=usd" \
  -d "automatic_payment_methods[enabled]=true" \
  -d "description=Order #1234" \
  -d "metadata[customer_id]=cus_AbCdEf"

Send an Idempotency-Key header on writes so retries during network blips don't produce duplicate charges.

Open the full guide →

§ Reference