Stripe Has a Free API (for Testing) — Build Payment Flows Without Spending a Cent

#javascript #webdev #api #tutorial

Test Mode Is Basically a Free Payment API

Stripe test mode gives you a fully functional payment API with fake money. Same endpoints, same webhooks, same everything — just no real charges.

Setup

pip install stripe
# or
npm install stripe

Use test keys from dashboard.stripe.com/test/apikeys.

Create a Payment Intent (Python)

import stripe
stripe.api_key = "sk_test_your_test_key"

intent = stripe.PaymentIntent.create(
    amount=2000,  # $20.00 in cents
    currency="usd",
    payment_method_types=["card"]
)
print(f"Client secret: {intent.client_secret}")

Create a Checkout Session

session = stripe.checkout.Session.create(
    payment_method_types=["card"],
    line_items=[{
        "price_data": {
            "currency": "usd",
            "product_data": {"name": "Pro Plan"},
            "unit_amount": 999,  # $9.99
        },
        "quantity": 1,
    }],
    mode="payment",
    success_url="https://example.com/success",
    cancel_url="https://example.com/cancel",
)
print(f"Checkout URL: {session.url}")

Test Cards

Card Number	Result
4242 4242 4242 4242	Success
4000 0000 0000 0002	Declined
4000 0000 0000 3220	3D Secure

Any future expiry date and any CVC work.

Handle Webhooks

from flask import Flask, request
app = Flask(__name__)

@app.route("/webhook", methods=["POST"])
def webhook():
    event = stripe.Webhook.construct_event(
        request.data, request.headers["Stripe-Signature"],
        "whsec_your_webhook_secret"
    )
    if event["type"] == "payment_intent.succeeded":
        payment = event["data"]["object"]
        print(f"Payment received: ${payment[amount]/100}")
    return "", 200