# Quickstart: Process Your First Payment

In this guide, you'll learn how to:
- Set up authentication with API keys
- Create a payment intent
- Charge a test credit card
- Handle the response

**Time to complete**: ~10 minutes

## Before You Begin

<Check>
- A free API account ([sign up here](/signup))
- Your API key from the [dashboard](/dashboard)
- Node.js 18+ or Python 3.8+ installed
- Basic familiarity with REST APIs
</Check>

<Info>
New to REST APIs? Check out our [API Basics](/docs/api-basics) guide first.
</Info>

## Step 1: Install the SDK

<CodeGroup>
```bash npm
npm install @yourapi/sdk
```

```bash yarn
yarn add @yourapi/sdk
```

```bash pip
pip install yourapi
```
</CodeGroup>

<Note>
Don't have an API key yet? [Generate one in your dashboard](/dashboard/keys).
</Note>

## Step 2: Initialize the Client

Create a new file called `app.js` and add:

```javascript
const YourAPI = require('@yourapi/sdk');

// Initialize with your API key
const client = new YourAPI({
  apiKey: 'your_api_key_here',
  environment: 'sandbox' // Use 'production' when ready to go live
});
```

<Warning>
Never commit your API key to version control. Use environment variables in production.
</Warning>

## Step 3: Create a Payment

Now let's process a test payment:

```javascript
async function processPayment() {
  try {
    // Create a payment intent
    const payment = await client.payments.create({
      amount: 2000,        // Amount in cents ($20.00)
      currency: 'usd',
      paymentMethod: {
        type: 'card',
        card: {
          number: '4242424242424242',  // Test card
          expMonth: 12,
          expYear: 2025,
          cvc: '123'
        }
      },
      description: 'Test payment'
    });
    
    console.log('Payment successful!', payment.id);
    return payment;
  } catch (error) {
    console.error('Payment failed:', error.message);
  }
}

processPayment();
```

Run the code:
```bash
node app.js
```

You should see output like:
```
Payment successful! pay_1A2B3C4D5E6F
```

## What You Should See

If everything worked correctly:

<Check>
✓ No error messages in the console
✓ A payment ID returned (starts with `pay_`)
✓ Payment appears in your [dashboard transactions](/dashboard/transactions)
</Check>

Example successful response:

```json
{
  "id": "pay_1A2B3C4D5E6F",
  "status": "succeeded",
  "amount": 2000,
  "currency": "usd",
  "created": 1640000000
}
```

## Troubleshooting

<AccordionGroup>
  <Accordion title="Error: Invalid API key">
    Make sure you copied your API key correctly from the dashboard. 
    Check for extra spaces or missing characters.
    
    Sandbox keys start with `sk_test_`, production keys with `sk_live_`.
  </Accordion>
  
  <Accordion title="Error: Card declined">
    You're using a real card number in sandbox mode. Use test cards:
    - Success: `4242424242424242`
    - Decline: `4000000000000002`
    
    See [all test cards](/docs/testing#test-cards).
  </Accordion>
  
  <Accordion title="Connection timeout">
    Check your internet connection and firewall settings. 
    Our API requires outbound HTTPS on port 443.
  </Accordion>
</AccordionGroup>

## Next Steps

Now that you've made your first API call, explore these resources:

- [Handle Webhooks](/docs/webhooks) - Listen for payment events asynchronously
- [Set Up Refunds](/docs/refunds) - Process refunds and cancellations
- [Go to Production](/docs/production) - Deploy with production API keys
- [API Reference](/reference) - Browse all available endpoints