Quickstart

You’ll need a Sandbox App ID and API key. See Authentication for how to get them.

Save your credentials

Put your credentials in environment variables so they stay out of your code and shell history.

export STREAMLINED_APP_ID="your-app-id"
export STREAMLINED_API_KEY="your-api-key"

List your customers

Every request sends both headers. This one returns the first page of customers.

curl https://api.staging.streamlinedpayments.com/api/v1/customers \
  -H "X-App-Id: $STREAMLINED_APP_ID" \
  -H "X-Api-Key: $STREAMLINED_API_KEY"

You get the customers and a meta object for paging through the rest:

{
  "customers": [
    {
      "uuid": "8f14e45f-ceea-467a-9575-1c8d3b2a9e01",
      "first_name": "Jane",
      "last_name": "Alvarez",
      "company_name": "Jane's Coffee",
      "website": "https://janescoffee.com",
      "quick_pay_enabled": true,
      "invoice_count": 12,
      "last_invoiced_at": "2026-10-02T17:20:00Z",
      "total_open_balance_amount": 113996
    }
  ],
  "meta": {
    "current_page": 1,
    "per_page": 20,
    "total_pages": 1,
    "total_count": 1
  }
}

Amounts are integers in cents, so 113996 is $1,139.96.If you get a 401, check that both headers are set and that you’re using Sandbox credentials with the Sandbox URL.

Create a customer

Send the customer’s details inside a customer object.

curl https://api.staging.streamlinedpayments.com/api/v1/customers \
  -X POST \
  -H "X-App-Id: $STREAMLINED_APP_ID" \
  -H "X-Api-Key: $STREAMLINED_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "customer": {
      "first_name": "Sam",
      "last_name": "Okafor",
      "company_name": "Northside Market",
      "net_terms": 30
    }
  }'

A 201 returns the new customer, including its uuid. Use the uuid to look up, update or invoice the customer later.

Next steps

Handle errors

What each status code means and what to do about it.

Set up webhooks

Hear about payments instead of polling for them.

⌘I

Get started

Guides

Next steps

Handle errors

Set up webhooks

​Next steps

Handle errors

Set up webhooks

Next steps