Quickstart

Make your first API call in under 2 minutes. No SDK required, just an API key and an HTTP client.

Create an account

Sign up at tryesperworks.com/register and complete your business profile. You need an active business to generate API keys.

Generate an API key

Go to Dashboard → Developer API and click New Key. Select the scopes your integration needs. Copy the key, it's shown only once.
Use an ew_test_ key while building, it skips real emails and lets you simulate payments.

Verify your key

curl https://api.tryesperworks.com/api/v1/ping \
  -H "Authorization: Bearer ew_live_xxxxxxxxxxxxxxxxxxxx"

# Response:
# { "status": "ok", "environment": "live", "business": { "name": "Your Business" }, "scopes": [...] }

Create a client, invoice, and send it

# 1. Create a client
curl -X POST https://api.tryesperworks.com/api/v1/clients \
  -H "Authorization: Bearer ew_live_xxxx" \
  -H "Content-Type: application/json" \
  -d '{"name":"Kofi Mensah","email":"kofi@example.com"}'

# 2. Create an invoice (use the client id from step 1)
curl -X POST https://api.tryesperworks.com/api/v1/invoices \
  -H "Authorization: Bearer ew_live_xxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "client_id": 1,
    "issue_date": "2026-05-01",
    "due_date": "2026-05-15",
    "currency": "GHS",
    "items": [{"description": "Web design", "quantity": 1, "rate": 2500}]
  }'

# 3. Send it, response includes payment_url to share with client
curl -X POST https://api.tryesperworks.com/api/v1/invoices/1/send \
  -H "Authorization: Bearer ew_live_xxxx"

The payment_url in the response is a public link your client can open to pay, no EsperWorks account needed on their end.

Next steps

Set up webhooks

Get notified when invoices are paid.

Embed a payment widget

Drop a payment button into your site.

Test mode

Simulate payments without real money.

Full API reference

All endpoints, scopes, and response shapes.