Start with a read request and review the exact draft fields before allowing software to create records.

1. Open the current reference

Go to Integrations → Developer API → API Reference. Copy the API address shown for your account.

API Reference contains authentication and endpoint examples.
API Reference contains authentication and endpoint examples.

2. Authenticate privately

Use the key in the Authorization header as described in the reference. Keep the key out of public URLs and logs. Confirm the key’s business and record access.

3. Read before creating

For example, use the reference’s GET /customers request to find the intended customer. Lists return at most 25 records per page. Use the returned record IDs rather than guessing them.

4. Create and verify a draft

Use the documented POST /invoices fields for an eligible invoice draft. Every POST needs an Idempotency-Key; retry the same request with the same key and body. Check the response and open the saved draft before any separate sending step.