API quickstart: send your first lead

Before you start

You need a Sendify Direct sub account, its API key, and at least one AI configured with an initial message. If any of that is missing, start with getting started and the AI builder guide.

Four steps

1. 1

   Authenticate

   Send your key as the x-api-key header on every request against the documented base URL.

2. 2

   Create the contact

   Push one contact to the contacts endpoint using your own phone number so you can watch it arrive.

3. 3

   Start the conversation

   Call the start conversation endpoint, or let the contacts endpoint fire the first message if your Lead Configuration is set up for that.

4. 4

   Confirm

   Watch the message arrive on your phone, reply, and confirm the AI answers inside Sendify.

Exact paths, headers, request bodies, and responses are in the API reference, which also has a copy for LLM button if you want to hand the whole reference to a coding assistant.

Existing contacts and duplicates

Pushing a contact who already exists updates them rather than creating a second person. That also matters for billing: the same lead running through again is not a new billable lead, which is covered in usage billing.

Getting events back

Sendify posts events to your outbound webhook URL so your system stays in sync. Set your endpoint to accept POST, return a 2xx quickly, and treat repeated deliveries as possible retries.

If nothing happens

Check the contact was created, the correct AI is attached, an initial message exists, and the line has capacity left for the day. Then work through why is my AI not responding.