A: **1) Yes, and yes. The "welcome email" is the Portal Access Invitation.**

When you create a Contact via POST /contact with send_welcome_email: true, the invitation goes out immediately. That email is built from your account's New User Registration email template and carries a one-time login link that drops the person straight into the Portal to set their password. There is no separate invitation call, because the welcome email is the invitation.

Three things to know. It only applies to Roles that get a Portal login, so Client and Prospect. A Lead has no Portal user, so the flag does nothing there. You can invite later with PUT /contact/{identifier} and send_welcome_email: true, but as the description you quoted says, that only fires if an invitation has never been sent to that Contact. It is not a resend, and resending is done from the Contact record in the app. On POST /company the same flag exists at primaryContact.send_welcome_email and behaves identically for the Primary Contact.

**2) Yes, but not with a direct endpoint. Use the flag pattern.**

There is no "send this email with this template" call in the API. What you do instead is use the API to set a flag and let the platform's automation engine send the email.

Create a Custom Field on the Contact and use it as a flag. Your external system writes a value to that field via the API. That value change triggers the Dynamic Logic Engine, because the value it is watching for is now true for that Target, and that instantly fires an Auto-Template against that Target.

Inside that Auto-Template you have five email Automations to choose from:

- Send Email to Target, using whichever email template you select
- Email External(s)
- Email Internal(s)
- Send Portal Access Invitation Email, the same invitation from question 1, triggered on demand
- Fire Email Cannon(s)
- A.I. Compose Automation

So yes, you can choose an email template and send an email via the API. You choose the template inside the Auto-Template, and the API call is what fires it.

The reason this pattern is worth learning is that it goes well beyond email. The Automations layer is much wider than the API endpoint list, and everything in it becomes reachable this way: create Projects, generate Invoices, assign Circles, start Drip Sequences, share Files, trigger Follow-Ups. Instead of asking whether an endpoint exists for a specific action, you set a flag and let the automation engine execute the work. One API call becomes a chain of twenty actions. It is the single most powerful integration technique on the platform and almost nobody uses it.

**3) Yes for Clients and Prospects. No for Leads.**

Both POST /contact and PUT /contact/{identifier} accept a circles object:

{
"role": "Client",
"first_name": "John",
"last_name": "Doe",
"email": "[email protected]",
"send_welcome_email": true,
"circles": { "add": ["VIP Clients", "Onboarding 2026"] }
}

On update you can also pass "remove": [...].

Circles are matched by name and must already exist. The API will not create one. Auto-generated Company Circles cannot be targeted, but regular Circles and Marketing List Circles can.

Leads cannot be placed in a Circle (Prospects/Clients only). Circle membership is attached to a Portal user account, and a Lead does not have one. If you send circles.add on a Lead the request still succeeds, but the Circles are ignored. Create the person as a Prospect, or convert the Lead, if you need them in a Circle.

Thanks,

Mike