---
ref: tool:clerk/create-invitation
name: Invite a user
company: company:clerk
workflows: []
access: [api]
tags: [capability:authenticate-users, category:auth, has:api]
docs: https://clerk.com/docs/reference/backend-api/tag/invitations/POST/invitations
updated: 2026-09-26
---

# Invite a user

Creates an invitation for an email address and sends the invitation email with a link to sign up.

Fails if the email address already has an invitation or belongs to an
existing user. Invitations expire after a month by default.

## Set up

Use the first option your agent supports.

### API (official)

- Base URL: https://api.clerk.com/v1
- Endpoint: `POST /invitations`
- Auth: send the header `Authorization: Bearer $CLERK_SECRET_KEY`
- Get a key: https://dashboard.clerk.com/~/api-keys
- Docs: https://clerk.com/docs/reference/backend-api

Before doing anything else, make one read-only call to confirm access.

## Rules

- Ask the user before anything that sends messages, costs money, or changes data.
- Never print API keys.