Overview

Memberships let you offer group subscriptions where one owner pays for multiple members. The owner handles all billing and controls who has access. Members share the same entitlements as the owner but never see invoices or payment details.

When the owner cancels or their subscription expires, all members immediately lose access.

How It Works

Owner subscribes - A customer purchases a membership plan with a specified number of seats
Owner adds members - The owner invites people by email, or configures automatic access by IP address or email domain
Members get access - Invited members register or log in to activate their access

Example: A university library purchases a 500-seat subscription. They configure their campus IP range (128.112.0.0/16) for automatic access. Students on campus get access without logging in. The library can also invite specific researchers by email for off-campus access.

API Endpoints

Method	Endpoint	Description
`GET`	List members	Retrieve a paginated list of membership records
`POST`	Create member	Add an existing customer as a member of a group subscription
`POST`	Invite member	Send an email invitation to join a group subscription
`GET`	Get member	Retrieve details for a specific membership
`PUT`	Update member	Update a membership record (address)
`DELETE`	Delete member	Remove a member from a group subscription
`POST`	IP authorization	Check if an IP address has membership access

Important Behaviors

Soft delete: Removing a member soft-deletes the record and frees up a seat for another member.
Pending activation: If a pending invitation exists for a customer's email, the create endpoint activates it instead of creating a new record (returns 200 instead of 201).
Seat capacity: Adding or inviting members is subject to the subscription's member_seat_capacity limit.
Address ownership: The address_id must belong to the member's customer.
Expand behavior: The subscription field returns an integer (subscription_id) by default. Pass expand=subscription to get the full object. Same for user/user_id.

Member Statuses

Status	What It Means
`pending`	Invitation sent, waiting for the member to register or log in
`active`	Member has access to the subscription's entitlements

Membership Object

Attribute	Type	Description
`id`	integer	Unique identifier for the membership
`user_id`	integer\|null	ID of the member. Null for pending invitations. (expandable)
`subscription`	integer\|object	Subscription ID by default. Full object when `expand=subscription` is used.
`subscription_id`	integer	ID of the parent subscription (always integer)
`site_id`	integer	ID of the site
`address_id`	integer	ID of the member's address. Returns 0 when not set.
`status`	string	Membership status: `pending` or `active`
`created_at`	integer	Unix timestamp of creation
`updated_at`	integer	Unix timestamp of last update