> ## Documentation Index
> Fetch the complete documentation index at: https://memberpulseptyltd.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Domain Rules

> Core invariants and lifecycle rules enforced in Convex mutations

This is the non-negotiable layer: rules enforced server-side, independent of UI.

## Memberships

* A member can have multiple historical memberships but at most one active membership period per plan.
* Grace period rules must be applied consistently (expiry vs grace end).

## Group memberships

* `occupiedSeats <= totalSeats`.
* You cannot remove seats below occupied count.
* Seat assignment must be tenant-scoped.

## Events

* `endAt > startAt`.
* Ticket sale windows must be within event lifecycle.
* Check-in only allowed for `confirmed/paid` registrations.

## Courses

* Completion and CPD awarding are idempotent.
* Enrollment uniqueness: a member should not have duplicate active enrollments for the same course.

## Payments / orders

* Payment status transitions must be monotonic and auditable.
* Refunds require privileged role and must log `refundedBy`.

## CRM sync

* `crmTags` must be stable (`slug`) and referenced, not free-typed strings.
* Sync records must include enough context to retry safely (idempotency keys).

## Features

### Domain Rules

#### Acceptance Criteria

##### Frontend

* [ ] Developer-facing configuration and usage is documented and internally consistent.

##### Backend / API

* [ ] Convex implementation matches the rules and contracts described on this page.

##### Permissions

* [ ] Tenant scoping and access controls are enforced as described.

##### Business Rules

* [ ] Domain rules/invariants are enforced as described.

##### Error Handling

* [ ] Access violations and validation failures produce deterministic errors.