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

# Lessons

> The ordered units a course is taught in.

A **Lesson** is one unit within a [course](/domains/courses). Lessons are ordered, and that order is what a learner moves through in Holos Learn.

## Key fields

| Field                   | Description                 |
| ----------------------- | --------------------------- |
| `title` / `description` | The lesson itself           |
| `courseId`              | The course it belongs to    |
| `lessonIndex`           | Position within that course |
| `createdBy`             | The member who created it   |

## Ordering

`lessonIndex` is not edited directly. `PATCH /lessons/reorder` takes the sequence and rewrites the indices together, so the order stays contiguous no matter how a lesson is moved.

## Endpoints

Full endpoint reference is available in the OpenAPI spec. Key operations:

* `GET /lessons`: list lessons, scoped to a course
* `POST /lessons`: create a lesson
* `GET /lessons/{id}`: get a lesson
* `PUT /lessons/{id}`: update it
* `PATCH /lessons/reorder`: reorder a course's lessons
* `DELETE /lessons/{id}`: delete a lesson