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

# The Lesson object

> The atomic learning unit. Holds content, activities, and at most one assignment.

```json Example theme={null}
{
  "id": "lsn_01HX9N5AB3...",
  "object": "lesson",
  "cohort_id": "coh_01HX9...",
  "unit_id": "uni_01HX9...",
  "name": "The postulates of special relativity",
  "type": "reading",
  "position": 2,
  "enabled": true,
  "approved_at": "2026-05-10T13:00:00Z",
  "evaluable": true,
  "optional": false,
  "url": "https://app.hawkings.education/lessons/lsn_01HX9N5AB3",
  "metadata": {},
  "content": null,
  "activities": [],
  "assignment": null
}
```

## Attributes

<ResponseField name="id" type="string">Prefix `lsn_`.</ResponseField>

<ResponseField name="cohort_id" type="string" />

<ResponseField name="unit_id" type="string | null">Null if the lesson hangs directly off the cohort.</ResponseField>

<ResponseField name="name" type="string" />

<ResponseField name="type" type="enum">`reading` | `video` | `practice` | `assessment`.</ResponseField>
<ResponseField name="position" type="integer">Order within unit (or cohort).</ResponseField>

<ResponseField name="enabled" type="boolean" />

<ResponseField name="evaluable" type="boolean">If true, completion contributes to course grade.</ResponseField>

<ResponseField name="optional" type="boolean" />

<ResponseField name="content" type="LessonContent | null" />

<ResponseField name="activities" type="Activity[]">Expand to inline.</ResponseField>

<ResponseField name="assignment" type="Assignment | null" />