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API ReferenceCSI Teachable Replacement AppUpdated March 13, 2026

Lesson Completion Marking API

Lesson Completion Marking API

Available since v1.0.39

This API records when a learner marks a lesson as complete, persists the completion timestamp, and triggers a recalculation of the learner's overall course progress percentage for the enrollment.

Mark a Lesson as Complete

POST /api/enrollments/{enrollmentId}/lessons/{lessonId}/complete

Path Parameters

ParameterTypeRequiredDescription
enrollmentIdstring✅The unique identifier of the learner's enrollment in the course.
lessonIdstring✅The unique identifier of the lesson being completed.

Request Body

No request body is required.

Response

200 OK — The lesson was successfully marked as complete and the enrollment progress has been updated.

{
  "enrollmentId": "enr_abc123",
  "lessonId": "les_xyz789",
  "completedAt": "2025-01-15T14:32:00Z",
  "courseProgress": {
    "completedLessons": 5,
    "totalLessons": 12,
    "progressPercentage": 41.67
  }
}

409 Conflict — The lesson has already been marked as complete for this enrollment. No duplicate record is created.

{
  "error": "LESSON_ALREADY_COMPLETED",
  "message": "This lesson has already been marked as complete for the given enrollment."
}

404 Not Found — The specified enrollment or lesson does not exist.

{
  "error": "NOT_FOUND",
  "message": "Enrollment or lesson not found."
}

Behavior

  • Idempotency — Calling this endpoint for a lesson that is already complete returns a 409 and does not create duplicate completion records.
  • Timestamp Persistence — The completedAt timestamp is recorded at the time the request is processed and stored permanently against the enrollment.
  • Progress Recalculation — Immediately after a completion is recorded, the course progress percentage is recalculated and returned in the response. The updated value is also reflected in the learner's sidebar and dashboard without requiring a page refresh.

Progress Calculation Formula

progressPercentage = (completedLessons / totalLessons) × 100

The totalLessons count includes all published lessons in the course at the time of the request.

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