LMS and LTI Integration

ColabEdu integrates bi-directionally with external Learning Management Systems (LMS such as Canvas, Moodle, and Google Classroom) via the ce-svc-lms-integrator module in ce-svc-parent.

The integration covers three main operational areas:

Operational Synchronization: Importing organizations, courses, student/teacher rosters from the LMS into ColabEdu.
Environment Provisioning: Automated creation and teardown of E2E test environments and onboarding courses via YAML templates.
Grade Syncing: Publishing completed evaluations back to the LMS gradebook (Canvas/Moodle REST APIs via Redis Streams).

Synchronization Architecture

┌─────────────────────────────────────────────────────────┐
│                    CANVAS / MOODLE                       │
│                                                          │
│  Course ──────────── Assignment ──── Submission          │
│    │                     │               │              │
│    │  LTI context_id     │ assignment_id │  webhook     │
│    ▼                     ▼               ▼              │
├──────────────────────────┼───────────────┼──────────────┤
│  Course ◄─ context_id   resource_links ◄── lms_         │
│    │                       │ assignment_id   │           │
│  Pathway               Exercise   student_exercise_      │
│    │                       │       attempts              │
│  users.lms_external_id ────┘           │                │
│    "canvas:12345"                      ▼                │
│                              LmsSubmissionIngestion      │
│                              Service.resolveUser()       │
│                                                          │
│                        COLABEDU                          │
└─────────────────────────────────────────────────────────┘

LTI v1.3 Bridge and the B→C Pattern

In a standard LTI 1.3 flow, linking requires manual teacher action (Deep Linking). To bypass this during automated testing and E2E pipelines, ColabEdu implements the B→C (Bypass Deep Linking) pattern:

The CLI executes lms register-link ➔ persists the native lms_assignment_id directly in the database (lms_resource_links).
When a submission event is triggered in the LMS, a webhook is sent to LmsWebhookController.
The system resolves the link without requiring a manual deep link, allowing the grading engine to score and push grades back automatically.

LmsGradeSyncWorker (Redis Queue)

Publishing grades back to the external LMS is asynchronous and managed via a Redis Stream consumer:

Grading Pipeline
     │
     ▼ (FINALIZED state)
Redis Stream: lms-grade-sync-queue
     │
     ▼
LmsGradeSyncWorker.onMessage()
     │
     ├── Retrieve student exercise evaluation
     ├── Resolve lms_assignment_id from lms_resource_links
     └── LmsService.publishGrade() ➔ Canvas/Moodle REST API

CLI Commands for LMS Operations

The CLI ce-svc-cli includes the lms command group to easily manage these integrations:

Check LMS Course Status

lms status --suffix lms-test-2026

Provision Environment from YAML

lms provision --yaml canvas_scenario.yaml --suffix test-01

Manually Force Grade Push

lms grade push --evaluationId <uuid>