# subhamsahu-25/course-companion architecture > Architecture diagram of the GitHub repository subhamsahu-25/course-companion, generated by GitDiagram from its file tree, README and a sample of source files (last updated 2026-10-30). It is an AI-made overview: check details against the source. - Interactive diagram: https://gitdiagram.com/subhamsahu-25/course-companion - Repository: https://github.com/subhamsahu-25/course-companion ## Overview Course Companion supports role-based course administration and a student Q&A workflow: course material is uploaded and ingested, questions are checked against course-scoped and TA-verified knowledge, new drafts enter TA review, and approved answers return to students. The backend owns authentication, course access, persistence, uploads, and the authenticated RAG boundary; the separate RAG service owns retrieval, generation, and its review queue. The README documents service-level integrations and capabilities; several subsystem details below rely on that documentation because their implementation was not sampled. Main entry points: [`frontend/src/App.jsx`](https://github.com/subhamsahu-25/course-companion/blob/main/frontend/src/App.jsx) (Role-based UI), [`backend/src/app.js`](https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/app.js) (HTTP API), [`rag/routes/review.js`](https://github.com/subhamsahu-25/course-companion/blob/main/rag/routes/review.js) (Question and review routes), [`backend/src/models`](https://github.com/subhamsahu-25/course-companion/tree/main/backend/src/models) (Course and user data) ## Diagram (Mermaid) ```mermaid flowchart TD subgraph group_frontend["Frontend"] node_role_ui["Role-based UI
[App.jsx]"] node_ask_ui["Ask and history
[Ask.jsx]"] node_review_ui["Review queue UI
[ReviewQueue.jsx]"] node_admin_ui["Course management UI
[Modules.jsx]"] node_api_client["API client
[client.js]"] end subgraph group_backend["Backend"] node_http_api["HTTP API
[app.js]"] node_auth["Authentication
[auth.controller.js]"] node_course_ops["Course and access"] node_documents["Document uploads"] node_qa_ops["Q&A orchestration
[qa.controller.js]"] node_backend_data[("Course and user data")] node_file_store["File storage
[cloudinary.js]"] node_mail["Email notifications
[mail.js]"] node_rag_proxy["RAG service client
[rag.service.js]"] end subgraph group_rag["RAG service"] node_ingestion["PDF ingestion
[ingest-logic.js]"] node_vector_store[("Vector search store
[qdrant.js]")] node_review_routes["Question and review routes
[review.js]"] node_retrieval["Scoped retrieval
[retrieval.js]"] node_drafting["Answer drafting
[answers.js]"] node_queue_data[("Review queue
[ReviewQueueItem.js]")] end node_student(("Student")) node_ta(("TA")) node_instructor(("Instructor")) node_admin(("Admin")) node_gemini(("Gemini API")) node_mongodb[("MongoDB")] node_qdrant[("Qdrant")] node_student -->|"uses"| node_role_ui node_ta -->|"uses"| node_role_ui node_instructor -->|"uses"| node_role_ui node_admin -->|"uses"| node_role_ui node_role_ui -->|"renders"| node_ask_ui node_role_ui -->|"renders"| node_review_ui node_role_ui -->|"renders"| node_admin_ui node_ask_ui -->|"requests"| node_api_client node_review_ui -->|"requests"| node_api_client node_admin_ui -->|"requests"| node_api_client node_api_client -->|"calls"| node_http_api node_http_api -->|"routes"| node_auth node_http_api -->|"routes"| node_course_ops node_http_api -->|"routes"| node_documents node_http_api -->|"routes"| node_qa_ops node_auth -->|"reads and writes"| node_backend_data node_course_ops -->|"reads and writes"| node_backend_data node_documents -->|"reads and writes"| node_backend_data node_documents -->|"stores files"| node_file_store node_documents -->|"requests ingestion"| node_rag_proxy node_qa_ops -->|"submits and reviews"| node_rag_proxy node_qa_ops -->|"checks access"| node_backend_data node_qa_ops -.->|"notifies"| node_mail node_rag_proxy -->|"calls"| node_review_routes node_review_routes -->|"checks verified matches"| node_retrieval node_review_routes -->|"generates drafts"| node_drafting node_review_routes -->|"persists queue"| node_queue_data node_drafting -->|"uses context"| node_retrieval node_retrieval -->|"searches vectors"| node_vector_store node_ingestion -->|"writes chunks"| node_vector_store node_ingestion -.->|"embeds and captions"| node_gemini node_drafting -.->|"generates text"| node_gemini node_vector_store -->|"stores vectors"| node_qdrant node_queue_data -->|"persists queue"| node_mongodb node_backend_data -->|"persists records"| node_mongodb node_ingestion -->|"adds approved goldens"| node_review_routes click node_role_ui "https://github.com/subhamsahu-25/course-companion/blob/main/frontend/src/App.jsx" click node_ask_ui "https://github.com/subhamsahu-25/course-companion/blob/main/frontend/src/pages/student/Ask.jsx" click node_review_ui "https://github.com/subhamsahu-25/course-companion/blob/main/frontend/src/pages/ta/ReviewQueue.jsx" click node_admin_ui "https://github.com/subhamsahu-25/course-companion/blob/main/frontend/src/pages/admin/Modules.jsx" click node_api_client "https://github.com/subhamsahu-25/course-companion/blob/main/frontend/src/api/client.js" click node_http_api "https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/app.js" click node_auth "https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/controllers/auth.controller.js" click node_course_ops "https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/controllers/course.controller.js" click node_documents "https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/controllers/document.controller.js" click node_qa_ops "https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/controllers/qa.controller.js" click node_backend_data "https://github.com/subhamsahu-25/course-companion/tree/main/backend/src/models" click node_file_store "https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/utils/cloudinary.js" click node_mail "https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/utils/mail.js" click node_rag_proxy "https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/services/rag.service.js" click node_ingestion "https://github.com/subhamsahu-25/course-companion/blob/main/rag/ingest-logic.js" click node_vector_store "https://github.com/subhamsahu-25/course-companion/blob/main/rag/qdrant.js" click node_review_routes "https://github.com/subhamsahu-25/course-companion/blob/main/rag/routes/review.js" click node_retrieval "https://github.com/subhamsahu-25/course-companion/blob/main/rag/services/retrieval.js" click node_drafting "https://github.com/subhamsahu-25/course-companion/blob/main/rag/services/answers.js" click node_queue_data "https://github.com/subhamsahu-25/course-companion/blob/main/rag/models/ReviewQueueItem.js" classDef toneNeutral fill:#f8fafc,stroke:#334155,stroke-width:1.5px,color:#0f172a classDef toneBlue fill:#dbeafe,stroke:#2563eb,stroke-width:1.5px,color:#172554 classDef toneAmber fill:#fef3c7,stroke:#d97706,stroke-width:1.5px,color:#78350f classDef toneMint fill:#dcfce7,stroke:#16a34a,stroke-width:1.5px,color:#14532d classDef toneRose fill:#ffe4e6,stroke:#e11d48,stroke-width:1.5px,color:#881337 classDef toneIndigo fill:#e0e7ff,stroke:#4f46e5,stroke-width:1.5px,color:#312e81 classDef toneTeal fill:#ccfbf1,stroke:#0f766e,stroke-width:1.5px,color:#134e4a class node_role_ui,node_ask_ui,node_review_ui,node_admin_ui,node_api_client toneBlue class node_http_api,node_auth,node_course_ops,node_documents,node_qa_ops,node_backend_data,node_file_store,node_mail,node_rag_proxy,node_mongodb,node_qdrant toneAmber class node_ingestion,node_vector_store,node_review_routes,node_retrieval,node_drafting,node_queue_data,node_gemini toneMint class node_student,node_ta,node_instructor,node_admin toneIndigo ``` ## Components ### Frontend - [Role-based UI](https://github.com/subhamsahu-25/course-companion/blob/main/frontend/src/App.jsx): `frontend/src/App.jsx` - [Ask and history](https://github.com/subhamsahu-25/course-companion/blob/main/frontend/src/pages/student/Ask.jsx): `frontend/src/pages/student/Ask.jsx` - [Review queue UI](https://github.com/subhamsahu-25/course-companion/blob/main/frontend/src/pages/ta/ReviewQueue.jsx): `frontend/src/pages/ta/ReviewQueue.jsx` - [Course management UI](https://github.com/subhamsahu-25/course-companion/blob/main/frontend/src/pages/admin/Modules.jsx): `frontend/src/pages/admin/Modules.jsx` - [API client](https://github.com/subhamsahu-25/course-companion/blob/main/frontend/src/api/client.js): `frontend/src/api/client.js` ### Backend - [HTTP API](https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/app.js): `backend/src/app.js` - [Authentication](https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/controllers/auth.controller.js): `backend/src/controllers/auth.controller.js` - [Course and access](https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/controllers/course.controller.js): `backend/src/controllers/course.controller.js` - [Document uploads](https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/controllers/document.controller.js): `backend/src/controllers/document.controller.js` - [Q&A orchestration](https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/controllers/qa.controller.js): `backend/src/controllers/qa.controller.js` - [Course and user data](https://github.com/subhamsahu-25/course-companion/tree/main/backend/src/models): `backend/src/models` - [File storage](https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/utils/cloudinary.js): `backend/src/utils/cloudinary.js` - [Email notifications](https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/utils/mail.js): `backend/src/utils/mail.js` - [RAG service client](https://github.com/subhamsahu-25/course-companion/blob/main/backend/src/services/rag.service.js): `backend/src/services/rag.service.js` ### RAG service - [PDF ingestion](https://github.com/subhamsahu-25/course-companion/blob/main/rag/ingest-logic.js): `rag/ingest-logic.js` - [Vector search store](https://github.com/subhamsahu-25/course-companion/blob/main/rag/qdrant.js): `rag/qdrant.js` - [Question and review routes](https://github.com/subhamsahu-25/course-companion/blob/main/rag/routes/review.js): `rag/routes/review.js` - [Scoped retrieval](https://github.com/subhamsahu-25/course-companion/blob/main/rag/services/retrieval.js): `rag/services/retrieval.js` - [Answer drafting](https://github.com/subhamsahu-25/course-companion/blob/main/rag/services/answers.js): `rag/services/answers.js` - [Review queue](https://github.com/subhamsahu-25/course-companion/blob/main/rag/models/ReviewQueueItem.js): `rag/models/ReviewQueueItem.js` ### Other components - **Student** - **TA** - **Instructor** - **Admin** - **Gemini API** - **MongoDB** - **Qdrant** ## Connections - Student → Role-based UI: uses - TA → Role-based UI: uses - Instructor → Role-based UI: uses - Admin → Role-based UI: uses - Role-based UI → Ask and history: renders (evidence: `frontend/src/App.jsx`) - Role-based UI → Review queue UI: renders (evidence: `frontend/src/App.jsx`) - Role-based UI → Course management UI: renders (evidence: `frontend/src/App.jsx`) - Ask and history → API client: requests (evidence: `frontend/src/pages/student/Ask.jsx`) - Review queue UI → API client: requests (evidence: `frontend/src/pages/ta/ReviewQueue.jsx`) - Course management UI → API client: requests (evidence: `frontend/src/pages/admin/Modules.jsx`) - API client → HTTP API: calls - HTTP API → Authentication: routes (evidence: `backend/src/app.js`) - HTTP API → Course and access: routes (evidence: `backend/src/app.js`) - HTTP API → Document uploads: routes (evidence: `backend/src/app.js`) - HTTP API → Q&A orchestration: routes (evidence: `backend/src/app.js`) - Authentication → Course and user data: reads and writes (evidence: `backend/src/controllers/auth.controller.js`) - Course and access → Course and user data: reads and writes (evidence: `backend/src/controllers/course.controller.js`) - Document uploads → Course and user data: reads and writes (evidence: `backend/src/controllers/document.controller.js`) - Document uploads → File storage: stores files (evidence: `backend/src/controllers/document.controller.js`) - Document uploads → RAG service client: requests ingestion (evidence: `backend/src/controllers/document.controller.js`) - Q&A orchestration → RAG service client: submits and reviews (evidence: `backend/src/controllers/qa.controller.js`) - Q&A orchestration → Course and user data: checks access (evidence: `backend/src/controllers/qa.controller.js`) - Q&A orchestration → Email notifications: notifies (evidence: `backend/src/controllers/qa.controller.js`) - RAG service client → Question and review routes: calls - Question and review routes → Scoped retrieval: checks verified matches (evidence: `rag/routes/review.js`) - Question and review routes → Answer drafting: generates drafts (evidence: `rag/routes/review.js`) - Question and review routes → Review queue: persists queue (evidence: `rag/routes/review.js`) - Answer drafting → Scoped retrieval: uses context (evidence: `rag/services/answers.js`) - Scoped retrieval → Vector search store: searches vectors (evidence: `rag/services/retrieval.js`) - PDF ingestion → Vector search store: writes chunks (evidence: `rag/ingest-logic.js`) - PDF ingestion → Gemini API: embeds and captions - Answer drafting → Gemini API: generates text - Vector search store → Qdrant: stores vectors - Review queue → MongoDB: persists queue - Course and user data → MongoDB: persists records - PDF ingestion → Question and review routes: adds approved goldens (evidence: `rag/routes/review.js`)