rootnode-academy/docs/REMOTE_AND_SELF_PACED_ARCHITECTURE.md

# Remote & Self-Paced Delivery Architecture

Phase 4.1 §12. This is an architecture review, not a new product — no self-registration,
payments, or public enrollment is built here (explicit non-goal). The question this document
answers: does the infrastructure and application assume "an instructor always provisions the
Lab," and if so, where, and what would need to change for self-paced delivery to work.

## The short answer: less of that assumption exists than expected

RootNode Academy's Lab lifecycle was built student-driven from Phase 1 — `POST
/api/environment/launch` is called by the STUDENT'S OWN session, not by an instructor action.
"Prepare Labs" (`POST /api/admin/cohorts/:id/prepare-labs`) is a classroom **convenience** that
front-loads several students' launches at once before a synchronous class session, not the only
path to a running Lab. This was true before Phase 4.1 and confirmed still true by this phase's
own regression suites (`platform/test/e2e-phase2a.js` roster's two students with `cohort_id:
null` and takes them through login → curriculum → launch → scenario work with zero cohort
involvement) and by two new Phase 4.1 drills built specifically to exercise the remote/returning
-student narrative:

- `infra/scripts/drills/test-lab-host-loss.js` — student launches, makes progress, their Lab is
  destroyed out from under them (standing in for an idle-reaper destroy), Platform stays up,
  progress is untouched, they launch again unprompted and continue.
- `infra/scripts/drills/test-fake-cohort-rehearsal.js` — the same "returns later, fresh Lab,
  curriculum continues" narrative as part of a fuller classroom rehearsal.

Both pass today, with zero application code changes needed for the self-paced-relevant parts of
this flow specifically — see the Phase 4.1 report for the full run results.

## What already works, unmodified

- **Student-initiated provisioning** — no instructor step is required between "student wants to
  work" and "Lab exists." (`platform/api/src/server.js`'s `/api/environment/launch`.)
- **Cohort-less students** — `cohort_id` is nullable on student creation
  (`POST /api/admin/students`); a student with no cohort logs in, sees the curriculum, launches
  Labs, and makes progress identically to a cohorted one. Confirmed by inspection AND by the
  existing regression suite, not just by schema reading.
- **Idle reaper → academic state survives → return → continue** — the exact lifecycle this
  section describes as the target self-paced experience is what Phase 1's reaper +
  Phase 2B's Postgres-backed academic data (separate from the disposable Lab) were already
  designed to produce. Phase 4.1 proved it end-to-end, twice (see above).
- **Curriculum content itself is not cohort-gated** — `GET /api/curriculum/path` reads the one
  curriculum path file directly (`curriculum.loadCurriculumPath()`); it never checks
  `curriculum_assignments` or cohort membership at all. A self-paced student sees the full
  curriculum with no instructor action required to "unlock" it.

## What's genuinely missing for a real self-paced product (Phase 5, not built here)

1. **No self-registration / public enrollment.** A student row is created only by an instructor
   (`POST /api/admin/students`, admin/owner RBAC-gated). There is no public "sign up" surface.
   This is almost certainly the right call to leave alone for now — it's explicitly a Phase 5+
   product/business decision (course commerce, is it free, who's allowed to enroll), not an
   infrastructure gap.

2. ~~**No real student authentication.**~~ **Closed in Phase 5A.** Students now have real
   credentials (email+password or login-identifier+password, `password_hash`/`scrypt` reusing
   `instructors`' exact `src/auth/password.js`), a first-login/reset token flow, and Postgres-
   backed rate-limited/CSRF-protected sessions on the same `sessions` table instructors use — see
   `docs/PHASE5A_STUDENT_IDENTITY_REMOTE_CLASSROOM.md`. The old bare-`student_id` `POST
   /api/login` still works for not-yet-converted pilot rows only; it's rejected (409) the moment
   an account has real credentials or a pending activation token.

3. **`curriculum_assignments.student_id` is schema-ready but unwired.** The table has supported
   a direct per-student curriculum assignment (independent of any cohort) since Phase 2B
   (`CONSTRAINT curriculum_assignment_target CHECK (cohort_id IS NOT NULL OR student_id IS NOT
   NULL)`) — but nothing in the application ever reads or writes that column today; there's only
   one curriculum path, so nothing has needed to differentiate yet. Not a gap that blocks
   self-paced delivery now (every student already sees the one path with no gate), but the
   moment a second curriculum path exists, this is where per-individual assignment lands — the
   schema was designed for exactly this and doesn't need a migration to support it.

4. **No delivery-mode concept anywhere.** In-person, remote, and self-paced sessions aren't
   distinguished in any data model today, and nothing currently needs them to be — capacity
   planning, the reaper, and academic records all behave identically regardless of how a student
   is attending. Worth being aware this is unmodeled, not worth building a taxonomy for before a
   real product reason exists (YAGNI).

## What Phase 4.1 deliberately did NOT do here

No signup flow, no student password/email auth implementation, no per-student curriculum
assignment route, no payments, no public course catalog, no held/premium scenario content. All
explicit non-goals per this phase's authorization. Student authentication (item 2, above) was
closed in Phase 5A; the rest remain open, unmodeled by design (YAGNI) until a real product
reason exists.