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 surface.** Still true, still deliberate — Phase 5B
   built the boundary a *separate* public website will call
   (`POST /api/integrations/enrollments`, see `docs/PHASE5B_SELF_PACED_ENROLLMENT.md` §11 and
   `docs/WEBSITE_ENROLLMENT_INTEGRATION.md`) rather than a public sign-up form here. A student
   row can now be created automatically by a trusted server-to-server enrollment event, but there
   is still no browser-facing "sign up" page anywhere in this codebase — that's the website's job.

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.**~~ **Addressed
   differently in Phase 5B.** `curriculum_assignments` itself remains unwired, unchanged — but
   the real problem it was meant to eventually solve (which curriculum a given student sees) is
   now solved at the enrollment layer instead: `enrollments.curriculum_path` snapshots
   `programs.curriculum_path` per enrollment. `curriculum_assignments` is still available for a
   future direct per-student assignment need outside the program/enrollment model — it wasn't
   removed, just not the mechanism Phase 5B ended up using. See
   `docs/PHASE5B_SELF_PACED_ENROLLMENT.md` §4.

4. ~~**No delivery-mode concept anywhere.**~~ **Closed in Phase 5B.**
   `programs.delivery_mode`/`enrollments.delivery_mode` (`self_paced`/`cohort`/`hybrid`) is now
   a real, snapshotted field. Capacity planning, the reaper, and Lab lifecycle mechanics still
   behave identically regardless of delivery mode — this only affects how enrollment/entitlement
   is modeled, not infrastructure.

5. **No self-paced enrollment/entitlement model.** ~~Closed in Phase 5B~~ — see
   `docs/PHASE5B_SELF_PACED_ENROLLMENT.md` for `programs`/`enrollments`, server-enforced
   entitlement (pending/future/expired/cancelled), server-derived completion, and the resulting
   self-paced student dashboard.

## 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 (Phase 5A) and the
self-paced enrollment/entitlement model (Phase 5B) have both since been built; a public
self-registration *page*, real payment processing, and a Parent/Guardian portal remain
deliberately out of scope — see `docs/PHASE5B_SELF_PACED_ENROLLMENT.md` §12.