0027. Course Builder access: one permission, author acts, admins look

• Status: Accepted (2026-10-09)
• Date: 2026-10-09

Context and problem statement

Builder sessions hold uploaded sources (possibly confidential) and spend AI budget. Every endpoint needs a policy and tenant isolation.

Decision

• New permission course_builder_use, seeded for the admin and tutor roles (CourseBuilderPermissionSeeder, called from PermissionsSeeder; existing tenants get it when the seeder is re-run).
• A session is visible to its author and to tenant admins; only the author can act on it (upload, answer, approve, apply, publish, edit). Admins see sessions read-only.
• Every endpoint resolves its session first (directly or via a source, fragment, version, run or step) and answers 404 for unknown ids and 403 for another author’s session. Data lives in the tenant database, so ids from another tenant are unknown ids.
• With AI_DRIVER=disabled (or no key) every builder endpoint answers 503 with a clear message; the rest of the LMS is unaffected.
• Limits (defaults, env-configurable): 20 MB and 300 pages per source, 400k source tokens per session, 3M tokens and USD 5 per session, 2 concurrent AI runs per author, 10 new sessions per author per day, USD 50 AI spend per tenant per month, USD 20 eval spend per month.

Consequences

• Good: tutors build their own courses; admins can audit without taking over.
• Bad: an admin cannot finish a tutor’s abandoned session; they can start their own from the same source.