Mission Rebuild the capability of Phase 19 without following the exact code line-by-line. The goal is transfer: can you use the ideas when the variable names, UI, or route shape changes?
Required outcome Enforce resource ownership, workspace membership, roles, and permissions on the API with server-side policies.
Required artifact Permission model + guards/policies protecting TaskFlow workspace/task actions with deliberate 401/403/404 semantics.
Constraints • Start from the previous phase checkpoint or a fresh branch. • Use the course architecture boundaries, but do not copy the reference implementation until after your first attempt. • Keep changes scoped to the capability. • Preserve validation, authorization, error handling, and observability expectations already earned in earlier phases. • Record any design decision where more than one implementation is reasonable.
Acceptance criteria • Can model permission checks by action/resource. • Can test authorization matrixes. • Can prevent IDOR. • Can explain 401/403/404 choices.
Independent build sequence 1. List TaskFlow actions such as workspace.read, task.create, task.update, member.manage. 2. Map roles to capabilities without scattering role-name if statements across controllers. 3. Load membership for the relevant workspace and treat it as authorization evidence. 4. Enforce owner/member/role checks in server-side policy code. 5. Decide when 403 reveals too much and when a 404-style response better protects resource existence. 6. Write a matrix test covering at least owner, member, outsider, unauthenticated caller, and missing resource.
Self-review Compare your implementation to the reference only after the acceptance criteria pass. Differences are not automatically mistakes. For each difference, ask: does it preserve the same contract, security boundary, correctness, maintainability, and operational behavior? Keep the alternative when you can justify it with evidence.
Stretch challenge Change one assumption: more users, a second tenant, a slow network, an expired session, a concurrent mutation, a deployment restart, or a failed dependency. Predict whether your design still behaves correctly. If not, document the next architectural improvement rather than adding complexity blindly.
Phase exit Run the relevant checks, inspect Git diff, and write a three-sentence summary: what the system can do now, which boundary owns the new responsibility, and which failure you now know how to diagnose. Only then mark the phase complete.
Authorization decides what an authenticated identity may do to a specific resource. UI hiding is never a substitute for server-side enforcement.
Restate the goal of “Phase Synthesis & Independent Challenge” as one observable behavior. Write the success signal before touching code.
Trace the boundary map: trusted identity → requested action → resource scope → policy decision → allow/deny. Mark the one boundary this lesson changes.
Inspect the current repository state and record the exact files, route, table, or runtime involved. Avoid creating an abstraction before you can name the existing owner.
Implement the smallest vertical slice. Add one coherent change, run the narrowest verification command, and read the output before continuing.
Connect the slice to TaskFlow’s phase artifact: Permission model + guards/policies protecting TaskFlow workspace/task actions with deliberate 401/403/404 semantics.. Verify behavior from the outside as a user or API client would.
Create one controlled failure that is safe to reproduce. Predict the symptom first, capture evidence, locate the earliest broken boundary, then fix only that cause.
Close the reference and rebuild or explain the core change from memory. Record what you would monitor or test before trusting the same change in production.
const canEdit =
user.role === "ADMIN" ||
(user.role === "MEMBER" && task.ownerId === user.id);
if (!canEdit) throw new ForbiddenException();Do not copy this as a finished answer. Predict what each boundary does, type the smallest useful slice, run it, then compare the result with your prediction.
Trace verified identity, role, resource owner/workspace, and policy inputs separately.
Add server-side resource authorization; UI visibility is only experience, never enforcement.
Without copying the final source, create a second small scenario that applies “Phase Synthesis & Independent Challenge” to a different TaskFlow resource or input. Write the acceptance criteria first, implement it, and provide the evidence that each criterion is satisfied.
Load membership for the relevant workspace and treat it as authorization evidence.
Use the smallest change that demonstrates this lesson. Stop after it works and capture evidence.Checking membership after performing the mutation
Predict the symptom before causing the failure. Then locate the earliest boundary where reality diverges from expectation.Why does this responsibility live here, what input does it trust, what output proves success, and what would go wrong if another layer owned it?
If your explanation is vague, repeat the boundary trace before moving on.Close the reference. Reproduce the core idea from memory or explain the exact request/data flow aloud. Then check your diff or notes for accidental shortcuts that bypass validation, authorization, error handling, or verification earned in earlier phases.