Environment Variables, Secrets, Domains, TLS, and CORS Configuration is environment-specific; secrets are never browser configuration. Both Vercel and Railway can provision HTTPS for custom domains, but CORS still has to match the API trust model.
Domain plan • app.taskflow.example.com -> Vercel
• api.taskflow.example.com -> Railway
• TLS is platform-managed after DNS verification
• Production API CORS should prefer the exact production origin, not * with credentials
Preview warning • Do not whitelist arbitrary *.vercel.app origins against production just to make previews convenient.
• Use staging API/Supabase for previews, or explicitly enumerate controlled preview access if a product requirement truly needs it. A URL is public configuration. A credential is secret. Keeping that distinction clear prevents many deployment leaks.
Sources: Vercel environment scopes; Railway custom domains/automatic SSL; TaskFlow Phase 29 security model.
Environment Secrets Domains TLS and CORS matters because it changes a real boundary in TaskFlow. The goal is to understand the inputs, owner, observable output, and failure modes before adding more abstraction.
Restate the goal of “Environment Secrets Domains TLS and CORS” as one observable behavior. Write the success signal before touching code.
Trace the boundary map: User intent → UI boundary → API contract → business rule → persistence → observable result. 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: Staging and production deployment runbooks with release identity, environment matrix, smoke tests, and rollback procedure.. 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.
OPTIONS /tasks HTTP/1.1
Origin: http://localhost:3000
Access-Control-Request-Method: POST
Access-Control-Request-Headers: authorization,content-type
HTTP/1.1 204 No Content
Access-Control-Allow-Origin: http://localhost:3000Do 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.
Return to the nearest observable boundary: input, network, process log, database, or rendered UI. Compare actual evidence with the predicted path.
Change one variable at a time and reproduce the original failure after the fix; otherwise you have correlation, not diagnosis.
Without copying the final source, create a second small scenario that applies “Environment Secrets Domains TLS and CORS” to a different TaskFlow resource or input. Write the acceptance criteria first, implement it, and provide the evidence that each criterion is satisfied.
Configure custom domains/TLS and the exact CORS/redirect origins for production.
Use the smallest change that demonstrates this lesson. Stop after it works and capture evidence.Preview deployment points to production database
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.