Adding an Edge Function

1. Decide the type

	Type A	Type B
Use when	client-triggered write/secret/external-HTTP	cron / internal / webhook
Auth	requireAuth(req)	deployed --no-verify-jwt
Name	domain-action	domain-noun-verb

2. Scaffold

Create supabase/functions/<name>/ with index.ts, helpers.ts, and tests/. Follow the shared entrypoint pattern:

const preflight = handleCors(req); if (preflight) return preflight;   // 1
try {
  const { user, serviceClient } = await requireAuth(req);            // 2 (Type A)
  const body = await req.json();
  if (!body.required) throw new ValidationError('required is required.'); // 3
  // 4 business logic — complex parts in helpers.ts
  return ok({ result });                                             // 5
} catch (e) { return err('<name>', e); }                            // 6

• Use ok() / err() from _shared/response.ts for all responses.
• Throw typed errors (ValidationError, ForbiddenError, NotFoundError, ConflictError) for status-safe responses.
• Log with _shared/logger.ts; INFO/WARN logs must carry an event field.
• Read secrets via Deno.env.get() — never log them.

3. Webhooks & idempotency

If receiving a webhook, verify the HMAC signature with a timestamp replay window + constant-time compare, and record each delivery in an audit table with a UNIQUE event id (mirror finfluencify-stream-webhook).

4. Register the name

Add it to the feature's EDGE_FN config map (e.g. edgeBuilderConfig.js). Never inline the string in a service.

5. Tests (before deploy)

Co-locate tests/. Cover: success paths, validation failures, auth/ownership (typed errors), safe 500s, and webhook signature/idempotency where relevant. Run npm run test:ef (or a targeted Deno command).

6. Document & regenerate

Re-run npm run docs:gen so the EF index picks it up. Add a dedicated page from backend/edge-functions/_template if it warrants one, and a row in Environment Variables for any new secret.

Templates + security checklist: documentations/claude/EF_PATTERNS.md and documentations/01-layout/guidelines/supabase-edge-functions-guidelines.md.