Full Stack Trace (Team B)

For when the fix was applied to the wrong layer. Systematically checks each layer of the stack to find where the issue actually lives.

When to Use

• Directly: when the fix changed behavior but didn't resolve the issue (wrong layer)
• Via router: /persistent-issue classifies as Category B

Input

• Evidence Document from /persistent-issue
• Which layer the prior fix targeted

Agent Team (Sequential Pipeline, all model: "opus")

Dispatch 4 agents in sequence — each passes findings to the next. The break point between "correct here" and "wrong here" identifies the real layer.

Agent 1: Frontend Inspector

Check the frontend layer for this issue.

Evidence: [paste Evidence Document]

Verify:
1. Component receives correct props from parent (read root component prop passing)
2. Component state is correct (check useState initial values, useEffect deps)
3. Memoization isn't hiding stale data (check useMemo/useCallback deps)
4. CSS isn't hiding/misplacing content (check display, visibility, overflow, z-index)
5. localStorage isn't serving stale saved state
6. Event handlers fire correctly (check onClick, onChange bindings)

If using Playwright: take a screenshot and inspect the DOM for the specific element.

Output:
- CLEAR: Frontend layer is correct, data arrives correctly but [specific observation]
- FOUND: Issue is in the frontend at [file:line] because [reason]

Agent 2: API Verifier

Check the API layer. Only runs if Agent 1 reports CLEAR.

Evidence: [paste Evidence Document + Agent 1 findings]

Verify:
1. Curl the endpoint directly (with auth headers if needed)
2. Check response shape — is it JSON? correct fields? correct values?
3. Check CORS headers — is the response being blocked or modified?
4. Check if the endpoint is hitting cache vs live data (look for cache calls)
5. Check request parameters — is the frontend sending the right query?
6. Compare dev vs prod endpoint responses if relevant

Output:
- CLEAR: API returns correct data
- FOUND: Issue is in the API at [file:line] because [reason]

Agent 3: Backend Prober

Check the backend data layer. Only runs if Agent 2 reports CLEAR.

Evidence: [paste Evidence Document + Agent 1-2 findings]

Verify:
1. Cache — is the cached data correct? Check TTL, check if stale
2. Database — query the source directly, compare with cached data
3. External API — if data comes from a third-party API, check the response
4. Data transformations — check mapping logic, normalization functions

Output:
- CLEAR: Backend data is correct
- FOUND: Issue is in the backend at [file:line] because [reason]

Agent 4: Infrastructure Checker

Check infrastructure. Only runs if Agent 3 reports CLEAR.

Evidence: [paste Evidence Document + Agent 1-3 findings]

Verify:
1. Secrets — are all required secrets/env vars set?
2. Bindings — are database/cache bindings configured correctly?
3. Deploy state — is the latest code actually deployed? Compare git HEAD with deploy
4. Cron triggers — are scheduled tasks registered and running?
5. Auth config — are tokens/JWTs valid?
6. DNS — is the domain resolving correctly?

Output:
- CLEAR: Infrastructure is correct (escalate — issue may be intermittent, try Team D)
- FOUND: Issue is in infrastructure: [specific misconfiguration]

Synthesis

The first agent that reports FOUND identifies the layer. Main agent presents: "The issue is in the [layer] layer at [file:line]. The prior fix targeted [other layer] instead."

If all 4 agents report CLEAR: escalate to Team D (Temporal Forensics) — the issue may be timing-dependent.