# Find the bugs 5 people hit but no one reported > Surface real errors that affect multiple users but never get filed as tickets. The biggest source of silent churn. ## Agent adaptation contract - Canonical human page: https://agentry.sh/workflows/silent-bugs - Execution mode: on_demand - Immutable automation template: none - Applies to: universal - Required example events: $exception - Required Agentry resources: none declared - Do not use when: - Do not use until the example events are mapped to observed project signals, the current onboarding state is verified, and live event/property reads prove the required data is present. - Ask before using: - Which observed events map to $exception? Is the current onboarding state verified, and do live event/property reads show non-synthetic traffic for them? - Which live properties provide $exception.fingerprint, $exception.users_affected, and which stable user or account identifier joins the signals? This is an adaptable workflow example, not an API recipe. Map event and property names to the project's saved signal map, require status: "verified" from GET /v1/projects/:project_id/onboarding, and confirm the required signals through live event/property metadata and rows. Fetch current OpenAPI or query-blueprint details before making calls. Do not infer unattended authority from this page. ## Why this matters For every customer who reports a bug, **8 silently leave**. That's the most well-replicated number in SaaS support research. Your error tracker probably has dozens of unique fingerprints hitting multiple users — sorted by frequency, you see the loud ones (5,000 events from one cron loop, mostly noise). Sorted by users-affected, you see the silent killers: 14 different paying customers hit the same checkout error and not one of them filed a ticket. Fixing the top 5 silent bugs every Friday afternoon is the highest-ROI hour of engineering you can spend. Agentry surfaces them with one prompt. ## What you get - A ranked list of open cases by **distinct users affected** - Filtered to cases you've never looked at (no `agent_summary` yet) - For each: the message, file/line, when it started, last seen ## Walk through it **You:** > Show me errors that affected 3+ users in the last 7 days, that I haven't triaged yet. **Agent:** > Let me pull open cases ranked by distinct users. ```text Endpoint: GET /v1/projects/:project_id/cases Exact shape: /v1/openapi.json?path=%2Fv1%2Fprojects%2F%7Bproject_id%7D%2Fcases&method=get Use query parameters, not a JSON body. Query/filter concept: status: "open", min_users_affected: 3, triaged: false, since: "7d" ``` ```text { "cases": [ { "id": "c_f72a", "fingerprint": "f_72a", "error_type": "TypeError", "message": "Cannot read properties of undefined (reading 'plan')", "users_affected": 14, "event_count": 89, "first_seen_at": 1746748800, "last_seen_at": 1747353200, "agent_summary": null }, { "id": "c_1cd9", "fingerprint": "f_1cd9", "error_type": "NetworkError", "message": "fetch failed: invoice.pdf download", "users_affected": 9, "event_count": 11, "first_seen_at": 1746834200, "last_seen_at": 1747291000, "agent_summary": null }, { "id": "c_a3e1", "fingerprint": "f_a3e1", "error_type": "ValidationError", "message": "phone_number format invalid (NANP expected)", "users_affected": 7, "event_count": 14, "first_seen_at": 1746920000, "last_seen_at": 1747350800, "agent_summary": null } ] } ``` **Agent:** > Three silent bugs worth your attention this week: > > 1. **14 users · TypeError on `.plan`** — checkout / settings code reads `user.plan` without a null check. Most likely cause: free-tier users who never set a plan. Started a week ago, fires daily. > 2. **9 users · invoice PDF download fails** — `fetch failed`. Maybe a CORS issue on the new invoice service? 11 events across 9 users suggests they each tried once and gave up. > 3. **7 users · phone number rejected (NANP-only)** — your validation only accepts US/Canada format. 7 international customers hit this and didn't tell you. > > #1 is the highest-leverage fix. Want me to draft the PR? ## The output ``` 🐛 3 silent bugs (3+ users, last 7d, untriaged) 14 users · TypeError: Cannot read properties of undefined (reading 'plan') UserMenu.tsx — null-check missing on free-tier path ↗ likely fix: 4-line guard 9 users · NetworkError: fetch failed: invoice.pdf download BillingPage.tsx — CORS on new invoice service? ↗ verify CORS headers in invoice-service deploy 7 users · ValidationError: phone_number format invalid (NANP expected) SignupForm.tsx — international users blocked ↗ switch validator to libphonenumber or relax the check Cumulative customers silently impacted: 30 ``` ## Setting it up This workflow works the moment errors start flowing — no extra instrumentation needed beyond what `/install.md` already wires up. To make it more useful, also send `user.id` or `user.email` with every error event so "users affected" is accurate. Agentry has no SDK — just raw `fetch`: ```ts async function logError(err: Error, currentUser?: { email: string }) { await fetch(`https://api.agentry.sh/v1/logs/`, { method: "POST", headers: { "Authorization": `Bearer ${process.env.AGENTRY_SERVER_API_KEY}`, "Content-Type": "application/json", "User-Agent": "myapp/1.0", // REQUIRED — Cloudflare 403s default UAs }, body: JSON.stringify({ message: err.message, stack: err.stack, user: { id: currentUser?.email ?? null }, // ← THIS LINE environment: process.env.NODE_ENV, }), }); } ``` Without that, "users affected" falls back to distinct IPs, which is OK for browser apps but undercount-prone for server errors. ## Variations - *"Same query but for production only — staging errors don't count."* - *"Show me silent bugs that have been around for 30+ days. We've collectively decided to ignore these — should we?"* - *"For each silent bug, tell me roughly how much revenue is impacted (cross-reference users-affected with their plan)."* - *"After I ship a fix for case `c_f72a`, watch for it to drop to zero and post a confirmation in #eng."*