Demo
A two-minute proof of production failure replay
This page uses one failed backend route to show the full loop: capture the failure, inspect it, replay with recorded IO, and turn the fix into a regression guard.
01
Backend route fails
A checkout or webhook path hits an upstream 503 that only appears with production inputs.
02
FluxRun captures execution
The SDK records request state, logs, network evidence, timers, random values, and result/error.
03
Dashboard shows failure
The run detail keeps root cause, timeline, network calls, payload state, and replay readiness together.
04
Replay uses recorded IO
The agent re-runs the same path without touching live DB, payment, email, queue, or external APIs.
05
Fix becomes guard
The repaired path is saved as a regression guard so the incident does not repeat silently.
Failed endpoint
One concrete backend failure
The demo stays focused on one route, one failure, and one replayable repair path.
Sample failed endpoint
The route depends on inventory and payment boundaries. The captured failure keeps the bad upstream response and the application fallback branch together.
POST /api/checkout
request: { orderId: "ord_01", customerTier: "enterprise" }
upstream: POST /inventory/check-stock -> 503
bug: fallback branch confirmed order without backorder state
replay: same request + recorded IO + zero live writesFailure detail
Inventory returned 503 after 670ms while checkout continued into a broken fallback branch.
Replay lab
Same input, fixed clock, recorded upstream response, no live production writes.
Regression guard
The fixed fallback branch becomes a deploy-time proof instead of tribal incident memory.
Interactive proof
Inspect the captured execution
The embed below is intentionally read-only for the public site, but it mirrors the product workflow: root cause, timeline, network evidence, replay lab, and regression action.
Step 3 of 5
Execution detail
- 1. Failures
- 2. Root cause
- 3. Execution detail
- 4. Replay Lab
- 5. Regression test
Guided demo mode
01
This failed in production
Inventory returned 503 during checkout.
02
Click replay
Run the same captured input with recorded IO.
03
See root cause
The failing response and fallback branch stay selected.
04
Save as test
Keep the fixed failure path as a regression test.
orders.getById
2.28sRoot Cause
inventory.checkStock returned 503
The selected timeline event is the failing network response. The request keeps moving, but this branch explains the backorder path.
event 06 / 00:00:00.955 / inventory.example.com/stock/check
Started
12:44:09.088
app runtime
Cursor
00:00:00.955
event 06
Events
9
1 important
Network
3 calls
503 selected
Insight
Slow 503 branch
response
Replay Lab
Confirm the failure without touching production systems
Original run
Inventory returned 503 after 670ms.
captured from production
Safe replay
Boundary responses are served from the recorded trace.
no fetch, queue, or database writes
Regression test
Save this execution as a test after the fix lands.
shareable with the team
This failure is now reproducible
Save this failure after signup, send the replay to your inbox, or install the SDK to capture your first production run. Start with one replay for free.
Selected Event Detail
Current activemkt-fetch-inventory-response
Event 06 / 00:00:00.955
inventory.example.com responded
Capability
fetch
Phase
response
Duration
670ms
{ "status": 503, "ok": false, "error": "inventory unavailable" }Payload access
Requires project decrypt role.
Suggested action
Open Replay Lab and save this trace as a regression test after the fix lands.
Debug Dock
resizable / bottom panel
Active tab
Network
Network evidence isolates the slow 503 branch without leaving the execution view.
Before FluxRun
2-4 hours recreating payloads, upstream responses, clocks, env, and local mocks.
During replay
Minutes to rerun the captured path with recorded IO and no live production writes.
After the fix
The same branch becomes a regression guard instead of a one-off incident note.