For coding agents

Reproduce once. Debug repeatedly.

Coding agents can already reproduce many browser bugs from competent textual instructions. ScenarioDeck preserves the first faithful reproduction as a State Card, so every normal fix iteration can start from the state the agent already found.

See the skill workflow

The differentiator

Reuse the successful reproduction.Basic browser automation is not the scarce part. Reconstructing the same useful route, account, form, and API state after every code change is.

Repeated reconstruction versus State Card reuse

The first confirmed reproduction becomes the stable input to the rest of the debugging loop.

Without ScenarioDeckbug report → reproduce → change code → reproduce again → state may drift

With ScenarioDeckbug report → faithful Capture → State Card
change code → reopen Card → compare

Next iterationchange code → reopen Card → compare

The skill saves the first faithful reproduction.

With the official ScenarioDeck debugging skill enabled, an applicable browser bug starts under Capture when no authoritative State Card exists. A wrong or inconclusive attempt is discarded or restarted; only a confirmed reproduction becomes the Card used by later runs.

You do not need to remember MCP tool names or add ‘use ScenarioDeck’ to every applicable bug request. The skill makes capture-then-reuse the default behavior while keeping typed fallback states explicit.

01Start CaptureNo authoritative Card exists for this browser-visible bug.
02Reproduce normallyThe coding agent follows the report in the managed Capture page.
03Confirm the symptomSave only when the described failure is faithfully observed.
04Create the State CardThe confirmed result becomes a normal reusable Card.
05Reopen and compareLater edits reuse the exact Card instead of repeating the original setup.

Exact state remains the technical proof.

The State Card gives the agent the captured route, supported browser state, request order, and explicit auth boundary. MCP exposes safe runtime actions and evidence, not a separate category of access.

Bug report

Enough to find the bug once.

The agent may still choose a different route, role, form state, or request sequence next time.

State Card

The useful result is now reusable.

captured route and browser context
supported form, storage, and API behavior
explicit authentication requirements
immutable revision and compare evidence

Keep the context. Change the selected dependency.

Supporting captured behavior can remain replayed while the dependency under investigation points to approved localhost/current code. Unexpected requests remain blocked instead of silently escaping.

/api/me: Replay
/api/account: Replay
/api/catalog: Replay
/api/calculate: Local

Frozen world

Reuse reduces repeated browser work and opportunities for state drift. It does not promise that every application or protocol can be captured.

Supporting behaviorReplay the approved captured responses.

Current codeRoute the selected dependency to approved Local.

EvidenceCompare structured results across repeated runs.

Two valid ways to start

ScenarioDeck does not require QA and the developer to adopt the same workflow at the same time.

QA sends a State Card

Open the exact handoff.

The developer or agent starts from the reviewed Card QA already captured.

QA sends text

Capture the first faithful reproduction.

The developer’s agent reproduces under Capture once, saves the confirmed Card, then reuses it.

Ground truth does not mean secret access.

Agents receive safe State Card/runtime metadata and actions. Raw passwords, tokens, Auth Bindings, and machine-local protected values are not handed to the agent.

A fresh reproduction can still be required when a Card is stale, the bug needs a different state, the workflow is unsupported, or the user explicitly asks to start again.

Make the successful reproduction reusable.

Configure MCP and the ScenarioDeck debugging skill from the maintained product guide.

Set up the agent workflow