What does it change in my repo?

It writes a verify-app skill and its feature map under your skills folder (.agents/skills by default), may add a small driver script, and adds data-testid (or platform-equivalent) attributes where key elements have no stable handle, with no behavior or styling change. It does not commit unless you ask.

Which kinds of apps does it support?

Web, Electron, iOS, Android, Flutter/React Native, backend HTTP APIs and CLIs. It picks a driver that is already a dependency of your repo where possible (Playwright or CDP, simulator tooling, an HTTP client, direct execution).

How do I know the generated skill actually works?

The last step is not optional: the agent verifies 2-3 features end to end from a cold start using only the generated skill and map, and returns evidence reports. A feature without a report is not marked verified.

Which agents does it work with?

Any agent that loads SKILL.md files and can read and write files and run terminal commands (Claude Code, Cursor, Codex and others). Exploration is faster with subagents; without them the agent covers the areas one after another.

Is it really free? Where is the source?

Yes. It is part of poteto-kit, MIT licensed, at https://github.com/EPISTEX0/poteto-kit, which also has the docs behind it and a runnable example app with a generated verify-app skill.

Is this an official Lauren Tan (poteto) skill?

No. poteto-kit is an unofficial community kit that distills her public talks and posts. It is not affiliated with or endorsed by her.

Create Verification: Let Your Agent Run Your App

Real run of this skill on the example Notes app in poteto-kit (React + Vite, an existing verify CLI, no verify-app skill yet).

create-verification report

Detected: app name poteto-kit-example (UI title "Notes"); skills dir .agents/skills; features dir src/features; gate command npm run gate.
Files written under .agents/skills/verify-app/: SKILL.md, references/cli-contract.md, references/worktree-isolation.md, references/features/{README,sidebar,editor,search,cross-cutting-flows}.md (+ the _feature.template.md copy source). The existing scripts/verify/cli.ts was kept as the CLI; capabilities it lacks (--target, heap, throttling, login) were deleted from the skill and listed in cli-contract.md.
Features mapped: 3 (sidebar, editor, search) + 1 cross-cutting flow = 13 entry points: 12 covered by 9 scenarios, 1 skip: (editor-empty-state, unreachable from the UI). npm run verify:coverage: ok.
Selectors added: 1, data-testid="sidebar-note-list" in src/features/sidebar/sidebar.tsx (the list had no handle; the rest already had aria-label / data-component / data-action-id). Made provable with one assertion (scripts/verify/selectors.ts, scripts/verify/scenarios/sidebar.ts): renaming the testid turned sidebar/create-note red (expectation failed: the note list holds four rows), restoring it turned it green.
Gates: lint, typecheck, check:deps, check:features ok; verify:all 9/9; verify:selftest ok. test:guardrails: 4 failures, tests that edit the example's original doc text by exact string.

Verification report

Target: search / all 4 scenarios, every entry point
Build: commit 7dbb0f2 (main), dirty (selector change), npm run verify -- --feature search; gates: build ok, lint ok, typecheck ok
Environment: Linux, Chrome for Testing 153.0.8010.12 headless, Node v26.11.1
Coverage: search-open-chord (Control+K and Meta+K), search-open-button, search-filter, search-navigate-arrows, search-select-enter, search-select-click, search-close-escape; each ends on the palette gone and the note open in the editor and highlighted in the sidebar; no skips
Doctor: healthy, port 20793 free, dist fresh
Verdict: PASS (4/4 scenarios, 0 failed checks)
Artifacts: artifacts/proof/2026-10-19T04-40-13-628Z/search-*/{screenshot.png,console.json,trace.json,report.md}
Console errors / failed requests: 0; known noise matched: none
Perf: long tasks (>50 ms): 0, longest 12.2 ms; tasks over 16.7 ms: 0 of 326 (shortcut-filters-and-selects)
Not verified: no match for a query that finds nothing (empty result list)

Verification report

Target: sidebar / create-note, select-note
Build: commit 7dbb0f2 (main), dirty, npm run verify -- --feature sidebar; gates as above
Coverage: sidebar-new-note (4 rows, "Untitled note" first and selected, editor title "Untitled note"), sidebar-select-note ("Grocery list" selected, body "Oat milk, coffee beans, lemons."); no skips
Verdict: PASS (2/2). Console: 0. Perf: long tasks 0, longest 15.9 ms; over 16.7 ms: 0 of 233
Artifacts: artifacts/proof/2026-10-19T04-40-12-185Z/sidebar-*/

Verification report

Target: editor / edit-title-updates-sidebar, edit-body-persists
Build: commit 7dbb0f2 (main), dirty, npm run verify -- --feature editor
Coverage: editor-edit-title (sidebar and search show "Renamed note"), editor-edit-body (text survives a switch away and back); editor-empty-state skip: unreachable from the UI, closest path covered: none
Verdict: PASS (2/2). Console: 0. Perf: long tasks 0, longest 16.8 ms; over 16.7 ms: 1 of 268 (edit-title)
Artifacts: artifacts/proof/2026-10-19T04-40-15-615Z/editor-*/
Not verified: persistence (the app has none)

About this skill

The bottleneck with coding agents isn't how fast they write code. It's how much you trust what they hand back. Until the agent can run your real app and show evidence, you are the verifier.

create-verification sets that up once per repo. Your agent:

Detects how your app runs: web, Electron, iOS, Android, Flutter/React Native, HTTP API or CLI, and the driver to use (Playwright/CDP, simulator tooling, HTTP client, direct execution). It launches the app once to prove it starts.
Explores the codebase with parallel read-only subagents: routes and screens, layout regions, menus, keybindings, test ids, feature boundaries and existing e2e tests, each claim cited by file:line.
Writes a feature map: one file per feature with sub-features, how a user gets there, and how to drive it (selectors, shortcuts, gotchas), plus cross-feature journeys.
Generates a verify-app skill from bundled templates: launch, drive, and capture evidence (screenshots, console errors, performance traces).
Adds missing stable selectors with the smallest possible diff.
Proves it by verifying 2-3 features end to end from a cold start, with evidence reports.

After that, "verify the fix" means your agent runs the real app and brings back proof, not "should work".

Everything it needs ships inside the package (verify-app templates, CLI contract, launch recipes per app type). It does not commit unless you ask.

Free and open source. Part of poteto-kit (MIT). Unofficial: poteto-kit distills public talks and posts by Lauren Tan (poteto) and is not affiliated with or endorsed by her.

Create Verification: Let Your Agent Run Your App