Michał Pierzchała
10ff339d14
* refactor: declare selector resolution policy as data (#1630) Five native consumers of "resolve a selector against the screen" each hand-declared their ambiguity contract as inline requireUnique/ disambiguateAmbiguous literals, so the repo's real policy matrix was only discoverable by reading four files. SELECTOR_RESOLUTION_POLICIES (packages/selectors) now declares one row per caller — ambiguity kind plus the structural columns (rect, occlusion, off-screen guard, promotion, poll) — and selectorResolutionKnobs turns a row into the engine knobs it stands for. Callers consume rows; zero ambiguity literals remain in src. Semantics are unchanged by construction: each row was read off its call site. The matrix names what was previously implicit — act and get text disambiguate, is/get attrs fail closed, exists/find-reads and wait take the first match, mutating find rejects candidates unless narrowed (#1625). `reject-candidates` is declaration-only and rejected by selectorResolutionKnobs at the type level, because find enforces it through its own narrowing rather than engine knobs. resolution-policy-parity.test.ts gate-tests the matrix against the callers (ADR 0011's declared-plus-gate-tested pattern): knobs must match the named ambiguity contract, every claimed structural column must appear in the caller's source, the read/wait pipelines must genuinely lack the machinery they disclaim, and no caller may reintroduce an inline literal. Verified revert-sensitive: flipping readUnique to disambiguate and faking wait's occlusion column each fail it. Out of scope, unchanged, per the issue: the Maestro engine (ADR 0015) and the open click-implicit-wait product decision. * refactor: route wait and mutating find through the policy interface (#1649 review) P1 was right: the first head declared seven rows but genuinely routed five. selector-wait.ts never imported its row (it called listSelectorChainMatches directly), findAct consumed only requireRect while its ambiguity contract stayed bespoke, and the parity test sniffed marker strings in source files — so it stayed green across exactly that gap. Asserting about the layer I had edited instead of the behavior it produces. resolveSelectorChainWithPolicy is now the one policy-driven entry: it returns a discriminated outcome (none / resolved / ambiguous) because the rows genuinely disagree about what several matches mean, which is what previously forced each caller to re-derive its contract inline. wait and find's selector branch both route through it; find additionally asserts its row still says reject-candidates rather than assuming. The parity test is rebuilt on fixture trees driven through that interface — no source sniffing. Wiring verified revert-sensitive: flipping the wait row fails the policy tests, and flipping findAct fails REAL find handler tests (ambiguous-candidate listing), which is the proof the previous version could not produce. One behavior nuance the fixture work surfaced and now pins: disambiguation declines on genuinely indistinguishable candidates (the tiebreak is evidence, not a coin flip), so an acting row surfaces ambiguity there rather than binding one silently. * fix(test): let fallow see the host-process mock helper's real consumers Rebase onto main brought #1642's host-process-mock.ts into this PR's fallow scope, where its export reports as unused. It is not: three suites consume it, but only through `(await import(...)).pinOwnProcessStartTime` inside vi.mock factories — vitest hoists those above static imports, so the dynamic form is required and fallow cannot trace it statically. Documented suppression rather than a restructure that would break the hoisting contract. Latent on main rather than introduced here: the audit gate is changed-files-only, so main sees the file in scope only from a PR whose diff contains it. * fix: keep every candidate when a policy resolves one winner (#1649 review P1) A real regression I introduced, not a test gap: routing wait through the policy interface collapsed the candidate set to the winner, and the #1349 landmark check is satisfied when SOME match carries the recorded identity. A first same-selector impostor therefore hid a later genuine landmark and timed the wait out. The resolved outcome now carries `matchedNodes` — the full candidate set of the alternative the winner came from — so a policy that picks one node no longer throws the rest away. wait passes that straight to the landmark check, restoring the original semantics. Regression test added at the within-one-poll shape the existing suite did not cover (both candidates in the SAME capture, impostor first); verified it goes red against the singleton reconstruction it replaces. * refactor: declare only the policy fields the matrix enforces (#1649 review) The occlusion / offscreenGuard / promotion / poll columns were never consumed by resolveSelectorChainWithPolicy or selectorResolutionKnobs: changing any of them left behavior and the suite green, so they were unverifiable claims that read as truth. (My earlier source-sniffing test "verified" them by grepping caller files for marker strings — which is why it also stayed green when a row was disconnected entirely.) The matrix now declares exactly what it enforces: the ambiguity contract and the rect requirement, both consumed by the resolution interface and pinned behaviorally. A new test asserts every row's field set, so an unenforceable column cannot reappear without coverage — verified by re-adding one and watching it fail. Routing the structural stages into typed behavior is tracked in #1656 with the constraint that each field must be consumed, not merely declared. * fix(selectors): flatten the policy outcome at the package boundary `PolicyResolutionOutcome.resolution` was typed as `AstSelectorResolution` and the root façade returned it unchanged, so the parser AST #1589 confined to `@agent-device/selectors/ast` came back through a nested field. `selector-wait.ts` reading `outcome.resolution.selector.raw` was the runtime proof. The existing boundary gate reads exported *names*, so it could not see this. The public outcome now lives beside `SelectorResolution` in public-resolution-types.ts with its selector as text; the parser-side shape is renamed `AstPolicyResolutionOutcome` and stays package-private, and the façade wrapper flattens on the way out — the same treatment `resolveSelectorChain` already gave `AstSelectorResolution`. Two new pins, both verified red against the shape they replace: a behavioral one asserting the façade returns selector text under every policy row, and a structural one asserting resolution shapes are re-exported from public-resolution-types.ts rather than from a parser-side module — which is what distinguishes the leak from a correct re-export in a name list. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017Rva4YGtSCAKJqH5PbpcCU --------- Co-authored-by: Claude <noreply@anthropic.com>
agent-device
Let your coding agent verify its changes in the running app.
agent-device lets coding agents inspect, control, and verify apps on iOS, Android, tvOS, Android TV, Amazon Vega OS TV through the Vega Virtual Device (VVD), web, macOS, and Linux. Agents can read token-efficient accessibility snapshots where supported, find elements by ref or selector, run device actions, and save evidence for review. Initial Vega OS support is VVD-only and covers discovery, app lifecycle, and complete TV-remote control; physical Fire TV, capture, and selector backends remain unsupported.
Your coding agent or QA tool reads each result and chooses the next command. agent-device runs the command and saves evidence when asked.
agent-device uses the inspect-act-verify process from Vercel's agent-browser for mobile, TV, and desktop apps. Basic --platform web support runs agent-browser in the same session and replay system.
Quick start
Install the CLI and check setup. It requires Node.js 22.12 or newer; web automation requires Node.js 24 or newer. See Installation for target requirements.
npm install -g agent-device@latest
agent-device doctor
agent-device help workflow
Run agent-device doctor yourself before handing the CLI to an agent. The installed CLI help defines current behavior. agent-device help workflow links to guides for debugging, replay, React Native profiling, and other tasks.
Add a contact in the built-in iOS Contacts app:
# Start a session.
agent-device open Contacts --platform ios
# Inspect the screen. The example below shows the output; refs vary.
agent-device snapshot -i
# @e2 [button] "Add"
# Use the ref and wait for the UI to settle.
agent-device press @e2 --settle
# The diff includes:
# + @e7 [text-field] "First name"
agent-device fill @e7 "Ada" --settle
# The next diff shows changed values and current refs:
# - @e7 [text-field] "First name"
# + @e14 [text-field] "Ada"
# = @e15 [text-field] "Last name"
# Capture evidence and close the session.
agent-device screenshot ./contact-form.png
agent-device close
Use refs only from the latest output. Do not assume an earlier @eN still identifies the same element. After a command with --settle, use the refs in its diff. Take another snapshot only if the diff omits what you need.
--settle works the same way on scroll and back, so scroll-then-observe and back-then-observe are one call too.
Snapshots use the app's accessibility tree. Clear labels, roles, and test IDs make agent runs more reliable. Use screenshots and videos as evidence or when accessibility data is poor. Use refs and selectors for actions and assertions when you can.
What agents can do
- Inspect app state through accessibility snapshots, refs, selectors, and React Native component trees.
- Act on visible UI by tapping or pressing elements, filling fields, scrolling, making gestures, waiting, asserting state, and handling alerts.
- Diagnose failures with screenshots, video, logs, traces, network data, performance samples, crash details, and React profiles.
- Repeat workflows by saving working steps as
.adscripts for local use or CI. Export strict Maestro YAML when needed.
See Commands for the commands and evidence each target supports.
Next steps
- Set up your agent: run the CLI from Cursor, Codex, Claude Code, Windsurf, or another agent terminal. See AI Agent Setup for skills, rules, MCP tools, and setup for each client.
- Try the sample app: clone the repo and run the bundled Expo test app. Quick Start covers a guided run with screenshots, replay, and performance data.
- Build repeatable tests: use Replay & E2E to repeat tests. Use Debugging & Profiling to find bugs.
Articles and videos
Articles
- Build an AI QA agent for Expo apps with EAS Workflows
- Agent Device: iOS & Android automation for AI agents
- Building mobile QA agents with Vercel Eve
- How we optimized Agent Device for mobile app automation
Videos
- Verifying mobile apps with agent-device
- Using agent-device in an AI coding workflow
- Cloud agents that test mobile apps on real devices
Where to run agent-device
| Path | Best for | Start with |
|---|---|---|
| Local | Trying commands and debugging apps on simulators, emulators, physical devices, macOS, and Linux. | Follow the Quick Start. |
| CI/CD | Automated pull request and merge validation with replay scripts and captured artifacts. | Try the EAS workflow template. GitHub Actions template coming soon. |
| Cloud / remote | Linux runners, managed devices, and remote jobs. | Use Agent Device Cloud, set a remote profile with Commands, or contact Callstack for team QA. |
How it works
agent-device keeps device state in sessions. It sends commands to XCTest on iOS and tvOS, ADB and the snapshot helper on Android, Vega CLI/VDA on the Vega Virtual Device, a local helper on macOS, and AT-SPI on Linux.
Node.js apps can use the typed client or public subpaths. agent-device/android-adb provides the Android ADB provider interface, helpers for logcat, the clipboard, the keyboard, and apps, and port reverse management.
FAQ
What is agent-device?
agent-device is a command-line tool that lets coding agents inspect, control, and verify apps and save evidence for review. It supports iOS, Android, TV, web, macOS, and Linux.
Does it work with React Native, Expo, Flutter, and native apps?
Yes. agent-device supports native iOS and Android apps, plus React Native, Expo, and Flutter apps on supported targets. The commands and evidence vary by target.
How is it different from Appium, Detox, or Maestro?
With agent-device, an agent reads app state and chooses each command at run time. Teams use Appium, Detox, and Maestro to write and maintain test suites. agent-device can complement them by saving its runs as .ad scripts or exporting them as strict Maestro YAML.
Can agent-device run in CI?
Yes. Record a run as an .ad script, replay it locally or in CI, and save screenshots, logs, and other artifacts for review. See Replay & E2E or start with the EAS workflow template.
Who uses agent-device?
Teams and developers at Callstack, JPMorgan Chase, Expensify, Shopify, Kindred, Total Wine & More, LegendList, HerLyfe, App & Flow, and others use agent-device.
Documentation
Contributing
See CONTRIBUTING.md.
Made at Callstack
agent-device is open source under the MIT license. Visit agent-device.dev or contact Callstack.