Testa

Testa

Drive the iOS Simulator like a human — from an AI agent.

Real HID touches (every gesture), screen reading via the accessibility tree or on-device OCR, token-efficient, fast, and zero third-party dependencies. Test React Native / Expo and native SwiftUI apps end-to-end — without adding a single testID.

[](https://github.com/seizeddev/testa/actions/workflows/ci.yml) [](LICENSE)

An agent tapping, pinching, rotating, dragging-and-dropping, and typing — all verified through the accessibility tree, no screenshots.

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Why Testa

Agents are great at writing iOS apps and clumsy at the part that comes next: actually exercising them in the simulator. Testa is built for that — and two things set it apart from the rest of the field: it drives screens that expose zero accessibility (via on-device OCR), and it's a single, fully-open, dependency-free binary.

• 🧠 No app setup required. Reads the accessibility tree, and falls back to

Apple Vision OCR to tap any visible text — so it drives canvas, games, WebViews and vibe-coded apps that never added a testID.

• 🪙 Token-efficient. One compact line per element (e5 Button "Save" #save @120,300)

with find / assert / ui diff — not screenshots.

• ⚡ Fast. A warm daemon keeps the connection, accessibility translator and HID

client hot: ~60 ms per snapshot.

• 👆 Every gesture, for real. Tap, long-press, swipe, drag-and-drop,

pinch/zoom, rotate, multi-touch, unicode/emoji text — genuine HID events.

• 🔌 Agent-native. Ships an MCP server (testa mcp) and a Claude Code skill.
• 🔒 Local & private. A 0600 per-user Unix socket. No network, no telemetry.
• 📦 Zero third-party runtime deps. Talks straight to Apple's CoreSimulator,

SimulatorKit, AccessibilityPlatformTranslation, Vision and simctl.

| | Testa | Argent | idb | Appium | Maestro | |---|:--:|:--:|:--:|:--:|:--:| | Agent-native (MCP + token-efficient snapshots) | ✅ | ✅ | ❌ | ❌ | ⚠️ | | Drives screens with zero accessibility (on-device OCR) | ✅ | ❌ | ❌ | ❌ | ❌ | | Pinch · rotate · drag-and-drop · multi-touch | ✅ | ⚠️ | ✅ | ✅ | ⚠️ | | Self-contained: one native binary, no Node/SDK runtime | ✅ | ❌ | ❌ | ❌ | ❌ | | Fully open source, no proprietary parts | ✅ MIT | ⚠️ | ✅ | ✅ | ✅ | | Platforms | iOS | iOS · Android | iOS | iOS · Android · web | iOS · Android | | Live debugging & profiling (logs · network · RN tree · Instruments) | ❌ | ✅ | ⚠️ | ❌ | ❌ |

High-level summary, verified against each project's docs as of 2026. These are all good tools. The closest is Argent (Software Mansion): broader than Testa (cross-platform, deep debugging & profiling), but accessibility-only (no OCR), Node-based, and Apache-2.0 source plus proprietary binaries. Testa's niche: fully-open, dependency-free, OCR-driven, iOS-focused.

Quick start

# Install (one line) — builds, installs the skill, registers the MCP server
brew install https://raw.githubusercontent.com/seizeddev/testa/main/Formula/testa.rb
testa setup

# …or from source
git clone https://github.com/seizeddev/testa && cd testa && ./install.sh

testa boot "iPhone 17 Pro"
testa install ./MyApp.app && testa launch com.example.myapp

testa ui                       # what's on screen (token-efficient)
testa tap "Continue"           # by visible text — falls back to OCR
testa typein "#email" "a@b.co"
testa assert "#welcome" exists # → PASS / FAIL (exit 0/1)

> First call boots a background daemon and warms accessibility (a few seconds, > once). Every call after is ~60 ms. Requires macOS + Xcode 26 (iOS 26 sims), Swift 6.

The loop

1. Observe — testa ui (on-screen elements) · testa see (OCR every visible

text) · testa find · testa scrollto .

1. Act — `tap · typein · setvalue · clear · swipe · drag · dragdrop · pinch ·

rotate. Address things by eN ref, #identifier, "label", or x y`.

1. Verify — testa assert [exists|gone|value=…|label=…] (exit 0/1).

$ testa ui
25 elements (on screen)
e1 Application "Testa Native" @201,437
e5 Button "Tap me" #tapButton @102,171
e16 TextField #textInput =type here @201,673
…

$ testa pinch "#map" 2.0      →  pinched
$ testa dragdrop "#card" "#trash"  →  drag-and-dropped
$ testa assert "#status" label=done  →  PASS exists e2 …

Full command reference

Observe
  ui [diff|full]            on-screen snapshot (diff = changes, full = incl. off-screen)
  see                       OCR every visible text + tap coords (any app)
  find               elements matching label/id/value/role
  scrollto             scroll until an element is visible
  assert  [exists|gone|value=..|label=..]
  wait  [timeoutMs]
  screenshot [path]

Act   (sel = eN ref · #identifier · "label")
  tap  | tap   | tapocr 
  typein   | type  | setvalue   | clear 
  key 
  swipe 
  drag 
  dragdrop 
  longpress  | pinch   | rotate  

App / device
  devices | boot  | shutdown 
  install  | launch  | terminate  | apps | open 
  logs [bundle] [seconds] | crashes [bundle]
  permission   
  record 

Setup / daemon
  setup | start | stop | status | info | mcp        (target a sim: --udid )

Works without app setup

You do not need the app to add testIDs. Visible text is enough:

• Native SwiftUI and RN Text / Pressable / TextInput already expose their

text as labels — testa tap "Continue".

• For anything else, testa see + testa tapocr "" reads pixels via

on-device Apple Vision (no key, no network). This even drives a HealthKit permission sheet or a canvas-rendered screen that exposes zero accessibility.

Adding testID / accessibilityIdentifier just makes targeting more precise.

The bottom row above is drawn with Canvas — it exposes zero accessibility. Most tools (and accessibility-only agents) are blind to it. Testa isn't:

$ testa ui            # accessibility tree
… no "Start" / "Settings" / "Profile" — they aren't accessibility elements

$ testa see           # on-device OCR
"Start" @79,702    "Settings" @200,703    "Profile" @322,702

$ testa tapocr "Settings"
tapped (ocr) "Settings" @200,703     →  #status = canvas:Settings

For AI agents

• Claude Code — testa setup installs the skill (skills/testa/SKILL.md).
• Any MCP client (Codex, Cursor, …) — claude mcp add testa -- testa mcp.

Tools: ui, see, find, scrollTo, tap, tapText, type, setValue, clear, key, swipe, drag, dragdrop, longpress, pinch, rotate, screenshot, assert, wait, install, launch, terminate, apps, logs, crashes, open, info.

How it works

agent ──► testa (CLI)            ──┐
agent ──► testa mcp (MCP server) ──┤ Unix socket (~/.testa/daemon-.sock, 0600)
                                   ▼
                              testad (warm daemon)
                                   │  Obj-C engine, dlopen'd private frameworks
                    ┌──────────────┼───────────────┐
                    ▼              ▼                ▼
              SimulatorKit    CoreSimulator   AccessibilityPlatformTranslation
              (Indigo HID)    (SimDevice)     (AXPTranslator → a11y tree)  + Vision (OCR)
                    └──────────────┴────────────────┘
                          booted iOS Simulator

• HID injection reimplements the Indigo touch wire-format

(SimDeviceLegacyHIDClient) — taps/drags/multitouch are byte-for-byte what the simulator's guest HID service expects.

• Accessibility drives AXPTranslator with a token delegate that bridges each

attribute read to an async SimDevice XPC request, yielding the element tree in point coordinates that match the tap space.

• OCR runs Apple Vision over an in-process framebuffer capture (IOSurface).

Showcase / tests

Two example apps with complex gestures double as the regression suite. Each mirrors the last recognized gesture into a #status element, so gestures are verified through the accessibility tree alone:

• examples/native — SwiftUI · examples/native/build.sh, then examples/native/e2e.sh.
• examples/rnshowcase — Expo / React Native · see TESTA_README.md there.

make build   # debug build
make test    # unit tests
make e2e     # gesture regression vs the native showcase (needs a booted sim)

Limitations (honest)

• Icon-only controls with no text and no accessibility label are ambiguous to

any automation — use coordinates, or add an accessibilityLabel.

• iOS Simulator only, by design. Real devices and Android are out of scope.
• The prebuilt binary isn't notarized unless built with your own Apple Developer

ID (release.sh); the clone and Homebrew paths build from source.

• testa record produces H.264 MP4; live FPS streaming isn't implemented.

Project

• [CONTRIBUTING](CONTRIBUTING.md) · [CHANGELOG](CHANGELOG.md) · [Onboarding](ONBOARDING.md)
• License: [MIT](LICENSE)

Verified on Xcode 26.4 / iOS 26.4 (iPhone 17 Pro), against SwiftUI + Expo/React Native showcases and a real production app.

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: valewnrt
• Source: valewnrt/testa
• License: MIT

Install and usage instructions live in the source repository linked above.