# IOS Sim Navigation > Drive an iOS app running in a Simulator via WebDriverAgent (WDA) to tap, swipe, scroll, type, take screenshots, inspect the accessibility tree, automate, or verify a UI flow. Use when the work specifically targets a running Simulator app (e.g. running an end-to-end test, automating an in-app flow, verifying on-screen state via the WDA tree, scripting taps in a simulator). Do not use for non-Simulator UI work, headless code paths, or UI tasks on real devices. - Skill: `wordpress-mobile/ios-sim-navigation` (Agent Skill, multi-file: 10 files) - Install (CLI): `npx skillmds@latest add wordpress-mobile/ios-sim-navigation` - Raw SKILL.md: https://api.skillmd.com/api/skills/wordpress-mobile/ios-sim-navigation/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Web & Frontend - Author: wordpress-mobile (https://skillmd.com/u/wordpress-mobile) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/wordpress-mobile/ios-sim-navigation --- # iOS Simulator Navigation with WebDriverAgent Drive an explicitly identified app on a user-identified Simulator through one explicitly identified WDA session. ## Required navigation target Retain these values in working context throughout the flow: - ``: resolve the Simulator identified by the user or established earlier in the task to its exact UDID. If the target cannot be determined unambiguously, ask the user which Simulator to use. - ``: use the bundle ID established earlier in the task, or resolve it from the app explicitly identified by the user. If the target app cannot be determined unambiguously, ask the user which app to use. Never choose an app merely because it is installed, running, or in the foreground. - ``: choose a random port from 8200 through 8999. If unavailable, choose another and retry. - ``: the exact value printed by `wda-session.rb`. Pass `` and `` explicitly to every WDA action. Keep using the resolved `` and `` throughout the flow. ## Fast-path cadence End-to-end runs have a limited time budget. Keep each user-visible action to about one tool call. ### Rule 1: Use `tap.rb` for every tap `tap.rb` validates the supplied session, finds the element, computes its coordinates, taps it, and can wait for the next screen in one invocation: ```bash ruby scripts/tap.rb aid create-post-button \ --port --session-id \ --wait-aid post-title-field ``` Use raw curl only for gestures that the scripts do not model. ### Rule 2: Never read a screenshot into model context Use the accessibility tree to make decisions. Screenshots are failure artifacts for human review only. Never read `/tmp/*.png` back into context. ### Rule 3: Fetch one tree per screen Fetch the description tree once on a new screen, locate the controls you need, then use the action scripts. Re-fetch only after reaching another screen or when an expected transition times out. ```bash curl -s "http://localhost:/session//source?format=description" \ | jq -r .value ``` ## Before starting WDA Verify that: - `` identifies a booted Simulator. - The app identified by `` is installed on that Simulator. ## WDA lifecycle Run `wda-start.rb` with both required options: ```bash ruby scripts/wda-start.rb --udid --port ``` Run that command using the coding environment's tracked background-command facility. Retain the returned task or terminal identifier. Do not append `&`, use `nohup`, or detach it another way. Startup may take several minutes on first use. Poll the selected port until WDA is ready: ```bash curl -sf "http://localhost:/status" >/dev/null ``` The script handles setup and one recovery attempt internally. If startup reports that the port is occupied, choose another random port from 8200 through 8999 and retry. If the background task exits for another reason, inspect its output and report the failure. Do not restart it automatically. When navigation finishes, stop the exact background task using its retained identifier. Do not scan for WDA processes or stop unrelated background tasks. No additional cleanup command is required. ## Create the app session Create a session before every navigation flow. Both options are required: ```bash ruby scripts/wda-session.rb --port --bundle ``` The command prints only the session ID to stdout. Retain that exact value as `` and pass it to every subsequent action. Creating the session launches or relaunches the app and binds WDA to it. Do not substitute `simctl launch`, because a later WDA session can relaunch the app and discard caller-supplied launch configuration. For launch arguments or environment variables, add repeatable options to the same session command: ```bash ruby scripts/wda-session.rb --port --bundle \ --arg -some-flag --arg value ruby scripts/wda-session.rb --port --bundle \ --env SOME_INSTRUMENT_VAR=1 ``` `--wait-quiescence` is off by default because a spinner can prevent an app from becoming quiescent. If a session becomes invalid, create a new session explicitly and use its new ID. Action scripts never replace sessions silently. See `references/sessions.md` for session details. ## Tap Use one of three locators: ```bash # Developer-assigned accessibility identifier (preferred). ruby scripts/tap.rb aid settings-button \ --port --session-id # Visible label or accessibility identifier. ruby scripts/tap.rb text "Continue" \ --port --session-id # Coordinates, only when no stable identifier or label exists. ruby scripts/tap.rb at 196,504 \ --port --session-id ``` ### Fuse tap and transition verification Use `--wait-aid` or `--wait-text` whenever you can name an element expected on the destination screen: ```bash ruby scripts/tap.rb aid tabbar_mysites \ --port --session-id \ --wait-aid switch-site-button ruby scripts/tap.rb text "Continue" \ --port --session-id \ --wait-text "My Site" ruby scripts/tap.rb aid publish-button \ --port --session-id \ --wait-text "Post published" --timeout 15 ``` The wait polls `/elements` every 250 ms. `--wait-aid` uses the stable accessibility identifier. `--wait-text` uses exact equality against label or identifier. Exit codes: - `0`: tap and optional wait succeeded. - `1`: target missing or wait timed out. - `2`: invalid options, WDA unavailable, or session invalid. ## Accessibility tree Use description format by default: ```bash curl -s "http://localhost:/session//source?format=description" \ | jq -r .value ``` Each line contains type, frame, identifier, label, and other useful state. Find elements in this order: 1. Developer-assigned `identifier` or `name`. 2. Accessibility `label`. 3. Type plus surrounding context. 4. Partial text matching. 5. Position, only as a last resort. For programmatic tree walking, read `references/json-tree.md`. ## Verify step success Verify presence through the explicit session: ```bash curl -s -X POST \ "http://localhost:/session//elements" \ -H 'Content-Type: application/json' \ -d '{"using":"accessibility id","value":"post-published-banner"}' \ | jq -e '.value | length > 0' ``` Verify visible text with one tree dump: ```bash curl -s "http://localhost:/session//source?format=description" \ | jq -r .value \ | grep -F "Category tag post" ``` Prefer adding a wait to the tap that triggers a confirmation. Capture a screenshot only after verification fails, and do not read the image back. ## Swipe Use `swipe.rb` for every swipe: ```bash ruby scripts/swipe.rb up --port --session-id ruby scripts/swipe.rb down --port --session-id ruby scripts/swipe.rb left --port --session-id ruby scripts/swipe.rb right --port --session-id ruby scripts/swipe.rb back --port --session-id ruby scripts/swipe.rb at 196,500,196,200 \ --port --session-id ruby scripts/swipe.rb up \ --port --session-id --duration 1000 ``` Directional swipes derive coordinates from the session's window size. Vertical swipes use the right edge to avoid interactive controls in the center. ## Scroll view navigation 1. Fetch the tree and look for the target. 2. Tap it if found. 3. Otherwise swipe up and fetch the tree again. 4. Stop when the tree is unchanged after a swipe, which indicates the end. 5. Report element-not-found if the target never appears. ## Type text Use `type.rb` for every typing action. It finds the field, taps it, waits for the keyboard, types, and verifies the exposed value or label: ```bash ruby scripts/type.rb aid post-title --text "Hello world" \ --port --session-id ruby scripts/type.rb text "Email" --text "user@example.com" \ --port --session-id ``` Use `--no-verify` only when the field genuinely does not expose typed text. Use `--no-focus` when the field is already focused: ```bash ruby scripts/type.rb aid post-title --text "Hello world" \ --port --session-id --no-focus ``` Do not use `hasKeyboardFocus`; iOS 26 rejects it. The valid attribute is `focused`. Do not tree-dump between characters or after successful verification. See `references/raw-actions.md` for control-code typing and clear-field details. ## Back navigation Find the Button inside the NavigationBar and tap its label. If no stable button exists, use the `back` swipe: ```bash ruby scripts/swipe.rb back --port --session-id ``` ## Screenshots Screenshots are failure artifacts for human review only. Use the resolved UDID: ```bash xcrun simctl io screenshot /tmp/screenshot.png ``` Do not re-resolve or switch the screenshot target after `` is established, and never read the resulting PNG into model context. ## Reference files | Read this | When you need to | |-----------|------------------| | `references/sessions.md` | Understand explicit session creation, relaunch behavior, or invalid sessions | | `references/raw-actions.md` | Perform long press, clear a field, send control codes, or build a custom gesture | | `references/json-tree.md` | Walk the JSON tree programmatically | | `references/troubleshooting.md` | Diagnose no-op actions, crashes, alerts, or WDA disconnections |