wait_until
Poll server-side for observable conditions like window appearance, element value changes, URL matches, or terminal output. Replaces screenshot-polling loops for state change detection.
Instructions
Purpose: Server-side poll for an observable condition — eliminates screenshot-polling loops when waiting for state changes. Details: condition selects what to watch: window_appears/window_disappears (target.windowTitle required), focus_changes (optional target.fromHwnd), element_appears/value_changes (target.windowTitle + target.elementName required, UIA; min 500ms interval), ready_state (target.windowTitle; visible + not minimized), terminal_output_contains (target.windowTitle + target.pattern required [+target.regex:true], needs terminal tools loaded), element_matches (target.by + target.pattern required, needs browser tools loaded), url_matches (target.pattern required [+target.regex:true]; matches the active tab's location.href via CDP — use for SPA route changes, redirects, OAuth flows). Returns {ok:true, elapsedMs, observed} on success, or WaitTimeout error with suggest hints. timeoutMs default 5000 (max 60000). Prefer: Use instead of run_macro({sleep:N}) + screenshot loops. Use terminal_output_contains to detect CLI command completion. Use element_matches for browser DOM readiness after navigation. Use url_matches when the URL is the most reliable signal (SPA routing / redirect cascades). Caveats: terminal_output_contains, element_matches, and url_matches require a browser CDP connection (open --remote-debugging-port=9222 first). element_appears/value_changes spawn a UIA process per poll — interval clamped to 500ms minimum. On elapsed-timeout the response is {ok:false, code:'WaitTimeout', error, suggest:[...]}; the suggest[] array lists three fixed actions: 'Increase timeoutMs', 'Verify the target is correct', 'Inspect intermediate state with screenshot(detail='meta')'. Non-timeout failures also occur — pre-poll validation and missing-hook errors classify as code:'ToolError' (read the descriptive error message), and CDP probe errors (url_matches / element_matches conditions) surface as code:'BrowserNotConnected' (re-attach via browser_open). Branch on code rather than assume WaitTimeout. Examples: wait_until({condition:'window_appears', target:{windowTitle:'Save As'}, timeoutMs:10000}) wait_until({condition:'terminal_output_contains', target:{windowTitle:'Terminal', pattern:'$ '}, timeoutMs:30000}) wait_until({condition:'element_matches', target:{by:'text', pattern:'Submit', scope:'#checkout-form'}}) wait_until({condition:'url_matches', target:{pattern:'/dashboard'}, timeoutMs:15000}) wait_until({condition:'url_matches', target:{pattern:'^https://app\\.example\\.com/orders/[0-9]+$', regex:true}})
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| condition | Yes | Condition to wait for. See per-condition target requirements. | |
| target | No | Target descriptor — fields used depend on condition. Accepts an object literal or a JSON-stringified object. | |
| timeoutMs | No | Maximum time to wait (default 5000ms) | |
| intervalMs | No | Poll interval (default 200ms — terminal_output_contains uses 500 internally) | |
| include | No | Optional response-shape opt-in. `['envelope']` returns the self-documenting envelope (`_version` / `data` / `as_of` / `confidence`). `['raw']` forces raw shape (overrides DESKTOP_TOUCH_ENVELOPE=1 server default). Default behaviour is raw shape (compat with existing clients). |