NAC3 + UiPath integration guide

NAC3 version: 2.2 (with v2.3 interop preview) Status: Stable. Tested against UiPath Studio 23.10 + Web Automation v23.10.

UiPath's web automation today scrapes the DOM with CSS selectors, visual targeting, or hardcoded coordinates. With NAC3, every clickable widget in your app advertises a stable data-nac-id; UiPath addresses elements by that id and survives UI redesigns trivially.

Why NAC3 + UiPath

| Today's pain | NAC3 fix | |--------------|---------| | Selectors break when CSS changes | data-nac-id is stable across visual redesigns | | Anchor / coordinate targeting fails after a button moves | Same | | Cross-tenant brittleness (different IDs per customer) | Manifest declares the verb; bot calls by verb | | Wait for "the element is ready" is fragile | nac:action:succeeded event is deterministic | | Multi-language UIs need per-locale automation | label_i18n is locale-agnostic; bot uses ids not labels |

Two integration paths

Path A -- Browser activity + JS injection (recommended)

UiPath's Inject JavaScript activity runs window.NAC.click(...) directly. No selectors, no fragility.

' UiPath sequence pseudocode
Open Browser https://your-app.example.com/
Inject JS: window.NAC.click('invoice.save')
Wait for Event: nac:action:succeeded

Implementation:

``js return await (async () => { const result = await window.NAC.click('@id@'); return JSON.stringify(result); })(); ``

{ok: true}.

Browser activity -- standard UiPath flow.
Inject JavaScript activity -- payload:
Assign the returned string to a variable. Parse to check

For verb-based dispatch:

await window.NAC.click_by_verb('@plugin@', '@verb@')

For fill:

await window.NAC.fill('@id@', '@value@')

Path B -- Selector-based with NAC-aware xpath

If your UiPath profile prefers selectors, use the data-nac-id attribute directly:

<webctrl tag='button' attr='data-nac-id' value='invoice.save' />

Same logic but consumes the Browser DOM via UiPath's tree explorer. Slightly less robust (depends on tree timing) but keeps the UiPath idiom.

Sample UiPath workflow

Examples_NAC_Invoice.xaml (download from the Yujin marketplace once published):

``js return new Promise(r => { const t = setInterval(() => { if (window.NAC) { clearInterval(t); r('ready'); } }, 100); }); ``

``js await window.NAC.click_by_verb('invoice', 'new'); await window.NAC.fill('invoice.client_name', @row("client")@); await window.NAC.fill('invoice.amount', @row("amount")@); await window.NAC.click_by_verb('invoice', 'save'); ``

Open Browser -- target tab to your NAC3 app.
Wait for window.NAC3 -- inject:
For Each Row -- iterate the source data table.
Inject JS -- per row:
Wait for -- nac:action:succeeded with action_id='invoice.save'.
Continue loop.

The whole flow is 5 activities regardless of how complex the underlying app is. Compare to the typical 30-50 activities for a CSS-selector-based equivalent.

Discovery: read the manifest

UiPath can introspect the manifest before automating:

return window.NAC.describe();

Returns the full plugin tree. Use it to build dynamic flowcharts that adapt to manifest changes without redeploying the .xaml.

Provenance (NAC3 Conformance Level 3)

UiPath dispatches synthetic clicks, so event.isTrusted === false on the NAC3 ack event. Apps that gate sensitive verbs on is_trusted (delete, payment, admin) WILL refuse the UiPath dispatch by default.

To enable RPA for those verbs, the host app must explicitly whitelist:

// In the host app's NAC bootstrap:
window.__NAC_ALLOW_UNTRUSTED__ = ['invoice.save', 'invoice.send'];

Discuss the threat model with the app owner -- bypassing isTrusted defeats the spec's anti-spoofing guarantee. UiPath runs in a controlled environment so the trade-off is usually acceptable, but document it.

Error handling

NAC3 throws structured errors UiPath can branch on:

try {
  await window.NAC.click('invoice.save');
} catch (e) {
  return JSON.stringify({ ok: false, code: e.code, message: e.message });
}

| e.code | Meaning | UiPath branch | |----------|---------|---------------| | not_found | id doesn't exist in current DOM | Re-discover via NAC.describe() | | invalid | argument shape wrong | Bot logic bug, escalate | | timeout | side effect didn't ack in 5s | Retry up to N times |

Tested matrix

We exercise the integration against the v21 data-table demo via UiPath 23.10 in CI. The reference workflow is in tools/rpa/uipath/InvoiceFromCSV.xaml of this repo (forthcoming).

License

Apache-2.0.