How Momentum works

The shape of the system

Momentum has four parts:

1. The Revit addin - a small DLL loaded by Revit when it starts. Subscribes to Revit's own events and writes a session log to Firestore.
2. Firestore (Google Cloud) - the database where each firm's session logs, tasks, projects, and team data live. Strict per-firm isolation enforced at the database layer.
3. Cloud Functions - the API that the dashboard talks to. Everything runs server-side, scoped to the calling user's tenant.
4. The dashboard - the web app at getmomentum.studio where admins and modelers see what's been logged.

What the addin captures, exactly

The complete list of event types the addin emits - there are no hidden ones. Source code: Source/Core/ActivityEvent.cs in the Momentum addin.

What Momentum does and does not do

The idle detector - full transparency

The idle detector is the part of Momentum closest to "monitoring." Here is what it actually does.

Once per timer tick, the addin calls a single Win32 API:

BOOL GetLastInputInfo(LASTINPUTINFO* plii);

This API returns one number: the millisecond count of the last keyboard or mouse event on the system. It does not return:

• Which key was pressed
• Where the mouse moved or what was clicked
• Which application received the input
• Which window was focused
• Anything you typed

This is the same API that Windows screensavers use to know whether to engage. Momentum uses it strictly to distinguish "modeler is at the desk" from "modeler walked away."

If the input timestamp is recent (within your idle threshold, default 15 min), the addin treats the modeler as active. If it stays silent past the threshold, an IdleSpanStart event is logged. When input resumes, an IdleSpanEnd event closes the span.

That is the entire idle mechanism. There is no foreground-app detection, no window-title capture, no per-application time tracking.

Modeler-chosen monitoring tier

On first Revit launch, the addin asks you to pick how much detail Momentum captures. The choice is yours, not your admin's - and filtering happens at the source, so events below your chosen tier are never recorded, locally or in the cloud.

Your workspace admin can see which tier you picked (it shows up in the Modeler acknowledgments card on their dashboard), but they don't get to override your choice. Some workspaces may require Full for billing reasons - if so, you'll be told before the notice closes.

The local session JSON file on your machine (%AppData%\Momentum\sessions\) reflects your choice too - if you picked Hours-only, the local file only contains hours data. We don't capture more locally and hide it from the server.

Roles and permissions

Momentum has three kinds of users. Each one sees a different slice of the workspace by design - team-wide visibility is gated to admins only, modelers see their own work, and the addin works for modelers who never touch the dashboard at all.

How roles get assigned

• The first person to sign up at /signup for a workspace becomes the admin. Their tenant is created at signup; they get the per-tenant API key and full visibility.
• The admin generates an invitation link from the dashboard and shares it however they want (email, Slack). Whoever accepts the link becomes a member of that tenant.
• An admin can promote a member to admin or demote an admin to member at any time, with one safeguard: the workspace must always have at least one admin (you can't demote yourself if you're the last one).
• A Revit-only modeler doesn't sign up for anything - they just install the addin (which contains the workspace's API key). The addin authenticates as the workspace's tenant; the modeler's Autodesk login id identifies them within the tenant. They never see a dashboard sign-in. They do see the Momentum ribbon tab in Revit and the My Tasks panel, and they see the first-launch monitoring notice.

Enforcement

Roles aren't just UI hints - they're enforced server-side at every layer:

• Firebase Auth custom claims stamp tenantId, role, and app:'momentum' on every signed-in user's ID token.
• Firestore security rules reject any read or write whose token tenant doesn't match the document's tenant - even a buggy server can't leak data across firms.
• Cloud Functions re-verify role on every admin action (requireStudio(), updateMember, createInvite, etc.). The dashboard hides admin-only buttons for members; the server rejects the calls anyway if anyone tries to bypass the UI.
• The Revit addin uses a per-tenant API key with no role permissions - it can only write sessions for its own tenant, never read or modify other tenants' data.

Where data lives

• Each firm gets its own tenant with a unique tenant ID and its own API key.
• Every database document is stamped with that tenant ID.
• Authentication tokens are scoped to a single tenant - a token cannot read or write any document outside its tenant.
• Firestore security rules enforce this at the database layer, not just in application code. Even a bug in our server code cannot leak data across tenants.
• Hosted in Google Cloud, US central region. Encrypted at rest with Google-managed AES-256, in transit with TLS 1.2+.

Things we deliberately ruled out

For transparency about what Momentum could plausibly do but doesn't:

• Foreground-app categorization. A common feature of monitoring tools - telling admins "modeler spent 2 hours in the browser today." We deliberately have not built this. It triggers stricter monitoring laws (Connecticut, Delaware, New York, GDPR Article 88) that we'd rather not impose on customers.
• Screenshots. No.
• Keystroke logging. No.
• Mouse heatmaps. No.
• Webcam pings or "are you at your desk" prompts. No.

For employers using Momentum

You should give your modelers written notice that Momentum is in use. Several US states require it (Connecticut, Delaware, New York), and most jurisdictions either require or strongly recommend it. We've made this easy: this page is shareable as-is, and we're happy to help you draft a notice. Email Info@getmomentum.studio if you want a template.

For modelers in the EU/UK or California, additional rights apply under the GDPR and CCPA/CPRA - see the Privacy Policy for details.

For modelers worried about Momentum

Reasonable concern. Here are the questions worth pushing on:

• "Can my employer see what I'm typing?" No. Momentum doesn't capture keystrokes.
• "Can they see other apps I'm using?" No. Momentum doesn't see anything outside Revit.
• "Can they see my screen?" No. No screenshots, no recording.
• "Will they know if I take a break?" Yes - after the configured idle threshold (default 15 min), Momentum logs that you went idle. They will know that you stepped away, not where you went.
• "Will they see which projects I worked on?" Yes. The names of the documents and views you opened are logged.
• Can Momentum staff access or release my personal or workspace data? Not during normal use, and we cannot release employer-controlled workspace data directly to you without your employer's authorization. Your employer owns and controls the data Momentum collects on its behalf; Momentum hosts and processes it for them. If you need a copy, ask your workspace admin for an export. If your employer does not respond and you believe you have access rights under GDPR, CCPA/CPRA, or another privacy law, contact the appropriate data-protection authority.

If you have other questions, email Info@getmomentum.studio. We'll answer honestly.