# Office Add-in - GateLLM for Microsoft 365

> GateLLM for Microsoft 365 add-in: Excel financial modeling, Word contract review, PowerPoint decks, Outlook inbox — self-hosted and wired to your own model gateway, data never leaves the network, zero pivot dependency, Entra SSO + Purview label gating.

Canonical: https://www.gatellm.io/office-addin/

## GateLLM for Microsoft 365
Use your own model gateway directly inside Excel, Word, PowerPoint & Outlook — self-hosted add-in, data never leaves the network, zero pivot dependency.
- Self-hosted · zero SaaS dependency
- Entra SSO
- Purview label gating
- Data stays local
### Excel
Financial modeling & analysis
- DCF / LBO / 3-statement modeling
- Formula & report tie-out checks
- Comps valuation & statistical benchmarks
### Word
Contract review & drafting
- Playbook-graded review (Critical/High/Med/Low)
- Redline version comparison
- Defined terms / cross-refs / signature-block checks
### PowerPoint
Decks & diligence materials
- Competitive analysis / industry overview frameworks
- Quarterly / data deck refresh
- Number-consistency QC (ib-check-deck)
### Outlook
Email & calendar
- Inbox triage & thread summaries
- meeting-prep / schedule / commitments
- Attachment reading & morning-claude
### How to deploy
#### Self-host the add-in SPA
The pre-bundled add-in is served from your own HTTPS static host (or CDN); the manifest points at your origin, with zero pivot dependency at runtime.
#### Connect your model gateway
The add-in talks directly to your LLM gateway (GATEWAY_URL must be HTTPS); or go straight to Vertex / Bedrock / Foundry if you don't run a gateway.
#### Deploy via M365 Admin Center
Upload the manifest to M365 Admin Center → Integrated apps → Upload custom apps for org-wide rollout; use sideload for local development.
### Enterprise governance
#### Entra SSO + gateway auth
Use your own Entra app; entra_sso turns the user's Entra token directly into the gateway Bearer, so auth and billing track the real user.
#### Purview label gating
access_policies match sensitivity-label GUIDs to block addin.access / file.upload — disable the add-in or attachment upload on confidential documents.
#### Per-user config & your own MCP
bootstrap_url delivers provider keys / skills / switches; mcp_servers mounts your own MCP, auto-wiring the gateway's own /mcp when unset.
#### Data stays local
Chat history and config live in the browser's local storage with no server copy; a read-only export script audits, and swapping manifests keeps data.
### How to buy
The add-in is a paid add-on on top of a GateLLM instance license (Pro / Enterprise). Contact sales for the add-in manifest and deployment support.
## FAQ
### Will the add-in leak data to a third party?

No. The self-hosted add-in has zero pivot dependency at runtime; requests go straight to your own model gateway, and the bundled Sentry / GrowthBook defaults are scrubbed off. What remains is your own gateway, Microsoft Entra / Graph (Office auth and mail/calendar), and your own bootstrap endpoint (if used).
### How does Outlook differ from Excel / Word / PowerPoint?

Outlook is a separate MailApp manifest and needs additional Microsoft Graph admin consent; direct Bedrock mode is not yet supported for Outlook (the gateway path is unaffected).
### Can I disable the add-in on a class of confidential documents?

Yes. access_policies deny addin.access by Microsoft Purview sensitivity-label GUID — the add-in refuses to run on documents carrying that label; file.upload similarly refuses attaching restricted-label files.

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