Hanzo AI for Microsoft Office

A task-pane add-in that puts Hanzo AI inside Word, Excel, and PowerPoint — desktop and Office on the web. Select text or a range, open the Hanzo pane from the Home tab, ask, and insert the result. This is the surface a non-developer (a lawyer drafting in Word, an analyst in Excel) actually uses — distinct from the browser extension and the IDE extensions.

It reuses the same backend as everything else Hanzo: model calls go through api.hanzo.ai/v1 (OpenAI-compatible), sign-in is Hanzo IAM (hanzo.id, authorization-code + PKCE, HIP-0111). No new API surface.

What it does

• Word — read the selection; draft, rewrite, summarize, or answer; insert after or replace the selection.
• Excel — read the selected range (as TSV); analyze/transform; write the result down a column from the selection.
• PowerPoint — read/replace the selected text on a slide.

The engine of the add-in is small, pure, and unit-tested (tests/): the chat request/response shaping (chat.ts), the PKCE + authorize URL (pkce.ts, verified against the RFC 7636 test vector), the Excel range↔text helpers (host.ts), and the endpoint contract (config.ts). The Office.js glue is thin.

Build

pnpm --filter @hanzo/office-addin build      # production (base https://office.hanzo.ai)
pnpm --filter @hanzo/office-addin test        # vitest

The build stamps the hosting base URL into dist/manifest.xml. Office loads the task pane from an HTTPS origin declared in the manifest; the same origin serves auth-callback.html (the IAM redirect target, which must be registered on the hanzo-office IAM client). Override the base for local dev:

HANZO_OFFICE_BASE=https://localhost:3000 pnpm --filter @hanzo/office-addin build

Try it (sideload — no store needed)

The add-in is not on AppSource yet, but sideloading gives a lawyer immediate use inside their own Office:

• Office on the web: open Word/Excel on the web → Insert → Add-ins → Upload My Add-in → pick dist/manifest.xml. (dist/ must be served at the base URL over HTTPS.)
• Windows / Mac desktop: put dist/manifest.xml in a shared-folder catalog (or use office-addin-debugging), then Home → Add-ins → Shared Folder.
• Whole firm: an M365 admin deploys manifest.xml org-wide from the Microsoft 365 admin center → Integrated apps — every user gets the Hanzo button with no per-person install.

Publish (AppSource — public listing)

dist/manifest.xml is a valid, submittable manifest (verified by office-addin-manifest validate). To list publicly:

1. Host dist/ at the production base (office.hanzo.ai) over HTTPS.
2. Register the hanzo-office client in IAM with redirect https://office.hanzo.ai/auth-callback.html.
3. Submit through Microsoft Partner Center → Office Store (needs a Partner Center account + Microsoft's validation pass).

Not here yet

• Outlook (mail) is a different host category with its own manifest shape — a tracked follow-up, not this add-in.
• Streaming responses (this v1 is a single non-streaming completion, which keeps the insert atomic).