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Anthropic Claude in Office Add-in

Anthropic ships a Claude add-in for Microsoft Office (Word, Excel, PowerPoint) hosted at https://pivot.claude.ai. The add-in talks to an Anthropic-compatible endpoint from the browser, so it can be pointed at LLMGW's /anthropic endpoint instead of api.anthropic.com.

Prerequisites

  • The Claude Office add-in installed in Word/Excel/PowerPoint (follow Anthropic's installation instructions).
  • An LLMGW API key (see User Tokens).
  • Your LLMGW deployment must allow the add-in's origin via CORS — see Admin setup below.

Configure the Add-in

In the Claude add-in settings, set:

Field Value
API endpoint / Base URL https://<llmgw-deployment-url>/anthropic
API key <YOUR_LLMGW_API_KEY>

The add-in calls GET /v1/models to list available models and POST /v1/messages to chat. LLMGW serves both at /anthropic.

Available Models

GET /anthropic/v1/models returns model groups that route to an Anthropic-compatible backend, filtered to those your token is allowed to use. The add-in's model picker is populated from this list — you do not configure model IDs manually.

For details on how groups are configured, see Models.

Admin Setup

The add-in runs in a browser context, so its origin must be on the LLMGW CORS allowlist. Set the CORS_ALLOWED_ORIGINS environment variable to include the add-in origin:

CORS_ALLOWED_ORIGINS=["https://pivot.claude.ai"]

Add other browser frontends (e.g. Langfuse) to the same list as needed. Backend-to-backend integrations do not need an entry.

Troubleshooting

  • CORS error in browser console — the add-in origin is not in CORS_ALLOWED_ORIGINS. Ask your administrator to add it.
  • Empty model list — your token has no allowed model groups that route to an Anthropic-compatible backend. Check your project's group assignments in the Admin Portal.
  • 401 / Invalid API key — verify the LLMGW token, and that it is pasted in full.