Warning

This project is unmaintained and no longer actively developed.

X21 - Excel Add-in

An Excel VSTO add-in that provides AI-powered formula fixing and chat functionality using AI.

Prerequisites

• Visual Studio 2022 Community Edition with Office/SharePoint development workload be sure to select 2022 not 2026 or anything else https://aka.ms/vs/17/release/vs_community.exe
• .NET Framework 4.8
• Node.js
• Deno
• git
• Microsoft Excel 2016 or later
• optional: Docker (optionally required for Semgrep security checks in pre-commit hooks)

Setup Instructions

Developement

For development run the 3 components locally Web UI, Deno server, and VSTO add-in. You can run them in any order but typically you would:

Web-UI

1. cd ..\x21\x21\web-ui
2. npm install
3. npm run dev

Deno Server

1. cd ..\x21\x21\deno-server
2. deno task start

VSTO Add-in

1. open ..\x21\X21.sln in Visual Studio
2. press F5 to start the add-in in Debug mode

Next Steps

1. Publish locally and test the installer
2. Publish and sign to distribute the add-in to users
3. Setup the pre-commit hooks for code quality checks
4. See the .env-example for optional environment variables like Anthropic, Supabase and posthog

Publish

Publishing Prerequisites

• Install the X21_TemporaryKey.pfx (no password) before publishing

• Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser

• Publish to local with .\Publish.ps1 -Environment Dev

Advanced Publish to Production (promote from staging)

• Publish to local with .\Publish.ps1 -Environment Dev
• Test
• Promote to staging with .\Promote.ps1 -Environment Staging
• Publish to local with .\Publish.ps1 -Environment Staging
• Merge back to dev

For production, you need to have the certificate installed on the machine and the hash of the certificate needs to match the value in Publish.ps1.

• for upload rclone must be installed for file deployment to Cloudflare R2 (see rclone setup below)

Publishing and Signing

Alternative you could generate your own temporary certificate for signing the add-in:

1. Open Visual Studio
2. Go to Project → X21 Properties
3. Click on the Signing tab
4. Check "Sign the ClickOnce manifests"
5. Click "Create Test Certificate..."
6. Leave the password fields empty and click OK
7. This will generate X21_TemporaryKey.pfx in your project
8. Click "Select from File..." and choose the certificate you just created

Afterwards look for the thumbprint of the certificate in the certificate manager (certmgr.msc) and update the PublishCore.psm1 script with the thumbprint value.

Then deploy this certificate to your users or get a real EV signing certificate, for example Azure Artifact Signing.

Things to check for if installation fails: Install location, Unblocking files, installing certificate to the right store (Trusted Publishers and Trusted Root Certification Authorities)

Git Operations

After successful publishing (but before deployment), the script will:

1. Check Changes: Verify that only the .csproj file has been modified (version increment)
2. Commit Changes: Automatically commit the version changes with a descriptive message
3. Create Tag: Create a Git tag in the format vX.X.X.X (e.g., v1.2.3.4)
4. Push Options: Offer to push both the commit and tag to the remote repository

Note: If changes are detected in files other than .csproj, the script will warn you and ask for confirmation before proceeding.

Pre-commit Hooks

Install pre-commit hooks to run code quality checks before commits:

# Install pre-commit (requires Python)
pip install pre-commit

# Install the git hooks
pre-commit install

# Install pre-push hooks (for build checks)
pre-commit install --hook-type pre-push

The hooks will automatically run on git commit and validate:

• Deno server format/lint
• Web UI ESLint
• File formatting and validation
• Python linting (flake8, isort)
• Markdown linting
• Spell checking
• Security checks (Semgrep via Docker)

Note: Build checks (Web UI and VSTO Add-in) and security checks (Semgrep) run on git push (pre-push hook) to keep commits fast.

rclone Setup for Cloudflare R2

• Download and install rclone: https://rclone.org/downloads

• Run rclone config and follow prompts: -- Run rclone config and follow prompts: -- Choose "n" for new remote -- Name it: x21 -- Select S3 as the storage type -- Choose Cloudflare R2 as provider -- Leave region empty -- Set access_key_id and secret_access_key with credentials https://dash.cloudflare.com/6bd46c67bb736bb693308127d72cd421/r2/api-tokens

  

-- Set endpoint to: https://6bd46c67bb736bb693308127d72cd421.r2.cloudflarestorage.com

• Your resulting configuration should look like:

type = s3
provider = Cloudflare
access_key_id = <your_key>
secret_access_key = <your_key>
endpoint = https://6bd46c67bb736bb693308127d72cd421.r2.cloudflarestorage.com