lucianocrossaniell/Custom-MCP-Server

MCP Filesystem Assistant – Azure Functions Backend

This project is an AI-powered file assistant with an Azure serverless backend.
It supports secure per-user storage and retrieval of files, ready for integration with a React frontend.

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Features

✅ Upload files to Azure Blob Storage
✅ List files stored for each user
✅ Download files via secure SAS URLs
✅ Delete files and metadata
✅ Per-user data isolation (userId folders and PartitionKeys)
✅ Fallback testuser mode for local/Postman testing
✅ Ready for React frontend with MSAL authentication

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Project Structure

backend/
├── Upload/
│   └── index.js         # Upload file endpoint
├── Download/
│   └── index.js         # Generate SAS URL
├── Delete/
│   └── index.js         # Delete file and metadata
├── List/
│   └── index.js         # List metadata
├── shared/
│   ├── auth.js          # Parses user claims (oid/sub)
│   └── storage.js       # Table Storage helpers

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Prerequisites

• Node.js v18+
• Azure Subscription
• Azure Function App deployed with:
  • Blob Storage container (userfiles)
  • Table Storage table (FileMetadata)
• App Registration in Azure AD (for authentication)

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Installation & Deployment

1. Clone this repo.

2. Install dependencies:

   npm install
   

3. Create the following Application Settings in Azure:

   • AzureWebJobsStorage
   • AZURE_BLOB_CONTAINER_NAME
   • AZURE_TABLE_NAME

4. Deploy to Azure Functions (e.g., using VS Code Azure Functions extension).

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Testing with Postman

✅ All endpoints can be tested without authentication using fallback testuser mode:

POST   /api/Upload
GET    /api/List
GET    /api/Download?filename=<name>
GET    /api/Delete?filename=<name>

Fallback Logic: If no valid claims are detected:

const userId = "testuser";

This allows you to test without needing tokens.

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How It Works

• Files are stored in:

  userfiles/<userId>/<filename>
  

• Metadata stored in Table Storage with:

  PartitionKey = <userId>
  RowKey = <filename>
  

• When your frontend is ready and you authenticate users via Azure AD:
  • The getUserFromHeaders() function will parse x-ms-client-principal.
  • Files will be isolated per user automatically.

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Next Steps

✅ Build React frontend (Phase 1.6)

• Add MSAL.js login flow
• Display per-user file lists
• Integrate Upload/Download/Delete UI

✅ Re-enable authentication in Azure Portal before production:

• Turn "Require Authentication" back on
• Remove fallback testuser logic if desired

✅ Add Application Insights for monitoring

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License

MIT License