R2 Upload MCP Server

What is R2 Upload MCP Server?

It is a Model Context Protocol (MCP) server for uploading files to Cloudflare R2 storage with automatic MIME type detection and environment variable configuration. It is intended for developers who want to integrate file uploads into MCP‑compatible AI tools.

How to use R2 Upload MCP Server?

Install via pnpm install and pnpm build. Set the required environment variables (R2_ACCOUNT_ID, R2_ACCESS_KEY_ID, R2_SECRET_ACCESS_KEY, R2_BUCKET_NAME) in your MCP configuration file. The server exposes the upload_file tool, which accepts a filePath (required) and optional key and contentType parameters.

Key features of R2 Upload MCP Server

• Upload files to R2 bucket with automatic MIME detection
• Support custom object keys and content types
• Returns public URLs for uploaded files
• Environment variable configuration
• Optional custom domain for public URLs

Use cases of R2 Upload MCP Server

• Upload AI‑generated images or documents to R2 storage
• Store JSON, PDF, or other files in MCP‑enabled workflows
• Automate file uploads in CI/CD pipelines
• Host files on a custom domain with R2 public URLs

FAQ from R2 Upload MCP Server

What environment variables are required?

You must set R2_ACCOUNT_ID, R2_ACCESS_KEY_ID, R2_SECRET_ACCESS_KEY, and R2_BUCKET_NAME.

How do I get R2 credentials?

In the Cloudflare Dashboard, create an R2 bucket, then generate an API token with read/write permissions and note the Access Key ID and Secret Access Key.

Can I use a custom domain for public URLs?

Yes. Set the R2_CUSTOM_DOMAIN environment variable, and the server will return URLs using your custom domain instead of the default R2 dev domain.

What file types are supported for MIME detection?

Images (.jpg, .jpeg, .png, .gif, .webp), documents (.pdf, .txt, .json, .html, .css), scripts (.js), videos (.mp4, .mov, .avi), and audio (.mp3, .wav). Other types default to application/octet-stream.

How does the server communicate?

It runs as a stdio MCP server and communicates via standard input/output.