R2 Upload MCP Server

Overview

The R2 Upload MCP Server is a lightweight, standards‑compliant service that lets AI assistants and other applications upload arbitrary files to Cloudflare R2 object storage without leaving the MCP ecosystem. By exposing a single tool, it turns any Claude or other MCP‑compatible assistant into a first‑class client for R2, enabling developers to persist data, host static assets, or feed media into downstream pipelines directly from conversational interfaces.

At its core, the server listens for JSON requests on stdin/stdout, parses the , optional , and optional parameters, then streams the file into a pre‑configured R2 bucket. It automatically detects MIME types for common extensions, ensuring that browsers and other consumers receive the correct header. If a custom key is supplied, the file can be stored under any path; otherwise, the original filename is used. After a successful upload, the server returns a public URL that points to the object, optionally using a custom domain if configured. This makes it trivial for an AI assistant to generate shareable links or embed media in generated content.

Key capabilities include:

• Seamless Cloudflare integration: The server pulls all authentication and endpoint details from environment variables, eliminating the need to hard‑code credentials or perform manual API calls.
• Automatic MIME detection: Supports a wide range of image, document, script, video, and audio formats out of the box, falling back to a generic binary type when necessary.
• Customizability: Developers can override the object key and content type, or point the server at a custom R2 endpoint or domain to match their infrastructure.
• Stateless operation: As a stdio MCP server, it can be launched as a single process or embedded in larger toolchains without additional networking overhead.

Typical use cases span from content creation workflows—where an AI writes a blog post and then uploads the accompanying image to R2 for hosting—to data ingestion pipelines, where an assistant receives a CSV or JSON file and stores it in R2 for later processing. Because the server returns a direct URL, downstream services can immediately reference the asset, enabling rapid iteration and integration with webhooks, notification systems, or content delivery networks.

By abstracting the complexities of R2’s API behind a simple MCP interface, this server empowers developers to extend AI assistants with persistent storage capabilities. Whether you’re building a chatbot that hosts user‑generated media, or automating asset management in a CI/CD pipeline, the R2 Upload MCP Server offers a secure, configurable, and developer‑friendly bridge to Cloudflare’s scalable object storage.