Desktop IDEs & AI Apps

Use Foldr with Claude Desktop (MCP)

Claude Desktop is the official Anthropic desktop client for Claude on macOS and Windows. It was the first mainstream app to ship MCP support in late 2024, making it the reference implementation for the protocol. Connecting Foldr lets Claude upload files, mint short links, and drop bio-page assets without leaving the chat window.

AnthropicmacOS, WindowsMCP: stable

Installation

Add the Foldr MCP server to Claude Desktop with the snippet below. Replace fs_… with an API key from foldr.space/developers/signup. Each upload costs 5¢ - top up account credits or subscribe to Pro tier to bypass per-call charges.

{
  "mcpServers": {
    "foldr": {
      "command": "npx",
      "args": ["-y", "@foldr/mcp-server"],
      "env": {
        "FOLDR_API_KEY": "fs_live_..."
      }
    }
  }
}

Setup tip: Edit ~/Library/Application Support/Claude/claude_desktop_config.json on macOS or %APPDATA%\Claude\claude_desktop_config.json on Windows, then restart Claude Desktop.

Official Claude Desktop MCP docs

What You Can Do

Upload any file from Claude Desktop to Foldr and get a permanent shareable URL back in the same turn (5¢ per upload, debited from credits)
Mint short-lived capability tokens to share files with downstream agents without leaking your API key
Organize uploads into per-API-key folders with hierarchical structure
Shorten long URLs to foldr.space/s/... links - free with any API key
Hand off build artifacts, screenshots, and logs to a URL without leaving your editor

Claude Desktop + Foldr FAQ

How do I install the Foldr MCP server in Claude Desktop?

Open Claude Desktop's MCP configuration (the JSON settings file) and paste the config block shown above. Set FOLDR_API_KEY to a key you create at foldr.space/developers/signup. Restart Claude Desktop if it doesn't hot-reload.

How much does it cost to use Foldr from Claude Desktop?

Each upload costs 5¢. You can pay by topping up account credits via the `top_up_credits` MCP tool (min $5) - every upload then debits from balance. Or subscribe to Pro tier ($25/mo) and per-call charges are bypassed entirely. Tools that don't write data (list_files, mint_capability, get_usage, etc.) are free.

I set the key but Claude Desktop says the Foldr tool isn't available - what's wrong?

Three common causes: (1) Claude Desktop wasn't restarted after editing the config - most MCP hosts need a restart to pick up new servers. (2) The API key is wrong or missing - verify the env var name your client reads (e.g. FOLDR_API_KEY) matches the config snippet above. (3) Your client doesn't support the streamable-http transport - most modern clients do, but check Claude Desktop's docs for the version that added MCP support.

Can Claude Desktop upload files directly to Foldr, or just generate URLs?

Claude Desktop can do both. The MCP server exposes tools for `upload_file` (base64-encoded file content), `bulk_upload` (up to 20 files in one call), `mint_capability` (short-lived shareable links), and `create_short_url`. Any file Claude Desktop can read from disk can be uploaded.

Is the Foldr MCP integration with Claude Desktop production-ready?

Foldr's MCP server is stable and used in production - streamable-http transport at https://foldr.space/api/mcp with 23 tools. Claude Desktop's MCP support is currently stable and generally available. Every write endpoint accepts an Idempotency-Key so retries are safe.

Related MCP Integrations

Foldr + Cursor

Desktop IDEs & AI Apps

Foldr + Windsurf

Desktop IDEs & AI Apps

Foldr + Cline

Desktop IDEs & AI Apps

Foldr + Zed

Desktop IDEs & AI Apps

Foldr + Continue

Desktop IDEs & AI Apps

Browse all MCP integrations

Connect Claude Desktop to Foldr in under a minute

Grab an API key, paste the snippet above into Claude Desktop's MCP config, top up credits (or grab a Pro subscription), and your agent can upload files and mint share links immediately.

Get your Foldr API key x402 details