ChangeThisFile MCP Server

Convert files between 690+ formats from any MCP client — image, video, audio, document, data, spreadsheet, font, ebook, and archive. Free, no API key, no signup.

Powered by ChangeThisFile.com. Conversions run on real engines (FFmpeg, LibreOffice, Calibre, 7-Zip, sharp, Ghostscript, fonttools, and more) and return a temporary signed download URL. Uploaded files are auto-deleted within 24 hours.

Tools

Tool	Description
convert_file	Convert a file. Pass a publicly accessible source_url or base64_content (max ~5MB), plus a target_format (e.g. pdf, mp3, json). Source format is auto-detected from the URL/filename, or pass source_format explicitly. Returns a download URL valid for 1 hour.
list_conversions	List all supported conversion routes, optionally filtered by source_format (e.g. docx → see every format you can convert DOCX into).

Option 1 — Remote endpoint (recommended, no install)

The server is hosted at https://changethisfile.com/mcp using streamable HTTP transport (MCP spec 2025-03-26). If your client supports remote MCP servers, point it straight at the endpoint:

{
  "mcpServers": {
    "changethisfile": {
      "type": "streamable-http",
      "url": "https://changethisfile.com/mcp"
    }
  }
}

Claude Code:

claude mcp add --transport http changethisfile https://changethisfile.com/mcp

Option 2 — Local stdio server (this package)

For clients that only speak stdio, this package bridges stdio ↔ the hosted endpoint:

{
  "mcpServers": {
    "changethisfile": {
      "command": "npx",
      "args": ["-y", "github:aadilr/changethisfile-mcp"]
    }
  }
}

Or clone and run directly:

git clone https://github.com/aadilr/changethisfile-mcp.git
cd changethisfile-mcp
npm install
node index.js

Option 3 — Agent Skill / Claude Code plugin

This repo doubles as an Agent Skill and Claude Code plugin.

Any skills-capable agent (Claude Code, Codex CLI, Cursor, Gemini CLI, Copilot, and more):

npx skills add aadilr/changethisfile-mcp

Claude Code plugin (bundles the MCP server + the skill):

/plugin marketplace add aadilr/changethisfile-mcp
/plugin install changethisfile@changethisfile

The file-conversion skill prefers the MCP tools when connected and otherwise falls back to a bundled script (skills/file-conversion/scripts/convert.sh) that talks to the hosted endpoint over plain HTTPS — no MCP client required.

Option 4 — Docker

docker build -t changethisfile-mcp .
docker run -i --rm changethisfile-mcp

Quick test

curl -X POST https://changethisfile.com/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

Supported formats

Category	Examples
Image	JPG, PNG, WebP, GIF, BMP, AVIF, ICO, SVG, TIFF, HEIC, PSD, RAW
Video	MP4, WebM, MKV, AVI, MOV, 3GP, FLV, WMV
Audio	MP3, WAV, FLAC, AAC, OGG, M4A, OPUS
Document	PDF, DOCX, DOC, ODT, RTF, TXT, HTML, MD, PPT, PPTX
Data	JSON, CSV, TSV, YAML, XML, TOML, XLSX, XLS
Font	TTF, OTF, WOFF, WOFF2
Ebook	EPUB, MOBI, AZW3, FB2, CBR, CBZ
Archive	ZIP, RAR, 7Z, TAR, TAR.GZ, TAR.BZ2, TAR.XZ

Use list_conversions for the full route table.

Environment variables

Variable	Default	Purpose
CHANGETHISFILE_MCP_URL	https://changethisfile.com/mcp	Override the upstream endpoint

Privacy & limits

• No authentication or account required.
• Files are processed server-side and auto-deleted within 24 hours; download URLs expire after 1 hour.
• Per-IP rate limiting applies. For higher volume, see the authenticated API.

License

MIT