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