ChangeThisFile — file conversion between 690+ formats (hosted Streamable HTTP + stdio)

ChangeThisFile MCP Server

Use ChangeThisFile's seven file tools from any MCP client: conversion across 1,000+ supported routes, document translation, table extraction, exact-size compression, natural-language routing, and job status checks.

Powered by ChangeThisFile.com. Discovery and paid-preview jobs are public. General convert_file works without a key for 25 conversions per month per network; after that it needs a free verified developer key (25 conversions/month, shared with the REST API), and paid API plans raise the limit.

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).
translate_file	Translate a document with its layout preserved. Returns a free preview and a one-time checkout link for the full output.
extract_tables	Extract tables from PDFs or images into Excel. Returns a free preview and a one-time checkout link for the full output.
compress_file	Compress a PDF, image, or video to an exact maximum size. Free with a daily limit.
do_file_job	Route a plain-language file instruction to conversion, translation, extraction, or compression.
check_job	Check a submitted job and retrieve its preview, checkout link, or download URL.

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. Clients that support custom headers can send Authorization: Bearer ctf_sk_... to use authenticated developer metering.

{
  "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"],
      "env": {
        "CTF_API_KEY": "ctf_sk_your_key_here"
      }
    }
  }
}

CTF_API_KEY is optional: without it you get 25 free conversions per month per network; after that convert_file asks for a key. Get a verified free key from the ChangeThisFile dashboard (or POST https://changethisfile.com/v1/keys/free with {"email":"[email protected]"} and click the verification email); its 25 monthly conversions are shared across MCP and REST. Paid plans start at $29/month.

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 -e CTF_API_KEY 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
CTF_API_KEY	unset	Optional verified developer key forwarded as a bearer token; the value is never logged
CTF_MCP_URL	https://changethisfile.com/mcp	Override the upstream endpoint
CHANGETHISFILE_MCP_URL	unset	Legacy alias for CTF_MCP_URL

Privacy & limits

• Discovery and paid-preview jobs require no account. General conversion is temporarily anonymous in compatibility mode; a verified key enables shared developer metering now.
• Files are processed server-side and auto-deleted within 24 hours; download URLs expire after 1 hour.
• MCP inputs are capped at 25 MB. Authenticated convert_file uses the developer account's shared API/MCP rate and monthly quota; other expensive tools retain per-account or per-IP abuse limits.

License

MIT