Agent-Skills.md

Agent Skills: File Conversion (ChangeThisFile)

Convert files between formats — PDF to Word, HEIC to JPG, MP4 to MP3, CSV to JSON, EPUB to MOBI, and 999 total routes across images, video, audio, documents, data, fonts, ebooks, and archives. Free via changethisfile.com, no API key or signup. Use when the user needs a file converted to a different format.

UncategorizedID: aadilr/changethisfile-mcp/file-conversion

Repository

aadilr/changethisfile-mcp
aadilrLicense: MIT

Install this agent skill to your local

pnpm dlx add-skill https://github.com/aadilr/changethisfile-mcp/tree/HEAD/skills/file-conversion

Skill Files

Browse the full folder contents for file-conversion.

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skills/file-conversion/SKILL.md

Skill Metadata

Name
file-conversion
Description
Convert files between formats — PDF to Word, HEIC to JPG, MP4 to MP3, CSV to JSON, EPUB to MOBI, and 1,000+ supported routes across images, video, audio, documents, data, fonts, ebooks, and archives. Anonymous compatibility access is currently available via changethisfile.com; verified keys use the shared developer meter. Use when the user needs a file converted to a different format.

File Conversion (ChangeThisFile)

Convert files across 1,000+ supported routes using ChangeThisFile. Anonymous conversion is temporarily available in compatibility mode; verified developer keys share quota with REST API usage. Conversions run server-side (FFmpeg, LibreOffice, Calibre, 7-Zip, sharp, Ghostscript); files are deleted within 24 hours.

Decision order

  1. If ChangeThisFile MCP tools are available (changethisfile:convert_file, changethisfile:list_conversions) — use them directly. convert_file takes source_url OR base64_content + source_format, plus target_format, and returns a temporary download URL.
  2. Otherwise, use the bundled script (requires network access to changethisfile.com):
scripts/convert.sh <input-file> <target-format> [output-file]
# e.g. scripts/convert.sh report.docx pdf
# prints the output file path on success

The script path is relative to this skill's directory. It base64-encodes the file, calls the hosted MCP endpoint over plain HTTPS, downloads the result, and writes it next to the input (or to [output-file]).

  1. Remote file (you have a URL, not a local file) — skip the download/re-upload; one curl does it:
curl -sS -X POST https://changethisfile.com/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"convert_file","arguments":{"source_url":"<FILE_URL>","target_format":"pdf"}}}'

The response text contains a download URL — fetch it with curl -o <output>.

Discovering supported routes

Ask before guessing if a conversion is exotic:

curl -sS -X POST https://changethisfile.com/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"list_conversions","arguments":{"source_format":"docx"}}}'

Omit source_format for a grouped summary of all supported routes.

Limits and errors

  • Max MCP input: 25 MB, including authenticated plans. Larger files should use POST /v1/convert; verified free keys include 25 conversions/month shared across REST and authenticated MCP.
  • Rate limit: 5 conversions/minute per IP. On "Rate limit exceeded", wait 60 seconds and retry once.
  • "Unsupported conversion: X→Y" errors list the valid targets for that source format.
  • Download URLs expire after 1 hour — download immediately, then work with the local file.

Environment notes

  • Needs outbound HTTPS to changethisfile.com. On claude.ai, the code-execution sandbox restricts egress by default — prefer the MCP connector there, or the user can allow the domain under Settings → Capabilities.
  • Full docs: https://changethisfile.com/docs/mcp