file-conversion

---
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):

```bash
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]`).

3. **Remote file (you have a URL, not a local file)** — skip the download/re-upload; one curl does it:

```bash
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:

```bash
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

• SKILL.md 3 KB
• scripts/convert.sh 2 KB