Download and install the latest version of Filestar.
Right click on one or more Spx file(s) on your desktop and select Convert with Filestar.
Type convert to mkv in the search box.
Press Convert.
Or let an AI agent do it: filestarcli -i file.spx -c "convert to mkv" (how).
Documents - File Explorer─☐✕
This PC › Documents
Home
Desktop
Downloads
Documents
Pictures
Music
.spxContract.spx
.xlsxBudget.xlsx
.pdfReport.pdf
.pngLogo.png
Filestar*Help✕
Drop files here to get started
ConvertMergeCompressExtractMoveZip
Let your AI agent convert SPX to MKV
Claude Code, Codex, Cursor and other agents can do this on your computer with Filestar. Your files stay on your machine.
Install Filestar and add it to your agents:
npm install -g filestar
filestarcli agent install
Then ask your agent:
“Convert the SPX files in my Downloads folder to MKV”
Or run it yourself:
filestarcli -i file.spx -c "convert to mkv"
Runs on your computer, so your files stay on it. Works on Windows, macOS and Linux. 50 free conversions with the npm install, no account needed.
Can my AI agent convert SPX to MKV?
Yes. Install the Filestar CLI with npm install -g filestar and your agent can run filestarcli -i file.spx -c "convert to mkv" on your computer, so your files stay on it.
Audio file compressed using Speex compression and saved in the Ogg Vorbis container format; designed as an audio compression format specifically for speech; compresses voice at 2 to 44 kbps and supports 8 kHz, 16 kHz, and 32 kHz compression in the same bitstream.
An MKV file is a video container format similar to the .AVI, .ASF, and .MOV formats. It supports several types of audio and video codecs and may include .SRT, .SSA, or .USF (Universal Subtitle Format) subtitles. MKV files also support VobSub subtitles from DVDs.