Reference for asciinema v3 .cast NDJSON format. TRIGGERS - cast format, asciicast spec, event codes.
Resources
1Install
npx skillscat add terrylica/cc-skills/format Install via the SkillsCat registry.
This skill provides technical documentation and parsing examples for the asciinema v3.cast NDJSON format. It assists developers in understanding header specifications, event codes, and data extraction methods. Use this tool when you need to validate, parse, or implement terminal session recordings using bash or jq.
/asciinema-tools:format
Display reference documentation for the asciinema v3 .cast format.
Self-Evolving Skill: This skill improves through use. If instructions are wrong, parameters drifted, or a workaround was needed — fix this file immediately, don't defer. Only update for real, reproducible issues.
Arguments
| Argument | Description |
|---|---|
header |
Show header field specification |
events |
Show event codes deep-dive |
parsing |
Show jq/bash parsing examples |
all |
Show complete format reference |
-f, --file |
Use specific .cast for examples |
--live |
Run parsing examples on file |
Execution
Invoke the asciinema-cast-format skill with user-selected section.
Skip Logic
- If section provided -> skip Phase 1 (section selection)
- If
-fprovided withparsing-> skip Phase 2 (example file)
Workflow
- Selection: AskUserQuestion for section
- Example: AskUserQuestion for example file (if parsing)
- Display: Show requested documentation
Examples
# Show header format
/asciinema-tools:format header
# Show event codes
/asciinema-tools:format events
# Parse specific file with live examples
/asciinema-tools:format parsing -f session.cast --liveTroubleshooting
| Issue | Cause | Solution |
|---|---|---|
| File not found | Invalid path | Use absolute path or ensure file exists |
| Parse error | Invalid NDJSON | Check file is valid asciinema v3 format |
| No output | Missing section | Specify one of: header, events, parsing, all |
Post-Execution Reflection
After this skill completes, check before closing:
- Did the command succeed? — If not, fix the instruction or error table that caused the failure.
- Did parameters or output change? — If the underlying tool's interface drifted, update Usage examples and Parameters table to match.
- Was a workaround needed? — If you had to improvise (different flags, extra steps), update this SKILL.md so the next invocation doesn't need the same workaround.
Only update if the issue is real and reproducible — not speculative.