format

format is a skill for Claude Code, Codex from terrylica/cc-skills. It costs 29 tokens per session (596 once invoked), scanned A, original, MIT.

A reference guide for asciinema v3 cast files, which store terminal recordings as newline-delimited JSON data.

In plain words
What is it for?
Use it to look up headers, events, parsing examples, or the complete format, optionally using a specific cast file.
Why use it?
It explains the file structure and event codes, reducing guesswork when reading or processing terminal recordings.

Skill for Claude CodeCodex

Part of the asciinema-tools plugin — 24 skills shipped together , and of cc-skills

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/terrylica/cc-skills/format
Any agent
npx skills add terrylica/cc-skills --skill format
Clone the repo
git clone --depth 1 https://github.com/terrylica/cc-skills

Made for: Claude Code, Codex.

Or install asciinema-tools, the plugin that ships this one along with the rest of its 24 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for format

README.md
[![agentmods](https://agentmods.dev/badge/skills/terrylica/cc-skills/format.svg)](https://agentmods.dev/skills/terrylica/cc-skills/format)
Your own site
<a href="https://agentmods.dev/skills/terrylica/cc-skills/format"><img src="https://agentmods.dev/badge/skills/terrylica/cc-skills/format.svg" alt="Measured on agentmods" height="20"></a>
Per session 29 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 596 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00029 $0.00596
Opus 5 $0.00015 $0.00298
Sonnet 5 $0.00006 $0.00119
Haiku 4.5 $0.00003 $0.00060

Measured 5d ago against content hash 64f4fd85444a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

format scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/asciinema-tools/skills/format/SKILL.md · 72 lines

How it starts

The opening of the file, as written. The whole thing — 72 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/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 -f provided with parsing -> skip Phase 2 (example file)

Workflow

  1. Selection: AskUserQuestion for section
  2. Example: AskUserQuestion for example file (if parsing)
  3. 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 --live

Troubleshooting

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:

  1. Did the command succeed? — If not, fix the instruction or error table that caused the failure.
  2. Did parameters or output change? — If the underlying tool's interface drifted, update Usage examples and Parameters table to match.
  3. 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.

Read the full file on GitHub · 72 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 72 lines · 29 tokens per session scan A 64f4fd85444a

Subscribe to this mod's changes

format is a skill published in the GitHub repository terrylica/cc-skills (62 stars, last pushed today), licensed MIT. It adds 29 tokens to every session and 596 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.