ck:preview

A viewer and visual-explanation tool for files, folders, and technical topics. It can also create slides and diagrams.

In plain words
What is it for?
Use it to browse files, explain a topic, create presentation slides, or draw architecture and terminal-friendly diagrams.
Why use it?
It helps you inspect project material or understand a system visually instead of relying only on text.

Skill for Claude CodeCodex

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/manhvann/codexkit/preview
Any agent
npx skills add manhvann/codexkit --skill preview
Clone the repo
git clone --depth 1 https://github.com/manhvann/codexkit

Made for: Claude Code, Codex.

Per session 17 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 707 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 $0.00017 $0.00707
Opus 5 $0.00009 $0.00353
Sonnet 5 $0.00003 $0.00141
Haiku 4.5 $0.00002 $0.00071

Measured 2d ago against content hash f9285fdc4e30, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ck:preview 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 2d 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.

.agents/skills/preview/SKILL.md · 76 lines

How it starts

The opening of the file, as written. The whole thing — 76 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Preview

Universal viewer + visual generator. View existing content OR generate new visual explanations.

Default (No Arguments)

If invoked without arguments, ask the user to choose available preview operations:

Operation Description
(view) View a file or directory
--explain Generate visual explanation
--slides Generate presentation slides
--diagram Generate architecture diagram
--ascii Terminal-friendly diagram
--stop Stop preview server

Present options with header "Preview Operation", question "What would you like to do?".

Usage

View Mode

  • $preview <file.md> - View markdown file in novel-reader UI
  • $preview <directory/> - Browse directory contents
  • $preview --stop - Stop running server

Generation Mode

  • $preview --explain <topic> - Generate visual explanation (ASCII + Mermaid + prose)
  • $preview --slides <topic> - Generate presentation slides (one concept per slide)
  • $preview --diagram <topic> - Generate focused diagram (ASCII + Mermaid)
  • $preview --ascii <topic> - Generate ASCII-only diagram (terminal-friendly)

Argument Resolution

When processing arguments, follow this priority order:

  1. --stop → Stop server (exit)
  2. Generation flags (--explain, --slides, --diagram, --ascii) → Generation mode. Load references/generation-modes.md
  3. Resolve path from argument:
    • If argument is an explicit path → use directly
    • If argument is a contextual reference → resolve from recent conversation context
  4. Resolved path exists on filesystem → View mode. Load references/view-mode.md
  5. Path doesn't exist or can't resolve → Ask user to clarify

Topic-to-slug conversion:

  • Lowercase the topic
  • Replace spaces/special chars with hyphens
  • Remove non-alphanumeric except hyphens
  • Collapse multiple hyphens → single hyphen
  • Trim leading/trailing hyphens
  • Max 80 chars - truncate at word boundary if longer

Multiple flags: If multiple generation flags provided, use first one; remaining treated as topic.

Read the full file on GitHub · 76 lines

Files

What ships with it

2 files 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. 2d ago First seen · 76 lines · 17 tokens per session scan A f9285fdc4e30

Subscribe to this mod's changes

ck:preview is a skill published in the GitHub repository manhvann/codexkit (88 stars, last pushed 3d ago), licensed MIT. It adds 17 tokens to every session and 707 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.

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