Borrowing it
Nothing to install: this file belongs to spelech/contextcortex. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/spelech/contextcortex/main/.agents/skills/caddy-preview/SKILL.mdgit clone --depth 1 https://github.com/spelech/contextcortexWrote 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.
[](https://agentmods.dev/skills/spelech/contextcortex/caddy-preview)<a href="https://agentmods.dev/skills/spelech/contextcortex/caddy-preview"><img src="https://agentmods.dev/badge/skills/spelech/contextcortex/caddy-preview/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/spelech/contextcortex/caddy-preview"><img src="https://agentmods.dev/badge/skills/spelech/contextcortex/caddy-preview.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00043 | $0.00690 |
| Opus 5.5 | $0.00017 | $0.00276 |
| Sonnet 5.5 | $0.00009 | $0.00138 |
| Haiku 4.5 | $0.00004 | $0.00069 |
Grade A, and why
agent-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 2mo 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.
How it starts
The opening of the file, as written. The whole thing — 68 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent Preview Hub (agent-preview)
The Agent Preview Hub provides a persistent, zero-friction preview subdomain (https://preview.wileyriley.com/<id>/ and http://preview.lan/<id>/) where agents can instantly host and share visual artifacts, web applications, charts, diagrams, or HTML reports without restarting Caddy.
When to Use
Use agent-preview whenever:
- You create an HTML mockup, single-page app (React/Vue/Vite), or interactive web component for the user to inspect.
- You generate visual diagrams, charts (Chart.js/D3/Plotly), or images that are hard to view over remote SSH terminals.
- You produce test coverage reports, Playwright traces, or benchmark dashboards.
- The user asks to "show me", "preview this", or "render this".
CLI Commands
The CLI utility is available globally as agent-preview (or publish-preview):
1. Publish a Directory / Built Webapp
agent-preview publish <slot-id> <source_dir> --title "My App Title" --category "Web App" --tags "React,Vite"
Copies the directory into the preview engine and generates the live URL.
2. Publish Inline HTML / Markdown Text
agent-preview text <slot-id> "<div class='p-6'><h1>Report Title</h1><p>Status: All checks passed.</p></div>" --title "Status Report"
Instantly creates an index.html with Tailwind styling.
3. Publish a Standalone Image / Diagram
agent-preview publish <slot-id> /path/to/diagram.png --title "Architecture Diagram v2"
Copies the image and generates a viewer wrapper.
4. Register a Live Dev Server / Container Port
agent-preview port <slot-id> <port_number> --title "FastAPI Live Demo"
Creates a live bridge to https://p-<port>.wileyriley.com (or https://preview.wileyriley.com/port/<port>/) without modifying Caddy.
5. Pin / Retention Control
By default, preview slots have a 7-day auto-TTL. Pass --keep or run pin to make it permanent:
agent-preview publish <slot-id> <path> --keep
# Or pin existing:
agent-preview pin <slot-id>
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.
- 2mo ago First seen · 68 lines · 43 tokens per session scan A 302b572760bb
agent-preview is a skill published in the GitHub repository spelech/contextcortex (0 stars, last pushed 9d ago), licensed MIT. It adds 43 tokens to every session and 690 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-31.
agent-preview compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| agent-previewspelech/contextcortex | Skill | 0 | 9d ago | MIT | A | 43 | Claude Code, Codex |
| swagjmagar/swag-mcp | Skill | 7 | 4d ago | MIT | A | 118 | Claude Code |
| @elad12390/web-research-assistantelad12390/web-research-assistant | Skill | 9 | 9d ago | MIT | A | 150 | Claude Code, Codex |
| scrape-batchn24q02m/wet-mcp | Skill | 17 | 1mo ago | Apache-2.0 | A | 84 | Claude Code |
| genpark-vision-coderalphaparkinc/genpark-vision-coder | Skill | 9 | 7d ago | MIT | A | 28 | Claude Code, Codex |
| archivebox-web-archivingKnuckles-Team/archivebox-api | Skill | 1 | yesterday | MIT | A | 127 | Claude Code, Codex |
| genpark-magic-uialphaparkinc/genpark-magic-ui | Skill | 9 | 7d ago | MIT | A | 12 | Claude Code, Codex |