seed: Skill for Claude Code

.agents/skills/testing-editor-harness/SKILL.md

testing-editor-harness is a skill for Claude Code, Codex from seed-hypermedia/seed. It costs 41 tokens per session (1,629 once invoked), scanned A, original, Apache-2.0.

Instructions for running and manually testing an end-to-end browser harness for the @shm/editor package, including mobile screen testing.

In plain words
What is it for?
Use it to test editor behavior, block rendering, badges, and mobile comment interactions through a local browser harness.
Why use it?
It provides a repeatable way to inspect the editor with realistic blocks, comment or citation badges, and mobile layouts.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

This is seed-hypermedia/seed's own configuration. It tells Claude Code and Codex how to work on seed itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything seed configures →

Not installable: its command points at a path on the author’s own machine, so it runs nowhere else. The line is /home/ubuntu/.local/bin/pnpm.

Reuse

Borrowing it

Nothing to install: this file belongs to seed-hypermedia/seed. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/seed-hypermedia/seed/main/.agents/skills/testing-editor-harness/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/seed-hypermedia/seed

Made for: Claude Code, Codex.

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 testing-editor-harness

README.md
[![agentmods](https://agentmods.dev/badge/skills/seed-hypermedia/seed/testing-editor-harness/github.svg)](https://agentmods.dev/skills/seed-hypermedia/seed/testing-editor-harness)
Your own site
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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.

agentmods 80×15 button for testing-editor-harness

Your own site · 80×15
<a href="https://agentmods.dev/skills/seed-hypermedia/seed/testing-editor-harness"><img src="https://agentmods.dev/badge/skills/seed-hypermedia/seed/testing-editor-harness.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,629 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00041 $0.01629
Opus 5.5 $0.00016 $0.00652
Sonnet 5.5 $0.00008 $0.00326
Haiku 4.5 $0.00004 $0.00163

Measured 1mo ago against content hash bfa9f38403de, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

testing-editor-harness 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 1mo 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/testing-editor-harness/SKILL.md · 121 lines

How it starts

The opening of the file, as written. The whole thing — 121 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Testing the editor E2E harness

Devin Secrets Needed

None.

Environment

  • Work from frontend/packages/editor.
  • Use Node 22.22.x and the pnpm fallback at /home/ubuntu/.local/bin/pnpm if mise/corepack is rate-limited.
  • The harness uses Vite: pnpm test:harness runs vite --config e2e/vite.config.ts on http://localhost:5180.

Running the harness

export PATH="/home/ubuntu/.local/bin:/home/ubuntu/.local/share/mise/installs/node/22.22.0/bin:$PATH"
cd /home/ubuntu/repos/seed/frontend/packages/editor
pnpm test:harness

Open the browser at a real-mode fixture URL, e.g.:

http://localhost:5180/?real=1&fixture=allBlocks&badges=1
  • real=1 mounts the actual DocumentEditor with a mock document machine.
  • fixture=allBlocks renders one of every block type defined in e2e/test-app/TestEditor.tsx.
  • badges=1 gives every fixture block a mock citation/comment count so supernumber badges render.

Mobile viewport emulation

The Chrome for Testing instance in this environment listens on remote-debugging port 29229. Use CDP to set a mobile viewport without keeping DevTools open:

// /tmp/set-mobile-viewport.js
const http = require('http');
const WebSocket = require('/home/ubuntu/repos/seed/node_modules/ws');

http.get('http://localhost:29229/json/list', (res) => {
  let data = '';
  res.on('data', (c) => (data += c));
  res.on('end', () => {
    const pages = JSON.parse(data);
    const page = pages.find((p) => p.type === 'page' && (p.url.includes('localhost:5180') || p.url === 'about:blank'));
    if (!page) { console.error('No suitable page found'); process.exit(1); }
    const ws = new WebSocket(page.webSocketDebuggerUrl);
    ws.on('open', () => {
      ws.send(JSON.stringify({id: 1, method: 'Page.navigate', params: {url: 'http://localhost:5180/?real=1&fixture=allBlocks&badges=1'}}));
      setTimeout(() => {
        ws.send(JSON.stringify({id: 2, method: 'Emulation.setDeviceMetricsOverride', params: {
          width: 390, height: 844, deviceScaleFactor: 2, mobile: true,
          screenWidth: 390, screenHeight: 844,
        }}));
        ws.send(JSON.stringify({id: 3, method: 'Emulation.setTouchEmulationEnabled', params: {enabled: true}}));
        setTimeout(() => ws.close(), 500);
      }, 300);
    });
  });
});

Read the full file on GitHub · 121 lines

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. 1mo ago First seen · 121 lines · 41 tokens per session scan A bfa9f38403de

Subscribe to this mod's changes

testing-editor-harness is a skill published in the GitHub repository seed-hypermedia/seed (59 stars, last pushed today), licensed Apache-2.0. It adds 41 tokens to every session and 1,629 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.

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