Compound Engineering is a plugin that organizes software work into brainstorming, planning, implementation, review, and recording lessons for future changes. It is used with AI coding agents including Claude Code, Cursor, and Codex, and the catalogue entries provide parts of its agent, skill, command, and hook workflow.
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.
npx skills add EveryInc/compound-engineering-plugin --skill ce-test-browsergit clone --depth 1 https://github.com/EveryInc/compound-engineering-pluginWrote 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/everyinc/compound-engineering-plugin/ce-test-browser)<a href="https://agentmods.dev/skills/everyinc/compound-engineering-plugin/ce-test-browser"><img src="https://agentmods.dev/badge/skills/everyinc/compound-engineering-plugin/ce-test-browser/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/everyinc/compound-engineering-plugin/ce-test-browser"><img src="https://agentmods.dev/badge/skills/everyinc/compound-engineering-plugin/ce-test-browser.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk warn
- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Excessive Agency · line 39 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 | $0.00031 | $0.01359 |
| Opus 5.5 | $0.00012 | $0.00544 |
| Sonnet 5.5 | $0.00006 | $0.00272 |
| Haiku 4.5 | $0.00003 | $0.00136 |
Grade A, and why
ce-test-browser 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.
How it starts
The opening of the file, as written. The whole thing — 51 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Browser Test Skill
Run end-to-end browser tests on pages affected by a PR or branch using the best approved browser driver available in the active harness.
Done: the run ends by reporting what it found — either the summary, with every affected route marked Pass, Fail, or Skip and each Skip carrying its reason, or, when a preflight blocker stops testing before any route can be exercised, the blocker and what would clear it. Reaching neither, or dropping a route from the summary because nobody could reach it, is the failure this done condition exists to prevent.
Modes
- Manual (default): the user controls the dev server. When the fallback driver is
agent-browser, ask whether to run headed or headless. - Pipeline (
mode:pipeline): invoked by LFG or another automated runner. The run is unattended — never block on a question. Readreferences/pipeline-orchestration.mdfrom this skill's directory and follow it; it overrides port selection (step 4, Determine the dev server port), dev-server startup (step 5, Verify the dev server is running), and visibility prompts (step 6, Set visibility), running the same port script with--freeinside the block that starts the server.
Browser Driver Policy
Select the driver before the first browser action:
- Prefer a host-native integrated browser. Use a browser-control surface embedded in or directly owned by the active harness when it can navigate local URLs, inspect rendered and interactive state, click/fill/press, capture screenshots, and inspect console errors. A separately configured browser extension or integration is not host-native. Load and follow the selected capability's own instructions before browser work.
- Otherwise fall back to
agent-browser. Readreferences/agent-browser-driver.mdbefore running any command. - Do not introduce a third browser stack. Never install or substitute standalone Playwright, Puppeteer, a separately configured browser extension or MCP, or other ad hoc browser automation. A Playwright API exposed inside the selected host-native browser remains host-native; it is not standalone Playwright.
What ships with it
4 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.
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.
- 1mo ago Changed 68d2445e2cc3
- 1mo ago First seen · 51 lines · 31 tokens per session scan A 074fd7d28134
ce-test-browser is a skill published in the GitHub repository EveryInc/compound-engineering-plugin (25,741 stars, last pushed today), licensed MIT. It adds 31 tokens to every session and 1,359 once invoked, about $0.0001 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 2026-09-03.
Other skills, from other repositories
proof-e2e
Build E2E test specs for critical user journeys — Playwright or Cypress, page objects, setup/teardown, CI config. Use when asked to "write E2E tests", "end-to-end testing", "browser tests", "UI tests", or "Playwright tests".
aif-web-testing
Test web apps with Playwright, Vitest and k6: E2E, unit, integration, load, security, visual and a11y.
browse
Drive a real browser through Aside: open a page, read it, click through a flow, take screenshots, check console errors. (gstack).
cua-driver
Use Cua Driver for desktop or browser tasks that are awkward or unavailable through Bash/APIs, or when the user explicitly wants GUI interaction: app testing, visual bug reproduction, form filling, calendar entry, screenshots, and demo recording. Also covers Cua setup; not OpenAI Codex Computer Use or web research.
create-verification-skill
Create a repo-local verification skill and exhaustive feature map for driving a real app through its UI, CLI, or API. Use for "create a verification skill", "make a verify skill for this repo", or "document how agents can verify this app".
browser-qa
A browser-based quality check for deployed web pages and user flows. It uses browser automation to test rendering, navigation, forms, interactions, responsive behaviour, and accessibility-related issues.