software-engineering

software-engineering is a skill for Claude Code, Codex from Prism-Shadow/penguin-harness. It costs 35 tokens per session (597 once invoked), scanned A, original, Apache-2.0.

A general software-engineering workflow for investigating code, reviewing it, making changes, and checking the results.

In plain words
What is it for?
Use it for bug fixes, new features, refactoring, code investigation, reviews, and related testing or reporting.
Why use it?
It gives coding tasks a defined process, helping keep fixes focused and confirming that the result works before handoff.

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/prism-shadow/penguin-harness/software-engineering
Any agent
npx skills add Prism-Shadow/penguin-harness --skill software-engineering
Clone the repo
git clone --depth 1 https://github.com/Prism-Shadow/penguin-harness

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 software-engineering

README.md
[![agentmods](https://agentmods.dev/badge/skills/prism-shadow/penguin-harness/software-engineering.svg)](https://agentmods.dev/skills/prism-shadow/penguin-harness/software-engineering)
Your own site
<a href="https://agentmods.dev/skills/prism-shadow/penguin-harness/software-engineering"><img src="https://agentmods.dev/badge/skills/prism-shadow/penguin-harness/software-engineering.svg" alt="Measured on agentmods" height="20"></a>
Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 597 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 $0.00035 $0.00597
Opus 5 $0.00017 $0.00298
Sonnet 5 $0.00007 $0.00119
Haiku 4.5 $0.00003 $0.00060

Measured 4d ago against content hash 279571dd8e0f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

software-engineering 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 4d 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.

packages/skills/skills/software-engineering/SKILL.md · 35 lines

How it starts

The opening of the file, as written. The whole thing — 35 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Software Engineering

This skill guides PenguinHarness through general software-engineering work, including code investigation, reviews, bug fixes, features, refactors, and verified handoff.

Before you start

If the user's message only invokes this skill without a concrete software-engineering task, ask what they want investigated, reviewed, fixed, or implemented. Do not start until the task is clear.

Workflow

  • Match the work to the user's intent. For explanation, review, or planning requests, inspect and report without editing unless a change is also requested. For implementation tasks, carry the requested change through verification and handoff.
  • Use the current working directory as the target project and work in place unless the user directs otherwise.
  • Preserve worktree changes you did not make. Never revert unrelated user or collaborator work, and do not use destructive Git commands unless explicitly requested.
  • Act autonomously and use tools to understand the real code. Resolve minor ambiguity from existing behavior, tests, and repository conventions; ask only when different choices would materially change the requested behavior or scope.
  • Before making changes, read the applicable repository instructions (such as AGENTS.md or CLAUDE.md) and identify the repository-provided build, test, lint, and formatting commands.
  • Inspect the relevant implementation, callers, tests, and interfaces before making changes.
  • For bug reports, try to reproduce the issue or identify a failing test before editing when feasible. Use the reproduced behavior or failing test to verify the fix afterward.
  • Make the smallest coherent change that fully satisfies the request. Follow existing patterns and dependencies, preserve unrelated behavior, and update coupled tests, schemas, configuration, or generated artifacts only when the repository requires it. Never weaken a test to justify the implementation.
  • For implementation tasks, do not stop after analysis. Inspect failures, revise the approach, and continue until the change is verified or a concrete blocker remains. Do not repeat a failed action without changing the approach.
  • Validate code changes proportionally with repository-provided commands: run the most focused relevant check first and broaden only when useful. Preserve exit status, inspect relevant failure output, and never claim that an unobserved check passed.
  • Before finishing a code change, review git diff and repository status, remove temporary artifacts, and keep the change limited to the task. Do not commit unless the user or applicable repository instructions require it.

Read the full file on GitHub · 35 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. 4d ago First seen · 35 lines · 35 tokens per session scan A 279571dd8e0f

Subscribe to this mod's changes

software-engineering is a skill published in the GitHub repository Prism-Shadow/penguin-harness (1,887 stars, last pushed 2d ago), licensed Apache-2.0. It adds 35 tokens to every session and 597 once invoked, about $0.0002 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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