engineeringX

A set of simple rules and a self-review checklist for making code changes.

In plain words
What is it for?
Use it to clarify the goal, follow existing project conventions, keep implementations small, and check the result before reporting completion.
Why use it?
It helps prevent unnecessary edits, unverified claims, leftover code, and changes that go beyond the request.

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/treex-x/workflowx/engineeringx
Any agent
npx skills add TreeX-X/WorkFlowX --skill engineeringx
Clone the repo
git clone --depth 1 https://github.com/TreeX-X/WorkFlowX

Made for: Claude Code, Codex.

Per session 15 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 207 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 $0.00015 $0.00207
Opus 5 $0.00008 $0.00103
Sonnet 5 $0.00003 $0.00041
Haiku 4.5 $0.00002 $0.00021

Measured 2d ago against content hash f12e3e5b778c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

engineeringX 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.

.claude/skills/engineeringX/SKILL.md · 32 lines

What it actually says

engineeringX

Use these principles when implementing or modifying code.

Implementation Principles

  • Understand the goal and scope before editing; do not guess about critical ambiguity.
  • Make the smallest change that solves the stated problem.
  • Prefer the simplest clear solution; avoid speculative abstractions, state, configuration, and dependencies.
  • Follow existing project patterns, naming, and tools.
  • Keep every change traceable to the requirement or a necessary constraint.
  • Never claim checks or tests that were not run.

Self-Review

Before reporting completion, inspect the result and ask:

  • Does it solve the requested problem?
  • Did the change exceed scope?
  • Can any code, state, branch, or dependency be removed?
  • Is the implementation path short and easy to understand?
  • Are obvious boundaries and failures handled?
  • Are stale imports, references, or configuration entries left behind?
  • What verification was actually performed?

Report unresolved concerns explicitly.

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 · 32 lines · 15 tokens per session scan A f12e3e5b778c

Subscribe to this mod's changes

engineeringX is a skill published in the GitHub repository TreeX-X/WorkFlowX (55 stars, last pushed 2d ago), licensed MIT. It adds 15 tokens to every session and 207 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.