System Architecture Designer
Jeffallan/claude-skills
Guides system architecture design end to end: gathering requirements, matching them to a pattern, documenting trade-offs with ADRs, and reviewing.
A skill your agent uses when designing architectural fitness functions as GC rules — periodic checks that verify system-wide properties like layer boundaries, coupling trends, and complexity…
Custom licenceAuto-check passed
Install Fitness Functions
$ npx skills add Habitat-Thinking/ai-literacy-superpowers --skill fitness-functions -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install Habitat-Thinking/ai-literacy-superpowers fitness-functions --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/Habitat-Thinking/ai-literacy-superpowers.git skills-src && mkdir -p .claude/skills && cp -r skills-src/ai-literacy-superpowers/skills/fitness-functions .claude/skills/fitness-functions && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "fitness-functions" agent skill from https://github.com/Habitat-Thinking/ai-literacy-superpowers/tree/main/ai-literacy-superpowers/skills/fitness-functions into .claude/skills/fitness-functions/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fitness-functions", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/Habitat-Thinking/ai-literacy-superpowers/tree/main/ai-literacy-superpowers/skills/fitness-functionsType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add Habitat-Thinking/ai-literacy-superpowers --skill fitness-functions -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install Habitat-Thinking/ai-literacy-superpowers fitness-functions --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/Habitat-Thinking/ai-literacy-superpowers.git skills-src && mkdir -p .agents/skills && cp -r skills-src/ai-literacy-superpowers/skills/fitness-functions .agents/skills/fitness-functions && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "fitness-functions" agent skill from https://github.com/Habitat-Thinking/ai-literacy-superpowers/tree/main/ai-literacy-superpowers/skills/fitness-functions into .agents/skills/fitness-functions/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fitness-functions", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add Habitat-Thinking/ai-literacy-superpowers --skill fitness-functions -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install Habitat-Thinking/ai-literacy-superpowers fitness-functions --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/Habitat-Thinking/ai-literacy-superpowers.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/ai-literacy-superpowers/skills/fitness-functions .cursor/skills/fitness-functions && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "fitness-functions" agent skill from https://github.com/Habitat-Thinking/ai-literacy-superpowers/tree/main/ai-literacy-superpowers/skills/fitness-functions into .cursor/skills/fitness-functions/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fitness-functions", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/Habitat-Thinking/ai-literacy-superpowers.git --path ai-literacy-superpowers/skills/fitness-functions--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add Habitat-Thinking/ai-literacy-superpowers --skill fitness-functions -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install Habitat-Thinking/ai-literacy-superpowers fitness-functions --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/Habitat-Thinking/ai-literacy-superpowers.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/ai-literacy-superpowers/skills/fitness-functions .gemini/skills/fitness-functions && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "fitness-functions" agent skill from https://github.com/Habitat-Thinking/ai-literacy-superpowers/tree/main/ai-literacy-superpowers/skills/fitness-functions into .gemini/skills/fitness-functions/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fitness-functions", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install Habitat-Thinking/ai-literacy-superpowers fitness-functionsInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add Habitat-Thinking/ai-literacy-superpowers --skill fitness-functions -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/Habitat-Thinking/ai-literacy-superpowers.git skills-src && mkdir -p .github/skills && cp -r skills-src/ai-literacy-superpowers/skills/fitness-functions .github/skills/fitness-functions && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "fitness-functions" agent skill from https://github.com/Habitat-Thinking/ai-literacy-superpowers/tree/main/ai-literacy-superpowers/skills/fitness-functions into .github/skills/fitness-functions/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fitness-functions", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add Habitat-Thinking/ai-literacy-superpowers --skill fitness-functions -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install Habitat-Thinking/ai-literacy-superpowers fitness-functions --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/Habitat-Thinking/ai-literacy-superpowers.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/ai-literacy-superpowers/skills/fitness-functions .opencode/skills/fitness-functions && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "fitness-functions" agent skill from https://github.com/Habitat-Thinking/ai-literacy-superpowers/tree/main/ai-literacy-superpowers/skills/fitness-functions into .opencode/skills/fitness-functions/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fitness-functions", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
fitness-functions- GitHub stars
- 114
- Token cost
- ~2.8k tokens
- SKILL.md length
- 1,180 words
- Files
- 2 (incl. references)
- Skills in repo
- 42
- Repo updated
- First seen
- Licence
- Custom licence
At a glance
A skill your agent uses when designing architectural fitness functions as GC rules — periodic checks that verify system-wide properties like layer boundaries, coupling trends, and complexity…
- Works in 4 steps: The same layer boundary violation… → A specific import pattern keeps… → The fitness function finding is always… → …
- Designing architectural fitness functions as GC rules — periodic checks that verify system-wide properties like layer boundaries
- SKILL.md covers Overview, The Constraint vs Fitness…, Fitness Function Catalogue and Tool Reference, plus 4 more sections
- Calls npx and semgrep
What it does
Fitness Functions is an agent skill from Habitat-Thinking/ai-literacy-superpowers. Use when designing architectural fitness functions as GC rules — periodic checks that verify system-wide properties like layer boundaries, coupling trends, and complexity hotspots, complementing per-change constraints with weekly architectural health monitoring
Its SKILL.md is about 2.8k tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including reference files (for example `references/fitness-catalogue.md`).
The repository describes itself as: A set of Claude Code and GitHub Copilot plugins providing the AI Literacy framework's complete development workflow — harness engineering, agent orchestration, literate….
When your agent uses it
- Designing architectural fitness functions as GC rules — periodic checks that verify system-wide properties like layer boundaries
- Coupling trends
- Complexity hotspots
- Complementing per-change constraints with weekly architectural health monitoring
Example prompts
- “/fitness-functions”
Requirements
- Python 3
- Node.js
Workflow steps
4 steps, taken from the first numbered list in SKILL.md.
- The same layer boundary violation appears in 3+ consecutive snapshots
- A specific import pattern keeps recurring despite issue creation
- The fitness function finding is always caused by new code (not legacy)
- The check is fast enough to run on every PR without slowing CI
What it can do on your machine
Read from SKILL.md and the folder at commit 9d35995. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
npxsemgrep
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md. Its commands use npx, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Fitness Functions loads about 2.8k tokens when it runs, and up to ~5.5k if it reads all its reference files. Until then it costs about 70 tokens; SKILL.md has 1,180 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 1,180 words (~2,829 tokens).
“Architectural fitness functions are periodic automated checks that verify system-wide architectural properties. The concept comes from Ford, Parsons, Kua & Sadalage's Building Evolutionary Architectures (O'Reilly, 2017/2022). Their key insight: architecture degrades not through single bad changes but through accumulated small…”
- name
- fitness-functions
Files
SKILL.md and 1 other file (references) in ai-literacy-superpowers/skills/fitness-functions of Habitat-Thinking/ai-literacy-superpowers.
- SKILL.md
- references/fitness-catalogue.md
Open the folder on GitHubat commit 9d35995
Compare with similar skills
Fitness Functions next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Fitness Functions this skillHabitat-Thinking/ai-literacy-superpowers | 114 | — | ~2.8k | Automated safety check: Pass | Custom licence | |
| System Architecture DesignerJeffallan/claude-skills | 12k | — | ~1.2k | Automated safety check: Pass | MIT | |
| Architecture Patternswshobson/agents | 40k | — | ~2k | Automated safety check: Pass | MIT | |
| Architecture Patternsdavila7/claude-code-templates | 33k | 4 repos | ~483 | Automated safety check: Pass | MIT | |
| Design Systemaffaan-m/ECC | 276k | — | ~698 | Automated safety check: Pass | MIT | |
| Design Guidepaperclipai/paperclip | 100k | 1 repos | ~3.1k | Automated safety check: Pass | MIT |
Similar skills
Architecture Patterns
wshobson/agents
Implement proven backend architecture patterns including Clean Architecture, Hexagonal Architecture, and Domain-Driven Design.
Architecture Patterns
davila7/claude-code-templates
Master proven backend architecture patterns including Clean Architecture, Hexagonal Architecture, and Domain-Driven Design to build maintainable, testable, and scalable systems.
Design System
affaan-m/ECC
Generate a design system from an existing codebase or audit one for visual consistency: extract tokens (colors, typography, spacing, shadows) into design-tokens.json and CSS custom properties with…
Design Guide
paperclipai/paperclip
Paperclip UI design system guide for building consistent, reusable frontend components.
Design Audit Against Rams' Principles
thedotmack/claude-mem
Audits a design against Dieter Rams' ten principles of good design, scores each with evidence, and hands off a make-plan prompt for a new, refined or redesigned outcome.
More from Habitat-Thinking/ai-literacy-superpowers
All 42 skills in this repoAdvocatus Diaboli
Habitat-Thinking/ai-literacy-superpowers
A skill your agent uses when acting as the adversarial spec reviewer — raises steel-manned objections across six categories before plan approval, requires evidence per objection, and discloses what…
AI Literacy Assessment
Habitat-Thinking/ai-literacy-superpowers
This skill should be used when the user asks to "assess AI literacy", "run an assessment", "check literacy level", "evaluate our AI collaboration", "where are we on the framework", or wants to…
Carpaccio
Habitat-Thinking/ai-literacy-superpowers
A skill your agent uses when acting as the cadence governor — slices a raw task description into thin, end-to-end-complete pieces before any spec is written; produces a structured slicing record for…
Choice Cartographer
Habitat-Thinking/ai-literacy-superpowers
A skill your agent uses when acting as the decision-archaeology agent — surfaces decisions a spec has made (including the silent ones), emits each material choice as a Henney-style pattern story for…
Constraint Design
Habitat-Thinking/ai-literacy-superpowers
This skill should be used when the user asks to "add a constraint", "design a constraint", "write a harness rule", "choose enforcement type", "promote a constraint", "configure a verification slot"…
Cost Tracking
Habitat-Thinking/ai-literacy-superpowers
A skill your agent uses when the user wants to capture AI tool costs, review spending trends, set cost budgets, or integrate cost data into health snapshots — guides quarterly cost capture, records…
Questions about Fitness Functions
What does Fitness Functions do?
A skill your agent uses when designing architectural fitness functions as GC rules — periodic checks that verify system-wide properties like layer boundaries, coupling trends, and complexity…. Fitness Functions is an agent skill from Habitat-Thinking/ai-literacy-superpowers.
When should I use Fitness Functions?
Fitness Functions fits situations like: designing architectural fitness functions as GC rules — periodic checks that verify system-wide properties like layer boundaries; coupling trends; complexity hotspots; complementing per-change constraints with weekly architectural health monitoring.
How do I install Fitness Functions in Claude Code?
Run `npx skills add Habitat-Thinking/ai-literacy-superpowers --skill fitness-functions -a claude-code`. Or copy the skill folder (ai-literacy-superpowers/skills/fitness-functions in Habitat-Thinking/ai-literacy-superpowers) into .claude/skills/fitness-functions in your project. Claude Code loads it when a task matches its description.
How do I install Fitness Functions in Codex?
Run `npx skills add Habitat-Thinking/ai-literacy-superpowers --skill fitness-functions -a codex`. Or copy the skill folder (ai-literacy-superpowers/skills/fitness-functions in Habitat-Thinking/ai-literacy-superpowers) into .agents/skills/fitness-functions in your project. Codex loads it when a task matches its description.
Can I use Fitness Functions in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add Habitat-Thinking/ai-literacy-superpowers --skill fitness-functions -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/fitness-functions, .gemini/skills/fitness-functions, .github/skills/fitness-functions and .opencode/skills/fitness-functions in your project.
What does Fitness Functions need to run?
Going by SKILL.md and its folder, Fitness Functions needs the command-line tools its instructions call (npx and semgrep). Our summary lists: Python 3; Node.js.
Does Fitness Functions access the network?
SKILL.md contains no URLs. Its commands use npx, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Is Fitness Functions safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Fitness Functions use?
Fitness Functions has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.
How many tokens does Fitness Functions use?
About 2.8k tokens (SKILL.md is roughly 11k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 2.7k tokens, read only when the agent opens those files.
What are the alternatives to Fitness Functions?
Skills that share tags, products or a category with Fitness Functions: System Architecture Designer (Jeffallan/claude-skills, 12k stars), Architecture Patterns (wshobson/agents, 40k stars), Architecture Patterns (davila7/claude-code-templates, 33k stars) and Design System (affaan-m/ECC, 276k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Fitness Functions?
Habitat-Thinking (a GitHub organization) maintains it in Habitat-Thinking/ai-literacy-superpowers, which has 114 GitHub stars. The repository holds 42 skills in this directory. The repository was last updated on September 20, 2026.
Source: Habitat-Thinking/ai-literacy-superpowers on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.