sKill Bill

Treat your AI skills like software — with stable interfaces, platform overrides, and validation that prevents the repo from rotting.

sKill Bill is a portable collection of 44 AI skills for code review, feature implementation, and developer tooling. One repo, synced to every supported agent. Currently strongest for Kotlin, Android/KMP, Kotlin backend/server, PHP backends, and Go backends/services.

Why this exists

Most prompt or skill repos degrade over time:

• names drift
• overlapping skills appear
• stack-specific behavior leaks into generic prompts
• different agents get different copies

sKill Bill treats skills more like software:

• stable base capabilities
• platform-specific overrides
• shared routing logic
• CI-enforced naming and structure
• one repo synced to every supported agent

What it looks like

You interact through a handful of stable base commands. They auto-detect your stack and route to the right specialists.

Code review — one command, stack-aware specialist reviews:

/bill-code-review

Detected stack: kotlin
Routed to: bill-kotlin-code-review
Specialist reviews: architecture, platform-correctness, testing

[ARCHITECTURE]
P0: Shared state mutation not protected by synchronization

[PLATFORM CORRECTNESS]
P1: ViewModel scope used outside main thread context

[TESTING]
Minor: Test coverage for error path incomplete

Feature implementation — end-to-end from design doc to PR:

/bill-feature-implement

1. Collects design doc, creates acceptance criteria
2. Creates branch, plans implementation tasks
3. Implements each task atomically
4. Runs /bill-code-review (auto-routed to your stack)
5. Completeness audit against acceptance criteria
6. Runs /bill-quality-check (auto-routed)
7. Generates PR description

Quality check — auto-routed to your stack's toolchain:

/bill-quality-check

Detected stack: kotlin
Routed to: bill-kotlin-quality-check

Running ./gradlew check...
Build: PASS
Tests: 247 passed
Lint: PASS

How routing works

A single feature-implement run chains 10-12 skill invocations:

/bill-feature-implement
├── plan + acceptance criteria
├── implementation (atomic tasks)
├── /bill-code-review (auto-routed)
│   └── e.g. bill-kotlin-code-review
│       ├── architecture (subagent)
│       ├── platform-correctness (subagent)
│       ├── security (subagent, if applicable)
│       └── testing (subagent, if applicable)
├── /bill-quality-check (auto-routed)
│   └── e.g. bill-kotlin-quality-check
├── completeness audit
└── /bill-pr-description

Base entry points stay stable for users:

• /bill-code-review routes to bill-kotlin-code-review | bill-backend-kotlin-code-review | bill-kmp-code-review | bill-php-code-review | bill-go-code-review
• /bill-quality-check routes to the matching stack-specific quality checker
• /bill-feature-implement orchestrates the full workflow

Supported agents

Agent	Install path
GitHub Copilot	~/.copilot/skills/
Claude Code	~/.claude/commands/
GLM	~/.glm/commands/
OpenAI Codex	~/.codex/skills/ or ~/.agents/skills/

The installer links all selected agents to the same repo so updates stay in sync.

Installation

git clone https://github.com/Sermilion/skill-bill.git ~/Development/skill-bill
cd ~/Development/skill-bill
chmod +x install.sh
./install.sh

If you want a stable install target instead of tracking main, clone a release tag and install from that checkout:

TAG=v0.x.y
git clone --branch "$TAG" --depth 1 https://github.com/Sermilion/skill-bill.git ~/Development/skill-bill
cd ~/Development/skill-bill
./install.sh

The installer first asks which agent targets to install to. You can choose one or more entries, including all:

all

It then shows the available platform packages and asks which ones to install. Base skills in skills/base/ are always installed; platform packages are installed only when selected.

Available options are shown as separate entries:

Kotlin backend
Kotlin
KMP
PHP
Go
all

Example platform selections:

Kotlin backend, Kotlin, KMP
PHP
Go
all

Each installer run replaces the existing Skill Bill links and reinstalls only the agent and platform selections from that run.

The installer always removes existing Skill Bill links before reinstalling the selected agents and platforms.

Uninstallation

To remove Skill Bill skill symlinks from the supported agent install paths:

chmod +x uninstall.sh
./uninstall.sh

The uninstaller is idempotent. It removes current Skill Bill skill names plus known legacy install names when they are present as symlinks, and skips non-symlink paths.

Skills Included

Code Review (32 skills)

Skill	Purpose
/bill-code-review	Shared review router
/bill-kotlin-code-review	Kotlin baseline review orchestrator
/bill-backend-kotlin-code-review	Backend Kotlin review override
/bill-kmp-code-review	Android/KMP review override
/bill-kotlin-code-review-architecture	Kotlin architecture and boundaries review
/bill-kotlin-code-review-platform-correctness	Kotlin lifecycle, coroutine, threading, and logic review
/bill-kotlin-code-review-performance	Kotlin performance review
/bill-kotlin-code-review-security	Kotlin security review
/bill-kotlin-code-review-testing	Kotlin test quality review
/bill-kmp-code-review-ui	KMP UI review
/bill-kmp-code-review-ux-accessibility	KMP UX and accessibility review
/bill-backend-kotlin-code-review-api-contracts	Backend API contract review
/bill-backend-kotlin-code-review-persistence	Backend persistence and migration review
/bill-backend-kotlin-code-review-reliability	Backend reliability and observability review
/bill-php-code-review	PHP backend review orchestrator
/bill-php-code-review-architecture	PHP architecture and boundary review
/bill-php-code-review-platform-correctness	PHP correctness, ordering, retry, and stale-state review
/bill-php-code-review-api-contracts	PHP API contract and serialization review
/bill-php-code-review-persistence	PHP persistence, transaction, and migration review
/bill-php-code-review-reliability	PHP reliability, retry, and observability review
/bill-php-code-review-security	PHP security review
/bill-php-code-review-performance	PHP performance review
/bill-php-code-review-testing	PHP test quality review
/bill-go-code-review	Go backend/service review orchestrator
/bill-go-code-review-architecture	Go architecture and package-boundary review
/bill-go-code-review-platform-correctness	Go correctness, goroutine safety, and context review
/bill-go-code-review-api-contracts	Go API contract and serialization review
/bill-go-code-review-persistence	Go persistence, transaction, and migration review
/bill-go-code-review-reliability	Go reliability, timeout, and observability review
/bill-go-code-review-security	Go security review
/bill-go-code-review-performance	Go performance review
/bill-go-code-review-testing	Go test quality review

Feature Lifecycle (4 skills)

Skill	Purpose
/bill-feature-implement	Spec-to-verified implementation workflow
/bill-feature-verify	Verify a PR against a task spec
/bill-feature-guard	Add feature-flag rollout safety
/bill-feature-guard-cleanup	Remove feature flags after rollout

Utilities (8 skills)

Skill	Purpose
/bill-quality-check	Shared quality-check router
/bill-kotlin-quality-check	Gradle/Kotlin quality-check implementation
/bill-php-quality-check	PHP quality-check implementation
/bill-go-quality-check	Go quality-check implementation
/bill-boundary-history	Maintain agent/history.md at module/package/area boundaries
/bill-unit-test-value-check	Audit unit tests for real value
/bill-pr-description	Generate PR title, description, and QA steps
/bill-new-skill-all-agents	Create a new skill and sync it to all agents

Project customization

Use AGENTS.md for repo-wide guidance.

Use .agents/skill-overrides.md for per-skill customization without editing this plugin. The file is intentionally strict:

• first line must be # Skill Overrides
• each section must be ## <existing-skill-name>
• each section body must be a bullet list
• freeform text outside sections is invalid

Precedence:

1. matching .agents/skill-overrides.md section
2. AGENTS.md
3. built-in skill defaults

Example:

# Skill Overrides

## bill-kotlin-quality-check
- Treat warnings as blocking work.

## bill-pr-description
- Keep QA steps concise.

Architecture

Core model

The repo is organized around a strict three-layer model:

• skills/base/ — canonical, user-facing capabilities such as bill-code-review, bill-quality-check, and bill-feature-implement
• skills/<platform>/ — platform-specific overrides and approved subskills
• orchestration/ — maintainer-facing reference snapshots for shared routing, review, and delegation contracts

Think of it as markdown with inheritance:

• base skills define the stable contracts
• platform skills specialize them
• orchestration snapshots document the shared routing, review, and delegation logic that runtime-facing skills can reference via sibling supporting files in the same skill directory

Fast mental model

If you only remember four things, remember these:

1. Users enter through stable skills in skills/base/.
2. Platform depth lives in skills/<platform>/.
3. Shared logic is documented in orchestration/, but runtimes consume it through sibling sidecars such as stack-routing.md, review-orchestrator.md, and review-delegation.md.
4. Topology changes should start in scripts/skill_repo_contracts.py, then flow into skills, tests, and docs.

That last file is the canonical map for:

• which shared playbook snapshots exist
• which runtime-facing skills require which sidecars
• which review skills are governed by the shared review/delegation contract

Current platform packages:

• kotlin
• backend-kotlin
• kmp
• php
• go

Naming and enforcement

Naming is intentionally strict:

• base skills may use any neutral bill-<capability> name
• platform overrides must use bill-<platform>-<base-capability>
• deeper specialization is only allowed for code review:
  • bill-<platform>-code-review-<area>

Approved code-review areas:

• architecture
• performance
• platform-correctness
• security
• testing
• api-contracts
• persistence
• reliability
• ui
• ux-accessibility

That means new stacks can extend the system, but they cannot invent random new naming shapes without intentionally updating the validator and docs.

Validation

This repo validates both content quality and taxonomy rules.

Local checks:

python3 -m unittest discover -s tests
npx --yes agnix --strict .
python3 scripts/validate_agent_configs.py

CI runs the same checks.

Versioning and releases

Skill Bill uses tag-driven GitHub Releases.

• stable releases use SemVer tags such as v0.4.0
• prereleases use SemVer prerelease tags such as v0.5.0-rc.1
• pushing a release tag reruns validation and publishes a GitHub Release with generated notes

See RELEASING.md for the maintainer checklist and versioning policy.

The validator enforces:

• package location rules
• naming rules
• README catalog drift
• cross-skill references
• required routing playbook references
• plugin metadata

Adding skills

Preferred path:

• run /bill-new-skill-all-agents

Manual path:

1. create skills/<package>/<skill-name>/SKILL.md
2. follow the naming rules above
3. run ./install.sh
4. update docs and validation if you intentionally add a new package or naming shape

License

MIT — free to use, copy, modify, merge, publish, distribute, sublicense, and sell, provided the license notice is retained.