Squirrel — Full-Cycle Software Development Skill
Overview
Squirrel is a full-cycle AI coding skill that works across 9 AI coding agents. It auto-detects project state (greenfield, in-progress, or mature) and adapts its 8-phase engineering pipeline accordingly. Instead of a one-size-fits-all workflow, it figures out where the project actually is and jumps in at exactly the right point.
When to Use This Skill
- Use when starting a new project from scratch (greenfield)
- Use when improving an existing codebase (in-progress or mature)
- Use when fixing bugs, adding features, or refactoring
- Use when adding tests, linting, or CI/CD to a project
- Use when writing production-grade documentation
- Use when the user says "build me", "fix this", "squirrel this project", or any multi-step development task
How It Works
Step 0: Detect Mode
Squirrel classifies the project directory:
| Signal |
Mode |
Entry Point |
| Empty directory |
Greenfield |
All 8 phases from scratch |
| Source files, no tests/docs |
In-Progress |
Audit first, then improve |
| Source + tests + CI + README |
Mature |
Targeted improvements |
| "fix this bug / add feature" |
Targeted |
Scoped work only |
The 8-Phase Pipeline
-
Discover — Understand the project (audit existing code or gather requirements)
-
Plan — Concrete task list with dependencies and done-criteria
-
Build — Write or modify code (parallel sub-agents when supported)
-
Test — Run existing tests, write new ones, 70%+ coverage target
-
Bug Hunt — Static analysis + manual review
-
Polish — Lint, format, type check, remove dead code
-
Document — README + inline docs (update existing, don't overwrite)
-
Ship — Final checklist: tests green, no secrets, CI configured
Failure Recovery (3-Strike Rule)
-
Strike 1: Fix the specific error. Run tests. Move on.
-
Strike 2: Re-read the code. Try a different approach.
-
Strike 3: STOP. Revert. Document what failed. Ask the user.
Examples
Example 1: Build a REST API
> build me a REST API for a todo app with TypeScript and Express
Squirrel auto-detects greenfield mode and runs all 8 phases.
Example 2: Fix a bug
> fix this bug in src/auth/login.py
Squirrel enters targeted mode — abbreviated audit, scoped fix, verify.
Example 3: Improve existing project
> squirrel this project — add tests, fix lint errors, write README
Squirrel audits the existing codebase, then applies phases 4-8.
Best Practices
- Respects existing code — matches naming conventions, test framework, import style, and architecture
- Reads 2-3 similar files before writing a new one
- Never suppresses type errors with
as any or @ts-ignore
- Never deletes failing tests to "pass"
- Never leaves code in a broken state
Platform Compatibility
Squirrel works on: Claude Code, Codex, Cursor, Antigravity, Gemini CLI, GitHub Copilot, Windsurf, OpenCode, Aider (9 total).
Install with:
# Universal installer
npx skills add flyingsquirrel0419/squirrel-skill
Limitations
- Does not replace environment-specific validation or expert review
- CI/CD templates are starting points, not drop-in guarantees
- Parallel sub-agent execution depends on platform support
Related Skills
-
@brainstorming - For planning before implementation
-
@test-driven-development - For TDD-oriented workflows
-
@systematic-debugging - For methodical problem-solving
