Superpowers Test Driven Development
christopherarter/superpowers-reasonix
Writing or fixing any code?. An agent skill from christopherarter/superpowers-reasonix.
Red-green-refactor scaffold for building new features with TDD.
Install TDD Feature
$ npx skills add gustavscirulis/snapgrid --skill tdd-feature -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install gustavscirulis/snapgrid tdd-feature --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/gustavscirulis/snapgrid.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/skills/testing/tdd-feature .claude/skills/tdd-feature && 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 "tdd-feature" agent skill from https://github.com/gustavscirulis/snapgrid/tree/main/.claude/skills/skills/testing/tdd-feature into .claude/skills/tdd-feature/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "tdd-feature", 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/gustavscirulis/snapgrid/tree/main/.claude/skills/skills/testing/tdd-featureType 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 gustavscirulis/snapgrid --skill tdd-feature -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install gustavscirulis/snapgrid tdd-feature --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/gustavscirulis/snapgrid.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.claude/skills/skills/testing/tdd-feature .agents/skills/tdd-feature && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "tdd-feature" agent skill from https://github.com/gustavscirulis/snapgrid/tree/main/.claude/skills/skills/testing/tdd-feature into .agents/skills/tdd-feature/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "tdd-feature", 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 gustavscirulis/snapgrid --skill tdd-feature -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install gustavscirulis/snapgrid tdd-feature --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/gustavscirulis/snapgrid.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.claude/skills/skills/testing/tdd-feature .cursor/skills/tdd-feature && 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 "tdd-feature" agent skill from https://github.com/gustavscirulis/snapgrid/tree/main/.claude/skills/skills/testing/tdd-feature into .cursor/skills/tdd-feature/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "tdd-feature", 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/gustavscirulis/snapgrid.git --path .claude/skills/skills/testing/tdd-feature--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 gustavscirulis/snapgrid --skill tdd-feature -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install gustavscirulis/snapgrid tdd-feature --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/gustavscirulis/snapgrid.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.claude/skills/skills/testing/tdd-feature .gemini/skills/tdd-feature && 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 "tdd-feature" agent skill from https://github.com/gustavscirulis/snapgrid/tree/main/.claude/skills/skills/testing/tdd-feature into .gemini/skills/tdd-feature/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "tdd-feature", 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 gustavscirulis/snapgrid tdd-featureInstalls 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 gustavscirulis/snapgrid --skill tdd-feature -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/gustavscirulis/snapgrid.git skills-src && mkdir -p .github/skills && cp -r skills-src/.claude/skills/skills/testing/tdd-feature .github/skills/tdd-feature && 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 "tdd-feature" agent skill from https://github.com/gustavscirulis/snapgrid/tree/main/.claude/skills/skills/testing/tdd-feature into .github/skills/tdd-feature/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "tdd-feature", 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 gustavscirulis/snapgrid --skill tdd-feature -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install gustavscirulis/snapgrid tdd-feature --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/gustavscirulis/snapgrid.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.claude/skills/skills/testing/tdd-feature .opencode/skills/tdd-feature && 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 "tdd-feature" agent skill from https://github.com/gustavscirulis/snapgrid/tree/main/.claude/skills/skills/testing/tdd-feature into .opencode/skills/tdd-feature/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "tdd-feature", 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
tdd-feature- GitHub stars
- 116
- Used in
- 1 other repo
- Token cost
- ~2.4k tokens
- SKILL.md length
- 476 words
- Files
- 1
- Skills in repo
- 118
- Repo updated
- First seen
- Licence
- Custom licence
At a glance
Red-green-refactor scaffold for building new features with TDD.
- Works in 6 steps: Define the Feature → Design the API Surface → RED — Write Failing Tests → …
- Building new features test-first
- SKILL.md covers When This Skill Activates, Why TDD for New Features with AI, Process and TDD Rhythm, plus 2 more sections
- Calls xcodebuild
What it does
TDD Feature is an agent skill from gustavscirulis/snapgrid. Red-green-refactor scaffold for building new features with TDD. Write failing tests first, then implement to pass. Use when building new features test-first.
Its SKILL.md is about 2.4k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Testing & QA, covering Test-driven development and Failing and flaky tests. The repository describes itself as: SnapGrid is an open-source Mac app for collecting, organizing, and analyzing UI screenshots. It uses AI to automatically detect UI components and patterns, making it a powerful…
When your agent uses it
- Building new features test-first
- Tasks that involve Test-driven development
- Tasks that involve Failing and flaky tests
Example prompts
- “/tdd-feature”
Requirements
- Pre-approved tools (allowed-tools): Read, Write, Edit, Glob, Grep, Bash, AskUserQuestion
Workflow steps
6 steps, taken from the step headings in SKILL.md.
- Define the Feature
- Design the API Surface
- RED — Write Failing Tests
- GREEN — Implement to Pass
- REFACTOR
- Integration
What it can do on your machine
Read from SKILL.md and the folder at commit eb7eaf4. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves these tools, so the agent can use them without asking each time:
ReadWriteEditGlobGrepBashAskUserQuestion
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
xcodebuild
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
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
TDD Feature loads about 2.4k tokens when it runs. Until then it costs about 42 tokens; SKILL.md has 476 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: notes
The automated check noted patterns worth knowing about, such as sudo or a known installer.
- NotePre-approves every shell command (allowed-tools: Bash)SKILL.md
allowed-tools: Read, Write, Edit, Glob, Grep, Bash, AskUserQuestion
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 476 words (~2,362 tokens).
“Build new features using the red-green-refactor cycle. Tests define the spec, AI generates the implementation, tests verify correctness.”
- name
- tdd-feature
- allowed-tools
- Read, Write, Edit, Glob, Grep, Bash, AskUserQuestion
Files
Just SKILL.md in .claude/skills/skills/testing/tdd-feature of gustavscirulis/snapgrid.
Open the folder on GitHubat commit eb7eaf4
Used in 1 other repository
We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in gustavscirulis/snapgrid, which our catalogue first saw on October 7, 2026.
Compare with similar skills
TDD Feature 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 |
|---|---|---|---|---|---|---|
| TDD Feature this skillgustavscirulis/snapgrid | 116 | 1 repos | ~2.4k | Automated safety check: Notes | Custom licence | |
| Superpowers Test Driven Developmentchristopherarter/superpowers-reasonix | 102 | — | ~1.9k | Automated safety check: Pass | MIT | |
| Openspec Plus TDDelastic/terraform-provider-elasticstack | 210 | 1 repos | ~4.7k | Automated safety check: Pass | Apache-2.0 | |
| Fix BugMelbourneDeveloper/dart_node | 113 | 1 repos | ~709 | Automated safety check: Notes | None | |
| Evanflow Debugevanklem/evanflow | 418 | — | ~760 | Automated safety check: Pass | Custom licence | |
| TDDcodeaholicguy/ai-devkit | 1.6k | — | ~838 | Automated safety check: Pass | Apache-2.0 |
Similar skills
- Official
Openspec Plus TDD
elastic/terraform-provider-elasticstack
MANDATORY skill that activates whenever code is written to implement an OpenSpec change task.
Fix Bug
MelbourneDeveloper/dart_node
Fix a bug using test-driven development. An agent skill from MelbourneDeveloper/dart_node.
Evanflow Debug
evanklem/evanflow
Root-cause discipline for bugs, test failures, and unexpected behavior.
TDD
codeaholicguy/ai-devkit
AI DevKit · Test-driven development — write a failing test before writing production code.
TDD Workflows TDD Green
aiskillstore/marketplace
Implement the minimal code needed to make failing tests pass in the TDD green phase.
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Related
Categories
Questions about TDD Feature
What does TDD Feature do?
Red-green-refactor scaffold for building new features with TDD. TDD Feature is an agent skill from gustavscirulis/snapgrid. Red-green-refactor scaffold for building new features with TDD.
When should I use TDD Feature?
TDD Feature fits situations like: building new features test-first; tasks that involve Test-driven development; tasks that involve Failing and flaky tests.
How do I install TDD Feature in Claude Code?
Run `npx skills add gustavscirulis/snapgrid --skill tdd-feature -a claude-code`. Or copy the skill folder (.claude/skills/skills/testing/tdd-feature in gustavscirulis/snapgrid) into .claude/skills/tdd-feature in your project. Claude Code loads it when a task matches its description.
How do I install TDD Feature in Codex?
Run `npx skills add gustavscirulis/snapgrid --skill tdd-feature -a codex`. Or copy the skill folder (.claude/skills/skills/testing/tdd-feature in gustavscirulis/snapgrid) into .agents/skills/tdd-feature in your project. Codex loads it when a task matches its description.
Can I use TDD Feature 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 gustavscirulis/snapgrid --skill tdd-feature -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/tdd-feature, .gemini/skills/tdd-feature, .github/skills/tdd-feature and .opencode/skills/tdd-feature in your project.
What does TDD Feature need to run?
Going by SKILL.md and its folder, TDD Feature needs the command-line tools its instructions call (xcodebuild). Its frontmatter pre-approves these tools: Read, Write, Edit, Glob, Grep, Bash, AskUserQuestion.
Does TDD Feature access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is TDD Feature safe to install?
Our automated static check of SKILL.md found notes only (pre-approves every shell command (allowed-tools: bash)), nothing it rates as a warning. It is not a guarantee. Review the folder before installing.
What licence does TDD Feature use?
TDD Feature 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 TDD Feature use?
About 2.4k tokens (SKILL.md is roughly 9.4k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to TDD Feature?
Skills that share tags, products or a category with TDD Feature: Superpowers Test Driven Development (christopherarter/superpowers-reasonix, 102 stars), Openspec Plus TDD (elastic/terraform-provider-elasticstack, 210 stars), Fix Bug (MelbourneDeveloper/dart_node, 113 stars) and Evanflow Debug (evanklem/evanflow, 418 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains TDD Feature?
gustavscirulis (a GitHub user) maintains it in gustavscirulis/snapgrid, which has 116 GitHub stars. The repository holds 118 skills in this directory. The repository was last updated on April 30, 2026.
Source: gustavscirulis/snapgrid on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.