Dev
npc-live/clawfirm
Software development workflow dispatcher. An agent skill from npc-live/clawfirm.
Generate a structured implementation contract before making any code changes to FastLED.
Install Feature Contract
$ npx skills add FastLED/FastLED --skill feature-contract -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install FastLED/FastLED feature-contract --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/FastLED/FastLED.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/feature-contract .claude/skills/feature-contract && 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 "feature-contract" agent skill from https://github.com/FastLED/FastLED/tree/master/.claude/skills/feature-contract into .claude/skills/feature-contract/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "feature-contract", 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/FastLED/FastLED/tree/master/.claude/skills/feature-contractType 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 FastLED/FastLED --skill feature-contract -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install FastLED/FastLED feature-contract --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/FastLED/FastLED.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.claude/skills/feature-contract .agents/skills/feature-contract && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "feature-contract" agent skill from https://github.com/FastLED/FastLED/tree/master/.claude/skills/feature-contract into .agents/skills/feature-contract/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "feature-contract", 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 FastLED/FastLED --skill feature-contract -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install FastLED/FastLED feature-contract --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/FastLED/FastLED.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.claude/skills/feature-contract .cursor/skills/feature-contract && 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 "feature-contract" agent skill from https://github.com/FastLED/FastLED/tree/master/.claude/skills/feature-contract into .cursor/skills/feature-contract/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "feature-contract", 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/FastLED/FastLED.git --path .claude/skills/feature-contract--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 FastLED/FastLED --skill feature-contract -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install FastLED/FastLED feature-contract --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/FastLED/FastLED.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.claude/skills/feature-contract .gemini/skills/feature-contract && 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 "feature-contract" agent skill from https://github.com/FastLED/FastLED/tree/master/.claude/skills/feature-contract into .gemini/skills/feature-contract/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "feature-contract", 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 FastLED/FastLED feature-contractInstalls 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 FastLED/FastLED --skill feature-contract -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/FastLED/FastLED.git skills-src && mkdir -p .github/skills && cp -r skills-src/.claude/skills/feature-contract .github/skills/feature-contract && 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 "feature-contract" agent skill from https://github.com/FastLED/FastLED/tree/master/.claude/skills/feature-contract into .github/skills/feature-contract/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "feature-contract", 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 FastLED/FastLED --skill feature-contract -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install FastLED/FastLED feature-contract --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/FastLED/FastLED.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.claude/skills/feature-contract .opencode/skills/feature-contract && 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 "feature-contract" agent skill from https://github.com/FastLED/FastLED/tree/master/.claude/skills/feature-contract into .opencode/skills/feature-contract/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "feature-contract", 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
feature-contract- GitHub stars
- 7.5k
- Token cost
- ~1.7k tokens
- SKILL.md length
- 628 words
- Files
- 1
- Skills in repo
- 23
- Repo updated
- First seen
- Licence
- MIT
At a glance
Generate a structured implementation contract before making any code changes to FastLED.
- Works in 7 steps: Understand the Request → Define Scope → Assess Platform Impact → …
- Tasks that involve Test generation
- SKILL.md covers Why Use a Contract, Steps, Rules and What Makes a Good Acceptance…
- Calls bash
What it does
Feature Contract is an agent skill from FastLED/FastLED. Generate a structured implementation contract before making any code changes to FastLED. Defines scope, affected files, API changes, platform impact, risk assessment, and test plan. Use before implementing any feature, bug fix, driver addition, or refactoring.
Its SKILL.md is about 1.7k 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 Development, covering Test generation, Debugging and Embedded systems. It works with ESP32. The repository describes itself as: The FastLED library for colored LED animation on Arduino. Please direct questions/requests for help to the FastLED Reddit community: http://fastled.io/r We'd like to use github… The licence is MIT.
When your agent uses it
- Tasks that involve Test generation
- Tasks that involve Debugging
- Tasks that involve Embedded systems
Example prompts
- “/feature-contract”
Workflow steps
7 steps, taken from the step headings in SKILL.md.
What it can do on your machine
Read from SKILL.md and the folder at commit 8d6ed12. 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:
bash
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
Feature Contract loads about 1.7k tokens when it runs. Until then it costs about 69 tokens; SKILL.md has 628 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
The full file from FastLED/FastLED at commit 8d6ed12, republished under its MIT licence (© FastLED). 628 words, ~1,687 tokens.
Download SKILL.mdSave it as
.claude/skills/feature-contract/SKILL.md (or your agent's skills folder).- name
- feature-contract
- description
- Generate a structured implementation contract before making any code changes to FastLED. Defines scope, affected files, API changes, platform impact, risk assessment, and test plan. Use before implementing any feature, bug fix, driver addition, or refactoring.
- argument-hint
- <feature or bug description>
- context
- fork
- agent
- feature-contract-agent
Generate an implementation contract for a FastLED change. The contract must be reviewed before any code is written.
$ARGUMENTS
Why Use a Contract
FastLED runs on 100+ microcontroller platforms. A change that seems simple can break:
- Platform-specific driver behavior (ESP32, Teensy, AVR, STM32, RP2040, nRF52...)
- Public API compatibility (users pin to specific versions)
- Timing-sensitive LED protocols (a single wrong bit ruins the strip)
- Build-system portability (meson, fbuild, Arduino IDE all involved)
The contract documents what changes, what risks exist, and how to prove it works — before a line of code is written.
Steps
1. Understand the Request
Determine:
- What is the requested change? (feature / bug fix / refactor / platform port / driver addition)
- Which LED chipsets or platforms are affected?
- What is the expected behavior after the change?
- Are there hardware constraints? (specific ESP32 variant, specific LED protocol, pin count)
- Is this a public API change or internal implementation?
2. Define Scope
Document:
- Summary: One-paragraph description of the change
- Non-goals: What this change explicitly does NOT do
- Affected files: Every file to be created, modified, or deleted
- APIs touched: Public functions, types, or macros that will change
3. Assess Platform Impact
For each affected area, evaluate impact:
| Platform Area | Impact | Notes |
|---|---|---|
| AVR (Arduino Uno/Mega/Nano) | [None/Low/Med/High] | RAM-constrained, no FPU |
| ESP32 (all variants) | [None/Low/Med/High] | RMT/I2S/SPI/PARLIO drivers |
| Teensy (3.x, 4.x) | [None/Low/Med/High] | ARM Cortex-M, bitbang & DMA |
| RP2040 (Raspberry Pi Pico) | [None/Low/Med/High] | PIO-based drivers |
| STM32 | [None/Low/Med/High] | HAL dependencies |
| WASM (web browser target) | [None/Low/Med/High] | Emulation only |
| nRF52 | [None/Low/Med/High] | BLE coexistence |
4. Assess Risks
Evaluate each risk category:
Timing Risks (critical for LED protocols):
- Does the change affect bit-timing (T0H, T1H, reset pulse)?
- Could added latency cause LED flicker or color errors?
- Is the change tested on hardware, not just WASM/emulation?
API Compatibility Risks:
- Does this change any public header or function signature?
- Will existing user sketches compile without modification?
- Is a deprecation path needed?
Memory Risks:
- Does this add to SRAM usage (critical for AVR with 2KB)?
- Does this add to flash usage?
- Are heap allocations properly checked for NULL?
Concurrency Risks (ESP32 / RTOS platforms):
- Shared state accessed from multiple tasks or ISR?
- DMA buffer lifetime during transfer?
- Interrupt-safe API used where required?
Build System Risks:
- Does this require changes to meson.build, library.properties, or component.mk?
- Is the new code compiled only on relevant platforms (guards correct)?
Show full SKILL.md (250 more words)Show less
5. Define Test Plan
Specify the test layers that apply:
| Layer | Applies | Tests |
|---|---|---|
Host unit tests (bash test) | Always | Logic, math, data structures |
WASM compile check (bash compile wasm) | Always | Catches most compile errors |
Platform compile (bash compile <platform>) | If driver code | Catches platform-specific errors |
Hardware validation (bash autoresearch) | If driver or timing change | Only definitive proof for LED output |
List specific test cases:
- Positive: Expected behavior with valid inputs
- Negative: Error handling, boundary values
- Regression: Existing tests that must still pass
6. Define Rollback Strategy
Document:
- How to revert the change (git revert, feature flag, etc.)
- Whether any NVS/EEPROM data migration is needed
- Whether users need to update their code if the API changes
7. Generate Contract Document
# Implementation Contract: [Title]
## Change Summary
[One-paragraph description of what changes and why]
## Non-Goals
- [What this explicitly does NOT include]
## Affected Files
| File | Action | Description |
|------|--------|-------------|
| src/platforms/esp/32/foo.h | MODIFY | [What changes] |
| src/fl/bar.h | CREATE | [Purpose] |
## APIs Touched
- `FastLED.addLeds<...>()` — [How it changes, if at all]
- `CRGB` — [Impact]
## Platform Impact
| Platform | Impact | Rationale |
|---------|--------|-----------|
| AVR | None | No new code on AVR path |
| ESP32 | High | New RMT encoder implementation |
| ... | ... | ... |
## Risk Assessment
### Timing: [LOW / MED / HIGH]
[Details — will LED protocols still work?]
### API Compatibility: [LOW / MED / HIGH]
[Details — will existing user code still compile and run?]
### Memory: [LOW / MED / HIGH]
[Details — RAM/flash impact, especially for AVR]
### Concurrency: [LOW / MED / HIGH]
[Details — ISR safety, DMA lifetime, task interaction]
### Build System: [LOW / MED / HIGH]
[Details — meson.build, guards, new dependencies]
## Test Plan
- [ ] Host unit test: [test name / description]
- [ ] WASM compile: `bash compile wasm --examples Blink`
- [ ] Platform compile: `bash compile <platform>`
- [ ] Hardware validation: [specific test on which board]
- [ ] Regression: `bash test --cpp` — all existing tests pass
## Rollback Strategy
[Steps to safely revert this change]
## Acceptance Criteria
- [ ] [Specific, measurable criterion]
- [ ] All platform compiles pass
- [ ] No regressions in host test suite
- [ ] [Hardware test evidence if applicable]Rules
- Never skip the contract for non-trivial changes. A "small" change to a shared header can break 100 platform builds.
- Define platform impact explicitly. Unknown = HIGH risk. Investigate before marking LOW.
- Hardware validation is required for any driver or timing change. WASM compilation is not sufficient proof.
- Public API changes need a compatibility note. FastLED users should not be surprised by breaking changes.
- Update the contract if scope changes. Scope creep must be re-reviewed.
What Makes a Good Acceptance Criterion
Good: "WS2812 output on ESP32 shows correct colors at 1000 LEDs without flicker, confirmed by hardware observation" Bad: "It works"
Good: "All existing host tests pass with bash test --cpp"
Bad: "Tests pass"
Good: "Sketch compiles on Arduino IDE 2.x with no warnings" Bad: "Compiles somewhere"
© FastLED, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in .claude/skills/feature-contract of FastLED/FastLED.
Open the folder on GitHubat commit 8d6ed12
Compare with similar skills
Feature Contract 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 |
|---|---|---|---|---|---|---|
| Feature Contract this skillFastLED/FastLED | 7.5k | — | ~1.7k | Automated safety check: Pass | MIT | |
| Devnpc-live/clawfirm | 156 | — | ~642 | Automated safety check: Pass | None | |
| Commodore64 Vice Debuggingidolpx/meatloaf | 128 | — | ~4.8k | Automated safety check: Pass | GPL-3.0 | |
| C64 Meatloaf Debugidolpx/meatloaf | 128 | — | ~12k | Automated safety check: Pass | GPL-3.0 | |
| Meatloaf Networkingidolpx/meatloaf | 128 | — | ~7.1k | Automated safety check: Pass | GPL-3.0 | |
| Embedded DebuggerAdancurusul/embedded-debugger-mcp | 199 | — | ~1.4k | Automated safety check: Pass | MIT |
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Works with
Categories
Questions about Feature Contract
What does Feature Contract do?
Generate a structured implementation contract before making any code changes to FastLED. Feature Contract is an agent skill from FastLED/FastLED. Generate a structured implementation contract before making any code changes to FastLED.
When should I use Feature Contract?
Feature Contract fits situations like: tasks that involve Test generation; tasks that involve Debugging; tasks that involve Embedded systems.
How do I install Feature Contract in Claude Code?
Run `npx skills add FastLED/FastLED --skill feature-contract -a claude-code`. Or copy the skill folder (.claude/skills/feature-contract in FastLED/FastLED) into .claude/skills/feature-contract in your project. Claude Code loads it when a task matches its description.
How do I install Feature Contract in Codex?
Run `npx skills add FastLED/FastLED --skill feature-contract -a codex`. Or copy the skill folder (.claude/skills/feature-contract in FastLED/FastLED) into .agents/skills/feature-contract in your project. Codex loads it when a task matches its description.
Can I use Feature Contract 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 FastLED/FastLED --skill feature-contract -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/feature-contract, .gemini/skills/feature-contract, .github/skills/feature-contract and .opencode/skills/feature-contract in your project.
What does Feature Contract need to run?
Going by SKILL.md and its folder, Feature Contract needs the command-line tools its instructions call (bash).
Does Feature Contract 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 Feature Contract 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 Feature Contract use?
Feature Contract is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Feature Contract use?
About 1.7k tokens (SKILL.md is roughly 6.7k 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 Feature Contract?
Skills that share tags, products or a category with Feature Contract: Dev (npc-live/clawfirm, 156 stars), Commodore64 Vice Debugging (idolpx/meatloaf, 128 stars), C64 Meatloaf Debug (idolpx/meatloaf, 128 stars) and Meatloaf Networking (idolpx/meatloaf, 128 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Feature Contract?
FastLED (a GitHub organization) maintains it in FastLED/FastLED, which has 7,506 GitHub stars. The repository holds 23 skills in this directory. The repository was last updated on October 7, 2026.
Source: FastLED/FastLED on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.