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alirezarezvani/claude-skills
Generate Playwright tests. An agent skill from alirezarezvani/claude-skills.
Formal verification from natural language. An agent skill from codejunkie99/Gateflow-Plugin.
Custom licenceAuto-check: notes
Install Gf Formal
$ npx skills add codejunkie99/Gateflow-Plugin --skill gf-formal -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install codejunkie99/Gateflow-Plugin gf-formal --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/codejunkie99/Gateflow-Plugin.git skills-src && mkdir -p .claude/skills && cp -r skills-src/plugins/gateflow/skills/gf-formal .claude/skills/gf-formal && 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 "gf-formal" agent skill from https://github.com/codejunkie99/Gateflow-Plugin/tree/main/plugins/gateflow/skills/gf-formal into .claude/skills/gf-formal/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gf-formal", 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/codejunkie99/Gateflow-Plugin/tree/main/plugins/gateflow/skills/gf-formalType 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 codejunkie99/Gateflow-Plugin --skill gf-formal -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install codejunkie99/Gateflow-Plugin gf-formal --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/codejunkie99/Gateflow-Plugin.git skills-src && mkdir -p .agents/skills && cp -r skills-src/plugins/gateflow/skills/gf-formal .agents/skills/gf-formal && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "gf-formal" agent skill from https://github.com/codejunkie99/Gateflow-Plugin/tree/main/plugins/gateflow/skills/gf-formal into .agents/skills/gf-formal/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gf-formal", 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 codejunkie99/Gateflow-Plugin --skill gf-formal -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install codejunkie99/Gateflow-Plugin gf-formal --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/codejunkie99/Gateflow-Plugin.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/plugins/gateflow/skills/gf-formal .cursor/skills/gf-formal && 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 "gf-formal" agent skill from https://github.com/codejunkie99/Gateflow-Plugin/tree/main/plugins/gateflow/skills/gf-formal into .cursor/skills/gf-formal/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gf-formal", 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/codejunkie99/Gateflow-Plugin.git --path plugins/gateflow/skills/gf-formal--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 codejunkie99/Gateflow-Plugin --skill gf-formal -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install codejunkie99/Gateflow-Plugin gf-formal --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/codejunkie99/Gateflow-Plugin.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/plugins/gateflow/skills/gf-formal .gemini/skills/gf-formal && 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 "gf-formal" agent skill from https://github.com/codejunkie99/Gateflow-Plugin/tree/main/plugins/gateflow/skills/gf-formal into .gemini/skills/gf-formal/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gf-formal", 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 codejunkie99/Gateflow-Plugin gf-formalInstalls 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 codejunkie99/Gateflow-Plugin --skill gf-formal -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/codejunkie99/Gateflow-Plugin.git skills-src && mkdir -p .github/skills && cp -r skills-src/plugins/gateflow/skills/gf-formal .github/skills/gf-formal && 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 "gf-formal" agent skill from https://github.com/codejunkie99/Gateflow-Plugin/tree/main/plugins/gateflow/skills/gf-formal into .github/skills/gf-formal/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gf-formal", 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 codejunkie99/Gateflow-Plugin --skill gf-formal -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install codejunkie99/Gateflow-Plugin gf-formal --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/codejunkie99/Gateflow-Plugin.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/plugins/gateflow/skills/gf-formal .opencode/skills/gf-formal && 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 "gf-formal" agent skill from https://github.com/codejunkie99/Gateflow-Plugin/tree/main/plugins/gateflow/skills/gf-formal into .opencode/skills/gf-formal/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gf-formal", 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
gf-formal- GitHub stars
- 117
- Token cost
- ~1.4k tokens
- SKILL.md length
- 321 words
- Files
- 5 (incl. references)
- Skills in repo
- 26
- Repo updated
- First seen
- Licence
- Custom licence
At a glance
Formal verification from natural language. An agent skill from codejunkie99/Gateflow-Plugin.
- Works in 6 steps: Parse request -- What properties to… → Read the design -- Understand ports,… → Spawn sv-formal agent -- Generate… → …
- SKILL.md covers Tool Detection, Workflow, Result Format and Integration with /gf…, plus 6 more sections
- Calls pip
What it does
Gf Formal is an agent skill from codejunkie99/Gateflow-Plugin. Formal verification from natural language. Generates SVA properties, configures SymbiYosys, runs proofs, and explains results. Example: "formally verify the FIFO never overflows"
Its SKILL.md is about 1.4k tokens, which your agent loads only when the skill is triggered. The skill folder holds 5 other files, including reference files (for example `references/counterexamples.md`, `references/engines-and-strategy.md` and `references/sby-templates.md`).
The repository describes itself as: AI-powered SystemVerilog development assistant — design, verify, debug, and deliver working RTL with natural language.
Example prompts
- “formally verify the FIFO never overflows”
- “/gf-formal”
Requirements
- Python 3
- Pre-approved tools (allowed-tools): Bash, Read, Write, Glob, Grep, Task, WebSearch, AskUserQuestion
Workflow steps
6 steps, taken from the first numbered list in SKILL.md.
- Parse request -- What properties to verify? Which module?
- Read the design -- Understand ports, signals, behavior
- Spawn sv-formal agent -- Generate properties + .sby config
- Run SymbiYosys: sby -f .sby
- Parse results -- Read sby output for pass/fail/counterexample
- Report -- 3-layer error translation if failed, clear summary if passed
What it can do on your machine
Read from SKILL.md and the folder at commit bf7e94c. 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:
BashReadWriteGlobGrepTaskWebSearchAskUserQuestion
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
pip
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md. Its commands use pip, 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
Gf Formal loads about 1.4k tokens when it runs, and up to ~2.6k if it reads all its reference files. Until then it costs about 47 tokens; SKILL.md has 321 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.
- NoteRuns commands with sudoSKILL.md:34
Linux: sudo apt install yosys z3 - NotePre-approves every shell command (allowed-tools: Bash)SKILL.md
allowed-tools: Bash, Read, Write, Glob, Grep, Task, WebSearch, 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 321 words (~1,436 tokens).
- name
- gf-formal
- allowed-tools
- Bash, Read, Write, Glob, Grep, Task, WebSearch, AskUserQuestion
Files
SKILL.md and 4 other files (references) in plugins/gateflow/skills/gf-formal of codejunkie99/Gateflow-Plugin.
- SKILL.md
- references/counterexamples.md
- references/engines-and-strategy.md
- references/sby-templates.md
- references/sva-patterns.md
Open the folder on GitHubat commit bf7e94c
Compare with similar skills
Gf Formal 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 |
|---|---|---|---|---|---|---|
| Gf Formal this skillcodejunkie99/Gateflow-Plugin | 117 | — | ~1.4k | Automated safety check: Notes | Custom licence | |
| Generatealirezarezvani/claude-skills | 28k | 1 repos | ~1.1k | Automated safety check: Pass | MIT | |
| Fal Generatenexu-io/open-design | 100k | — | ~306 | Automated safety check: Pass | Apache-2.0 | |
| Video Generationbytedance/deer-flow | 83k | 3 repos | ~1.4k | Automated safety check: Pass | MIT | |
| Image Generationonyx-dot-app/onyx | 32k | 1 repos | ~1.7k | Automated safety check: Pass | Custom licence | |
| Structured Image Generationbytedance/deer-flow | 83k | 5 repos | ~2.9k | Automated safety check: Pass | MIT |
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Questions about Gf Formal
What does Gf Formal do?
Formal verification from natural language. An agent skill from codejunkie99/Gateflow-Plugin. Gf Formal is an agent skill from codejunkie99/Gateflow-Plugin. Formal verification from natural language.
How do I install Gf Formal in Claude Code?
Run `npx skills add codejunkie99/Gateflow-Plugin --skill gf-formal -a claude-code`. Or copy the skill folder (plugins/gateflow/skills/gf-formal in codejunkie99/Gateflow-Plugin) into .claude/skills/gf-formal in your project. Claude Code loads it when a task matches its description.
How do I install Gf Formal in Codex?
Run `npx skills add codejunkie99/Gateflow-Plugin --skill gf-formal -a codex`. Or copy the skill folder (plugins/gateflow/skills/gf-formal in codejunkie99/Gateflow-Plugin) into .agents/skills/gf-formal in your project. Codex loads it when a task matches its description.
Can I use Gf Formal 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 codejunkie99/Gateflow-Plugin --skill gf-formal -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/gf-formal, .gemini/skills/gf-formal, .github/skills/gf-formal and .opencode/skills/gf-formal in your project.
What does Gf Formal need to run?
Going by SKILL.md and its folder, Gf Formal needs the command-line tools its instructions call (pip). Our summary lists: Python 3. Its frontmatter pre-approves these tools: Bash, Read, Write, Glob, Grep, Task, WebSearch, AskUserQuestion.
Does Gf Formal access the network?
SKILL.md contains no URLs. Its commands use pip, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Is Gf Formal safe to install?
Our automated static check of SKILL.md found notes only (runs commands with sudo; 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 Gf Formal use?
Gf Formal 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 Gf Formal use?
About 1.4k tokens (SKILL.md is roughly 5.7k 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 1.1k tokens, read only when the agent opens those files.
What are the alternatives to Gf Formal?
Skills that share tags, products or a category with Gf Formal: Generate (alirezarezvani/claude-skills, 28k stars), Fal Generate (nexu-io/open-design, 100k stars), Video Generation (bytedance/deer-flow, 83k stars) and Image Generation (onyx-dot-app/onyx, 32k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Gf Formal?
codejunkie99 (a GitHub user) maintains it in codejunkie99/Gateflow-Plugin, which has 117 GitHub stars. The repository holds 26 skills in this directory. The repository was last updated on September 16, 2026.
Source: codejunkie99/Gateflow-Plugin on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.