Gumroad Prod Console
antiwork/gumroad
Execute read-only Ruby/Rails commands against Gumroad's production database for debugging and investigation.
Port Ruby gems with native C extensions to Fil-C. An agent skill from mbrock/filnix.
No licenceAuto-check passed
Install Gem Port
$ npx skills add mbrock/filnix --skill gem-port -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install mbrock/filnix gem-port --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/mbrock/filnix.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/gem-port .claude/skills/gem-port && 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 "gem-port" agent skill from https://github.com/mbrock/filnix/tree/main/.claude/skills/gem-port into .claude/skills/gem-port/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gem-port", 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/mbrock/filnix/tree/main/.claude/skills/gem-portType 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 mbrock/filnix --skill gem-port -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install mbrock/filnix gem-port --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mbrock/filnix.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.claude/skills/gem-port .agents/skills/gem-port && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "gem-port" agent skill from https://github.com/mbrock/filnix/tree/main/.claude/skills/gem-port into .agents/skills/gem-port/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gem-port", 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 mbrock/filnix --skill gem-port -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install mbrock/filnix gem-port --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mbrock/filnix.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.claude/skills/gem-port .cursor/skills/gem-port && 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 "gem-port" agent skill from https://github.com/mbrock/filnix/tree/main/.claude/skills/gem-port into .cursor/skills/gem-port/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gem-port", 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/mbrock/filnix.git --path .claude/skills/gem-port--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 mbrock/filnix --skill gem-port -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install mbrock/filnix gem-port --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mbrock/filnix.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.claude/skills/gem-port .gemini/skills/gem-port && 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 "gem-port" agent skill from https://github.com/mbrock/filnix/tree/main/.claude/skills/gem-port into .gemini/skills/gem-port/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gem-port", 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 mbrock/filnix gem-portInstalls 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 mbrock/filnix --skill gem-port -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/mbrock/filnix.git skills-src && mkdir -p .github/skills && cp -r skills-src/.claude/skills/gem-port .github/skills/gem-port && 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 "gem-port" agent skill from https://github.com/mbrock/filnix/tree/main/.claude/skills/gem-port into .github/skills/gem-port/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gem-port", 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 mbrock/filnix --skill gem-port -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install mbrock/filnix gem-port --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mbrock/filnix.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.claude/skills/gem-port .opencode/skills/gem-port && 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 "gem-port" agent skill from https://github.com/mbrock/filnix/tree/main/.claude/skills/gem-port into .opencode/skills/gem-port/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gem-port", 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
gem-port- GitHub stars
- 125
- Token cost
- ~940 tokens
- SKILL.md length
- 246 words
- Files
- 4
- Skills in repo
- 1
- Repo updated
- First seen
- Licence
- None found
At a glance
Port Ruby gems with native C extensions to Fil-C. An agent skill from mbrock/filnix.
- Works in 6 steps: Unpack gem → Find ext structure → Run extconf.rb → …
- Fixing gem compilation errors
- SKILL.md covers Context, Workflow, ast-grep Usage and rubyports.nix Helpers, plus 1 more section
- Calls nix, ruby and make; needs ERROR_TOKEN
What it does
Gem Port is an agent skill from mbrock/filnix. Port Ruby gems with native C extensions to Fil-C. Use when fixing gem compilation errors, VALUE/int type mismatches, rbattr/rbprotect issues, or using ast-grep for Ruby C extensions.
Its SKILL.md is about 940 tokens, which your agent loads only when the skill is triggered. The skill folder holds 3 other files (for example `AST_GREP.md`, `FIXES.md` and `REFERENCE.md`).
It works with Ruby. The repository describes itself as: Fil-C as a Nix C/C++ toolchain and cross platform.
When your agent uses it
- Fixing gem compilation errors
- VALUE/int type mismatches
- Rbattr/rbprotect issues
- Using ast-grep for Ruby C extensions
Example prompts
- “/gem-port”
Requirements
- A credential in ERROR_TOKEN
Workflow steps
6 steps, taken from the step headings in SKILL.md.
- Unpack gem
- Find ext structure
- Run extconf.rb
- Build and capture errors
- Fix and iterate
- Add to rubyports.nix and verify
What it can do on your machine
Read from SKILL.md and the folder at commit 54c476a. 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:
nixrubymake
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 these keys or tokens, usually read from environment variables:
ERROR_TOKEN
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Gem Port loads about 940 tokens when it runs. Until then it costs about 48 tokens; SKILL.md has 246 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
Without a licence we can't republish the file, so here is its outline and opening line. It has 246 words (~940 tokens).
“Fil-C is a memory-safe C compiler. Ruby's VALUE type becomes a pointer (struct rb_value_unit_struct *) instead of an integer. This breaks code that:”
- name
- gem-port
Files
SKILL.md and 3 other files in .claude/skills/gem-port of mbrock/filnix.
- SKILL.md
- AST_GREP.md
- FIXES.md
- REFERENCE.md
Open the folder on GitHubat commit 54c476a
Compare with similar skills
Gem Port 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 |
|---|---|---|---|---|---|---|
| Gem Port this skillmbrock/filnix | 125 | — | ~940 | Automated safety check: Pass | None | |
| Gumroad Prod Consoleantiwork/gumroad | 9.8k | — | ~2.9k | Automated safety check: Notes | MIT | |
| Fastlane Pull Request Reviewfastlane/fastlane | 42k | — | ~550 | Automated safety check: Pass | MIT | |
| Antipattern Preventiondoorkeeper-gem/doorkeeper | 5.5k | — | ~1.1k | Automated safety check: Pass | MIT | |
| Mutantmbj/mutant | 2.2k | — | ~2k | Automated safety check: Pass | Proprietary | |
| Evaluating Pegslineofflight/frankfurter | 2k | — | ~1.6k | Automated safety check: Pass | MIT |
Similar skills
Fastlane Pull Request Review
fastlane/fastlane
Reviews a fastlane pull request against its linked issue and the project guides, separating blocking from non-blocking findings and handling vulnerabilities privately.
Antipattern Prevention
doorkeeper-gem/doorkeeper
Avoid common Ruby and Rails antipatterns that degrade maintainability and performance.
Mutant
mbj/mutant
Run mutant, read mutation reports, fix alive mutations, and verify coverage.
Evaluating Pegs
lineofflight/frankfurter
A skill your agent uses when adding, evaluating, or removing an entry in db/seeds/pegs/, when the user mentions a pegged or fixed currency, or when an issue suggests we should "pin" or "lock" a…
Swig CI Repro
swig/swig
Reproduce a GitHub Actions Linux CI failure locally when it does not happen on your machine: a podman/docker image that mirrors the ubuntu-22.04 runner by reusing the real Tools/CI-linux-.sh install…
Related
Works with
Questions about Gem Port
What does Gem Port do?
Port Ruby gems with native C extensions to Fil-C. An agent skill from mbrock/filnix. Gem Port is an agent skill from mbrock/filnix. Port Ruby gems with native C extensions to Fil-C.
When should I use Gem Port?
Gem Port fits situations like: fixing gem compilation errors; VALUE/int type mismatches; rbattr/rbprotect issues; using ast-grep for Ruby C extensions.
How do I install Gem Port in Claude Code?
Run `npx skills add mbrock/filnix --skill gem-port -a claude-code`. Or copy the skill folder (.claude/skills/gem-port in mbrock/filnix) into .claude/skills/gem-port in your project. Claude Code loads it when a task matches its description.
How do I install Gem Port in Codex?
Run `npx skills add mbrock/filnix --skill gem-port -a codex`. Or copy the skill folder (.claude/skills/gem-port in mbrock/filnix) into .agents/skills/gem-port in your project. Codex loads it when a task matches its description.
Can I use Gem Port 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 mbrock/filnix --skill gem-port -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/gem-port, .gemini/skills/gem-port, .github/skills/gem-port and .opencode/skills/gem-port in your project.
What does Gem Port need to run?
Going by SKILL.md and its folder, Gem Port needs the command-line tools its instructions call (nix, ruby and make) and credentials named ERROR_TOKEN. Our summary lists: A credential in ERROR_TOKEN.
Does Gem Port 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 Gem Port 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 Gem Port use?
No licence was found for Gem Port or its repository. Without one, default copyright applies: ask the author before reusing or redistributing it.
How many tokens does Gem Port use?
About 940 tokens (SKILL.md is roughly 3.8k 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 Gem Port?
Skills that share tags, products or a category with Gem Port: Gumroad Prod Console (antiwork/gumroad, 9.8k stars), Fastlane Pull Request Review (fastlane/fastlane, 42k stars), Antipattern Prevention (doorkeeper-gem/doorkeeper, 5.5k stars) and Mutant (mbj/mutant, 2.2k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Gem Port?
mbrock (a GitHub user) maintains it in mbrock/filnix, which has 125 GitHub stars. The repository was last updated on October 6, 2026.
Source: mbrock/filnix on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.