Spacecraft Software Construct

A collection of Claude / LLM agent skills used across the Spacecraft Software ecosystem. Each top-level directory is a self-contained skill — a SKILL.md that the agent loads on demand, plus optional references/ files consulted only when a deeper lookup is warranted.

These skills encode conventions, tool preferences, brand rules, and compliance requirements so agents produce Spacecraft Software-consistent output without needing the rules re-attached to every prompt.

Audience

• LLM agents (Claude Code, Gemini CLI, Copilot CLI, Codex, etc.) loading skills from ~/.claude/skills/, ~/.gemini/skills/, ~/.codex/skills/.
• Humans reviewing, extending, or auditing Spacecraft Software's conventions.

Skills in this repository

Skill	Purpose
gnu-coding-standards	Applies the GNU Coding Standards to C, Rust, GNU Guile, Go, and Python — error-message grammar, CLI contract, i18n, build conventions, and free-software philosophy.
gnu-free-software	Self-sufficient, distributable skill to produce and enforce free software in the FSF/GNU tradition — free license + COPYING, GNU Coding Standards (--version/--help, Texinfo, ChangeLog) across C/Guile/Rust/Go/Python, the JavaScript Trap, and GNU vocabulary. FSF-default; stands alone (no other skill required).
spacecraft-guile-guidelines	Write idiomatic, functional, concurrent GNU Guile (Guile Scheme 3.x) — fibers/CSP, SRFI-1, tail calls, hygienic macros.
microsoft-rust-guidelines	Enforces Microsoft Pragmatic Rust Guidelines before any .rs edit.
spacecraft-ada-guidelines	Provably-correct safety-critical Ada/SPARK guidance — the gnatprove assurance ladder (Stone→Platinum), design-by-contract (Pre/Post/Global/Depends), strong typing, SPARK ownership, Ravenscar/Jorvik tasking, the AdaCore Safe & Secure 41-rule catalogue (adapted, in references/), and the Alire/GNAT toolchain.
spacecraft-agentic-cli	Agent-facing UX layer for Spacecraft Software CLIs — pairs with spacecraft-cli-standard.
spacecraft-brand-guidelines	Applies Spacecraft Software's official colors and typography to artifacts.
spacecraft-chez-guidelines	Functional, safe, concurrent Chez Scheme guidance — R6RS libraries + Akku, pure-first design, optimize-level as the safety lever (level 3 = unsafe), hand-built mailboxes/channels over real threads (no Fibers), the FFI + AOT/whole-program compilation, and Guile-habit guardrails.
spacecraft-cli-preference	Modern CLI substitutions: eza for ls, rg for grep, gitway for Git SSH, etc.
spacecraft-cli-standard	Enforces the Spacecraft Software Dual-Mode Self-Documenting CLI Standard (SFRS v1.0.0) on every CLI.
spacecraft-cli-shell	Syntax-compliance guard for Nushell / Ion / POSIX / Bash commands.
spacecraft-clojure-guidelines	Functional, safe-concurrent Clojure guidance — immutable-first design, reference-type decision tree (atoms / refs+STM / agents / core.async), transducers, lazy-seq discipline, ClojureScript and Babashka platform notes, and standard-clj formatting.
spacecraft-document-format	Texinfo-first document authoring: .texi is canonical for prose (one source → Info/text, HTML, PDF, and GFM; Standard §8), ODF (.odt/.ods/.odp) is secondary for prose and primary for spreadsheets/presentations, MS Office (.docx/.xlsx/.pptx) is the last-resort fallback; GFM Markdown companion paired with every binary deliverable; PDF always an export; CC-BY-SA-4.0 document license; Void Navy + Standard §11 palette.
spacecraft-elixir-guidelines	Fault-tolerant concurrent Elixir/OTP guidance — supervision trees, GenServer/Task.async_stream, "let it crash" resilience, share-nothing message passing, pattern matching & with flow, ExUnit/StreamData testing, and mix format/Credo/Dialyzer gates.
spacecraft-erlang-guidelines	Fault-tolerant concurrent Erlang/OTP guidance — gen_server/gen_statem/supervisor behaviours, restart strategies, links & monitors, "let it crash", ETS/Mnesia state, -spec + Dialyzer, and the rebar3 (eunit/Common Test/xref/dialyzer) toolchain.
spacecraft-golang-guidelines	High-performance concurrent Go guidance — goroutines, channels, errgroup, context cancellation, atomics, sync.Pool, pprof / race-detector workflow, and memory-safe parallelism patterns.
spacecraft-markdown-document	Produces well-formed GFM documents conforming to the GitHub Flavored Markdown spec and Spacecraft Software house style. Slash-command only: /spacecraft-markdown-document.
spacecraft-missing-pkg	Handles missing-package situations in the Spacecraft Software workflow.
spacecraft-rust-guidelines	High-performance concurrent Rust guidance — concurrency model selection, lock-free synchronisation, memory layout, tooling gates, and unsafe hygiene — plus a distilled idiom layer (references/idioms.md, adapted from Apollo's Rust Best Practices, MIT) covering borrowing, clippy discipline, testing, dispatch, and type-state.
spacecraft-standard	Authoritative compliance reference (The Steelbore Standard).
spacecraft-texinfo	How-to layer for authoring, building, linting, and converting GNU Texinfo — the canonical Spacecraft prose format (one .texi → Info/HTML/PDF/DocBook/text/EPUB); house-style header/licensing, node/menu discipline, @def* API docs, the texi2any/texi2pdf toolchain, and HTML/PDF brand theming.
spacecraft-theme-factory	Generates Spacecraft Software-compliant themes for IDEs and terminals.
spacecraft-zig-guidelines	Memory-safe high-performance concurrent Zig guidance — std.Thread.Pool / std.Io.Threaded, atomics, allocator discipline, comptime safety, and CPU-bound scaling patterns.

Directory layout

Every skill follows the same shape:

<skill-name>/
├── SKILL.md           # Frontmatter + the agent-facing instructions
├── LICENSE.md         # Skill license (Standard §4.1.1: skills are GPL-3.0-or-later; third-party-derived skills keep their upstream license)
├── CREDITS.md         # Required when the skill builds on third-party work (Standard §15.3)
└── references/        # Optional; consulted only when depth is needed
    ├── <topic>.md
    └── ATTRIBUTION.md # Optional deeper credit file for adapted references

Skills are also distributed as <skill-name>.skill bundles (zipped) at the repository root for drop-in installation.

Installation

Direct clone

Clone into any of the supported agent skill directories:

# Claude Code
git clone git@github.com:Spacecraft-Software/Construct.git ~/.claude/skills

# Gemini CLI
git clone git@github.com:Spacecraft-Software/Construct.git ~/.gemini/skills

# Codex
git clone git@github.com:Spacecraft-Software/Construct.git ~/.codex/skills

# Grok
git clone git@github.com:Spacecraft-Software/Construct.git ~/.grok/skills

The SSH remote is configured to work with Gitway, Spacecraft Software's pinned-host-key SSH transport for Git.

Nix flake (Home Manager)

The repository is a Nix flake. Add it as an input and import the Home Manager module:

{
  inputs.construct.url = "github:Spacecraft-Software/Construct";

  outputs = { self, nixpkgs, home-manager, construct, ... }: {
    homeConfigurations."you" = home-manager.lib.homeManagerConfiguration {
      pkgs = nixpkgs.legacyPackages.x86_64-linux;
      modules = [
        construct.homeManagerModules.default
        {
          spacecraft.construct.enable = true;       # cross-platform skills
          spacecraft.construct.enableGrok = true;   # Grok skills
        }
      ];
    };
  };
}

With enable, all cross-platform skills are installed to ~/.agents/skills/ and every known agent harness's skill path (~/.claude/skills, ~/.gemini/skills, ~/.codex/skills, ~/.ai/skills, ~/.agent/skills) becomes a directory symlink to that canonical location. Add more paths via spacecraft.construct.agentPaths.

With enableGrok, Grok-specific skills (from grok-skills/) install to ~/.grok/skills/ — kept separate because Grok's bundle format is flat (no enclosing skill-name directory) and is not interchangeable with the Claude/Gemini/Codex layout.

To pick up the latest commit, run nix flake update construct in the consumer flake and rebuild.

Individual skills are also exposed as packages — e.g. nix build github:Spacecraft-Software/Construct#spacecraft-standard produces a result/ directory with that skill's contents.

Grok skills

Skills authored for the Grok agent platform live in grok-skills/ with their own catalogue. The bundle layout differs (flat zip root); see the section's README for details.

Standards

All skills in this repository are expected to conform to The Steelbore Standard — including:

• §4 SPDX/REUSE-compliant licensing (§4.3): two-tag headers / REUSE.toml, a LICENSES/ directory, reuse lint-clean. Skills are GPL-3.0-or-later (§4.1.1); third-party-derived skills preserve their upstream license (§4.2).
• §14 ISO 8601 dates throughout.
• Functional naming (no codenames for skill IDs).

License

This repository follows the REUSE specification — see REUSE.toml and the LICENSES/ directory; run reuse lint to verify. Per Standard §4.1.1, skills are GPL-3.0-or-later by default; third-party-derived skills keep their upstream license (e.g. microsoft-rust-guidelines is MIT, gnu-coding-standards is GFDL-1.3-or-later). The published Standard document is CC-BY-SA-4.0, but the spacecraft-standard skill here is GPL-3.0-or-later.

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─── Forged in Spacecraft Software ───