Skills¶

Skills are Claude Code slash commands bundled in the lightcone-cli plugin. Each shapes the agent's workflow around a recurring research operation: scoping an analysis, wrapping existing code, reproducing a paper.

If you want to use these, start with The Agentic Workflow in the user guide. This page is for maintainers.

Available skills¶

/lightcone is the entry point — activate it first whenever an astra.yaml project is in play (see Entry point below). The /lc-from-* family is parallel in what you start from: a question, code, or a paper. /lc-from-paper is the entry point of a five-skill paper-reproduction bundle; the four siblings stand alone and are user-invokable directly.

Entry point¶

Skill	Command	Purpose
lightcone	`/lightcone`	Start here. Carries the lay of the land (what ASTRA is, the Spec-Code Invariant, the core `lc` loop), bundles the two references at `references/{astra,lc-cli}.md`, and routes to the task skill for the job. The PreToolUse skill-gate opens once it's activated.

Project lifecycle¶

Skill	Command	Purpose
lc-new	`/lc-new`	Scope a research question into an `astra.yaml`, with optional literature extraction.
lc-from-code	`/lc-from-code`	Wrap an existing codebase in ASTRA: scan, generate spec, parameterize, run.
lc-from-paper	`/lc-from-paper`	Reproduce a published paper in ASTRA — two interactive bookends in your main session wrapping one autonomous Workflow that carries the heavy middle.
lc-feedback	`/lc-feedback`	File a GitHub issue against the right Lightcone repo with auto-collected context.

Paper-reproduction bundle (sibling skills)¶

Co-located with lc-from-paper so a single lc init brings the full toolkit. Each stands alone and is user-invokable; lc-from-paper dispatches them by role during the reproduction.

Skill	Command	Purpose
paper-extraction	`/paper-extraction`	Turn an arXiv ID or DOI into a standardized `work/reference/` directory: substrate, figures, tables, citations (with resolved DOIs), and a stub `astra.yaml`.
narrative	`/narrative`	Author the `narrative:` prose and decision `rationale:` against an existing `astra.yaml`, in paper-reproduction, retrofit, or co-drafting mode.
figure-comparison	`/figure-comparison`	Build a self-contained HTML side-by-side: paper figures, tables, and numerics vs reproduced artifacts.
check-sentence-by-sentence	`/check-sentence-by-sentence`	Static audit of paper claims against code locations (`file:line` or `NOT FOUND`).

See the bundle README for the rationale behind co-location vs plugin install.

References (bundled under `/lightcone`)¶

Not skills. These are reference documents bundled with the /lightcone entry point at lightcone/references/. Activating /lightcone is enough — read the section you need when you need it; the references stay available throughout the session.

Reference	Path	Purpose
`astra`	`references/astra.md`	Reference for the `astra.yaml` spec: structure, decisions, options, prior insights, findings, evidence, sub-analyses, narrative anchors, composition mechanics.
`lc-cli`	`references/lc-cli.md`	Reference for `lc` workflow: commands, the Spec-Code Invariant, status interpretation, failure diagnosis, multiverse runs, publishing via WRROC.

These intentionally stay out of the top-level README. Researchers use the project-lifecycle skills directly; the references are infrastructure carried by /lightcone.

How a skill is wired¶

Each skill is a claude/lightcone/skills/<name>/SKILL.md file with YAML frontmatter:

---
name: lc-new
description: >
  Scope a new ASTRA analysis from a research question...
allowed-tools: Read, Write(astra.yaml), Edit(astra.yaml), Glob, Grep, Bash(astra:*), ...
argument-hint: "[DESCRIPTION]"
---

The frontmatter tells Claude Code which tools the skill may invoke and what the slash command's argument hint looks like. The body is the prompt itself: phase definitions, rules, references to guide files, anti-patterns. Skills bundle their own helper scripts under scripts/ and longer prompt fragments under assets/ when relevant.

Plugin layout¶

claude/lightcone/
├── skills/
│   ├── lightcone/{SKILL.md, references/{astra,lc-cli}.md}  # entry point + bundled references
│   ├── lc-new/{SKILL.md, references/*.md}
│   ├── lc-from-code/SKILL.md
│   ├── lc-from-paper/{SKILL.md, reproduce_workflow.js, references/*.md, templates/{plan.md, CLAUDE.md}}
│   ├── lc-feedback/SKILL.md
│   ├── paper-extraction/{SKILL.md, scripts/*.py}
│   ├── narrative/{SKILL.md, references/*.md}
│   ├── figure-comparison/{SKILL.md, scripts/*.py}
│   └── check-sentence-by-sentence/SKILL.md
├── agents/lc-extractor.md             # literature subagent for /lc-new
├── templates/CLAUDE.md                # the project CLAUDE.md template
└── scripts/*.sh                       # session lifecycle hooks (incl. session-start primer)

The plugin is force-included into the wheel via pyproject.toml::tool.hatch.build.targets.wheel.force-include, so lc init finds it whether you're running from source or PyPI.

Other plugin files¶

The two references (astra and lc-cli) are now bundled under /lightcone at lightcone/references/{astra,lc-cli}.md and are listed in the References (bundled under /lightcone) section above. Remaining plugin files:

File	Purpose
`claude/lightcone/agents/lc-extractor.md`	Literature extraction subagent invoked by `/lc-new`.
`claude/lightcone/scripts/session-start.sh`	Session-start hook — surfaces validation + materialization status and primes Claude with the substrate CLIs and the `/lightcone` entry point.

Authoring a new skill¶

See Authoring Skills.