Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
git clone --depth 1 https://github.com/cameronfreer/lean4-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/commands/cameronfreer/lean4-skills/refactor)<a href="https://agentmods.dev/commands/cameronfreer/lean4-skills/refactor"><img src="https://agentmods.dev/badge/commands/cameronfreer/lean4-skills/refactor/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/commands/cameronfreer/lean4-skills/refactor"><img src="https://agentmods.dev/badge/commands/cameronfreer/lean4-skills/refactor.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00014 | $0.01350 |
| Opus 5.5 | $0.00006 | $0.00540 |
| Sonnet 5.5 | $0.00003 | $0.00270 |
| Haiku 4.5 | $0.00001 | $0.00135 |
Grade A, and why
refactor scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
1 near-identical copy found in the catalogue:
- refactor — 98% identical, 5 lines differ
How it starts
The opening of the file, as written. The whole thing — 99 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Lean4 Refactor
Strategy-level proof simplification: find better proof approaches, leverage mathlib, and extract reusable helpers. Complements /lean4:golf (tactic-level optimization) and /lean4:review (read-only audit).
Mutating command: Edits files with user approval. Does not change theorem statements, introduce axioms, or create commits.
Escalation target for /lean4:golf. Golf performs local, statement-preserving proof cleanup, potentially across many proofs; when a golf replacement needs a multi-file or strategy-level change — extracting a helper, moving declarations between files, switching the proof approach — golf hands off here. Axiom/assumption hygiene goes to the axiom-eliminator agent instead; a needed statement change is reported to you rather than applied by either.
Usage
/lean4:refactor File.lean # Refactor all proofs in file
/lean4:refactor File.lean:149 # Refactor proof at line 149
/lean4:refactor --scope=changed # Refactor files modified since last commit
/lean4:refactor --scope=changed --dry-run # Report opportunities without editing
Inputs
| Arg | Required | Description |
|---|---|---|
| target | No | File or File.lean:line |
| --scope | No | file (default with target), changed (default without target) |
| --dry-run | No | Report only, do not edit |
| --search | No | quick (default) or full (exhaustive mathlib search) |
| --extract-helpers | No | on (default) or off (skip helper extraction) |
Scope Behavior
| Input | Scope |
|---|---|
File.lean |
All proofs in file |
File.lean:149 |
Single proof containing line 149 |
| No target | --scope=changed (files modified since last commit) |
--scope=changed |
Files modified since last commit |
Line target: Identifies the enclosing theorem/lemma/def containing the given line and refactors that proof only.
Large-run confirmation: When --scope=changed touches >5 files or >20 opportunities, confirm before proceeding.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago Changed · +2 lines 13e6753636a8
- 1mo ago First seen · 97 lines · 14 tokens per session scan A 899abf463ba5
refactor is a command published in the GitHub repository cameronfreer/lean4-skills (465 stars, last pushed 19d ago), licensed MIT. It adds 14 tokens to every session and 1,350 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other commands, from other repositories
checklist
Generate a custom checklist for the current feature based on user requirements.
clarify
Identify underspecified areas in the current feature spec by asking up to 5 highly targeted clarification questions and encoding answers back into the spec.
specify
Create or update the feature specification from a natural language feature description.
analyze
Perform a non-destructive cross-artifact consistency and quality analysis across spec.md, plan.md, and tasks.md after task generation.
converge
Assess the current codebase against the feature's spec, plan, and tasks, then append any remaining unbuilt work as new tasks to tasks.md so implement can complete it.
implement
Execute the implementation plan by processing and executing all tasks defined in tasks.md.