Borrowing it
Nothing to install: this file belongs to shelkesays/safelint. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/shelkesays/safelint/main/.claude/skills/add-language-support/SKILL.mdgit clone --depth 1 https://github.com/shelkesays/safelintWrote 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/skills/shelkesays/safelint/add-language-support)<a href="https://agentmods.dev/skills/shelkesays/safelint/add-language-support"><img src="https://agentmods.dev/badge/skills/shelkesays/safelint/add-language-support/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/skills/shelkesays/safelint/add-language-support"><img src="https://agentmods.dev/badge/skills/shelkesays/safelint/add-language-support.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00091 | $0.04154 |
| Opus 5 | $0.00046 | $0.02077 |
| Sonnet 5 | $0.00018 | $0.00831 |
| Haiku 4.5 | $0.00009 | $0.00415 |
Grade A, and why
add-language-support 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 12d 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.
How it starts
The opening of the file, as written. The whole thing — 304 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Adding a language or framework preset to safelint
This is the development checklist for extending safelint itself. The
tracked human walkthrough is docs/contributing/adding-a-language.md (read it
first; it has a worked TypeScript example). This skill is the enforcement
layer: every item below must be done or explicitly recorded as deliberately
skipped with a rationale. History shows the misses are never the engine code -
they are the docs fan-out, the counts, the examples, and the bundled skill
files.
Two workflows: Part A (new language), Part B (framework / runtime preset). Part C lists the conventions and the validation gate shared by both.
Part A: Adding a new language
A1. Grammar packaging
-
pyproject.toml: addtree-sitter-<lang>as its own optional extra (every language is opt-in; the base install ships no grammars), fold it into the[all]extra (single source of truth -devpullssafelint[all]), and extend the extras comment block. -
uv lockregenerates; commituv.lock.
A2. Language module: src/safelint/languages/<lang>.py
- Optional grammar import with
_GRAMMAR_AVAILABLEflag (silentexcept ImportErrorfallback carries# nosafe: SAFE203, matching the five existing modules). -
EXTRA_NAME,GRAMMAR_INSTALL_HINT, parser factory raisingImportErrorwith the hint when the grammar is absent. -
LanguageDefinition(extensions,comment_node_type,comment_prefix). Line-comment directives only; block-commentnosafeis a documented non-feature. - Node-type string constants (rules must import these, never hardcode
strings) and a
FUNCTION_TYPESaggregate containing body-bearing function nodes only (see the Rust module's note on excluding signatures).
A3. Registry: src/safelint/languages/__init__.py
- Add the parallel registration block (grammar present ->
_REGISTRY; absent ->_UNAVAILABLE_EXTENSIONS+_UNAVAILABLE_EXTRA_NAMESso the CLI can hintpip install 'safelint[<lang>]'). Keep the blocks grep-parallel with the existing five. - Export the definition in
__all__. Do NOT reach into_REGISTRYfrom elsewhere;supported_extensions()is the public surface.
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.
- 12d ago First seen · 304 lines · 91 tokens per session scan A a2395c5032fe
add-language-support is a skill published in the GitHub repository shelkesays/safelint (7 stars, last pushed 7d ago), licensed MIT. It adds 91 tokens to every session and 4,154 once invoked, about $0.0005 per session on Opus 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 2026-08-31.
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