zig-check

A checker for Zig source code that looks for APIs and coding patterns no longer correct in Zig 0.15.x or 0.16.x. Zig is a programming language with changes between these versions.

In plain words
What is it for?
Use it to audit one Zig file or the Zig files changed in a Git diff. It reports problems with file paths, line numbers, and the specific outdated pattern.
Why use it?
It catches version-related mistakes before they become harder to diagnose. Without a file argument, it checks modified Zig files in the current Git changes.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/kelp/agent-plugins/zig-check
Any agent
npx skills add kelp/agent-plugins --skill zig-check
Clone the repo
git clone --depth 1 https://github.com/kelp/agent-plugins

Made for: Claude Code, Codex.

Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,314 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00054 $0.02314
Opus 5 $0.00027 $0.01157
Sonnet 5 $0.00011 $0.00463
Haiku 4.5 $0.00005 $0.00231

Measured yesterday against content hash 85dc900460a9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

zig-check 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 yesterday.

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.

plugins/zig-claude-kit/skills/zig-check/SKILL.md · 226 lines

How it starts

The opening of the file, as written. The whole thing — 226 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/zig-check [file]

Audit Zig source files for outdated APIs. The plugin supports both Zig 0.15.x and 0.16.x; this skill detects the target version and applies the matching rule set. If a file path is given, check that file. Otherwise check all *.zig files, in any directory, that were modified in the current git diff (staged and unstaged).

Procedure

1. Detect Zig version

Run:

${CLAUDE_PLUGIN_ROOT}/scripts/detect-zig-version.sh

Capture the output as $VERSION (0.15 or 0.16).

2. Determine target files

If argument provided:

  • Check only that file

If no argument:

  • Run git diff --name-only and git diff --cached --name-only
  • Filter to *.zig files, recursively, regardless of directory
  • If no modified Zig files, report "No modified Zig files to check" and exit

3. Read each target file

Use the Read tool to read the full contents of each file.

4. Apply the version-specific rule set

Search each file for the patterns below. Report each violation with file path, line number, and the specific issue.

Rules that apply to BOTH 0.15.x and 0.16.x

These are wrong on every supported Zig version:

  1. Deleted-in-0.15 APIs:

    • std.io.getStdOut / std.io.getStdErr -- use buffered writer pattern
    • usingnamespace -- removed from language
    • async / await -- removed from language
    • std.BoundedArray -- use ArrayListUnmanaged.initBuffer
    • std.json.Parser -- use std.json.parseFromSlice
  2. Renamed APIs (still valid in both versions):

    • std.mem.tokenize( without Any/Scalar/Sequence -- use tokenizeAny, tokenizeScalar, or tokenizeSequence
  3. ArrayList without allocator:

    • .append(, .appendSlice(, .deinit() etc. without allocator as first argument (for ArrayListUnmanaged)
  4. Ambiguous format strings:

    • "{}" in print/format calls -- must use {s}, {d}, {any}, etc.
  5. Signed division without builtins:

    • / or % on runtime signed integer variables -- use @divTrunc, @divFloor, @divExact, @rem, @mod

Read the full file on GitHub · 226 lines

Changes

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.

  1. yesterday First seen · 226 lines · 54 tokens per session scan A 85dc900460a9

Subscribe to this mod's changes

zig-check is a skill published in the GitHub repository kelp/agent-plugins (2 stars, last pushed 9d ago), licensed MIT. It adds 54 tokens to every session and 2,314 once invoked, about $0.0003 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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