zig

name: zig description: Write, review, explain, and update Zig code using current official Zig language and standard-library APIs. Use when Codex needs up-to-date Zig guidance for language features, typing, enums, control flow, allocators, data structures, std, std.posix, std.fs, std.Io, testing, build.zig, packages, C interop, or cross-platform systems programming.

Zig

Use current official Zig sources, not stale model memory.

This skill snapshot is written against Zig sources current on 2026-04-15:

• latest stable: 0.16.0 released 2026-04-14
• current master: use the download page for the exact current dev snapshot

Default to stable 0.16.0 unless the repo clearly pins master or a specific dev snapshot.

Start Here

1. Confirm the target Zig version before editing: check zig version, CI, Dockerfiles, build.zig.zon, README snippets, and download URLs.
2. Default to stable docs and APIs when the repo does not pin a dev build.
3. If the repo targets master, use the exact dev snapshot when possible; do not assume master APIs from memory.
4. Match the repo's style, but prefer current non-deprecated APIs when the codebase is already on current Zig.
5. Treat allocators, ownership, sentinels, alignment, and error sets as semantic design choices.

Workflow

1. Classify the task first

Sort the task into one or more of these buckets:

• language and typing
• enums, tagged unions, and control flow
• allocators, containers, and ownership
• strings, slices, pointers, and alignment
• std modules such as mem, fmt, json, testing, and Random
• std.fs, std.Io, std.process, std.net, and std.posix
• build.zig or package/import wiring
• C interop or cross-platform OS work

2. Load only the matching reference

• Read references/version-policy.md first when the target Zig version is unclear.
• Read references/language-core.md for typing, enums, tagged unions, control flow, comptime, and builtin usage.
• Read references/stdlib-and-containers.md for allocators, ArrayList, maps, enum collections, strings, formatting, JSON, and testing helpers.
• Read references/posix-and-os.md for std.posix, file descriptors, sockets, child processes, std.net, and cross-platform boundaries.
• Read references/build-and-interop.md for build.zig, modules, dependencies, tests, and C interop.

Default Review Heuristics

• Check whether version-specific assumptions are explicit and current.
• Check whether pointer, slice, sentinel, and alignment types match what the callee actually expects.
• Check whether error sets, optionals, and tagged unions are modeled explicitly instead of being flattened into magic values.
• Check whether switch, for, while, labeled blocks, defer, and errdefer are being used idiomatically rather than imitating C or Rust control flow.
• Check whether container ownership and allocator lifetime are obvious at the call site.
• Check whether std.mem, std.fmt, std.json, std.testing, and std.posix helpers already solve the problem before inventing custom utilities.
• Check whether the code should use std.net or higher-level std APIs before dropping to raw std.posix.
• Check whether build.zig is using current std.Build patterns instead of cargo-like or cmake-like abstractions.

Reference Map

• Read references/version-policy.md for the current stable-vs-master rule and official source order.
• Read references/language-core.md for typing, enums, unions, error handling, comptime, and control flow.
• Read references/stdlib-and-containers.md for allocators, collections, common std helpers, and testing utilities.
• Read references/posix-and-os.md for std.posix, file descriptors, sockets, and OS-facing APIs.
• Read references/build-and-interop.md for build.zig, modules, dependencies, tests, and C interop.
• Read references/official-sources.md when you need the exact upstream doc or release-note entry.