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.
npx agentmods add skills/fusengine/agents/go-core-idiomsnpx skills add fusengine/agents --skill go-core-idiomsgit clone --depth 1 https://github.com/fusengine/agentsWrote 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/fusengine/agents/go-core-idioms)<a href="https://agentmods.dev/skills/fusengine/agents/go-core-idioms"><img src="https://agentmods.dev/badge/skills/fusengine/agents/go-core-idioms.svg" alt="Measured on agentmods" 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 | $0.00037 | $0.01277 |
| Opus 5 | $0.00018 | $0.00639 |
| Sonnet 5 | $0.00007 | $0.00255 |
| Haiku 4.5 | $0.00004 | $0.00128 |
Grade A, and why
go-core-idioms 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 today.
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 — 135 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Go Core Idioms
Idiomatic sequential Go for 1.26. For anything touching goroutines, channels,
errgroup, or context cancellation, use go-concurrency instead.
Agent Workflow (MANDATORY)
Before ANY implementation, spawn 3 agents in parallel, one Agent call each with a name:
- fuse-ai-pilot:explore-codebase - Map existing error/logging/interface patterns
- fuse-ai-pilot:research-expert - Verify latest Go docs via Context7/Exa
- mcp__context7__query-docs - Confirm stdlib signatures (errors, log/slog)
After implementation, run fuse-ai-pilot:sniper for validation.
Overview
| Feature | Description |
|---|---|
| Error handling | Explicit if err != nil, %w wrapping, errors.Join, errors.AsType (1.26) |
| Structured logging | log/slog stdlib — handlers, attrs, groups, LogValuer |
| Generics | Type params, constraints, self-referential types (1.26) |
| Interfaces | Small, consumer-side — "accept interfaces, return structs" |
| Modernizers | go fix auto-applies dozens of idiom/API fixers (1.26) |
Critical Rules
- Explicit
if err != nil- No sugar exists; never discard with_ = err - Wrap with
%w, not%v- Preserves the chain forerrors.Is/As/AsType - Accept interfaces, return structs - Define interfaces where consumed, not where produced
- Value receivers by default - Use pointer receivers only for mutation or large structs
- Run
go fix+go vet- Let modernizers migrate to current idioms (1.26)
Architecture
internal/
├── user/
│ ├── user.go # struct + value-receiver methods
│ ├── errors.go # sentinel + typed errors
│ └── repository.go # consumer-side interface, concrete struct returned
└── platform/
└── logging/
└── logger.go # slog setup, one *slog.Logger injected downward
What ships with it
7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- today Changed 85730689ab6b
- 2d ago First seen · 135 lines · 37 tokens per session scan A 9b0fc097524a
go-core-idioms is a skill published in the GitHub repository fusengine/agents (25 stars, last pushed yesterday), licensed MIT. It adds 37 tokens to every session and 1,277 once invoked, about $0.0002 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 2026-09-03.
Other skills, from other repositories
building-telegram-bots
Writes correct, version-aware Telegram bot code. Use when writing, extending, or debugging a Telegram bot in python-telegram-bot, aiogram, grammY, or Telegraf. Not for Telegram client API (TDLib), languages other than Python and Node.js, or non-Telegram platforms.
phx-deps-update
Bump outdated Hex deps — inventory, snapshot changelogs, update, fix breaks, split reviewable PRs (patches bundled, majors solo). Use to upgrade/bump Elixir dependencies or when versions fall behind. NOT for deps.get failures (phx-investigate).
phx-document
Generate @moduledoc/@doc for tested Elixir features; may update their README section or ADR. Not for docs lookup, documentation audits/reviews, or capturing standalone decisions.
craftcms
Craft CMS 5 plugin and module development — extending Craft with PHP. Covers elements, element queries, services, models, records, controllers, migrations, queue jobs, console commands, field types, native fields, events, behaviors, Twig extensions, widgets, filesystems, permissions, project config, GraphQL, testing…
craft-php-guidelines
Craft CMS 5 PHP coding standards and conventions. ALWAYS load when writing, editing, reviewing, or discussing any PHP in a Craft plugin or module — even small edits. Also when running ECS, PHPStan, or scaffolding with ddev craft make. Covers: PHPDoc blocks (@author, @since, @throws chains), section headers…
craft-pest
Testing Craft CMS 5 plugins and modules with Pest — test isolation, database safety, and the markhuot/craft-pest-core harness. ALWAYS load when writing, running, fixing, or reviewing tests for a Craft plugin or module, and whenever a suite touches a real Craft install. Covers why rollback is opt-in, tests/Pest.php +…