go-127

go-127 is a skill for Claude Code, Codex from dimetron/pi-go. It costs 177 tokens per session (6,865 once invoked), scanned A, original, MIT.

A reference guide to changes introduced in Go 1.27, the 2026 release of the Go programming language. It explains how those changes affect code written in pi-go.

In plain words
What is it for?
Use it when writing or reviewing pi-go code, updating go.mod to Go 1.27, or investigating toolchain-related build and test changes.
Why use it?
It helps prevent confusion when code, builds, or tests behave differently after moving to Go 1.27. It also explains environment settings that can disable new features.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions CLAUDE.md.

Good fit Use it when writing or reviewing pi-go code, updating go.mod to Go 1.27, or investigating toolchain-related build and test changes.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/dimetron/pi-go/go-127
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.

Any agent
npx skills add dimetron/pi-go --skill go-127
Clone the repo
git clone --depth 1 https://github.com/dimetron/pi-go

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for go-127

README.md
[![agentmods](https://agentmods.dev/badge/skills/dimetron/pi-go/go-127.svg)](https://agentmods.dev/skills/dimetron/pi-go/go-127)
Your own site
<a href="https://agentmods.dev/skills/dimetron/pi-go/go-127"><img src="https://agentmods.dev/badge/skills/dimetron/pi-go/go-127.svg" alt="Measured on agentmods" height="20"></a>
Per session 177 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,865 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium analysis-evasion · line 1
    Suspicious Unicode normalization or mixed-script content
    Fix: Review the flagged content for security risks. Ensure no credentials, secrets, or sensitive data are exposed.
How audits are shown
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 5.1 $0.00177 $0.06865
Opus 5 $0.00088 $0.03432
Sonnet 5 $0.00035 $0.01373
Haiku 4.5 $0.00018 $0.00686

Measured 8d ago against content hash c025e8a2baaf, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

go-127 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 8d 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.

.pi-go/skills/go-127/SKILL.md · 510 lines

How it starts

The opening of the file, as written. The whole thing — 510 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Go 1.27 — What Changed and What To Do About It

Released: August 2026, six months after Go 1.26. Go 1 compatibility holds; almost all programs compile and run unchanged.

Sources: go.dev/doc/go1.27 (authoritative) · victoriametrics.com/blog/go-1-27 (worked examples). Every claim below is from one of those two, or from reading $(go env GOROOT)/src on the installed 1.27.0 toolchain.

Companion skill: code-guidelines-go holds the standing style rules. This skill holds only what 1.27 changed.


0. Read this first — GOEXPERIMENT=none is set on this machine

go env on this host persists GOEXPERIMENT=none, which does not mean "no extra experiments" — it clears the 1.27 baseline, which enables JSONv2, GreenTeaGC, SizeSpecializedMalloc, Dwarf5 and RandomizedHeapBase64 (src/internal/buildcfg/exp.go:81). Verified consequences here:

$ go build ./...                      # importing encoding/json/v2
imports encoding/json/v2: build constraints exclude all Go files in .../encoding/json/v2

$ golangci-lint --version
golangci-lint has version 2.13.1 built with go1.27.0-X:nojsonv2,nogreenteagc,
norandomizedheapbase64,nosizespecializedmalloc

So on this machine encoding/json/v2 will not import, and the 1.27 allocator and GC work are switched off. Before benchmarking anything or trying a v2 snippet:

go env GOEXPERIMENT          # prints "none" -> baseline is cleared
go env -u GOEXPERIMENT       # restore the default baseline (user decision — ask first)
GOEXPERIMENT=jsonv2 go build ./...   # or scope it to one command

Do not silently change the user's go env config. Flag it, and scope the experiment to the command you are running.


1. Language changes

1.1 Generic methods — methods may declare their own type parameters

The headline change. Before 1.27 a generic operation on a type had to be a package-level function; now it can live on the type.

Read the full file on GitHub · 510 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. 8d ago First seen · 510 lines · 177 tokens per session scan A c025e8a2baaf

Subscribe to this mod's changes

go-127 is a skill published in the GitHub repository dimetron/pi-go (154 stars, last pushed yesterday), licensed MIT. It adds 177 tokens to every session and 6,865 once invoked, about $0.0009 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 2026-08-30.

Related

Other skills, from other repositories

golang-testing

Production-ready Golang tests — table-driven tests, testify suites and mocks, parallel tests, fuzzing, fixtures, goroutine leak detection with goleak, snapshot testing, code coverage, integration tests, idiomatic test naming. Use when writing or reviewing Go tests, choosing a testing approach, setting up Go test CI…

alexastrum/skl · 115 tokens

golang-stretchr-testify

Comprehensive guide to stretchr/testify for Golang testing. Covers assert, require, mock, and suite packages in depth. Use when writing tests with testify, creating mocks, setting up test suites, or choosing between assert and require. Covers testify assertions, mock expectations, argument matchers, call verification…

alexastrum/skl · 97 tokens

use-modern-go

Use the Modern Go Guidelines CLI whenever writing, modifying, fixing, or refactoring Go code. Apply its version-specific guidance to generated changes.

JetBrains/go-modern-guidelines · 32 tokens

gograph

Go repository intelligence for Claude Code. Use when reading, navigating, editing, reviewing, or refactoring a Go codebase. Exposes 64 query, analysis, and workflow capabilities through the local gograph MCP server, including bounded first-call exploration, AST-aware call graphs, blast-radius analysis, impact, and…

ozgurcd/gograph · 69 tokens

test-runner

Run and triage Go tests with correct environment handling; produce compact, actionable failure summaries.

pilinux/gorest · 22 tokens

test-fix

Diagnose and minimally fix a failing test, then re-run.

patriceckhart/zot · 17 tokens