go

Go language and toolchain rules for a project using Go 1.26, including preferred standard-library features, error handling, pointer syntax, and command setup.

In plain words
What is it for?
Writing, reviewing, or running Go code in this repository, including error handling, optional values, tests, and toolchain commands.
Why use it?
They make new Go code match the project's version and style and help avoid unsupported patterns or unnecessary helper functions.

Cursor rule for Cursor

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 rules/hiromaily/docs-ssot/go
Clone the repo
git clone --depth 1 https://github.com/hiromaily/docs-ssot

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 1,229 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 $0.00000 $0.01229
Opus 5 $0.00000 $0.00615
Sonnet 5 $0.00000 $0.00246
Haiku 4.5 $0.00000 $0.00123

Measured 2d ago against content hash 950640c920d6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

go 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 2d 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.

.cursor/rules/go.mdc · 106 lines

How it starts

The opening of the file, as written. The whole thing — 106 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Go File Rules

Go version

This project uses Go 1.26. Prefer modern language and standard library features:

  • for range over integers (for i := range n) — available since Go 1.22
  • slices and maps packages from the standard library
  • any instead of interface{}
  • t.Context() in tests instead of context.Background()
  • errors.New for static error strings; fmt.Errorf("...: %w", err) for error wrapping
  • new(expr) for pointer literals — available since Go 1.26

Pointer literals

Go 1.26 allows passing expressions directly to new, eliminating the need for a temporary variable or helper functions like ToPtr():

// Before Go 1.26 — create a temp variable first
n := int64(300)
ptr := &n

// Also before — helper function workaround
func ToPtr[T any](v T) *T { return &v }
ptr := ToPtr(int64(300))

// Go 1.26+ — pass the expression directly
ptr := new(int64(300))

Rules:

  • Do not define or use ToPtr, Ptr, or similar pointer-helper functions.
  • Do not create a temporary variable solely to take its address.
  • Use new(expr) for all pointer literals to optional/nullable fields.

Toolchain setup

All Go commands run from mcp-server/. The module lives at github.com/hiromaily/claude-forge/mcp-server.

To set up the dev environment (installs lefthook hooks and pins golangci-lint as a tool in go.mod):

cd mcp-server && make install

golangci-lint is pinned as a Go tool dependency (go get -tool — available since Go 1.24). Run it via go tool golangci-lint, not a globally installed binary. The version is locked in go.mod under the tool directive.

Running tests

cd mcp-server && go test ./...

Git hooks (lefthook)

Lefthook runs automatically on git operations. Both hooks only trigger when **/*.go files are staged/pushed, and both run from mcp-server/.

Hook Command Behaviour
pre-commit make go-fmt Formats staged .go files and re-stages the fixes (stage_fixed: true)
pre-push make go-lint Lints and auto-fixes .go files before push

Read the full file on GitHub · 106 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. 2d ago First seen · 106 lines · 0 tokens per session scan A 950640c920d6

Subscribe to this mod's changes

go is a cursor rule published in the GitHub repository hiromaily/docs-ssot (2 stars, last pushed 4mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,229 tokens. 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.