Borrowing it
Nothing to install: this file belongs to beel-collab/presets.dev. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/beel-collab/presets.dev/main/release/go/native/copilot/.github/instructions/go.instructions.mdgit clone --depth 1 https://github.com/beel-collab/presets.devWrote 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/instructions/beel-collab/presets.dev/go)<a href="https://agentmods.dev/instructions/beel-collab/presets.dev/go"><img src="https://agentmods.dev/badge/instructions/beel-collab/presets.dev/go/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/beel-collab/presets.dev/go"><img src="https://agentmods.dev/badge/instructions/beel-collab/presets.dev/go.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00867 | $0.00867 |
| Opus 5.5 | $0.00347 | $0.00347 |
| Sonnet 5.5 | $0.00173 | $0.00173 |
| Haiku 4.5 | $0.00087 | $0.00087 |
Grade A, and why
presets.dev go.instructions.md 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 — 67 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Go Copilot Instructions: Errors, Context and Goroutines
Path-specific Copilot instructions for Go. They apply through applyTo and leave .github/copilot-instructions.md in place.
Updated for Go 1.27.4, Nov 2026
Do not upgrade dependencies or the framework version unless the task asks.
Go 1.27.4 is the current stable release on go.dev/dl. Go 1.26.11 is the other stable line. Stay on the version in go.mod. Go 1.27 adds generic methods. encoding/json is backed by encoding/json/v2 on this release. Behavior of the v1 API is preserved. GOEXPERIMENT=nojsonv2 restores the old implementation and is a temporary opt-out, not the default. The simd package stays experimental and turns on only with GOEXPERIMENT=simd. Do not set that flag because it exists. Import encoding/json/v2 only when the task asks for the new API.
Project shape
go.mod names the module. Packages are small and named for what they provide. internal/ is for code other modules must not import. Match the existing layout. Commands live in cmd/ when the repo already does that.
Format with gofmt. Vet and the project's linters are part of the check, not optional decoration.
Errors
Check every error. _ = do() is a bug unless the comment says why the error cannot matter. Wrap with %w when the caller should use errors.Is or errors.As. A sentinel or a typed error is the project's existing style. Do not panic for a request failure. panic is for a broken invariant during startup, and even then main should fail with an error when it can.
Context and goroutines
The first argument of a request-scoped function is context.Context. Pass ctx. Do not store a context in a struct. When the caller cancels, the work stops: a select on ctx.Done(), a query that takes ctx, an HTTP request built with NewRequestWithContext.
A goroutine has an owner and an end. A go with no way to finish is a leak. Use errgroup or the project's worker helper when you start more than one. Send results on a channel that is closed by the sender. Do not copy a WaitGroup by value.
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 First seen · 67 lines · 867 tokens per session scan A d237f4baa738
presets.dev go.instructions.md is an instructions file published in the GitHub repository beel-collab/presets.dev (3 stars, last pushed yesterday), licensed MIT. It adds 867 tokens to every session, about $0.0035 per session on Opus 5.5. 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 2026-11-13.
presets.dev go.instructions.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| presets.dev go.instructions.mdbeel-collab/presets.dev | Instructions file | 3 | yesterday | MIT | A | 867 | GitHub Copilot |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | today | MIT | A | 7,461 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 5,685 | GitHub Copilot |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | today | MIT | A | 4,680 | Codex, OpenCode |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 3,086 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 280k | 2d ago | MIT | A | 4,325 | Codex, OpenCode |