What is go-matter copilot-instructions.md?

A set of coding instructions for the go-matter project, a Go library that implements the Matter smart-home protocol. It documents the required build, formatting, linting, and test commands.

It is for building, testing, linting, and maintaining go-matter code, including running individual Go tests and generating coverage reports.

It gives an AI coding assistant the project’s technical context and the exact checks expected before changes are accepted.

How cybergarage/go-matter configures GitHub Copilot

Reuse

Borrowing it

Nothing to install: this file belongs to cybergarage/go-matter. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/cybergarage/go-matter/main/.github/copilot-instructions.md

Clone the repo

git clone --depth 1 https://github.com/cybergarage/go-matter

Made for: GitHub Copilot.

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/cybergarage/go-matter/copilot-instructions/github.svg)](https://agentmods.dev/instructions/cybergarage/go-matter/copilot-instructions)

Your own site

<a href="https://agentmods.dev/instructions/cybergarage/go-matter/copilot-instructions"><img src="https://agentmods.dev/badge/instructions/cybergarage/go-matter/copilot-instructions/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/cybergarage/go-matter/copilot-instructions"><img src="https://agentmods.dev/badge/instructions/cybergarage/go-matter/copilot-instructions.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,006 This file is loaded in full into every session.

When invoked 1,006 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.01006	$0.01006
Opus 5.5	$0.00402	$0.00402
Sonnet 5.5	$0.00201	$0.00201
Haiku 4.5	$0.00101	$0.00101

Measured 2mo ago against content hash 986a1139b614, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

go-matter copilot-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 2mo 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.

.github/copilot-instructions.md · 73 lines

How it starts

The opening of the file, as written. The whole thing — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Copilot Instructions for go-matter

Specification & Reference

go-matter implements Matter Specification Version 1.5. Code comments cite relevant spec sections (e.g., // 2.5.2. Vendor Identifier). The implementation is based on the official C++ reference: https://github.com/project-chip/connectedhomeip.

Build, Test, and Lint

# Format, vet, lint, then test with coverage
make test

# Steps individually
make format   # gofmt + version.go generation
make vet      # go vet
make lint     # golangci-lint
make install  # build and install matterctl CLI, regenerate doc/matterctl.md

# Run a single test
go test -v -run TestName ./matter/...
go test -v -run TestName ./mattertest/...

# Run all tests without linting
go test -v -p 1 -timeout 10m -cover -coverpkg=github.com/cybergarage/go-matter/matter/... \
  -coverprofile=matter-cover.out \
  github.com/cybergarage/go-matter/matter/... \
  github.com/cybergarage/go-matter/mattertest/...

The Makefile pipeline is: format → vet → lint → test. make test runs all steps.

Architecture

go-matter is a Go library implementing the Matter smart home protocol. The module root is github.com/cybergarage/go-matter.

Package Layout

Package	Role
`matter/`	Core public interfaces and type aliases (entry point for users)
`matter/ble/`	BLE transport — BTP (Bluetooth Transport Protocol), Central/scanner
`matter/mdns/`	mDNS discovery of commissionable devices
`matter/encoding/`	Encoding: `base38`, `tlv`, `message` (frame format), `qr`, `pairing`
`matter/protocol/mrp/`	Message Reliability Protocol (acknowledgement, session)
`matter/protocol/pase/`	PASE commissioning handshake (SPAKE2+)
`matter/crypto/`	Elliptic curve, SPAKE2+, PBKDF, signature primitives
`matter/types/`	Fundamental Matter types (VendorID, ProductID, Discriminator, …)
`matter/errors/`	Shared error definitions
`matter/io/`	Transport interface abstraction
`mattertest/`	Integration tests (a separate Go package; not in `matter/`)
`cmd/matterctl/`	CLI built with Cobra + Viper

Read the full file on GitHub · 73 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.

2mo ago First seen · 73 lines · 1,006 tokens per session scan A 986a1139b614

Subscribe to this mod's changes

go-matter copilot-instructions.md is an instructions file published in the GitHub repository cybergarage/go-matter (44 stars, last pushed 22d ago), licensed Apache-2.0. It adds 1,006 tokens to every session, about $0.0040 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 2026-09-02.

Go Hardware and IoT Languages

go-matter copilot-instructions.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
go-matter copilot-instructions.mdcybergarage/go-matter	Instructions file	44	22d ago	Apache-2.0	A	1,006	GitHub Copilot
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	today	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

go-matter: Instructions file for GitHub Copilot