go-matter: Instructions file for Gemini CLI

GEMINI.md

go-matter GEMINI.md is an instructions file for Gemini CLI from cybergarage/go-matter. It costs 717 tokens per session, scanned A, original, Apache-2.0.

A project-specific instruction file for Gemini CLI, describing the Go implementation of Matter, a connectivity standard for smart-home and IoT devices.

In plain words
What is it for?
It helps agents work on Matter device discovery, pairing, Bluetooth and network transports, data encoding, and security features.
Why use it?
It gives the coding agent the project context needed to understand the codebase, its structure, and how to build and run it.

Instructions file for Gemini CLI

Written for Gemini CLI: the file is GEMINI.md.

This is cybergarage/go-matter's own configuration. It tells Gemini CLI how to work on go-matter itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything go-matter configures →

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/GEMINI.md
Clone the repo
git clone --depth 1 https://github.com/cybergarage/go-matter

Made for: Gemini CLI.

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-matter GEMINI.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/cybergarage/go-matter/gemini-md.svg)](https://agentmods.dev/instructions/cybergarage/go-matter/gemini-md)
Your own site
<a href="https://agentmods.dev/instructions/cybergarage/go-matter/gemini-md"><img src="https://agentmods.dev/badge/instructions/cybergarage/go-matter/gemini-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 717 This file is loaded in full into every session.
When invoked 717 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00717 $0.00717
Opus 5 $0.00358 $0.00358
Sonnet 5 $0.00143 $0.00143
Haiku 4.5 $0.00072 $0.00072

Measured 5d ago against content hash acbaeea3f08b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

go-matter GEMINI.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 5d 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.

GEMINI.md · 70 lines

How it starts

The opening of the file, as written. The whole thing — 70 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Gemini Context: go-matter

This project is a Go implementation of the Matter connectivity standard for smart home and IoT devices.

Project Overview

  • Core Library: Located in the matter/ directory, providing interfaces for Commissioners, Commissionees, and Devices.
  • CLI Tool: matterctl (in cmd/matterctl/) for scanning and pairing Matter devices.
  • Transports: Supports BLE (Bluetooth Low Energy) and mDNS (Multicast DNS) for device discovery.
  • Encoding: Implements Matter-specific encodings including TLV (Tag-Length-Value), Base38, and Message Frame formats.
  • Security: Includes implementations for PASE (Passcode-Authenticated Session Establishment) and PAKE (Password-Authenticated Key Exchange).

Key Technologies

  • Language: Go
  • CLI Framework: Cobra and Viper
  • Logging: github.com/cybergarage/go-logger
  • External Dependencies:
    • github.com/cybergarage/go-ble: BLE communication.
    • github.com/cybergarage/go-mdns: mDNS service discovery.

Architecture

The project follows a modular structure:

  • matter/: Core interfaces and common types.
  • matter/ble/: BLE transport protocol and scanning.
  • matter/mdns/: mDNS service discovery.
  • matter/encoding/: Data encoding and decoding (TLV, Base38, QR, Message).
  • matter/crypto/: Cryptographic primitives.
  • matter/protocol/: Higher-level protocols (MRP, PASE).
  • mattertest/: Comprehensive test suites and helpers.

Building and Running

The project uses a Makefile for common tasks.

Build and Install

  • Install matterctl CLI:
    make install
    
    Or directly via Go:
    go install ./cmd/matterctl
    

Development Commands

  • Format Code: make format (runs gofmt)
  • Lint: make lint (runs golangci-lint)
  • Vet: make vet (runs go vet)
  • Test: make test (runs tests with coverage)
  • Clean: make clean

Read the full file on GitHub · 70 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. 5d ago First seen · 70 lines · 717 tokens per session scan A acbaeea3f08b

Subscribe to this mod's changes

go-matter GEMINI.md is an instructions file published in the GitHub repository cybergarage/go-matter (40 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 717 tokens to every session, about $0.0036 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 2026-09-02.

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