agentmods.dev

matrix: Instructions file for Codex

AGENTS.md

matrix AGENTS.md is an instructions file for Codex, OpenCode from aminfara/matrix. It costs 854 tokens per session, scanned A, original, MIT.

Repository instructions for AI coding agents working on MATRIX, a project with requirements, architecture documentation, a database, task workflows, a command-line interface, and a web interface.

In plain words
What is it for?
Use it when an agent needs to develop, test, or deploy the MATRIX command-line or web application.
Why use it?
It explains the repository structure, development setup, testing, and build process so agents can work in the correct parts of the project.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md.

This is aminfara/matrix's own configuration. It tells Codex and OpenCode how to work on matrix 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 matrix configures →

not rated 0repo 6d ago A scan 854 tokens original MIT
View source ↗ aminfara/matrix
Reuse

Borrowing it

Nothing to install: this file belongs to aminfara/matrix. 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/aminfara/matrix/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/aminfara/matrix

Made for: Codex, OpenCode.

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 matrix AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/aminfara/matrix/agents-md/github.svg)](https://agentmods.dev/instructions/aminfara/matrix/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/aminfara/matrix/agents-md"><img src="https://agentmods.dev/badge/instructions/aminfara/matrix/agents-md/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.

agentmods 80×15 button for matrix AGENTS.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/aminfara/matrix/agents-md"><img src="https://agentmods.dev/badge/instructions/aminfara/matrix/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 854 This file is loaded in full into every session.
When invoked 854 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 $0.00854 $0.00854
Opus 5.5 $0.00342 $0.00342
Sonnet 5.5 $0.00171 $0.00171
Haiku 4.5 $0.00085 $0.00085

Measured 2mo ago against content hash f3cc5ef03c40, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

matrix AGENTS.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.

AGENTS.md · 54 lines

How it starts

The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Project: MATRIX

Structure

  • requirements/ — Product requirements and backlog (managed by Percy)
  • architecture/ — System architecture docs (managed by Archie)
    • database.md — DB schema, tables, indexes, pragmas, design decisions
    • overview.md — Module map, tool catalogue, error-handling model
    • interface.md — CLI + Web UI architecture, file map, route table, library choices
  • src/ — Source code (server, db, models, requirements, tasks, task-workflow, task-helpers, tools, errors, instructions) plus interface/ sub-folder for CLI + web UI
  • src/interface/ — CLI (matrix-mcp-cli) and embedded web server for human users
    • cli.js — Entry point binary; commander + @inquirer/prompts; DB path resolution
    • commands/ — CLI handlers for requirements, tasks, workflow; shared utils.js
    • web/ — Express app (server.js) + server-side rendered HTML views (views/)
  • tests/ — Unit tests (vitest, in-memory SQLite)

Development Setup

  • Install: npm install
  • Start MCP server: node src/server.js (or via MCP client config)
  • Start CLI: node src/interface/cli.js --help (or matrix-mcp-cli after npm link)
  • Start web UI: node src/interface/cli.js serve [--port 3000] — binds to 127.0.0.1 only
  • DB path (CLI): --matrix-db-path arg > MATRIX_DB_PATH env var > .matrix/matrix.db
  • Node.js required: ≥ 22.5.0 (requires node:sqlite built-in)
  • Environment variables: MATRIX_DB_PATH — override default DB path (.matrix/matrix.db relative to cwd)

Testing

  • Unit tests: npm test (vitest, all tests use in-memory SQLite via initDb)
  • Type check: npm run typecheck
  • Current coverage: 112 tests across 6 files — unit tests (requirements, tasks, task-workflow), MCP tool layer integration tests (tests/tools.test.js), interface service integration tests (tests/interface-services.test.js), and web server HTTP tests (tests/web-server.test.js).

Build & Deploy

  • Publish: npm publish (package name: matrix-mcp, bins: matrix-mcp → src/server.js, matrix-mcp-cli → src/interface/cli.js)
  • Run via npx: npx matrix-mcp (run in project cwd so DB resolves correctly)

Read the full file on GitHub · 54 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. 2mo ago First seen · 54 lines · 854 tokens per session scan A f3cc5ef03c40

Subscribe to this mod's changes

matrix AGENTS.md is an instructions file published in the GitHub repository aminfara/matrix (0 stars, last pushed 6d ago), licensed MIT. It adds 854 tokens to every session, about $0.0034 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 2026-08-31.

Related

matrix AGENTS.md compared with instructions from other repositories

matrix AGENTS.md next to 6 instructions from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
matrix AGENTS.mdaminfara/matrixInstructions file06d agoMITA854Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscodeInstructions file195ktodayMITA9,719GitHub Copilot
next.js AGENTS.mdvercel/next.jsInstructions file143ktodayMITA7,461Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscodeInstructions file195ktodayMITA5,516GitHub Copilot
langchain AGENTS.mdlangchain-ai/langchainInstructions file149ktodayMITA4,680Codex, OpenCode
vscode copilot-instructions.mdmicrosoft/vscodeInstructions file195ktodayMITA3,093GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harnessInstructions file275k3d agoMITA4,313Codex, OpenCode