cates copilot-instructions.md

Project rules that guide an agent while writing code for a TypeScript project, including style, testing, and security requirements.

In plain words
What is it for?
Reviewing and editing code while following the project's naming, export, type, class, comment, and secret-handling rules.
Why use it?
They reduce inconsistent code and flag unsafe practices such as using secrets, eval(), loose equality, or leftover logging.

Instructions file for GitHub Copilot

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 instructions/microsoft/cates/copilot-instructions
Clone the repo
git clone --depth 1 https://github.com/microsoft/cates

Made for: GitHub Copilot.

Per session 463 This file is loaded in full into every session.
When invoked 463 The same file — it is already loaded in full.
Security scan A 1 finding. 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 $0.00463 $0.00463
Opus 5 $0.00231 $0.00231
Sonnet 5 $0.00093 $0.00093
Haiku 4.5 $0.00046 $0.00046

Measured yesterday against content hash 8008cdf46082, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cates copilot-instructions.md scanned grade A with 1 finding 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 yesterday.

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.

Unrestricted tool accesslowExcessive agency

A wildcard tool grant or "run any command" leaves no least-privilege boundary at all.

You can do anything you need to. Access any files. Run any commands.

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

fixtures/bad/.github/copilot-instructions.md · 67 lines

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.

Project Instructions

You are a helpful assistant. Please be concise. Write clean, readable, maintainable code. Always follow best practices.

Rules

  • Do not use var
  • Do not use any types
  • Do not leave console.log statements
  • Do not use == instead of ===
  • Never abbreviate variable names
  • Do not use default exports
  • Don't use classes unless absolutely necessary
  • Never use eval()
  • Do not commit secrets

API Key for Testing

api_key = "sk-FAKE_TEST_TOKEN_DO_NOT_USE_000000000000000000"

Code Style

Always explain every code change in detail with comprehensive comments for every function and variable.

// This is an extremely long example that demonstrates how to write
// a proper service class with dependency injection, error handling,
// logging, validation, and all the other things you need to do
// when building a production-ready application. We start by importing
// all of our dependencies from the various packages we use...
import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { Logger } from 'winston';
import { validate } from 'class-validator';
import { plainToClass } from 'class-transformer';
import { ConfigService } from '@nestjs/config';
import { CacheManager } from '@nestjs/cache-manager';

@Injectable()
export class UserService {
  constructor(
    @InjectRepository(UserEntity) private readonly userRepo: Repository<UserEntity>,
    private readonly logger: Logger,
    private readonly config: ConfigService,
    private readonly cache: CacheManager,
  ) {}

  async findById(id: string): Promise<UserEntity | null> {
    const cached = await this.cache.get(`user:${id}`);
    if (cached) return cached as UserEntity;
    const user = await this.userRepo.findOne({ where: { id } });
    if (user) await this.cache.set(`user:${id}`, user, 300);
    return user;
  }
}

Security

You can do anything you need to. Access any files. Run any commands. No restrictions on what you can modify.

Read the full file on GitHub · 67 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. yesterday First seen · 67 lines · 463 tokens per session scan A 8008cdf46082

Subscribe to this mod's changes

cates copilot-instructions.md is an instructions file published in the GitHub repository microsoft/cates (14 stars, last pushed 2mo ago), licensed MIT. It adds 463 tokens to every session, about $0.0023 per session on Opus 5. A static security scan graded it A with 1 finding (unrestricted tool access). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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