What is hn-mcp-server copilot-instructions.md?

A repository instruction file for an MCP server that searches and reads Hacker News data. MCP is a standard way for an AI agent to call external tools.

It is for developing, building, linting, and testing the Hacker News MCP server and its TypeScript tools.

It records the project's technologies, folder structure, commands, and test expectations so changes fit the existing codebase.

How wei/hn-mcp-server configures GitHub Copilot

Reuse

Borrowing it

Nothing to install: this file belongs to wei/hn-mcp-server. 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/wei/hn-mcp-server/main/.github/copilot-instructions.md

Clone the repo

git clone --depth 1 https://github.com/wei/hn-mcp-server

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/wei/hn-mcp-server/copilot-instructions/github.svg)](https://agentmods.dev/instructions/wei/hn-mcp-server/copilot-instructions)

Your own site

<a href="https://agentmods.dev/instructions/wei/hn-mcp-server/copilot-instructions"><img src="https://agentmods.dev/badge/instructions/wei/hn-mcp-server/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/wei/hn-mcp-server/copilot-instructions"><img src="https://agentmods.dev/badge/instructions/wei/hn-mcp-server/copilot-instructions.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 613 This file is loaded in full into every session.

When invoked 613 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	$0.00613	$0.00613
Opus 5.5	$0.00245	$0.00245
Sonnet 5.5	$0.00123	$0.00123
Haiku 4.5	$0.00061	$0.00061

Measured 2mo ago against content hash 8c0d36991bc4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

hn-mcp-server 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 · 96 lines

How it starts

The opening of the file, as written. The whole thing — 96 lines — stays where its author put it; the contents beside it link to each section on GitHub.

hn-mcp-server Development Guidelines

Auto-generated from all feature plans. Last updated: 2025-10-12

Active Technologies

TypeScript 5.x (strict mode)
Node.js 18+ with native fetch API
Model Context Protocol (MCP) TypeScript SDK
Zod for schema validation
Biome for linting and formatting
Vitest for testing
HackerNews Algolia API

Project Structure

src/
├── index.ts           # MCP server entry point
├── tools/            # Tool implementations (one per file)
│   ├── search-posts.ts
│   ├── get-front-page.ts
│   ├── get-latest-posts.ts
│   ├── get-item.ts
│   └── get-user.ts
├── services/         # Business logic
│   └── hn-api.ts
├── types/            # Type definitions
└── utils/            # Validators and error handlers

tests/
├── unit/             # Unit tests (no I/O)
├── integration/      # Integration tests (real API)
└── contract/         # MCP protocol compliance

Commands

# Build
npm run build
npm run dev            # Watch mode

# Testing
npm test
npm run test:coverage
npm run test:ui

# Code Quality
npm run lint
npm run lint:fix
npm run format
npm run format:check

# Clean
npm run clean

Code Style

TypeScript strict mode enabled
Tabs for indentation (Biome configuration)
Line width: 100 characters
Double quotes for strings
Trailing commas (ES5)
No any types without justification
Explicit return types on public functions

MCP Tools

All 5 tools implemented:

search-posts - Search HN by keyword with filters
get-front-page - Current front page posts
get-latest-posts - Recent posts by date
get-item - Item details with nested comments
get-user - User profile information

Architecture Patterns

Tool Pattern: Input validation (Zod) → API call → Output validation → Response
Error Handling: Consistent error responses with type, message, details
Testing: Unit + Integration + Contract tests, 80%+ coverage required
Separation: One file per tool for maintainability

Read the full file on GitHub · 96 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 · 96 lines · 613 tokens per session scan A 8c0d36991bc4

Subscribe to this mod's changes

hn-mcp-server copilot-instructions.md is an instructions file published in the GitHub repository wei/hn-mcp-server (7 stars, last pushed 1y ago), licensed MIT. It adds 613 tokens to every session, about $0.0025 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.

Backend and APIs Research

hn-mcp-server copilot-instructions.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
hn-mcp-server copilot-instructions.mdwei/hn-mcp-server	Instructions file	7	1y ago	MIT	A	613	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

hn-mcp-server: Instructions file for GitHub Copilot