mcp-server: Instructions file for Codex

AGENTS.md

mcp-server AGENTS.md is an instructions file for Codex, OpenCode from berryj85/mcp-server. It costs 710 tokens per session, scanned A, original, MIT.

Project instructions for an MCP server template written in TypeScript and built with Bun. They describe its tools, tests, documentation, logging, retries, validated inputs, and standard input/output message handling.

In plain words
What is it for?
Use them when adding or changing MCP tool handlers, types, logging, retry logic, unit tests, integration tests, or tool documentation.
Why use it?
They explain the project's structure and conventions so changes fit the existing server design.

Instructions file for CodexOpenCode

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

This is berryj85/mcp-server's own configuration. It tells Codex and OpenCode how to work on mcp-server 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 mcp-server configures →

Reuse

Borrowing it

Nothing to install: this file belongs to berryj85/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/berryj85/mcp-server/master/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/berryj85/mcp-server

Made for: Codex, OpenCode.

Wrote this? Show the measurements

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README.md
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Per session 710 This file is loaded in full into every session.
When invoked 710 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 $0.00710 $0.00710
Opus 5.5 $0.00284 $0.00284
Sonnet 5.5 $0.00142 $0.00142
Haiku 4.5 $0.00071 $0.00071

Measured 2mo ago against content hash 12c9d6cf2340, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mcp-server 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 · 100 lines

How it starts

The opening of the file, as written. The whole thing — 100 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MCP Server Template

Project Overview

  • Project Name: mcp-server-template
  • Language: TypeScript
  • Build Tool: Bun
  • Runtime: Bun / Node.js

Technology Stack

Core Framework

  • Framework: Model Context Protocol (MCP) SDK
  • Version: 1.0.0
  • Runtime Version: Bun 1.0+ / Node.js 18+

Architecture & Design Patterns

Overall Pattern

  • Pattern: Transport-based Server
  • Description: MCP server using stdio transport for JSON-RPC message handling

Package Structure

mcp-server-template/
 ├─ src/
 │   ├─ server.ts          # Main server entry point
 │   ├─ tools/
 │   │   └─ index.ts       # Tool handlers and definitions
 │   ├─ lib/
 │   │   ├─ logger.ts      # Structured logging (stderr only)
 │   │   └─ retry.ts       # Retry utilities
 │   └─ types/
 │       └─ index.ts       # Zod schemas and types
 │
 ├─ tests/
 │   ├─ unit/              # Unit tests
 │   └─ integration/       # Integration tests
 │
 └─ docs/
     └─ tools/             # Tool documentation

Design Principles

  • Single Responsibility: Each tool handler in its own function
  • Dependency Injection: Tools receive validated input
  • Dependency Rule: No circular imports between modules
  • Error Handling: All errors caught and returned as structured responses
  • Testability: Pure functions for tool handlers

Development Standards

Code Style

  • Style Guide: Biome linter/formatter
  • Line Length: 100 characters
  • Indentation: 2 spaces
  • Naming:
    • Classes: PascalCase
    • Functions: camelCase
    • Constants: UPPER_SNAKE_CASE or camelCase
    • Files: snake_case for tools, camelCase otherwise
    • Tests: *.test.ts

API Standards

  • Protocol: JSON-RPC 2.0 (MCP)
  • Validation: Zod schemas for all tool inputs
  • Response Format: Structured JSON with isError flag
  • Logging: stderr only (console.error)

Security Guidelines

  • No secrets in code or logs
  • Input validation with Zod before processing
  • Error messages don't expose internal details
  • stdin/stdout only for JSON-RPC (no console.log)

Read the full file on GitHub · 100 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 · 100 lines · 710 tokens per session scan A 12c9d6cf2340

Subscribe to this mod's changes

mcp-server AGENTS.md is an instructions file published in the GitHub repository berryj85/mcp-server (0 stars, last pushed 7mo ago), licensed MIT. It adds 710 tokens to every session, about $0.0028 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 2026-09-01.

Related

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