Borrowing it
Nothing to install: this file belongs to chrisleekr/mcp-server-playground. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/chrisleekr/mcp-server-playground/main/AGENTS.mdgit clone --depth 1 https://github.com/chrisleekr/mcp-server-playgroundWrote 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.
[](https://agentmods.dev/instructions/chrisleekr/mcp-server-playground/agents-md)<a href="https://agentmods.dev/instructions/chrisleekr/mcp-server-playground/agents-md"><img src="https://agentmods.dev/badge/instructions/chrisleekr/mcp-server-playground/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.
<a href="https://agentmods.dev/instructions/chrisleekr/mcp-server-playground/agents-md"><img src="https://agentmods.dev/badge/instructions/chrisleekr/mcp-server-playground/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.02621 | $0.02621 |
| Opus 5.5 | $0.01048 | $0.01048 |
| Sonnet 5.5 | $0.00524 | $0.00524 |
| Haiku 4.5 | $0.00262 | $0.00262 |
Grade C, and why
mcp-server-playground AGENTS.md scanned grade C with 2 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.
Downloads and executes remote codehighSupply chain
curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.
curl -fsSL https://bun.sh/install | bash Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl -fsSL https://bun.sh/install | bash How it starts
The opening of the file, as written. The whole thing — 281 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md: AI Collaboration Guide
This document provides essential guidelines for AI models interacting with this MCP (Model Context Protocol) server playground project. Adhering to these standards ensures consistency and maintains code quality.
Project Overview
MCP Server Playground - A TypeScript-based Model Context Protocol server with HTTP transport, OAuth proxy for 3rd party authorization (Auth0), and stateful session management using Valkey. Provides tools for AWS services, system utilities, and streaming capabilities.
Project Structure:
/src: Source code directory/core: MCP server core implementation/mcpServer.ts: Main server with capabilities and handlers/server/http/: Express.js HTTP transport with middleware/server/auth/: OAuth proxy with dynamic client registration/server/transport/: Session management and transport handling/storage/: Pluggable storage abstraction (Memory/Valkey) with EventStore for SSE resumability
/tools: MCP tool implementations with streaming support/prompts: MCP prompt handlers and registry/resources: MCP resource implementations with templates/libraries: External service integrations (AWS SDK)/config: Centralized configuration with Zod validation
/test: Test files and setup utilities
Development Commands
- Build:
bun run build(Bun bundler) - Development:
bun run dev(auto-reload + pretty logging) - Production:
bun run start - Type check:
bun run typecheck - Lint:
bun run lint/bun run lint:fix - Format:
bun run format/bun run format:fix - Test:
bun test/bun test --watch - Test Coverage:
bun test --coverage - MCP Inspector:
bun run test:inspector - Docker:
bun run docker:build/docker compose up -d
TypeScript & Code Style
- Language: Use TypeScript for all development with strict mode enabled
- Strictness: Maximum TypeScript strictness (
exactOptionalPropertyTypes,noUncheckedIndexedAccess,noImplicitReturns) - Module System: ESM with bundler resolution, path aliases (
@/→src/) - Import Organization: Auto-sorted with
simple-import-sortplugin - Functions: MUST include explicit return types for all functions
- Naming Conventions: Use meaningful variable/function names; prefer "URL" (not "Url"), "API" (not "Api"), "ID" (not "Id")
- Comments: Add JSDoc comments for complex logic and public APIs
- Complexity Limits: Max 15 complexity, 4 depth, 120 lines/function, 5 params
- Error Handling: No floating promises, require await, strict boolean expressions
- Type Safety: NEVER use
@ts-expect-erroror@ts-ignore- fix type issues properly - Patterns: Prefer functional programming,
constoverlet, template literals, async/await - Comments policy: Only write high-value comments if at all. Avoid talking to the user through comments.
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 · 281 lines · 2,621 tokens per session scan C 8a79911fd2a3
mcp-server-playground AGENTS.md is an instructions file published in the GitHub repository chrisleekr/mcp-server-playground (7 stars, last pushed 5mo ago), licensed MIT. It adds 2,621 tokens to every session, about $0.0105 per session on Opus 5.5. A static security scan graded it C with 2 findings (downloads and executes remote code, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
mcp-server-playground AGENTS.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| mcp-server-playground AGENTS.mdchrisleekr/mcp-server-playground | Instructions file | 7 | 5mo ago | MIT | C | 2,621 | Codex, OpenCode |
| 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 |