mcp-apps-playground: Instructions file for Codex

AGENTS.md

mcp-apps-playground AGENTS.md is an instructions file for Codex, OpenCode from digitarald/mcp-apps-playground. It costs 67 tokens per session, scanned A, original, MIT.

Project-specific guidance for building MCP Apps Playground, an example server that provides tools and interactive HTML screens to MCP clients.

In plain words
What is it for?
Use it when changing the MCP server, registering tools or resources, or editing the TypeScript functions that generate the playground’s HTML screens.
Why use it?
It gives coding agents the project layout and conventions they need to make consistent changes without first working them out from the code.

Instructions file for CodexOpenCode

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

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

Reuse

Borrowing it

Nothing to install: this file belongs to digitarald/mcp-apps-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.

Copy the file
curl -O https://raw.githubusercontent.com/digitarald/mcp-apps-playground/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/digitarald/mcp-apps-playground

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 mcp-apps-playground AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/digitarald/mcp-apps-playground/agents-md.svg)](https://agentmods.dev/instructions/digitarald/mcp-apps-playground/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/digitarald/mcp-apps-playground/agents-md"><img src="https://agentmods.dev/badge/instructions/digitarald/mcp-apps-playground/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 67 This file is loaded in full into every session.
When invoked 67 The same file — it is already loaded in full.
Security scan A 0 findings. 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 5.1 $0.00067 $0.00067
Opus 5 $0.00034 $0.00034
Sonnet 5 $0.00013 $0.00013
Haiku 4.5 $0.00007 $0.00007

Measured 6d ago against content hash 9c7656da64fe, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

mcp-apps-playground 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 6d 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 · 11 lines

What it actually says

MCP Apps Playground

Example MCP server with interactive HTML UIs. For MCP Apps development guidance, see the mcp-apps skill.

Project Structure

src/
  index.ts       # MCP server - tool + resource registration
  ui/*.ts        # HTML template functions (return full HTML strings)
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. 6d ago First seen · 11 lines · 67 tokens per session scan A 9c7656da64fe

Subscribe to this mod's changes

mcp-apps-playground AGENTS.md is an instructions file published in the GitHub repository digitarald/mcp-apps-playground (73 stars, last pushed 7mo ago), licensed MIT. It adds 67 tokens to every session, about $0.0003 per session on Opus 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 2026-08-30.

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