What is blackjack CLAUDE.md?

Repository-specific instructions for developing nanobot-ai/blackjack, a full-stack React application with a server and an HTTP tool interface. They describe its commands, architecture, source locations, and import aliases.

Use them when changing the blackjack application, especially its React user interface, server, routes, or tool endpoints. They also help run the project's checks and development server correctly.

They give a coding agent the project context needed to work within the repository's existing structure and conventions. They also identify the commands for development, production builds, type checking, linting, and formatting.

How nanobot-ai/blackjack configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to nanobot-ai/blackjack. 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/nanobot-ai/blackjack/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/nanobot-ai/blackjack

Made for: Claude Code.

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/nanobot-ai/blackjack/claude-md/github.svg)](https://agentmods.dev/instructions/nanobot-ai/blackjack/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/nanobot-ai/blackjack/claude-md"><img src="https://agentmods.dev/badge/instructions/nanobot-ai/blackjack/claude-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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/nanobot-ai/blackjack/claude-md"><img src="https://agentmods.dev/badge/instructions/nanobot-ai/blackjack/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 551 This file is loaded in full into every session.

When invoked 551 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	$0.00551	$0.00551
Opus 5.5	$0.00220	$0.00220
Sonnet 5.5	$0.00110	$0.00110
Haiku 4.5	$0.00055	$0.00055

Measured 2mo ago against content hash e31a7fc4e9a6, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

blackjack CLAUDE.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.

CLAUDE.md · 62 lines

How it starts

The opening of the file, as written. The whole thing — 62 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Development Commands

npm run dev - Start development server with HMR at http://localhost:5173
npm run build - Create production build
npm run start - Run production server
npm run typecheck - Run React Router typegen and TypeScript checking
npm run lint - Run Prettier check and ESLint (removes dist folder first)
npm run format - Format code with Prettier

Architecture Overview

This is a full-stack React Router application with an integrated MCP (Model Context Protocol) server that provides tools via HTTP endpoints.

Key Architectural Components

Frontend (React Router SSR)

Uses React Router v7 with server-side rendering enabled
UI code lives in src/ui/ (configured in react-router.config.ts)
Built with React 19, TypeScript, Tailwind CSS, and DaisyUI
DaisyUI provides pre-built components and themes on top of Tailwind CSS
Routes defined in src/ui/routes.ts with components in src/ui/routes/

Backend (Express + MCP)

Express server in server/app.ts integrates React Router SSR and MCP middleware
MCP server exposes tools at /mcp endpoint using custom framework in src/framework/
Custom MCP framework provides DefineTool utility and middleware for Express integration

MCP Tools System

Tools defined in src/tools/ directory, exported via src/tools/index.ts
Currently includes a bash tool that executes shell commands with UI integration
Tools use custom DefineTool wrapper with Zod schemas for input validation
Tools can return text and UI resources for rich client experiences

Directory Structure

src/
├── framework/     # Custom MCP framework (tools definition, server middleware)
├── lib/           # Utility libraries (shell execution, headers, UUID)
├── tools/         # MCP tools (bash tool implementation)
└── ui/           # React Router frontend application
    ├── routes/    # Route components
    └── welcome/   # Welcome page assets

Read the full file on GitHub · 62 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 · 62 lines · 551 tokens per session scan A e31a7fc4e9a6

Subscribe to this mod's changes

blackjack CLAUDE.md is an instructions file published in the GitHub repository nanobot-ai/blackjack (9 stars, last pushed 1y ago), licensed Apache-2.0. It adds 551 tokens to every session, about $0.0022 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.

blackjack CLAUDE.md next to 6 instructions from other repositories
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blackjack: Instructions file for Claude Code