Borrowing it
Nothing to install: this file belongs to mitchdenny/hex1b. 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/mitchdenny/hex1b/main/AGENTS.mdgit clone --depth 1 https://github.com/mitchdenny/hex1bWrote 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/mitchdenny/hex1b/agents-md)<a href="https://agentmods.dev/instructions/mitchdenny/hex1b/agents-md"><img src="https://agentmods.dev/badge/instructions/mitchdenny/hex1b/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/mitchdenny/hex1b/agents-md"><img src="https://agentmods.dev/badge/instructions/mitchdenny/hex1b/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 | $0.03371 | $0.03371 |
| Opus 5.5 | $0.01348 | $0.01348 |
| Sonnet 5.5 | $0.00674 | $0.00674 |
| Haiku 4.5 | $0.00337 | $0.00337 |
Grade A, and why
hex1b 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 301 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AI Coding Agent Guidelines for Hex1b
This document provides context and conventions for AI coding agents (GitHub Copilot, Claude, Cursor, etc.) working with the Hex1b codebase.
🛠️ Available Skills
This repository includes specialized skills in .github/skills/ that provide detailed guidance for specific tasks. Invoke these skills when working on related tasks - they contain step-by-step procedures, templates, and best practices.
| Skill | When to Use |
|---|---|
| widget-creator | Creating new widgets (widget records, nodes, theming, tests) |
| writing-unit-tests | Writing unit tests for widgets, nodes, or terminal functionality |
| test-fixer | Diagnosing flaky tests, especially timing-related failures in CI |
| api-reviewer | Reviewing API design, accessibility modifiers, and naming conventions |
| doc-writer | Writing XML API documentation or end-user guides |
| doc-tester | Validating documentation accuracy against library behavior |
| surface-benchmarker | Running performance benchmarks after modifying src/Hex1b/Surfaces/ |
| aspire | Working with .NET Aspire (running samples, debugging, MCP tools) |
Skills are invoked automatically by AI agents based on the task context. They contain comprehensive procedures that complement the high-level guidance in this file.
📋 Project Overview
Hex1b is a .NET library for building terminal user interfaces (TUI) with a React-inspired declarative API. The library ships to NuGet as Hex1b.
Key Technologies
- .NET 10.0 (preview) - Target framework
- C# 12+ - Modern C# features enabled
- MSTest (MSTest.Sdk 4.x with Microsoft.Testing.Platform) - Testing framework
- .NET Aspire - Used for running sample applications
Repository Layout
src/Hex1b/ → Main library (THE shipped package)
tests/Hex1b.Tests/ → Unit tests
samples/ → Example applications
apphost.cs → Aspire app host for samples
🏗️ Architecture Concepts
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.
- 1mo ago Changed · +2 lines · +139 tokens per session 7397dd35e064
- 2mo ago First seen · 299 lines · 3,232 tokens per session scan A effad8d14326
hex1b AGENTS.md is an instructions file published in the GitHub repository mitchdenny/hex1b (181 stars, last pushed today), licensed MIT. It adds 3,371 tokens to every session, about $0.0135 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 2026-08-30.
Other instructions, from other repositories
plan-forge api-patterns.instructions.md
API patterns for .NET — REST conventions, ProblemDetails, pagination, versioning, error responses.
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).