What is rgbds-lsp CLAUDE.md?

A project guide for Claude Code that explains RGBDS-LSP, a tool for Game Boy assembly language, and how to build and test its parts. It covers a monorepo, meaning one repository containing several related projects, including a parser, language server, and VS Code extension.

Building the project, regenerating its parser, running grammar, unit, and integration tests, and building the VS Code extension.

It gives the coding agent the project context and the correct commands, including important build order requirements. This reduces mistakes when changing or testing the repository.

How retro-dev-tools/rgbds-lsp configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to retro-dev-tools/rgbds-lsp. 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/retro-dev-tools/rgbds-lsp/master/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/retro-dev-tools/rgbds-lsp

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/retro-dev-tools/rgbds-lsp/claude-md.svg)](https://agentmods.dev/instructions/retro-dev-tools/rgbds-lsp/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/retro-dev-tools/rgbds-lsp/claude-md"><img src="https://agentmods.dev/badge/instructions/retro-dev-tools/rgbds-lsp/claude-md.svg" alt="Measured on agentmods" height="20"></a>

Per session 580 This file is loaded in full into every session.

When invoked 580 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	$0.00580	$0.00580
Opus 5	$0.00290	$0.00290
Sonnet 5	$0.00116	$0.00116
Haiku 4.5	$0.00058	$0.00058

Measured 8d ago against content hash ebb15d686edb, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

rgbds-lsp 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 8d 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 · 49 lines

How it starts

The opening of the file, as written. The whole thing — 49 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.

Project Overview

RGBDS-LSP is a Language Server Protocol implementation for RGBDS (Game Boy assembly). Monorepo: Tree-sitter grammar, LSP server, VS Code extension.

Build Commands

npm install && npm run build          # Install and build everything
npm run clean                         # Clean all build artifacts

cd src/tree-sitter-rgbds && npx tree-sitter generate  # Regenerate parser after grammar.js changes
cd src/tree-sitter-rgbds && npx tree-sitter test      # Grammar corpus tests

cd src/server && npm run build   # Build server (required before integration tests)
cd src/server && npm test        # Unit + integration tests (vitest)
cd src/server && npx vitest run tests/unit.test.ts     # Single test file

cd src/vscode && npm run build   # Build extension

Critical: tree-sitter generate must run before npm install — the native addon build depends on src/parser.c. The root build script handles this.

Integration tests spawn dist/index.js as a subprocess — build the server first.

Architecture

VS Code Extension (IPC client)  →  LSP Server (tree-sitter)  →  Tree-sitter Parser
src/vscode                    src/server               src/tree-sitter-rgbds

Assembled bytes are text decorations via custom rgbds/assembledBytes RPC — NOT inlay hints. The extension manages rendering.
Inlay hints show constant values (= $FF40) and macro parameter labels (\1:). These are separate from assembled bytes.
Local labels starting with . are stored as GlobalLabel.local in the index.
Symbol types: label, constant, macro, section, charmap
Per-file reverse index: fileDefinitions/fileReferences maps enable O(1) lookups. allDefinitions tracks all defs per name for duplicate detection.
Charmap state: extractAllCharmaps is the single source of truth — runs after initial indexing and each reindex.
Indexer cache: ~/.rgbds-lsp/cache/ keyed by workspace path hash. Clear after changing symbol extraction logic.

Read the full file on GitHub · 49 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.

8d ago First seen · 49 lines · 580 tokens per session scan A ebb15d686edb

Subscribe to this mod's changes

rgbds-lsp CLAUDE.md is an instructions file published in the GitHub repository retro-dev-tools/rgbds-lsp (2 stars, last pushed 1mo ago), licensed MIT. It adds 580 tokens to every session, about $0.0029 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 2026-08-31.

Game development

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.

vercel/next.js · 7,296 tokens

codex AGENTS.md

AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.

openai/codex · 5,153 tokens

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).

microsoft/vscode · 6,785 tokens

rgbds-lsp: Instructions file for Claude Code