excalidraw-mcp: Instructions file for Codex

AGENTS.md

excalidraw-mcp AGENTS.md is an instructions file for Codex, OpenCode from lesleslie/excalidraw-mcp. It costs 1,262 tokens per session, scanned A, original, BSD-3-Clause.

Repository instructions for Excalidraw MCP, a service that lets software work with Excalidraw diagrams. They cover the Python server, TypeScript canvas, frontend, project commands, and tests.

In plain words
What is it for?
Use them when installing dependencies, developing the canvas or server, building the project, or running its Python and TypeScript tests.
Why use it?
They explain where the main parts live and which commands to use, reducing setup mistakes and inconsistent changes.

Instructions file for CodexOpenCode

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

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

Reuse

Borrowing it

Nothing to install: this file belongs to lesleslie/excalidraw-mcp. 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/lesleslie/excalidraw-mcp/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/lesleslie/excalidraw-mcp

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 excalidraw-mcp AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/lesleslie/excalidraw-mcp/agents-md.svg)](https://agentmods.dev/instructions/lesleslie/excalidraw-mcp/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/lesleslie/excalidraw-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/lesleslie/excalidraw-mcp/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 1,262 This file is loaded in full into every session.
When invoked 1,262 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.01262 $0.01262
Opus 5 $0.00631 $0.00631
Sonnet 5 $0.00252 $0.00252
Haiku 4.5 $0.00126 $0.00126

Measured 4d ago against content hash 541dd7b73d00, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

excalidraw-mcp 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 4d 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 · 65 lines

How it starts

The opening of the file, as written. The whole thing — 65 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Repository Guidelines

Project Structure & Module Organization

Excalidraw MCP couples a Python FastMCP backend with a TypeScript canvas stack. Core FastMCP logic, CLI entry points, and process supervision live in excalidraw_mcp/. The realtime canvas service and shared TS utilities are in src/, while the React surface that renders Excalidraw sits under frontend/src/. Python automated tests reside in tests/ (unit, integration, e2e, performance, security folders); TypeScript and UI tests live in test/. Generated builds are shipped in dist/, and example agent payloads live in examples/ and example.mcp.json.

Build, Test, and Development Commands

  • uv sync && npm install install Python and Node dependencies.
  • uv run python excalidraw_mcp/server.py launches the MCP server and supervises the canvas service.
  • npm run dev runs TypeScript watch mode plus Vite for iterative UI work; npm run build compiles frontend + server assets.
  • npm run canvas starts only the built canvas server; npm run production rebuilds and boots both services.
  • uv run pytest executes the Python suite (coverage reports emitted to htmlcov/ and coverage.xml).
  • Use Crackerjack-aligned Python quality checks alongside the existing Node and TypeScript validation flow for CI-sensitive changes.

Coding Style & Naming Conventions

Python code targets 3.13+, uses 4-space indentation, exhaustive type hints, import typing as t, f-strings, and pathlib. Run uv run ruff check --fix before committing; keep modules small and single-purpose per RULES.md. TypeScript follows strict tsconfig settings with 2-space indentation, snake-case filenames for back-end modules (e.g., storage/index.ts) and PascalCase for React components. Prefer interfaces over type aliases, const assertions for invariants, and Zod schemas for runtime validation.

Testing Guidelines

Pytest is configured in pyproject.toml with --cov-fail-under=85; keep new Python tests in tests/test_*.py and mark them (@pytest.mark.integration, etc.) so CI filtering works. Jest enforces 70% global coverage (jest.config.cjs); add .test.ts files under test/ and import stubs from test/setup.ts. Use npm run test:coverage for TS coverage and npm run type-check before submitting runtime changes.

Read the full file on GitHub · 65 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.

  1. 4d ago Changed · +34 lines · +540 tokens per session 541dd7b73d00
  2. 8d ago First seen · 31 lines · 722 tokens per session scan A 0b0a3f5c7f60

Subscribe to this mod's changes

excalidraw-mcp AGENTS.md is an instructions file published in the GitHub repository lesleslie/excalidraw-mcp (14 stars, last pushed 7d ago), licensed BSD-3-Clause. It adds 1,262 tokens to every session, about $0.0063 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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