cursorrules

A set of rules for using NVIDIA Isaac Sim, a robotics simulator, through its tools. It covers scene setup, physics initialisation, robot creation, simulation steps, and retrying failed tool calls.

In plain words
What is it for?
Use it when creating robots, preparing simulation scenes, running physics simulations, and executing Isaac Sim code safely.
Why use it?
It reduces setup mistakes that can prevent robotics code from running correctly, such as using an uninitialised physics world.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/whats2000/isaacsim-mcp-server/cursorrules
Clone the repo
git clone --depth 1 https://github.com/whats2000/isaacsim-mcp-server

Made for: Cursor.

Per session 775 This file is loaded in full into every session.
When invoked 775 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 $0.00775 $0.00775
Opus 5 $0.00387 $0.00387
Sonnet 5 $0.00155 $0.00155
Haiku 4.5 $0.00077 $0.00077

Measured 2d ago against content hash a13db8a54c91, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cursorrules 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 2d 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.

Origin

Copies of this mod

2 near-identical copies found in the catalogue:

isaac.sim.mcp_extension/.cursorrules · 61 lines

How it starts

The opening of the file, as written. The whole thing — 61 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Isaac Sim MCP Rules

General Rules

  • Before executing any code, always check if the scene is properly initialized by calling get_scene_info()
  • When working with robots, try using create_robot() first before using execute_script()
  • If execute_script() fails due to communication error, retry up to 3 times at most
  • For any creation of robot, call create_physics_scene() first
  • Always print the formatted code into chat to confirm before execution

Physics Rules

  • If the scene is empty, create a physics scene with create_physics_scene()
  • For physics simulation, avoid using simulation_context to run simulations in the main thread
  • Use the World class with async methods for initializing physics and running simulations
  • When needed, use my_world.play() followed by multiple step_async() calls to wait for physics to stabilize
  • SingleArticulation.initialize() requires World.physics_sim_view to be non-None. The adapter's play() and create_action_graph() call _ensure_physics_world() to guarantee this. When user presses Play from UI, the script must do its own World + initialize_physics() in a warmup phase.

Robot Creation Rules

  • Before creating a robot, verify availability of connection with get_scene_info()
  • Available robot types: "franka", "frankafr3", "jetbot", "carter", "g1", "go1" (use list_available_robots for full list)
  • Position robots using their appropriate parameters
  • For custom robot configurations, use execute_script() only when create_robot() is insufficient

Physics Scene Rules

  • Objects should include 'type' and 'position' at minimum
  • Object format example: {"path": "/World/Cube", "type": "Cube", "size": 20, "position": [0, 100, 0]}
  • Default gravity is [0, 0, -981.0] (cm/s^2)
  • Set floor=True to create a default ground plane

Script Execution Rules

  • Use World class instead of SimulationContext when possible
  • Initialize physics before trying to control any articulations
  • When controlling robots, make sure to step the physics at least once before interaction
  • For robot joint control, first initialize the articulation, then get the controller

Read the full file on GitHub · 61 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. 2d ago First seen · 61 lines · 775 tokens per session scan A a13db8a54c91

Subscribe to this mod's changes

cursorrules is a cursor rule published in the GitHub repository whats2000/isaacsim-mcp-server (56 stars, last pushed 2d ago), licensed MIT. It adds 775 tokens to every session, about $0.0039 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.