Agent skill

Nox Py Dev

Contribute to the Elodin Python SDK (nox-py). An agent skill from elodin-sys/elodin.

Apache-2.0Auto-check passedAI & LLM Engineering

Install Nox Py Dev

skills CLI

$ npx skills add elodin-sys/elodin --skill nox-py-dev -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install elodin-sys/elodin nox-py-dev --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/elodin-sys/elodin.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.cursor/skills/nox-py-dev .claude/skills/nox-py-dev && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "nox-py-dev" agent skill from https://github.com/elodin-sys/elodin/tree/main/.cursor/skills/nox-py-dev into .claude/skills/nox-py-dev/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "nox-py-dev", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/elodin-sys/elodin/tree/main/.cursor/skills/nox-py-dev

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add elodin-sys/elodin --skill nox-py-dev -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install elodin-sys/elodin nox-py-dev --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/elodin-sys/elodin.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.cursor/skills/nox-py-dev .agents/skills/nox-py-dev && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "nox-py-dev" agent skill from https://github.com/elodin-sys/elodin/tree/main/.cursor/skills/nox-py-dev into .agents/skills/nox-py-dev/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "nox-py-dev", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add elodin-sys/elodin --skill nox-py-dev -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install elodin-sys/elodin nox-py-dev --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/elodin-sys/elodin.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.cursor/skills/nox-py-dev .cursor/skills/nox-py-dev && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "nox-py-dev" agent skill from https://github.com/elodin-sys/elodin/tree/main/.cursor/skills/nox-py-dev into .cursor/skills/nox-py-dev/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "nox-py-dev", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/elodin-sys/elodin.git --path .cursor/skills/nox-py-dev

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add elodin-sys/elodin --skill nox-py-dev -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install elodin-sys/elodin nox-py-dev --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/elodin-sys/elodin.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.cursor/skills/nox-py-dev .gemini/skills/nox-py-dev && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "nox-py-dev" agent skill from https://github.com/elodin-sys/elodin/tree/main/.cursor/skills/nox-py-dev into .gemini/skills/nox-py-dev/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "nox-py-dev", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install elodin-sys/elodin nox-py-dev

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add elodin-sys/elodin --skill nox-py-dev -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/elodin-sys/elodin.git skills-src && mkdir -p .github/skills && cp -r skills-src/.cursor/skills/nox-py-dev .github/skills/nox-py-dev && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "nox-py-dev" agent skill from https://github.com/elodin-sys/elodin/tree/main/.cursor/skills/nox-py-dev into .github/skills/nox-py-dev/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "nox-py-dev", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add elodin-sys/elodin --skill nox-py-dev -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install elodin-sys/elodin nox-py-dev --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/elodin-sys/elodin.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.cursor/skills/nox-py-dev .opencode/skills/nox-py-dev && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "nox-py-dev" agent skill from https://github.com/elodin-sys/elodin/tree/main/.cursor/skills/nox-py-dev into .opencode/skills/nox-py-dev/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "nox-py-dev", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: nox-py-dev
GitHub stars: 547
Token cost: ~1.5k tokens
SKILL.md length: 469 words
Files: 1
Skills in repo: 14
Repo updated: Oct 7, 2026
First seen: Oct 7, 2026
Licence: Apache-2.0

At a glance

Contribute to the Elodin Python SDK (nox-py). An agent skill from elodin-sys/elodin.

Works in 5 steps: Define the Rust type in component.rs or… → Add PyO3 #[pyclass] bindings → Export in lib.rs module registration → …
Editing PyO3 bindings in libs/nox-py/
SKILL.md covers Build & Test, Architecture, Python API Surface and Key Rust Modules, plus 3 more sections
Calls just, pytest and python

What it does

Nox Py Dev is an agent skill from elodin-sys/elodin. Contribute to the Elodin Python SDK (nox-py). Use when editing PyO3 bindings in libs/nox-py/, adding new Python API surface, modifying the JAX integration, working on component/system compilation, or changing the Python package in python/elodin/.

Its SKILL.md is about 1.5k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in AI & LLM Engineering, covering Deep learning. It works with Python and Rust. The repository describes itself as: Elodin simulation and flight software monorepo. The licence is Apache-2.0.

When your agent uses it

Editing PyO3 bindings in libs/nox-py/
Adding new Python API surface
Modifying the JAX integration
Working on component/system compilation

Example prompts

“/nox-py-dev”

Requirements

Python 3

Workflow steps

5 steps, taken from the first numbered list in SKILL.md.

Define the Rust type in component.rs or a new module
Add PyO3 #[pyclass] bindings
Export in lib.rs module registration
Add Python-side type alias in python/elodin/init.py
Test: spawn an entity with the component, verify it appears in the editor

What it can do on your machine

Read from SKILL.md and the folder at commit 3bc1d99. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
- just
- pytest
- python
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Nox Py Dev loads about 1.5k tokens when it runs. Until then it costs about 64 tokens; SKILL.md has 469 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~64
When it runs · the whole SKILL.md, loaded when a task matches: ~1.5k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from elodin-sys/elodin at commit 3bc1d99, republished under its Apache-2.0 licence (© elodin-sys). 469 words, ~1,496 tokens.

Download SKILL.mdSave it as .claude/skills/nox-py-dev/SKILL.md (or your agent's skills folder).

name: nox-py-dev
description: Contribute to the Elodin Python SDK (nox-py). Use when editing PyO3 bindings in libs/nox-py/, adding new Python API surface, modifying the JAX integration, working on component/system compilation, or changing the Python package in python/elodin/.

nox-py Development

nox-py is the Elodin Python SDK — PyO3 bindings that bridge Python simulations to the Rust ECS engine (in nox-py/src/), the NOX tensor compiler (→ cranelift / JAX), and Impeller telemetry.

Build & Test

bash

just install py

# Run tests
pytest libs/nox-py/tests/

# Quick verification with an example
elodin editor examples/three-body/main.py

Rebuild the wheel after any Rust changes. Python-only changes in python/elodin/ are picked up immediately.

Architecture

Python user code
    │
    ▼
python/elodin/__init__.py    ← Python API surface, decorators, Query/GraphQuery
    │
    ▼
libs/nox-py/src/lib.rs       ← PyO3 module registration
    │
    ├── world_builder.rs      ← World creation, spawn, run
    ├── system.rs             ← System compilation pipeline
    ├── component.rs          ← Component types and metadata
    ├── archetype.rs          ← Archetype definitions
    ├── query.rs              ← Query system (map, map_seq)
    ├── graph.rs              ← GraphQuery and edge_fold
    ├── spatial.rs            ← SpatialTransform, SpatialMotion, SpatialForce, SpatialInertia
    ├── entity.rs             ← EntityId management
    ├── exec.rs               ← WorldExec enum (Iree/Jax), profiling, DB integration
    ├── jax_exec.rs           ← JaxExec, JaxWorldExec (JAX JIT per-tick execution)
    ├── step_context.rs       ← StepContext for pre/post step callbacks
    ├── impeller_client.rs    ← Impeller client for DB connection
    ├── asset.rs              ← Mesh, Material, GLB asset handling
    ├── linalg.rs             ← Linear algebra utilities
    ├── ukf.rs                ← Unscented Kalman Filter
    ├── s10.rs                ← S10 recipe integration
    └── error.rs              ← Error types and Python exception mapping
    │
    ▼
libs/nox/                     ← Tensor library, symbolic backend
    │
    ▼
libs/cranelift-mlir/          ← Pure Rust StableHLO runtime

Python API Surface

`python/elodin/init.py`

The main API module. Exports:

Decorators: @system, @map, @map_seq
Types: World, Query, GraphQuery, Component, Archetype, Body
Spatial types: SpatialTransform, SpatialMotion, SpatialForce, SpatialInertia, Quaternion
Built-in components: WorldPos, WorldVel, Inertia, Force, WorldAccel
Utilities: six_dof(), Panel, GraphEntity, Mesh, Material, Edge

`python/elodin/jaxsim.py`

JAX-only execution mode. Compiles the simulation world into pure JAX functions for RL training and jax.vmap batching.

`python/elodin/egm08.py` / `python/elodin/j2.py`

Earth gravity models. EGM08 is a high-fidelity spherical harmonics model; J2 is simple oblate Earth.

Key Rust Modules

`world_builder.rs`

Central orchestrator. Handles World.spawn(), World.insert(), World.run(), World.build(), World.to_jax(). This is where simulation execution modes branch.

`system.rs`

Compiles Python-defined systems into executable computations via cranelift (default) or JAX. Handles the @system, @map, @map_seq decorator logic on the Rust side. System composition (pipe |) is implemented here.

`exec.rs`

Defines WorldExec enum with Cranelift(CraneliftWorldExec) and Jax(JaxWorldExec) variants. Both implement the same interface for tick execution, profiling, and DB integration. The backend parameter in w.run() / w.build() selects between the cranelift and JAX execution modes.

`jax_exec.rs`

JAX backend: compiles Noxpr graph → jax.jit() callable, then executes each tick by calling the JAX function via PyO3. Slower than cranelift but supports all JAX operations and the GPU.

`component.rs`

Maps Python Component annotations to component schemas. Handles type inference, metadata, and the ComponentType / PrimitiveType hierarchy.

`spatial.rs`

PyO3 bindings for spatial vector algebra types. Each type wraps a nox tensor and exposes Python-friendly constructors, accessors, and arithmetic operators.

Show full SKILL.md (193 more words)Show less

`graph.rs`

Graph query implementation. edge_fold is the core operation — it iterates edges, queries left/right entity components, and accumulates results.

Adding a New Feature

New Component Type

Define the Rust type in component.rs or a new module
Add PyO3 #[pyclass] bindings
Export in lib.rs module registration
Add Python-side type alias in python/elodin/__init__.py
Test: spawn an entity with the component, verify it appears in the editor

New System Decorator

Implement the Rust compilation logic in system.rs
Add the Python decorator in python/elodin/__init__.py
Ensure it composes with | (pipe operator)
Test: write a simulation using the new decorator, verify output

New Execution Mode

Add the mode in exec.rs (or world_builder.rs for world-level API)
Wire CLI support in apps/elodin/ if needed
Add Python API in world_builder.rs

Dependencies

Crate	Purpose
`pyo3`	Python ↔ Rust bindings
`numpy`	NumPy array interop (via pyo3-numpy)
nox-py (Rust core)	ECS world, component storage, system execution
`nox`	Tensor library, spatial math
`impeller`	Telemetry protocol
`stellarator`	Async runtime for DB connections
`tokio`	Async runtime (for some I/O paths)

Key References

Full SDK documentation: libs/nox-py/README.md
Python API reference: docs/public/content/reference/python-api.md
nox-py Rust source: libs/nox-py/src/
Impeller protocol: libs/impeller/

Files

Just SKILL.md in .cursor/skills/nox-py-dev of elodin-sys/elodin.

Open the folder on GitHubat commit 3bc1d99

Compare with similar skills

Nox Py Dev next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Nox Py Dev compared with similar skills
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Nox Py Dev this skillelodin-sys/elodin	547	—	~1.5k	Automated safety check: Pass	Apache-2.0	yesterday
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Onnxtxtonnx/onnx	22k	—	~1.3k	Automated safety check: Pass	Apache-2.0	yesterday
Benchmark Pyreflyfacebook/pyrefly	7.1k	—	~1.8k	Automated safety check: Pass	MIT	today
Document Public APIspytorch/pytorch	104k	—	~4.2k	Automated safety check: Pass	Custom licence	today

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Questions about Nox Py Dev

What does Nox Py Dev do?

Contribute to the Elodin Python SDK (nox-py). An agent skill from elodin-sys/elodin. Nox Py Dev is an agent skill from elodin-sys/elodin. Contribute to the Elodin Python SDK (nox-py).

When should I use Nox Py Dev?

Nox Py Dev fits situations like: editing PyO3 bindings in libs/nox-py/; adding new Python API surface; modifying the JAX integration; working on component/system compilation.

How do I install Nox Py Dev in Claude Code?

Run `npx skills add elodin-sys/elodin --skill nox-py-dev -a claude-code`. Or copy the skill folder (.cursor/skills/nox-py-dev in elodin-sys/elodin) into .claude/skills/nox-py-dev in your project. Claude Code loads it when a task matches its description.

How do I install Nox Py Dev in Codex?

Run `npx skills add elodin-sys/elodin --skill nox-py-dev -a codex`. Or copy the skill folder (.cursor/skills/nox-py-dev in elodin-sys/elodin) into .agents/skills/nox-py-dev in your project. Codex loads it when a task matches its description.

Can I use Nox Py Dev in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add elodin-sys/elodin --skill nox-py-dev -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/nox-py-dev, .gemini/skills/nox-py-dev, .github/skills/nox-py-dev and .opencode/skills/nox-py-dev in your project.

What does Nox Py Dev need to run?

Going by SKILL.md and its folder, Nox Py Dev needs the command-line tools its instructions call (just, pytest and python). Our summary lists: Python 3.

Does Nox Py Dev access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Nox Py Dev safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Nox Py Dev use?

Nox Py Dev is published under the Apache-2.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Nox Py Dev use?

About 1.5k tokens (SKILL.md is roughly 6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Nox Py Dev?

Skills that share tags, products or a category with Nox Py Dev: Paddle Build (PaddlePaddle/Paddle, 24k stars), Paddle Design Compiler (PaddlePaddle/Paddle, 24k stars), Onnxtxt (onnx/onnx, 22k stars) and Benchmark Pyrefly (facebook/pyrefly, 7.1k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Nox Py Dev?

elodin-sys (a GitHub organization) maintains it in elodin-sys/elodin, which has 547 GitHub stars. The repository holds 14 skills in this directory. The repository was last updated on October 7, 2026.

Source: elodin-sys/elodin on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Nox Py Dev

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

nox-py Development

Build & Test

Architecture

Python API Surface

python/elodin/__init__.py

python/elodin/jaxsim.py

python/elodin/egm08.py / python/elodin/j2.py

Key Rust Modules

world_builder.rs

system.rs

exec.rs

jax_exec.rs

component.rs

spatial.rs

graph.rs

Adding a New Feature

New Component Type

New System Decorator

New Execution Mode

Dependencies

Key References

Files

Compare with similar skills

Similar skills

More from elodin-sys/elodin

Related

Questions about Nox Py Dev

`python/elodin/init.py`

`python/elodin/jaxsim.py`

`python/elodin/egm08.py` / `python/elodin/j2.py`

`world_builder.rs`

`system.rs`

`exec.rs`

`jax_exec.rs`

`component.rs`

`spatial.rs`

`graph.rs`