fluidsim

fluidsim is a skill for Claude Code, Codex from magic3007/dotfiles. It costs 69 tokens per session (2,531 once invoked), scanned A, a copy of fluidsim, MIT.

A Python framework for running computational fluid dynamics simulations, which model how liquids and gases move. It includes solvers for Navier–Stokes, shallow-water, and stratified-flow equations, plus tools for analysing results.

In plain words
What is it for?
Use it to simulate fluid flow, turbulence, vortices, shallow water, or geophysical flows. It can run two- and three-dimensional calculations and help inspect their output.
Why use it?
It avoids building simulation infrastructure and numerical solvers from scratch. It also supports configured runs, output handling, visual analysis, and optional parallel computing.

Skill for Claude CodeCodex

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 skills/magic3007/dotfiles/fluidsim
Any agent
npx skills add magic3007/dotfiles --skill fluidsim
Clone the repo
git clone --depth 1 https://github.com/magic3007/dotfiles

Made for: Claude Code, Codex.

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 fluidsim

README.md
[![agentmods](https://agentmods.dev/badge/skills/magic3007/dotfiles/fluidsim.svg)](https://agentmods.dev/skills/magic3007/dotfiles/fluidsim)
Your own site
<a href="https://agentmods.dev/skills/magic3007/dotfiles/fluidsim"><img src="https://agentmods.dev/badge/skills/magic3007/dotfiles/fluidsim.svg" alt="Measured on agentmods" height="20"></a>
Per session 69 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,531 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 88% copy Near-identical to another mod 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 $0.00069 $0.02531
Opus 5 $0.00034 $0.01265
Sonnet 5 $0.00014 $0.00506
Haiku 4.5 $0.00007 $0.00253

Measured 2d ago against content hash d3bc2d1481cf, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

fluidsim 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

This is a copy

88% identical to fluidsim — 14 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

claude/skills/scientific-agent-skills/skills/fluidsim/SKILL.md · 349 lines

How it starts

The opening of the file, as written. The whole thing — 349 lines — stays where its author put it; the contents beside it link to each section on GitHub.

FluidSim

Overview

FluidSim is an object-oriented Python framework for high-performance computational fluid dynamics (CFD) simulations. It provides solvers for periodic-domain equations using pseudospectral methods with FFT, delivering performance comparable to Fortran/C++ while maintaining Python's ease of use.

Key strengths:

  • Multiple solvers: 2D/3D Navier-Stokes, shallow water, stratified flows
  • High performance: Pythran/Transonic compilation, MPI parallelization
  • Complete workflow: Parameter configuration, simulation execution, output analysis
  • Interactive analysis: Python-based post-processing and visualization

Core Capabilities

1. Installation and Setup

Install fluidsim using uv with appropriate feature flags:

# Basic installation
uv pip install fluidsim

# With FFT support (required for most solvers)
uv pip install "fluidsim[fft]"

# With MPI for parallel computing
uv pip install "fluidsim[fft,mpi]"

Set environment variables for output directories (optional):

export FLUIDSIM_PATH=/path/to/simulation/outputs
export FLUIDDYN_PATH_SCRATCH=/path/to/working/directory

No API keys or authentication required.

See references/installation.md for complete installation instructions and environment configuration.

2. Running Simulations

Standard workflow consists of five steps:

Step 1: Import solver

from fluidsim.solvers.ns2d.solver import Simul

Step 2: Create and configure parameters

params = Simul.create_default_params()
params.oper.nx = params.oper.ny = 256
params.oper.Lx = params.oper.Ly = 2 * 3.14159
params.nu_2 = 1e-3
params.time_stepping.t_end = 10.0
params.init_fields.type = "noise"

Step 3: Instantiate simulation

sim = Simul(params)

Step 4: Execute

sim.time_stepping.start()

Step 5: Analyze results

sim.output.phys_fields.plot("vorticity")
sim.output.spatial_means.plot()

See references/simulation_workflow.md for complete examples, restarting simulations, and cluster deployment.

Read the full file on GitHub · 349 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 349 lines · 69 tokens per session scan A d3bc2d1481cf

Subscribe to this mod's changes

fluidsim is a skill published in the GitHub repository magic3007/dotfiles (11 stars, last pushed yesterday), licensed MIT. It adds 69 tokens to every session and 2,531 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to fluidsim, differing in 14 lines, and is treated as a copy.

Related

Other skills, from other repositories

scaffold-python

Scaffold a complete Python project with CI/CD, release pipeline, justfile, sr.yaml, pyproject.toml, .envrc, and standard files. Uses uv, ruff, and justfile (Python lacks a native task runner like pnpm scripts, so just fills that gap). Loads on top of scaffold-project (run that first for cross-language standard files).…

urmzd/dotfiles · 135 tokens

scaffold-go

Scaffold a complete Go project with CI/CD, release pipeline, Makefile, sr.yaml, .envrc, and standard files. Uses go toolchain and make as the native build system. Loads on top of scaffold-project (run that first for cross-language standard files). Use when creating a new Go CLI, service, or module, or when the user…

urmzd/dotfiles · 116 tokens

scaffold-node

Scaffold a complete Node/TypeScript project with CI/CD, release pipeline, sr.yaml, .envrc, and standard files. Uses pnpm and biome. Loads on top of scaffold-project (run that first for cross-language standard files). Use when creating a new Node.js app, TypeScript library, or website, or when the user mentions "new…

urmzd/dotfiles · 119 tokens

write-code

Operational tech-stack picks and coding patterns: error handling per language, commit conventions, interface design (Go SDKs), workspace layout, junior-friendly bias. Use when writing or reviewing implementation code and you need a concrete answer for "what tool, pattern, or idiom." Do NOT use for design-tradeoff…

urmzd/dotfiles · 112 tokens

scaffold-rust

Scaffold a complete Rust project with CI/CD, release pipeline, and sr.yaml. Uses cargo as the native build system. Loads on top of scaffold-project (run that first for cross-language standard files). Use when creating a new Rust CLI, library, or workspace, or when the user mentions "new Rust project", "cargo init", or…

urmzd/dotfiles · 102 tokens

rust-design-patterns

Rust idioms and design patterns for writing idiomatic code. Use when: (1) Writing new Rust code, (2) Reviewing Rust code, (3) Solving borrow checker issues, (4) Designing Rust APIs. Triggers on: Rust ownership problems, lifetime errors, API design questions, 'how to do X idiomatically in Rust'.

ahonn/dotfiles · 77 tokens