Wasm Compatibility
ericmjl/llamabot
Check if a marimo notebook is compatible with WebAssembly (WASM) and report any issues.
Write a marimo notebook in a Python file in the right format.
$ npx skills add cosanlab/nltools --skill marimo-notebook -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install cosanlab/nltools marimo-notebook --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/cosanlab/nltools.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/marimo-notebook .claude/skills/marimo-notebook && rm -rf skills-srcUse ~/.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/
Install the "marimo-notebook" agent skill from https://github.com/cosanlab/nltools/tree/master/.claude/skills/marimo-notebook into .claude/skills/marimo-notebook/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "marimo-notebook", 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 install https://github.com/cosanlab/nltools/tree/master/.claude/skills/marimo-notebookType 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.
$ npx skills add cosanlab/nltools --skill marimo-notebook -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install cosanlab/nltools marimo-notebook --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cosanlab/nltools.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.claude/skills/marimo-notebook .agents/skills/marimo-notebook && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "marimo-notebook" agent skill from https://github.com/cosanlab/nltools/tree/master/.claude/skills/marimo-notebook into .agents/skills/marimo-notebook/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "marimo-notebook", 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.
$ npx skills add cosanlab/nltools --skill marimo-notebook -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install cosanlab/nltools marimo-notebook --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cosanlab/nltools.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.claude/skills/marimo-notebook .cursor/skills/marimo-notebook && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "marimo-notebook" agent skill from https://github.com/cosanlab/nltools/tree/master/.claude/skills/marimo-notebook into .cursor/skills/marimo-notebook/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "marimo-notebook", 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 https://github.com/cosanlab/nltools.git --path .claude/skills/marimo-notebook--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add cosanlab/nltools --skill marimo-notebook -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install cosanlab/nltools marimo-notebook --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cosanlab/nltools.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.claude/skills/marimo-notebook .gemini/skills/marimo-notebook && rm -rf skills-srcUse ~/.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/
Install the "marimo-notebook" agent skill from https://github.com/cosanlab/nltools/tree/master/.claude/skills/marimo-notebook into .gemini/skills/marimo-notebook/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "marimo-notebook", 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.
$ gh skill install cosanlab/nltools marimo-notebookInstalls 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).
$ npx skills add cosanlab/nltools --skill marimo-notebook -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/cosanlab/nltools.git skills-src && mkdir -p .github/skills && cp -r skills-src/.claude/skills/marimo-notebook .github/skills/marimo-notebook && rm -rf skills-srcUse ~/.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/
Install the "marimo-notebook" agent skill from https://github.com/cosanlab/nltools/tree/master/.claude/skills/marimo-notebook into .github/skills/marimo-notebook/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "marimo-notebook", 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.
$ npx skills add cosanlab/nltools --skill marimo-notebook -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install cosanlab/nltools marimo-notebook --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cosanlab/nltools.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.claude/skills/marimo-notebook .opencode/skills/marimo-notebook && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "marimo-notebook" agent skill from https://github.com/cosanlab/nltools/tree/master/.claude/skills/marimo-notebook into .opencode/skills/marimo-notebook/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "marimo-notebook", 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.
marimo-notebookWrite a marimo notebook in a Python file in the right format.
Marimo Notebook is an agent skill from cosanlab/nltools. Write a marimo notebook in a Python file in the right format.
Its SKILL.md is about 2.1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 13 other files, including reference files (for example `references/ANYWIDGET.md`, `references/CONFIGURATION.md` and `references/DEPLOYMENT.md`).
It sits in Data & Analytics, covering Jupyter notebooks. It works with marimo and Python. The repository describes itself as: Python toolbox for analyzing imaging data. The licence is MIT.
Read from SKILL.md and the folder at commit cf366c2. It shows what the files ask for, not the result of running them.
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.
Shell commands in SKILL.md call:
uvuvxpytestFrom the folder's file list and the shell code blocks in SKILL.md.
No URLs in SKILL.md. Its commands use uv and uvx, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Marimo Notebook loads about 2.1k tokens when it runs, and up to ~9.3k if it reads all its reference files. Until then it costs about 19 tokens; SKILL.md has 589 words of instructions outside code blocks.
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.
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.
The full file from cosanlab/nltools at commit cf366c2, republished under its MIT licence (© cosanlab). 589 words, ~2,065 tokens.
.claude/skills/marimo-notebook/SKILL.md (or your agent's skills folder). This skill also uses 12 other files; get the full folder from GitHub.marimo uses Python to create notebooks, unlike Jupyter which uses JSON. Here's an example notebook:
# /// script
# dependencies = [
# "marimo",
# "numpy==2.4.3",
# ]
# requires-python = ">=3.14"
# ///
import marimo
__generated_with = "0.20.4"
app = marimo.App(width="medium")
@app.cell
def _():
import marimo as mo
import numpy as np
return mo, np
@app.cell
def _():
print("hello world")
return
@app.cell
def _(np, slider):
np.array([1,2,3]) + slider.value
return
@app.cell
def _(mo):
slider = mo.ui.slider(1, 10, 1, label="number to add")
slider
return (slider,)
@app.cell
def _():
return
if __name__ == "__main__":
app.run()
Notice how the notebook is structured with functions can represent cell contents. Each cell is defined with the @app.cell decorator and the inputs/outputs of the function are the inputs/outputs of the cell. marimo usually takes care of the dependencies between cells automatically.
# Run as script (non-interactive, for testing)
uv run <notebook.py>
# Run interactively in browser
uv run marimo run <notebook.py>
# Edit interactively
uv run marimo edit <notebook.py>Use mo.app_meta().mode == "script" to detect CLI vs interactive:
@app.cell
def _(mo):
is_script_mode = mo.app_meta().mode == "script"
return (is_script_mode,)Show all UI elements always. Only change the data source in script mode.
if not is_script_mode conditionals# Always show the widget
@app.cell
def _(ScatterWidget, mo):
scatter_widget = mo.ui.anywidget(ScatterWidget())
scatter_widget
return (scatter_widget,)
# Only change data source based on mode
@app.cell
def _(is_script_mode, make_moons, scatter_widget, np, torch):
if is_script_mode:
# Use synthetic data for testing
X, y = make_moons(n_samples=200, noise=0.2)
X_data = torch.tensor(X, dtype=torch.float32)
y_data = torch.tensor(y)
data_error = None
else:
# Use widget data in interactive mode
X, y = scatter_widget.widget.data_as_X_y
# ... process data ...
return X_data, y_data, data_error
# Always show sliders - use their .value in both modes
@app.cell
def _(mo):
lr_slider = mo.ui.slider(start=0.001, stop=0.1, value=0.01)
lr_slider
return (lr_slider,)
# Auto-run in script mode, wait for button in interactive
@app.cell
def _(is_script_mode, train_button, lr_slider, run_training, X_data, y_data):
if is_script_mode:
# Auto-run with slider defaults
results = run_training(X_data, y_data, lr=lr_slider.value)
else:
# Wait for button click
if train_button.value:
results = run_training(X_data, y_data, lr=lr_slider.value)
return (results,)Variables between cells define the reactivity of the notebook for 99% of the use-cases out there. No special state management needed. Don't mutate objects across cells (e.g., my_list.append()); create new objects instead. Avoid mo.state() unless you need bidirectional UI sync or accumulated callback state. See STATE.md for details.
if StatementsMarimo's reactivity means cells only run when their dependencies are ready. Don't add unnecessary guards:
# BAD - the if statement prevents the chart from showing
@app.cell
def _(plt, training_results):
if training_results: # WRONG - don't do this
fig, ax = plt.subplots()
ax.plot(training_results['losses'])
fig
return
# GOOD - let marimo handle the dependency
@app.cell
def _(plt, training_results):
fig, ax = plt.subplots()
ax.plot(training_results['losses'])
fig
returnThe cell won't run until training_results has a value anyway.
Don't wrap code in try/except blocks unless you're handling a specific, expected exception. Let errors surface naturally.
# BAD - hiding errors behind try/except
@app.cell
def _(scatter_widget, np, torch):
try:
X, y = scatter_widget.widget.data_as_X_y
X = np.array(X, dtype=np.float32)
# ...
except Exception as e:
return None, None, f"Error: {e}"
# GOOD - let it fail if something is wrong
@app.cell
def _(scatter_widget, np, torch):
X, y = scatter_widget.widget.data_as_X_y
X = np.array(X, dtype=np.float32)
# ...Only use try/except when:
Marimo only renders the final expression of a cell. Indented or conditional expressions won't render:
# BAD - indented expression won't render
@app.cell
def _(mo, condition):
if condition:
mo.md("This won't show!") # WRONG - indented
return
# GOOD - final expression renders
@app.cell
def _(mo, condition):
result = mo.md("Shown!") if condition else mo.md("Also shown!")
result # This renders because it's the final expression
returnNotebooks created via marimo edit --sandbox have these dependencies added to the top of the file automatically but it is a good practice to make sure these exist when creating a notebook too:
# /// script
# requires-python = ">=3.12"
# dependencies = [
# "marimo",
# "torch>=2.0.0",
# ]
# ///When working on a notebook it is important to check if the notebook can run. That's why marimo provides a check command that acts as a linter to find common mistakes.
uvx marimo check <notebook.py>Make sure these are checked before handing a notebook back to the user.
Important: you have a tendency to over-do variables with an underscore prefix. You should only apply this to one or two variables at most. Consider creating a new variable instead of prefixing entire cells in marimo.
If the user specifically wants you to use a marimo function, you can locally check the docs via:
uv --with marimo run python -c "import marimo as mo; help(mo.ui.form)"By default, marimo discovers and executes tests inside your notebook.
When the optional pytest dependency is present, marimo runs pytest on cells that
consist exclusively of test code - i.e. functions whose names start with test_.
If the user asks you to add tests, make sure to add the pytest dependency is added and that
there is a cell that contains only test code.
For more information on testing with pytest see PYTEST.md
Once tests are added, you can run pytest from the commandline on the notebook to run pytest.
pytest <notebook.py>--watch mode WATCHING.md© cosanlab, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
SKILL.md and 12 other files (references) in .claude/skills/marimo-notebook of cosanlab/nltools.
Open the folder on GitHubat commit cf366c2
We found 4 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 4 other GitHub owners. This page covers the copy in cosanlab/nltools, which our catalogue first saw on October 7, 2026.
Marimo Notebook 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.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Marimo Notebook this skillcosanlab/nltools | 131 | 4 repos | ~2.1k | Automated safety check: Pass | MIT | |
| Wasm Compatibilityericmjl/llamabot | 182 | 2 repos | ~1.6k | Automated safety check: Pass | None | |
| Marimo PairPhySpace/SimpleCADAPI | 140 | — | ~3k | Automated safety check: Pass | Apache-2.0 | |
| Marimo Pair Vscodemarimo-team/marimo-lsp | 130 | — | ~2.7k | Automated safety check: Pass | Apache-2.0 | |
| Marimobrycewang-stanford/Auto-Empirical-Research-Skills | 4.5k | — | ~2.8k | Automated safety check: Pass | Custom licence | |
| Marimo Notebookminicoohei/ai-agent-camp | 347 | — | ~1.5k | Automated safety check: Pass | None |
ericmjl/llamabot
Check if a marimo notebook is compatible with WebAssembly (WASM) and report any issues.
PhySpace/SimpleCADAPI
Drive a live marimo notebook as a workspace: run Python in the same kernel the user does, inspect live notebook state, and commit durable notebook changes.
marimo-team/marimo-lsp
Drive a live marimo notebook in VS Code as a workspace: run Python in the same kernel the user does, inspect and explore live notebook state and data, prototype and debug code, and commit durable…
brycewang-stanford/Auto-Empirical-Research-Skills
Reactive Python notebook system. An agent skill from brycewang-stanford/Auto-Empirical-Research-Skills.
minicoohei/ai-agent-camp
marimo ノートブックを正しいフォーマットでPythonファイルに作成するスキル. An agent skill from minicoohei/ai-agent-camp.
aiskillstore/marketplace
Expert guidance for creating and working with marimo notebooks - reactive Python notebooks that can be executed as scripts and deployed as apps.
cosanlab/nltools
Work inside a running marimo notebook's kernel — execute code, create cells, and build a notebook as an artifact.
cosanlab/nltools
Comprehensive nilearn (neuroimaging) API reference and best practices.
Categories
Write a marimo notebook in a Python file in the right format. Marimo Notebook is an agent skill from cosanlab/nltools. Write a marimo notebook in a Python file in the right format.
Marimo Notebook fits situations like: tasks that involve Jupyter notebooks.
Run `npx skills add cosanlab/nltools --skill marimo-notebook -a claude-code`. Or copy the skill folder (.claude/skills/marimo-notebook in cosanlab/nltools) into .claude/skills/marimo-notebook in your project. Claude Code loads it when a task matches its description.
Run `npx skills add cosanlab/nltools --skill marimo-notebook -a codex`. Or copy the skill folder (.claude/skills/marimo-notebook in cosanlab/nltools) into .agents/skills/marimo-notebook in your project. Codex loads it when a task matches its description.
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add cosanlab/nltools --skill marimo-notebook -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/marimo-notebook, .gemini/skills/marimo-notebook, .github/skills/marimo-notebook and .opencode/skills/marimo-notebook in your project.
Going by SKILL.md and its folder, Marimo Notebook needs the command-line tools its instructions call (uv, uvx and pytest). Our summary lists: Python 3.
SKILL.md contains no URLs. Its commands use uv and uvx, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
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.
Marimo Notebook is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
About 2.1k tokens (SKILL.md is roughly 8.3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 7.2k tokens, read only when the agent opens those files.
Skills that share tags, products or a category with Marimo Notebook: Wasm Compatibility (ericmjl/llamabot, 182 stars), Marimo Pair (PhySpace/SimpleCADAPI, 140 stars), Marimo Pair Vscode (marimo-team/marimo-lsp, 130 stars) and Marimo (brycewang-stanford/Auto-Empirical-Research-Skills, 4.5k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
cosanlab (a GitHub organization) maintains it in cosanlab/nltools, which has 131 GitHub stars. The repository holds 3 skills in this directory. The repository was last updated on October 1, 2026.
Source: cosanlab/nltools on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.