marimo copilot-instructions.md

Contribution and review instructions for marimo, a Python tool with a web interface for interactive notebooks. They include checks for frontend appearance and backend behavior across different situations.

In plain words
What is it for?
Reviewing pull requests, checking frontend changes in different notebook views, testing backend changes with varied cases, and requesting screenshots or edge-case checks when needed.
Why use it?
They help catch changes that look correct in one view or scenario but fail elsewhere, reducing review problems and regressions.

Instructions file for GitHub Copilot

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 instructions/marimo-team/marimo/copilot-instructions
Clone the repo
git clone --depth 1 https://github.com/marimo-team/marimo

Made for: GitHub Copilot.

Per session 91 This file is loaded in full into every session.
When invoked 91 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 $0.00091 $0.00091
Opus 5 $0.00046 $0.00046
Sonnet 5 $0.00018 $0.00018
Haiku 4.5 $0.00009 $0.00009

Measured 2d ago against content hash 1fdb681589e2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

marimo copilot-instructions.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 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.

.github/copilot-instructions.md · 9 lines

What it actually says

Code Review Process

  1. If the PR seems AI-generated, you should request the contributor to:
  • Provide screenshots of the fixed output (if possible)
  • Check if it satisfies edge cases instead of just the direct problem it addresses.

For example, if there is a frontend change to make a border thicker, how does this look in run mode, app-view and edit-view? For a backend change, has the user tested different scenarios?

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 · 9 lines · 91 tokens per session scan A 1fdb681589e2

Subscribe to this mod's changes

marimo copilot-instructions.md is an instructions file published in the GitHub repository marimo-team/marimo (22,550 stars, last pushed 2d ago), licensed Apache-2.0. It adds 91 tokens to every session, about $0.0005 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.