retro-marimo-pair

retro-marimo-pair is a skill for Claude Code from marimo-team/marimo-pair. It costs 84 tokens per session (1,494 once invoked), scanned A, original, Apache-2.0.

A session retrospective guide for the marimo-pair coding skill and marimo's code-mode API. It helps review a pairing session to find friction, causes, and possible improvements.

In plain words
What is it for?
Reviewing what went wrong during a marimo pairing session and deciding whether to improve the skill instructions, the underlying API, or both.
Why use it?
It turns confusion, repeated corrections, or inefficient steps into concrete improvements while requiring analysis before proposing changes.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the marimo-pair plugin — 2 skills shipped together

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/marimo-team/marimo-pair/retro-marimo-pair
Any agent
npx skills add marimo-team/marimo-pair --skill retro-marimo-pair
Clone the repo
git clone --depth 1 https://github.com/marimo-team/marimo-pair

Made for: Claude Code.

Or install marimo-pair, the plugin that ships this one along with the rest of its 2 skills.

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 retro-marimo-pair

README.md
[![agentmods](https://agentmods.dev/badge/skills/marimo-team/marimo-pair/retro-marimo-pair.svg)](https://agentmods.dev/skills/marimo-team/marimo-pair/retro-marimo-pair)
Your own site
<a href="https://agentmods.dev/skills/marimo-team/marimo-pair/retro-marimo-pair"><img src="https://agentmods.dev/badge/skills/marimo-team/marimo-pair/retro-marimo-pair.svg" alt="Measured on agentmods" height="20"></a>
Per session 84 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,494 The whole file, excluding the scripts and references it only reads on demand.
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 5.1 $0.00084 $0.01494
Opus 5 $0.00042 $0.00747
Sonnet 5 $0.00017 $0.00299
Haiku 4.5 $0.00008 $0.00149

Measured 6d ago against content hash 187b0e13e0f9, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

retro-marimo-pair 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 6d 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.

skills/retro-marimo-pair/SKILL.md · 142 lines

How it starts

The opening of the file, as written. The whole thing — 142 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Session Retrospective

You are helping a marimo team member review a pairing session to find friction and turn it into improvements. The target is always one or both of:

  1. The marimo-pair skill (github://marimo-team/marimo-pair)
  2. marimo._code_mode — the underlying notebook metaprogramming API

This is a conversation, not an automated report. You surface findings, the user steers which ones matter, and together you decide what to do about them.

Guard Rails

  • NEVER edit files in github://marimo-team/marimo-pair without explicit user approval.
  • ALWAYS start with session analysis (Step 1) — do not jump to solutions.
  • Present friction points before root causes — let the user choose which ones to dig into.
  • If the user invoked with a specific complaint, focus your analysis there but still scan for other friction in the background.

Step 1: Session Analysis

Review the current conversation and identify friction. Look for:

Signal What to look for
User frustration Corrections ("no not that"), repeated attempts, backtracking, confusion, tone shifts
Inefficiency Multiple rounds for a one-step task, over-engineering, wrong API usage
Errors Compile-check failures, runtime errors, silent failures, wrong output
Workarounds User or Claude working around a limitation instead of doing it directly
Context loss Claude forgetting instructions from earlier, re-asking things the skill covers

Present a numbered summary of friction points found. For each, note:

  • What happened (brief)
  • Where in the conversation it occurred (quote or paraphrase)
  • Initial category guess (skill structure / skill gap / API issue / etc.)

Then ask: "Which of these should we dig into? Or is there something I missed?"

Step 2: Root Cause Discussion

For each friction point the user selects, work through these lenses:

Lens Question Example improvement
Skill structure Was the right info in the skill but hard to find? Buried in reference/ when it should be in SKILL.md? Promote to guard rail, restructure progressive disclosure
Skill gap Was information missing entirely from the skill? Add new section, example, or anti-pattern
Misleading docs Did the skill say something that led Claude astray? Correct the docs, add clarifying examples
API ergonomics Was _code_mode clunky or unintuitive for this task? Propose API improvement (better defaults, clearer errors)
Missing API Is there something _code_mode simply can't do that it should? Design a new API surface
API bug Did _code_mode behave incorrectly? Characterize the bug, propose fix or workaround
Context window Did Claude forget instructions due to long context? Shorter, more prominent guard rails

Read the full file on GitHub · 142 lines

Files

What ships with it

1 file 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. 6d ago First seen · 142 lines · 84 tokens per session scan A 187b0e13e0f9

Subscribe to this mod's changes

retro-marimo-pair is a skill published in the GitHub repository marimo-team/marimo-pair (405 stars, last pushed 9d ago), licensed Apache-2.0. It adds 84 tokens to every session and 1,494 once invoked, about $0.0004 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.

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