Marimo pair
Reactive Python notebooks as environments for agents
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Hi HN! We're excited to share marimo pair [1] [2], a toolkit that drops AI agents into a running marimo notebook [3] session. This lets agents use marimo as working memory and a reactive Python runtime, while also making it easy for humans and agents to collaborate on computational research and data work.GitHub repo: https://github.com/marimo-team/marimo-pairDemo: https://www.youtube.com/watch?v=6uaqtchDnocmarimo pair is implemented as an agent skill. Connect your agent of choice to a running notebook with:/marimo-pair pair with me on my_notebook.pyThe agent can do anything a human can do with marimo and more. For example, it can obtain feedback by running code in an ephemeral scratchpad (inspect variables, run code against the program state, read outputs). If it wants to persist state, the agent can add cells, delete them, and install packages (marimo records these actions in the associated notebook, which is just a Python file). The agent can even manipulate marimo's user interface — for fun, try asking your agent to greet you from within a pair session.The agent effects all actions by running Python code in the marimo kernel. Under the hood, the marimo pair skill explains how to discover and create marimo sessions, and how to control them using a semi-private interface we call code mode.Code mode lets models treat marimo as a REPL that extends their context windows, similar to recursive language models (RLMs). But unlike traditional REPLs, the marimo "REPL" incrementally builds a reproducible Python program, because marimo notebooks are dataflow graphs with well-defined execution semantics. As it uses code mode, the agent is kept on track by marimo's guardrails, which include the elimination of hidden state: run a cell and dependent cells are run automatically, delete a cell and its variables are scrubbed from memory.By giving models full control over a stateful reactive programming environment, rather than a collection of ephemeral scripts, marimo pair makes agents active participants in research and data work. In our early experimentation [4], we've found that marimo pair accelerates data exploration, makes it easy to steer agents while testing research hypotheses, and can serve as a backend for RLMs, yielding a notebook as an executable trace of how the model answered a query. We even use marimo pair to find and fix bugs in itself and marimo [5]. In these examples the notebook is not only a computational substrate but also a canvas for collaboration between humans and agents, and an executable, literate artifact comprised of prose, code, and visuals.marimo pair is early and experimental. We would love your thoughts.[1] https://github.com/marimo-team/marimo-pair[2] https://marimo.io/blog/marimo-pair[3] https://github.com/marimo-team/marimo[4] https://www.youtube.com/watch?v=VKvjPJeNRPk[5] https://github.com/manzt/dotfiles/blob/main/.claude/skills/m...
HN · launched Apr 7, 2026 · 140 upvotes (top 7%) · 0 views
Niche: ai agent runtime environments · 745 launches, 500 in the last 7 days ▲ +942% · Explore this niche →
Category and tags
- Horizontal
- Dev tools
- Developer
- AI feature
- Hobby / open-source project
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More like this: all 745 launches in ai agent runtime environments →
Could you build this?
Partial Connecting an agent to a notebook can be prototyped, but building a robust reactive DAG execution environment that syncs real-time state safely between human edits and autonomous agent commands is a complex systems problem.
What it would actually take: The architecture relies on Marimo's reactive dataflow graph engine in Python communicating via WebSockets or IPC to a sandboxed agent runtime. The hard part is managing concurrent execution state, resolving topological DAG conflicts when an agent mutates cells while a user edits, and ensuring deterministic reactive cell evaluation. Implementing this requires specialized knowledge of compiler theory, reactive programming runtimes, and process isolation.
Discussion
20 comments analyzed.
Competitors mentioned: Claude Code, Observable, Pluto.jl, solveit/ipyai, replsh
Concerns raised: Anthropic restricting Claude subscription usage, Deployment for internal users not yet available (molab limitation), Long-running computations on large datasets - agent behavior unclear
Feature requests: Easy deployment story for internal users, Widget composition (widgets within widgets), SSH support for remote sessions
Competitors
Other products that read as similar to this one : 142 launches clear the similarity bar, closest 8 shown.
Attention rank: #14 of 143 (itself plus its competitors, highest first, normalized so YC and Product Hunt are compared fairly).
Launched 155 days after the earliest competitor.
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