Fractal by Plasma AI

Plasma AI released Fractal, an open-source framework for recursive agent loops that lets developers run hierarchical, multi-step tasks with per-node budgets and persistent memory. The system, built on Plasma Wiki and compatible with Claude Code and Codex, enables complex work such as large refactors and migrations by spawning child agents that each run their own loop on separate git branches. Fractal is available on GitHub under Apache 2.0, with a cloud version in early access.

Plasma Fractal Nicholas Diao, Andrew Turner, Colton Berry July 21, 2026Recursive agent loops for complex, multi-step work. Agent graphs have taken over agentic engineering. Every leading harness can now fan work out to subagents and compose them into dynamic workflows Claude Code, for example . Long-running recursive loops, though, are not yet first-class. Fractal is our take on recursive agent loops: a hierarchy of agents, each running its own loop, with a budget at every level. We use Fractal for some of our most complex work. Giant tasks By giant tasks we mean work that outlives any single context window and branches into parts that can proceed independently: large refactors and migrations, features that span services, research and experiment campaigns. Three we've run for real: Every node is a loop The node A node is one agent working toward a goal in its own git worktree. Unlike a subagent inside a session, it is a persistent loop with its own branch, memory, and lifecycle. The loop continues until the agent signals completion or hits a limit you set, but you can stop it at any time. The default loop has five steps: - Prepare: pull in the parent's latest commits and fold in finished child work. - Plan: decide what this iteration will do. - Execute: make the changes in the worktree. - Review: check the diff, fix mistakes, and fold what it learned into memory. - Commit: save the iteration to the node's branch. Each step spins up a fresh coding agent Claude Code or Codex in the node's worktree, and that agent is free to use its own subagents and dynamic workflows within the step. You set the goal in a NODE.md file and steer by editing it. Its content is included in every agent invocation, so you can redirect a running node without stopping it. The steps are defaults, not fixed. Add, remove, or replace them in a node's steps/ folder to reshape the loop. Across iterations, a node keeps what it learns in its memory: a folder of plain Markdown pages, indexed and cross-linked into a knowledge graph. It is Plasma Wiki /research/wiki underneath, so the memory is files on the node's branch, organized by topic, not a transcript. The hierarchy When a goal has separable parts, a node can spawn children to work on narrower sub-goals. Each child gets its own branch and runs the same loop, so every node in the hierarchy owns one part of the work. During Prepare, the parent merges ready child branches into its own. Budgets follow the same shape: every node carries its own, tracks what it and its descendants spend, and a run that drains its budget wraps up at the next iteration boundary. Nodes coordinate over Fractal Radio, the built-in message channel: a parent sends direction, a child reports back. Before each step, a short sync pass handles messages from the rest of the tree, so a node stays aware of its parent and children. The durable record is always the branch and the memory. Try it Fractal is open source under Apache 2.0 on GitHub https://github.com/plasma-ai/fractal . Install the fractal and wiki CLIs, then add the /fractal skill to Claude Code or Codex: The fractal and wiki CLIs pip install fractal The /fractal and /wiki skills for your agent fractal install Drive it from inside the agent you already run: /fractal spawn a node to migrate the payments service off the legacy client Then watch it work: fractal open brings up the terminal UI from the top of this post. Give it a real task, and tell us what you run it on. Fractal Cloud Fractal is coming to the cloud. See the tree, steer its nodes, and track costs as the work runs. Early access opens soon. Occasional emails. Unsubscribe anytime.