Fractal

Fractal is an open-source agent orchestration harness and plugin framework developed by Plasma AI. Designed to coordinate coding workflows and agent execution across environments, Fractal provides modular integration layers, shims, and skills tailored for AI coding ecosystems. In daily use, Fractal acts as an intermediary harness that bridges AI agents with local runtime environments, toolsets, and contextual repositories. It includes native integration plugins for platforms such as Claude Code and OpenAI Codex environments, allowing developers to execute structured tasks, manage tool shims, and coordinate context caching and documentation pipelines directly from the terminal. Fractal distinguishes itself through its explicit multi-agent plugin architecture, including support for dedicated agent extensions (.claude-plugin and .codex-plugin structures) and lightweight environment shims. This design allows development teams to run standardized developer workflows, manage cache-derived repository knowledge, and orchestrate scripted tool executions across multiple AI client backends. Fractal is distributed as an open-source project hosted on GitHub under the Plasma AI organization, allowing developers to inspect, modify, and integrate the harness directly into their custom automation pipelines.

Tags: agent harness, AI, ai agent, cli, developer tools, OpenSource

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Key features

  • Claude Plugin Architecture — Provides native plugin integration (.claude-plugin) for Anthropic's Claude-based coding agent ecosystems. - Codex Plugin Integration — Supplies dedicated tooling definitions and interfaces (.codex-plugin) for OpenAI Codex compatibility. - Tool and Environment Shims — Includes execution shims to standardize agent command dispatching and script execution across environments. - Wiki and Cache Management — Implements context synchronization and derived documentation caching to feed project knowledge into agent prompts. - Example Automation Scripts — Features pre-configured execution examples and workflow scripts for orchestrating multi-step agent actions.

Use cases

Use Case: Orchestrating Agent Tool Execution Developers use Fractal as a runner harness to execute multi-step shell scripts and context-aware tools under Claude Code and Codex environments. This allows external tools and tests to be invoked with consistent shims and environment variables.

Use Case: Context and Knowledge Synchronization Teams utilize Fractal's built-in wiki and cache indexing to parse repository documentation and provide structured context chunks to connected AI models without polluting git commit history.

Use Case: Multi-Model Workflow Integration Engineering teams managing hybrid toolchains deploy Fractal to share custom developer skills and plugins across both Anthropic and OpenAI command-line developer tools.

Who it is for

Fractal is built for software engineers and AI platform developers who build, customize, or orchestrate CLI agent workflows across Claude and Codex plugins. It is not intended for non-technical users looking for a standalone graphical code assistant.

Install guide

Installation Clone the repository and install the project in editable mode using Python's package manager: bash git clone https://github.com/plasma-ai/fractal.git cd fractal pip install -e . (Note: Standard pip editable install based on Python repository layout; check docs/ for specific environment prerequisites.)

First Run Verify that the required environment variables for your AI provider (e.g., Anthropic or OpenAI) are configured in your shell environment: bash export ANTHROPIC_API_KEY="your-api-key" export OPENAI_API_KEY="your-api-key"

Example Session Run a test execution or check the shim tools available in the harness: bash # Inspect available examples and verify shim execution ./examples/run_task.sh --help

Part of CLI Coding Agents

Categories: AI Coding Agents, Developer Tools, Experiments

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