OpenFlow has landed on Hacker News, offering a visual builder for multi-agent AI workflows that sits directly on top of the OpenCode engine. The project, hosted on GitHub by user SeeRay11, allows developers to drag role cards onto a canvas, wire pipelines such as planner to architect to coder, and execute them with real parallel agents. This isn't just another wrapper; it's a fork that leverages the headless engine of OpenCode while keeping its own code isolated in packages/flow to ensure clean upstream merges.

Architecture and Dependencies

The technical foundation of OpenFlow is strictly Bun-based, requiring version 1.3 or newer to run the engine, build, and canvas. The system operates on two specific ports: 4096 for the underlying engine and 5174 for the visual interface. A key design choice is the isolation of OpenFlow's logic; because it doesn't modify upstream OpenCode packages, users can stay current with the core engine's updates without breaking their custom workflows. The installation process pulls the entire workspace, including native dependencies for the engine's prebuilt helpers.

Execution and Configuration

Running OpenFlow is handled by a single command, bun openflow.ts, which manages the startup of both the engine and the canvas. The tool includes smart port handling, reusing ports if they are already serving and freeing them if a previous run left them bound. Configuration is flexible, supporting environment variables and command-line flags for project directories, server ports, and management modes. For Windows users, PowerShell shims are available, though the documentation recommends the direct Bun command to avoid execution policy issues common with unsigned local scripts.

Agent Management and Data

OpenFlow introduces a shift in how generated agents are keyed, moving from per-role to per-node identification. This change means pipelines saved prior to the update require a one-time 'merge agents' re-run to function correctly. The system defaults to auto-approving permissions for file edits and bash commands, but users can switch to a manual 'ask me' mode via the toolbar. All decisions are logged, providing a clear audit trail of what each agent did during the parallel execution.

Key Takeaways

  • OpenFlow is a fork of OpenCode, isolating custom logic in packages/flow to prevent upstream conflicts.
  • The tool requires Bun 1.3+ and uses ports 4096 (engine) and 5174 (canvas).
  • Visual pipelines allow dragging and wiring agent roles like planner, architect, and coder for parallel execution.
  • Users can run the tool immediately without API keys using the free tier of the OpenCode Zen provider.
  • A one-time 'merge agents' step is required for pipelines created before the per-node keying update.

The Bottom Line

This is a solid step toward making multi-agent orchestration less abstract. By leveraging the existing OpenCode engine, OpenFlow avoids reinventing the wheel and focuses on the UI/UX layer that many developers actually need.