Contrabass

Contrabass is an open source, terminal first orchestrator for AI coding agents that turns issue tracker tickets into agent runs. It is a reimplementation in Go of OpenAI's Symphony concept, built on the Charm terminal stack, and its guiding idea is to manage work rather than individual agents: the developer queues issues and Contrabass assigns, runs, monitors and verifies them. It is built for engineers running several coding agents against a real backlog. Contrabass reads a WORKFLOW.md file with YAML front matter and Liquid prompt templates, pulls issues from Linear, GitHub Issues or a built in local board, and provisions an isolated git worktree for each issue. Supported runners include the Codex app server, OpenCode and several community agent runtimes. The orchestrator handles claim and release, dependency gating, orphaned claim recovery, stall detection, retry backoff and completion estimates. A Teams mode coordinates multiple agents through a plan, execute and verify pipeline, using either tmux based processes or in process workers. Developers can watch progress in a Bubble Tea terminal UI, run headless, or open an optional React web dashboard with live streaming, queue navigation and agent logs. Contrabass is free under the Apache 2.0 license and installs through Homebrew or Nix. There is no paid tier; users supply their own agent runtime and tracker credentials, and pay any model costs to those providers. It requires Go 1.25 or later, Git and, for the default team mode, tmux. The Nix package is a headless build without the web dashboard.