HarnessRouter Community Edition

Harness Engineering is Ryan Lopopolo’s anthology, field guide, and agent-context repository for improving coding-agent output without changing the underlying model or coding agent. It shapes the surrounding environment through context and tools so an agent can recover intent, operate the real system, respect authority, prove its outcome, and incorporate lessons from accepted work, corrections, failures, and user responses. The repository uses AGENTS.md to route agents to relevant arguments, cases, and proof, and provides a thesis index, playbooks, source material, and executable constraints for encoding organizational requirements and decisions. Repository-authored material is licensed under CC BY 4.0.

Better Harness is an open-source Harness Engineering platform for coding agents. It analyzes project and, where supported, session evidence around an agent's work rather than only its final code diff, evaluating the Agent Work Loop for issues such as task understanding, validation, delivery control, and retained lessons. It turns supported gaps into prioritized findings linked to their evidence, expected outcomes, repair boundaries, and acceptance checks, and produces host-specific reports in formats including HTML, paired Markdown, or native Canvas reports. The platform also supports defining harnesses as code, running controlled experiments, inspecting evidence, and comparing outcomes across coding-agent hosts such as Claude Code, Codex, Qoder, Cursor, and GitHub Copilot CLI.

FrontierHarness Eval is an open evaluation benchmark and repository for measuring how coding-agent harness configurations affect software-engineering task results when the underlying model and runtime are held constant. It publishes benchmark definitions, task instructions and metadata, harness-version metadata, normalized aggregate and task-level results, and an agent-neutral workflow for evaluating additional harnesses. The benchmark runs the same model through multiple harness configurations on 30 tasks, using a frozen golden checkpoint and a fresh restore for each task. Its scripts provision the environment, run trials, record verifier-based pass/fail outcomes, measure cost, cache behavior, and speed, then normalize results and generate charts and reports. The repository also provides a CLI and skill-based workflow for evaluating a third-party harness, with infrastructure failures marked separately from task failures. The project focuses on terminal-based software-engineering tasks and states that its results may not generalize to other knowledge-work domains. The repository is published under the frontier-harness-eval organization, with isolated runtimes and checkpoint restores provided by Runta.

OpenRig is an open-source, self-hosted multi-agent harness for coordinating AI coding agents such as Claude Code and Codex as one managed team. It uses a local daemon, CLI, terminal UI, MCP server, SQLite, tmux, and runtime adapters. Users define agent topologies in YAML with pods, seats, communication edges, and continuity policies, then use commands such as `rig up`, `rig send`, `rig broadcast`, `rig chatroom`, `rig down --snapshot`, and `rig discover`/`rig adopt` to launch, coordinate, inspect, snapshot, restore, or take over existing sessions. Its MCP tools let agents manage their own topology, while the TUI exposes topology, seat, project, feed, terminal, and system views. OpenRig requires Node.js and tmux; herdr, cmux, and Docker are optional for terminal workspaces and service-backed rigs. It is distributed through the `@openrig/cli` npm package and licensed under Apache 2.0.

Open Interpreter is a command-line coding agent optimized for open and low-cost models. It is a fork of OpenAI's Codex focused on emulating provider-specific agent harnesses; its Rust-native harnesses can be switched with `/harness`, while providers and models can be changed from its terminal interface. It supports native sandboxing on macOS, Linux, and Windows, MCP, skills, hooks, permissions, AGENTS.md instructions, and local configuration and session state under `~/.openinterpreter`. The agent can run as an Agent Client Protocol agent for compatible editors, speak the Codex exec protocol, and provide a one-line binary override for applications using the Codex SDK. Its built-in QA skill can test web applications through a real browser and native applications through trycua. The project is distributed for macOS, Linux, and Windows through shell or PowerShell installation commands and uses shared agent directories and protocols where available.