Open Harness is a Docker-based agent harness for one project, agent-tended over time. One docker compose up gives you a long-lived sandbox where Claude (or another agent of your choice) runs against a single repo, branch, and identity — not a multi-tenant comparison rig.
- One project, one sandbox. A single container scoped to a single repo. The agent owns its branch and its workspace; you keep your laptop clean.
- Agents that work while you sleep. A tiny croner runtime reads
crons/*.mdmarkdown and wakes the agent on a schedule. - Only host dependency: Docker. No Node, no Python, no toolchain rot on your laptop.
- Composable infra. Cherry-pick Postgres, Cloudflare tunnels, SSH, Caddy gateway via Compose overlays.
- Slack-ready. The in-tree Pi extension at
.pi/extensions/slack/bridges Slack to a Pi agent — see docs/integrations/slack.md. - Multi-agent? Add a pack. Other multi-agent setups ship as separate packs — see
@ryaneggz/mifune.
Option A — Upstream (try it without any setup):
curl -fsSL https://oh.mifune.dev/install.sh | bashClones into ~/.openharness, offers to share your host gh token, writes .devcontainer/.env, and builds the image (~10 min cold, ~30s warm). Only host dependency: Docker.
Option B — Fork and clone (recommended for self-hosting):
# 1. Fork on GitHub, then clone YOUR fork:
git clone https://github.com/<your-org>/<your-fork>.git && cd <your-fork>
# 2. Bootstrap — installer auto-detects the local clone, no env vars needed:
bash scripts/install.shOption C — Clone upstream, then re-point to your repo:
git clone https://github.com/ryaneggz/open-harness.git my-harness && cd my-harness
git remote set-url origin https://github.com/<your-org>/<your-repo>.git
bash scripts/install.shAdvanced: install directly from your fork without cloning first
OH_GITHUB_REPO=<your-org>/<your-fork> curl -fsSL \
https://raw.githubusercontent.com/<your-org>/<your-fork>/main/scripts/install.sh | bashIf your fork uses a default branch other than main, set OH_GITHUB_REF=<branch> and replace main in the URL. See Installation docs for all environment overrides.
cd ~/.openharness
make shell # enter the isolated sandbox
# inside the sandbox, launch any core agent:
# claude # Claude Code (default)
# codex # OpenAI Codex CLI
# opencode # OpenCode (optional: set INSTALL_OPENCODE=true and rebuild)
# pi # Pi Coding Agent
# deepagents # LangChain DeepAgents (optional: set INSTALL_DEEPAGENTS=true and rebuild)
# hermes # Nous Research Hermes (optional: set INSTALL_HERMES=true and rebuild)
make destroy # stop and remove the sandbox
make help # all targets- Property-based testing convention: docs/property-testing.md
Prefer VS Code or remote SSH? Use the Dev Containers extension's "Attach to Running Container" against openharness, or SSH into your host first and then attach.
.devcontainer/.env is generated with safe defaults during install. Open
it any time to change SANDBOX_NAME, set a different GH_TOKEN, change
TZ, or set SLACK_* tokens for the Pi Slack extension. Apply with
make destroy && make sandbox.
Manual setup (no installer)
git clone https://github.com/ryaneggz/open-harness.git && cd open-harness
make sandbox
make shell| Core agents | Defaults: Claude Code, Codex, Pi. Optional: OpenCode, DeepAgents, Hermes |
| Runtimes | Node 22, pnpm, Bun, uv (Python) |
| DevOps | Docker CLI + Compose, GitHub CLI, cloudflared, tmux, croner |
| Browser | agent-browser + Chromium (headless) |
| One project, one sandbox | A single container scoped to a single repo and branch |
| Crons | Markdown-defined schedules in crons/*.md driven by the in-container croner runtime |
| Multi-agent | Install a harness pack such as @ryaneggz/mifune for additional multi-agent setups |
- Quickstart — full step-by-step
- Crons — markdown-defined autonomous tasks
make destroyIssues and PRs welcome at github.com/ryaneggz/open-harness. If Open Harness is useful to you, please give us a star.
MIT.