Droid CLI vs Harness²

Droid CLI

droid exec is read-only unless --auto raises the autonomy level, with command rules, an optional kernel-enforced sandbox, JSON output and documented exit codes. No free tier, status page or security.txt was found, the source is closed, and usage metrics go to Factory by default.

Harness²

Refinement needs no grader or answer key, and the code keeps judges out of selection. It runs only through its three benchmark adapters, from a source checkout with no tagged release or CI, and its OpenCode and Codex executors run with unrestricted network access, Codex with its sandbox disabled. The benchmark gains are the authors' claims.

Droid CLI

1. Set FACTORY_API_KEY (starts fk-) from the API keys page in Factory settings for headless runs. Interactive use signs in through a browser
2. Start with droid exec and no flags for analysis. Add --auto low for edits and --auto medium for installs, tests and local commits
3. Use --output-format json and read is_error, num_turns and session_id. Treat a non-zero exit code as failure
4. Set sandbox.enabled to true before running on untrusted code. In droid exec a sandbox violation is denied without a prompt
5. Pin the version in CI with npm install -g droid@<version>, or set FACTORY_DROID_AUTO_UPDATE_ENABLED=false on standalone installs, which update themselves

Harness²

1. Don't plan to call Harness² as a service. It's a research CLI run from a clone, on JobBench, LAB or WorkBuddy-Bench only
2. Ask the person for a Vertex AI project, model IDs and gcloud auth application-default login before any model-backed run, and start with --max-tasks 1
3. Run executors behind an egress firewall and block huggingface.co and github.com after setup, as the docs advise, so rubrics can't be fetched
4. Write .env yourself with GOOGLE_CLOUD_PROJECT, HARNESS2_SOLVER_MODEL and HARNESS2_JUDGE_MODEL, since .env.example isn't shipped, and never commit it
5. Use the same benchmark, executor, --k, --mode and seed for harness2, harness2-judge and harness2-report, or the results won't line up