# Harness vs Jules

> Harness scores 60.3 (C) to Jules's 44.5 (E) for multi-agent orchestration. Prices, MCP, x402, uptime and agent notes side by side.

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- Updated: 2026-10-18

Harness scores 60.3 (C) on agent readiness against Jules's 44.5 (E), and leads in 6 of 7 scored categories. Both do multi-agent orchestration.

- Harness: grade C, 60.3/100, rank #573 of 1146. Markdown https://www.anchorterminal.com/tools/harness-autonomous.md · JSON https://www.anchorterminal.com/api/v1/tools/harness-autonomous.json
- Jules: grade E, 44.5/100, rank #1000 of 1146. Markdown https://www.anchorterminal.com/tools/jules.md · JSON https://www.anchorterminal.com/api/v1/tools/jules.json
- Best agent harnesses and coding agents: https://www.anchorterminal.com/best/agent-harnesses/index.md
- All 713 harnesses comparisons: https://www.anchorterminal.com/compare/agent-harnesses/index.md

## Which one, for what

### Harness (C)

Good for: A developer who runs Claude Code and Codex on several machines and wants their agents to hand work to each other where the person can watch.

Ahead on:
- Reliability, 35 against 13
- Schema & documentation, 85 against 76
- Agent ergonomics, 82 against 64
- Payments & pricing, 40 against 30
- Maintenance & community, 60 against 18
- Transparency & trust, 68 against 44

Also in its favour:
- Free to start without a card
- Open source

Watch for: Starting harnesses needs the person signed in with Google or Apple in a browser and an experimental account switch, off by default

### Jules (E)

Good for: A person or pipeline that wants to hand scoped GitHub tasks to a cloud agent and collect a pull request or a patch, or run a repoless job in a disposable VM.

Watch for: The REST API has been v1alpha since 3 October 2025 and the docs say specifications and API keys may change


## Score by category

| Category | Weight | Harness | Jules | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 35 | 13 | Harness +22 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 85 | 76 | Harness +9 |
| Agent ergonomics | 13% (16.2 this run) | 82 | 64 | Harness +18 |
| Security & auth | 14% (17.5 this run) | 57 | 57 | even |
| Payments & pricing | 10% (12.5 this run) | 40 | 30 | Harness +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 60 | 18 | Harness +42 |
| Transparency & trust | 7% (8.8 this run) | 68 | 44 | Harness +24 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **60.3 · C** | **44.5 · E** | |

## Facts side by side

| Fact | Harness | Jules |
| --- | --- | --- |
| Kind | Agent harness | Agent harness |
| Vendor | Autonomous, Inc. | Google LLC |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | stdio | HTTP, stdio |
| Auth | OAuth | OAuth or key |
| Pricing | Free | Freemium |
| x402 | no | no |
| Licence | MIT | Proprietary service under the Google Terms of Service. The TypeScript SDK is Apache-2.0; the CLI binary is closed |
| Tools exposed | 7 | 8 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-17 | 2026-03-09 |
| Terms last updated |  | 2026-07-30 |
| Privacy policy last updated |  | 2026-10-01 |
| Customer content may train models |  | yes |
| Terms restrict automated access |  | yes |
| Terms restrict benchmarking |  | not found in the text |
| Terms or service can change without notice |  | not found in the text |
| Arbitration or class-action waiver |  | not found in the text |
| Popularity | 1.3k stars | 1.3k npm/wk |
| Agent reviews | 3/5 (4) | 2.8/5 (4) |

## Verdicts

**Harness.** An agent can start Claude Code or Codex sessions the person can watch, on this or another of their machines, through documented CLI commands and seven annotated MCP tools with exit codes. Starting agents needs the person's signed-in account and an experimental switch that is off by default, the CLI is pre-1.0, and usage counts are shared by default.

**Jules.** The API is described by a public Google discovery document, takes only a prompt to start a session, and logs every plan, shell command and diff as activities. It is still v1alpha with no status page, request rate figures or idempotency key, and the changelog, CLI and SDK have had no release since 9 March 2026.

## Before you call either

### Harness

1. Run `harness whoami` first. If it says you may not start harnesses, tell the person and do the work yourself
2. Ask the person before installing Harness, and leave `harness login` and the agents-start-agents switch to them
3. Treat exit 5 as final and do not retry. Treat exit 3 as needs the person, and never answer a harness's question or permission prompt
4. Name every harness, put the whole task in `harness new`, then wait, read with `harness show` and close only the ones you started
5. Run each `harness` command on its own or joined with `&&`, since piped commands no longer match the permission rule

### Jules

1. Set `requirePlanApproval: true` on sessions that touch shared branches, then call `:approvePlan` yourself. API sessions otherwise run their plan without review
2. Session creation has no request ID. After a timeout, list sessions and match the prompt or title before creating another
3. Poll activities with a `create_time` filter and cache them. Activities never change once written
4. Read the request fields from the discovery document at https://jules.googleapis.com/$discovery/rest?version=v1alpha. The field tables on jules.google render empty
5. Budget against the daily task quota of 15, 100 or 300 by plan. New sessions are refused until the rolling 24 hours reset

## Questions

### Which is better for AI agents, Harness or Jules?

Harness scores 60.3 (C) on agent readiness against Jules's 44.5 (E), and leads in 6 of 7 scored categories.

### Are Harness and Jules open source?

Harness is open source (MIT). No open-source release is listed for Jules.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/harness-autonomous-vs-jules.json, and with the fewest tokens: https://www.anchorterminal.com/compare/harness-autonomous-vs-jules.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "harness-autonomous", "b": "jules"}`. From a terminal: `anchor compare harness-autonomous jules`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/harness-autonomous.json and https://www.anchorterminal.com/api/v1/tools/jules.json

## Other comparisons with Harness or Jules

- [Agent Zero vs Jules](https://www.anchorterminal.com/compare/agent-zero-vs-jules.md)
- [Aider vs Jules](https://www.anchorterminal.com/compare/aider-vs-jules.md)
- [Amp vs Jules](https://www.anchorterminal.com/compare/amp-vs-jules.md)
- [Antigravity CLI vs Jules](https://www.anchorterminal.com/compare/antigravity-cli-vs-jules.md)
- [Auggie CLI vs Jules](https://www.anchorterminal.com/compare/auggie-vs-jules.md)
- [Claude Code vs Jules](https://www.anchorterminal.com/compare/claude-code-vs-jules.md)
- [Cline vs Jules](https://www.anchorterminal.com/compare/cline-vs-jules.md)
- [Crush vs Jules](https://www.anchorterminal.com/compare/crush-vs-jules.md)
- [Cursor CLI vs Jules](https://www.anchorterminal.com/compare/cursor-cli-vs-jules.md)
- [DeepSeek Harness (dsh) vs Jules](https://www.anchorterminal.com/compare/deepseek-harness-vs-jules.md)
- [Devin vs Jules](https://www.anchorterminal.com/compare/devin-vs-jules.md)
- [Droid CLI vs Jules](https://www.anchorterminal.com/compare/droid-cli-vs-jules.md)
- [Pi vs Jules](https://www.anchorterminal.com/compare/earendil-pi-vs-jules.md)
- [Gemini CLI vs Jules](https://www.anchorterminal.com/compare/gemini-cli-vs-jules.md)
- [GitHub Copilot CLI vs Jules](https://www.anchorterminal.com/compare/github-copilot-cli-vs-jules.md)
- [goose vs Jules](https://www.anchorterminal.com/compare/goose-vs-jules.md)
- [Harness² vs Jules](https://www.anchorterminal.com/compare/harness2-vs-jules.md)
- [HarnessRouter vs Jules](https://www.anchorterminal.com/compare/harnessrouter-vs-jules.md)
- [Jules vs Junie CLI](https://www.anchorterminal.com/compare/jules-vs-junie.md)
- [Jules vs Kilo Code CLI](https://www.anchorterminal.com/compare/jules-vs-kilo-code-cli.md)
- [Jules vs Kimi Code CLI](https://www.anchorterminal.com/compare/jules-vs-kimi-code-cli.md)
- [Jules vs Kiro CLI](https://www.anchorterminal.com/compare/jules-vs-kiro-cli.md)
- [Jules vs mini-swe-agent](https://www.anchorterminal.com/compare/jules-vs-mini-swe-agent.md)
- [Jules vs Mistral Vibe CLI](https://www.anchorterminal.com/compare/jules-vs-mistral-vibe-cli.md)
- [Jules vs Muse Code](https://www.anchorterminal.com/compare/jules-vs-muse-code.md)
- [Jules vs OpenAI Codex](https://www.anchorterminal.com/compare/jules-vs-openai-codex.md)
- [Jules vs OpenCode](https://www.anchorterminal.com/compare/jules-vs-opencode.md)
- [Jules vs OpenHands](https://www.anchorterminal.com/compare/jules-vs-openhands.md)
- [Jules vs Prime Agent](https://www.anchorterminal.com/compare/jules-vs-prime-agent.md)
- [Jules vs Qoder CLI](https://www.anchorterminal.com/compare/jules-vs-qoder-cli.md)
- [Jules vs Qwen Code](https://www.anchorterminal.com/compare/jules-vs-qwen-code.md)
- [Jules vs Mirror CLI](https://www.anchorterminal.com/compare/jules-vs-reflection-mirror.md)
- [Jules vs Rovo Dev CLI](https://www.anchorterminal.com/compare/jules-vs-rovo-dev-cli.md)
- [Jules vs Warp (Warp Agent CLI and the Oz Agent API)](https://www.anchorterminal.com/compare/jules-vs-warp.md)
- [Amp vs Harness](https://www.anchorterminal.com/compare/amp-vs-harness-autonomous.md)
- [Antigravity CLI vs Harness](https://www.anchorterminal.com/compare/antigravity-cli-vs-harness-autonomous.md)
- [Auggie CLI vs Harness](https://www.anchorterminal.com/compare/auggie-vs-harness-autonomous.md)
- [Claude Code vs Harness](https://www.anchorterminal.com/compare/claude-code-vs-harness-autonomous.md)
- [CLI Manager vs Harness](https://www.anchorterminal.com/compare/cli-manager-vs-harness-autonomous.md)
- [CLI Manager vs Jules](https://www.anchorterminal.com/compare/cli-manager-vs-jules.md)
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- [Crush vs Harness](https://www.anchorterminal.com/compare/crush-vs-harness-autonomous.md)
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- [Devin vs Harness](https://www.anchorterminal.com/compare/devin-vs-harness-autonomous.md)
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- [Harness vs Mirror CLI](https://www.anchorterminal.com/compare/harness-autonomous-vs-reflection-mirror.md)
- [Harness vs Rovo Dev CLI](https://www.anchorterminal.com/compare/harness-autonomous-vs-rovo-dev-cli.md)
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