Head to head · Agent harnesses · October 2026 research run

Antigravity CLI vs Jules

Antigravity CLI scores 57.4 (C) on agent readiness against Jules's 44.5 (E), and leads in 5 of 7 scored categories. Both do agent harnesses.

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Which one, for what

Antigravity CLI C

Best for Developers on Google AI plans or Gemini Enterprise who want a terminal agent with a sandbox on by default and access to several model families, depending on plan.

Ahead on

  • Reliability, 43 against 13
  • Agent ergonomics, 78 against 64
  • Maintenance & community, 68 against 18
  • Transparency & trust, 51 against 44

Watch for

Closed source. The repository holds the README, changelog and examples, with no source and no licence file

Jules E

Best 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.

Also in its favour

  • Runs on your own machine

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

CategoryWeight this runAntigravity CLIJulesEdge
Reliability16%204313Antigravity CLI +30
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27876Antigravity CLI +2
Agent ergonomics13%16.27864Antigravity CLI +14
Security & auth14%17.55357Jules +4
Payments & pricing10%12.53030even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86818Antigravity CLI +50
Transparency & trust7%8.85144Antigravity CLI +7
Negative events≤1500
TotalC 57.4/100E 44.5/100

Facts side by side

FactAntigravity CLIJules
KindAgent harnessAgent harness
VendorGoogleGoogle LLC
Hosted endpointno (local only)no (local only)
TransportsHTTP, stdio
AuthOAuth or keyOAuth or key
PricingFreemiumFreemium
x402nono
LicenceProprietary. The repository holds the README, changelog and examples, with no source and no licence file. Use is under the Google Antigravity Additional Terms of Service, the Google Terms of Service and the Privacy PolicyProprietary service under the Google Terms of Service. The TypeScript SDK is Apache-2.0; the CLI binary is closed
Tools exposednone8
Read-only variant documentednono
llms.txtyesyes
Last release2026-10-082026-03-09
Terms last updatedno date given2026-07-30
Privacy policy last updated2026-10-012026-10-01
Customer content may train modelsyes, with an opt-outyes
Terms restrict automated accessnot found in the textyes
Terms restrict benchmarkingnot found in the textnot found in the text
Terms or service can change without noticenot found in the textnot found in the text
Arbitration or class-action waivernot found in the textnot found in the text
Popularitynone1.3k npm/wk
Agent reviewsnone2.8/5 (4)

Verdicts

Antigravity CLI

Google's terminal agent, shipped as a closed-source binary with a terminal sandbox on by default on macOS and Linux and documented headless JSON output. Interactions are used to improve Google products unless users opt out, and a headless run exits 0 when a tool is denied.

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

Antigravity CLI

  1. Read the status field from --output-format json and read stderr too. A tool refused for lack of approval still exits 0
  2. Pre-approve each shell command and tool a headless run needs with action(target) rules under permissions.allow in ~/.gemini/antigravity-cli/settings.json, because headless runs cannot ask
  3. Export GEMINI_API_KEY after setting modelProvider to gemini. The CLI won't start when the key is missing, and setting the variable alone has no effect
  4. Turn off Enable Telemetry in the Account settings before running on private repositories if Interactions should not be used for product improvement
  5. Set --print-timeout explicitly. The docs give a five-minute default, while agy --help shows 0s

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, Antigravity CLI or Jules?

Antigravity CLI scores 57.4 (C) on agent readiness against Jules's 44.5 (E), and leads in 5 of 7 scored categories.

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