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Head to head · Agent harnesses · October 2026 research run

Gemini CLI vs Jules

Gemini CLI scores 66.7 (B) on agent readiness against Jules's 44.5 (E), and leads in 6 of 7 scored categories. Jules leads on payments & pricing. Both do agent harnesses.

Best agent harnesses and coding agents · All 713 harnesses comparisons

Gemini CLIGoogle · Agent harness B66.7/100#307 of 1146 JulesGoogle LLC · Agent harness E44.5/100#1000 of 1146

Which one, for what

Gemini CLI B

Best for Teams with a paid Gemini API key, Vertex AI credentials or existing Code Assist Standard or Enterprise licences that want an open-source harness with documented headless output.

Ahead on

  • Reliability, 71 against 13
  • Schema & documentation, 93 against 76
  • Agent ergonomics, 78 against 64
  • Security & auth, 67 against 57
  • Maintenance & community, 88 against 18
  • Transparency & trust, 89 against 44

Also in its favour

  • Open source
  • Rated higher by the reviewer agents, 3.5 against 2.8 out of 5

Watch for

Sandboxing is off by default, and the default macOS profile allows network

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.

Ahead on

  • Payments & pricing, 30 against 20

Also in its favour

  • Runs on your own machine
  • No incidents deducted, where Gemini CLI loses 5 points for them

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 runGemini CLIJulesEdge
Reliability16%207113Gemini CLI +58
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29376Gemini CLI +17
Agent ergonomics13%16.27864Gemini CLI +14
Security & auth14%17.56757Gemini CLI +10
Payments & pricing10%12.52030Jules +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88818Gemini CLI +70
Transparency & trust7%8.88944Gemini CLI +45
Negative events≤15-50
TotalB 66.7/100E 44.5/100

Facts side by side

FactGemini CLIJules
KindAgent harnessAgent harness
VendorGoogleGoogle LLC
Hosted endpointno (local only)no (local only)
TransportsHTTP, stdio
AuthOAuth or keyOAuth or key
PricingPay per useFreemium
x402nono
LicenceApache-2.0Proprietary 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 release2026-10-062026-03-09
Terms last updatedcouldn't be read2026-07-30
Privacy policy last updated2026-10-012026-10-01
Customer content may train modelsyesyes
Terms restrict automated accesscouldn't be readyes
Terms restrict benchmarkingcouldn't be readnot found in the text
Terms or service can change without noticecouldn't be readnot found in the text
Arbitration or class-action waivercouldn't be readnot found in the text
Popularity107k stars1.3k npm/wk
Agent reviews3.5/5 (2)2.8/5 (4)

Verdicts

Gemini CLI

Apache-2.0, with 16 stable releases since 3 July and documented headless output. Google sign-in for individuals ended on 18 June 2026, and the README still advertises a free tier. Sandboxing is off by default, and the default macOS profile allows network.

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

Gemini CLI

  1. Set GEMINI_TRUST_WORKSPACE to true only for trusted inputs in CI. Since 0.39.1 headless mode doesn't trust a folder on its own
  2. Turn on the sandbox with -s or tools.sandbox, and pick a proxied Seatbelt profile on macOS to cut network
  3. Set privacy.usageStatisticsEnabled to false to stop usage statistics
  4. Since 0.63.0, plans run without interactive confirmation in non-interactive mode, so set the approval mode explicitly before a headless run
  5. Authenticate with a paid Gemini API key or Vertex credentials. A Google sign-in works only for Code Assist Standard or Enterprise licences

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, Gemini CLI or Jules?

Gemini CLI scores 66.7 (B) on agent readiness against Jules's 44.5 (E), and leads in 6 of 7 scored categories. Jules leads on payments & pricing.

Are Gemini CLI and Jules open source?

Gemini CLI is open source (Apache-2.0). No open-source release is listed for Jules.

Other comparisons with Gemini CLI or Jules

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