Head to head · Agent harnesses · October 2026 research run

Agent Zero vs Jules

Agent Zero scores 54.2 (C) on agent readiness against Jules's 44.5 (E), and leads in 4 of 7 scored categories. Jules leads on schema & documentation. Both do agent harnesses.

Best agent harnesses and coding agents · All 713 harnesses comparisons

Which one, for what

Agent Zero C

Best for A technical owner who wants an agent with its own Linux machine, reachable from Telegram, WhatsApp or email, with scheduled tasks and editable memory.

Ahead on

  • Reliability, 57 against 13
  • Payments & pricing, 60 against 30
  • Maintenance & community, 75 against 18
  • Transparency & trust, 55 against 44

Also in its favour

  • No key needed to call it
  • Open source

Watch for

No approval step before shell commands, file changes or outgoing messages. Tool Access defaults to allow

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

  • Schema & documentation, 76 against 64

Also in its favour

  • Runs on your own machine
  • No incidents deducted, where Agent Zero loses 6 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 runAgent ZeroJulesEdge
Reliability16%205713Agent Zero +44
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26476Jules +12
Agent ergonomics13%16.26264Jules +2
Security & auth14%17.55457Jules +3
Payments & pricing10%12.56030Agent Zero +30
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87518Agent Zero +57
Transparency & trust7%8.85544Agent Zero +11
Negative events≤15-60
TotalC 54.2/100E 44.5/100

Facts side by side

FactAgent ZeroJules
KindAgent harnessAgent harness
VendorAgent Zero, s.r.o.Google LLC
Hosted endpointno (local only)no (local only)
TransportsHTTP, stdio
AuthNoneOAuth or key
PricingFreeFreemium
x402nono
LicenceMITProprietary 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 release2026-09-232026-03-09
Terms last updatedno document linked2026-07-30
Privacy policy last updatedno document linked2026-10-01
Customer content may train modelsyes
Terms restrict automated accessyes
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticenot found in the text
Arbitration or class-action waivernot found in the text
Popularity19k stars1.3k npm/wk
Agent reviewsnone2.8/5 (4)

Verdicts

Agent Zero

Self-hosted under the MIT licence, with nine releases in the 90 days to 12 October 2026 and breaking changes listed in the release notes. The agent runs shell commands in its container with no approval step, the web interface has no login by default, and five CVEs from the past year have no published GitHub advisory.

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

Agent Zero

  1. Set a UI login and password in Settings before publishing the port or opening a tunnel. The default has none
  2. Fill allowed_users, allowed_numbers or sender_whitelist before enabling a channel. An empty list accepts every sender
  3. Enable the Infection Check plugin when the agent reads mail, web pages or MCP results. It ships disabled
  4. Run v2.12 or later. It fixes a Telegram webhook authentication bypass and a WhatsApp media path traversal
  5. Call POST /api_message with the X-API-KEY header. The token changes when the UI login or password changes

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, Agent Zero or Jules?

Agent Zero scores 54.2 (C) on agent readiness against Jules's 44.5 (E), and leads in 4 of 7 scored categories. Jules leads on schema & documentation.

Are Agent Zero and Jules open source?

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

Other comparisons with Agent Zero or Jules

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