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Head to head · Agent harnesses · October 2026 research run

Agent Zero vs Junie CLI

Agent Zero scores 54.2 (C) on agent readiness against Junie CLI's 53.2 (D), and leads in 5 of 7 scored categories. Junie CLI leads on transparency & trust. Both do agent harnesses.

Best agent harnesses and coding agents · All 713 harnesses comparisons

Agent ZeroAgent Zero, s.r.o. · Agent harness C54.2/100#775 of 1146 Junie CLIJetBrains · Agent harness D53.2/100#804 of 1146

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 45
  • Agent ergonomics, 62 against 55
  • Payments & pricing, 60 against 42

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

Junie CLI D

Best for Teams on JetBrains IDEs who want the same agent in a terminal, CI and ACP editors, and people who want a free tier or their own model keys and local endpoints.

Ahead on

  • Transparency & trust, 78 against 55

Also in its favour

  • Free to start without a card

Watch for

One-shot, piped, ACP and Gateway runs trust the project by design and load its MCP servers, hooks, agents and skills without a prompt

Score by category

CategoryWeight this runAgent ZeroJunie CLIEdge
Reliability16%205745Agent Zero +12
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26462Agent Zero +2
Agent ergonomics13%16.26255Agent Zero +7
Security & auth14%17.55456Junie CLI +2
Payments & pricing10%12.56042Agent Zero +18
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87572Agent Zero +3
Transparency & trust7%8.85578Junie CLI +23
Negative events≤15-6-3
TotalC 54.2/100D 53.2/100

Facts side by side

FactAgent ZeroJunie CLI
KindAgent harnessAgent harness
VendorAgent Zero, s.r.o.JetBrains
Hosted endpointno (local only)no (local only)
Transports
AuthNoneOAuth or key
PricingFreeFreemium
x402nono
LicenceMITProprietary, JetBrains s.r.o., all rights reserved, under the JetBrains AI Terms of Service. The GitHub repository holds the README, release binaries and the issue tracker, not source
Read-only variant documentednono
llms.txtyesyes
Last release2026-09-232026-10-16
Terms last updatedno document linked
Privacy policy last updatedno document linked2026-06-12
Customer content may train models
Terms restrict automated access
Terms restrict benchmarking
Terms or service can change without notice
Arbitration or class-action waiver
Popularity19k stars487 stars, 3.2k 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.

Junie CLI

Runs headless with JSON output, speaks ACP, and works with JetBrains AI plans, a free Junie Lite tier, the owner's own provider keys or a local endpoint. Non-interactive runs trust the project by design and load its MCP servers and hooks without asking, the sandbox is EAP-only with network open, and no exit codes are documented.

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

Junie CLI

  1. Run headless only in repositories you trust. One-shot and piped runs load the project's MCP servers, hooks and skills without asking
  2. Set JUNIE_API_KEY (from junie.jetbrains.com/cli) or a provider key such as JUNIE_ANTHROPIC_API_KEY in CI. The default sign-in opens a browser
  3. Add --output-format json or --json-output-file to parse results. Check the output, since exit codes aren't documented
  4. Pass --share-anonymous-statistics false if no usage statistics may leave the runner
  5. Pin a build with --use-version and --skip-update-check. The CLI updates itself on start by default

Questions

Which is better for AI agents, Agent Zero or Junie CLI?

Agent Zero scores 54.2 (C) on agent readiness against Junie CLI's 53.2 (D), and leads in 5 of 7 scored categories. Junie CLI leads on transparency & trust.

Are Agent Zero and Junie CLI open source?

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

Other comparisons with Agent Zero or Junie CLI

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