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Head to head · Agent harnesses · October 2026 research run

Agent Zero vs Prime Agent

Prime Agent scores 60.5 (C) on agent readiness against Agent Zero's 54.2 (C), and leads in 4 of 7 scored categories. Agent Zero leads on schema & documentation. Both do agent harnesses.

Best agent harnesses and coding agents · All 205 harnesses comparisons

Agent ZeroAgent Zero, s.r.o. · Agent harness C54.2/100#709 of 986 Prime AgentPrime Intellect · Agent harness C60.5/100#525 of 986

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

  • Schema & documentation, 64 against 42

Watch for

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

Prime Agent C

Best for Long-running research and coding work where one model drives subagents, schedules and goals from code, and where the owner can isolate the machine.

Ahead on

  • Reliability, 65 against 57
  • Agent ergonomics, 73 against 62
  • Transparency & trust, 64 against 55

Also in its favour

  • Free to start without a card
  • No incidents deducted, where Agent Zero loses 6 points for them

Watch for

No approval prompts and no sandbox. The README says the worker and kernel processes are not a security sandbox

Score by category

CategoryWeight this runAgent ZeroPrime AgentEdge
Reliability16%205765Prime Agent +8
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26442Agent Zero +22
Agent ergonomics13%16.26273Prime Agent +11
Security & auth14%17.55450Agent Zero +4
Payments & pricing10%12.56060even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87579Prime Agent +4
Transparency & trust7%8.85564Prime Agent +9
Negative events≤15-60
TotalC 54.2/100C 60.5/100

Facts side by side

FactAgent ZeroPrime Agent
KindAgent harnessAgent harness
VendorAgent Zero, s.r.o.Prime Intellect
Hosted endpointno (local only)no (local only)
Transports
AuthNoneNone
PricingFreeFree
x402nono
LicenceMITMIT
Read-only variant documentednono
llms.txtyesno
Last release2026-09-232026-10-07
Terms last updatedno document linkedno date given
Privacy policy last updatedno document linkedno date given
Customer content may train modelsnot found in the text
Terms restrict automated accessyes
Terms restrict benchmarkingyes
Terms or service can change without noticeyes
Arbitration or class-action waiveryes
Popularity19k stars22k stars

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.

Prime Agent

Budgets for turns, tokens and time bound an autonomous run, and sessions survive a closed terminal through a supervising daemon. Model-written Python and shell commands run with the user's rights, with no approval step and no sandbox, and the Rust build on the main branch ships only as nightly betas.

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

Prime Agent

  1. Run it in a disposable clone, container or VM. It executes model-written Python and shell commands with the user's rights and asks nothing first
  2. Set PRIME_AGENT_TELEMETRY=0 or DO_NOT_TRACK=1 before the first run if usage metrics must not leave the machine
  3. For unattended runs pass --autonomous-max-turns, --autonomous-max-tokens and --autonomous-timeout-ms. Reaching a limit does not mean the task succeeded
  4. Headless use is -p with --mode json per the argument parser. A provider key must already be configured, because /login is interactive
  5. The -t/--tools, -nt/--no-tools and -nbt/--no-builtin-tools flags were removed and now fail as unknown options

Questions

Which is better for AI agents, Agent Zero or Prime Agent?

Prime Agent scores 60.5 (C) on agent readiness against Agent Zero's 54.2 (C), and leads in 4 of 7 scored categories. Agent Zero leads on schema & documentation.

Are Agent Zero and Prime Agent open source?

Yes. Agent Zero is open source (MIT). Prime Agent is open source (MIT).

Other comparisons with Agent Zero or Prime Agent

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