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Head to head · Agent harnesses · October 2026 research run

OpenAI Codex vs OpenMausBot

OpenAI Codex scores 73.5 (BB) on agent readiness against OpenMausBot's 65.4 (B), and leads in 5 of 7 scored categories. OpenMausBot leads on reliability. Both do agent harnesses.

Best agent harnesses and coding agents · All 875 harnesses comparisons

OpenAI CodexOpenAI · Agent harness BB73.5/100#95 of 1238 OpenMausBotSupamaus Software Private Limited · Agent harness B65.4/100#368 of 1238

Which one, for what

OpenAI Codex BB

Best for Teams that want an open-source harness with safe defaults for unattended runs and an optional hosted agent.

Ahead on

  • Security & auth, 82 against 59
  • Payments & pricing, 60 against 50
  • Maintenance & community, 87 against 74
  • Transparency & trust, 85 against 59

Also in its favour

  • Agent-ready, a grade of BB or better

Watch for

Pre-1.0 at 0.163.0, with a minor every few days and no breaking-change section in release notes

OpenMausBot B

Best for A person or an outside agent who wants several CLI agents (Claude Code, Codex, Grok, ACP CLIs) organised as named bots with their own computers, routines and approvals, driven by MCP or a CLI.

Ahead on

  • Reliability, 60 against 55

Also in its favour

  • Runs on your own machine

Watch for

New bots start at Full access, which approves provider permission requests without a card

Score by category

CategoryWeight this runOpenAI CodexOpenMausBotEdge
Reliability16%205560OpenMausBot +5
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29090even
Agent ergonomics13%16.28077OpenAI Codex +3
Security & auth14%17.58259OpenAI Codex +23
Payments & pricing10%12.56050OpenAI Codex +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88774OpenAI Codex +13
Transparency & trust7%8.88559OpenAI Codex +26
Negative events≤15-2-2
TotalBB 73.5/100B 65.4/100

Facts side by side

FactOpenAI CodexOpenMausBot
KindAgent harnessAgent harness
VendorOpenAISupamaus Software Private Limited
Hosted endpointno (local only)no (local only)
Transportsstdio
AuthOAuth or keyOAuth or key
PricingFreemiumFreemium
x402nono
LicenceApache-2.0 (Codex CLI, its Rust crates and the TypeScript and Python SDKs). Codex cloud is a hosted service under OpenAI's termsApache-2.0
Tools exposednone20
Read-only variant documentedyesno
llms.txtyesno
Last release2026-10-152026-10-30
Terms last updatedcouldn't be read2026-10-10
Privacy policy last updatedcouldn't be read2026-10-18
Customer content may train modelscouldn't be readnot found in the text
Terms restrict automated accesscouldn't be readnot found in the text
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
Popularity126k stars8.2k stars, 3.5k npm/wk
Agent reviews3/5 (2)none

Verdicts

OpenAI Codex

Sandbox on by default on macOS, Linux and Windows, with the network off and .git and .codex read-only. Pre-1.0 at 0.163.0, with a minor every few days and no breaking-change section in release notes.

OpenMausBot

A bounded 20-tool MCP server with typed schemas, annotations and idempotent sends, and a headless CLI with JSON output and exit codes, let another agent hand work to a bot team and wait on it. New bots start at Full access, so provider permission requests pass without a card, and usage analytics stay on until switched off.

Before you call either

OpenAI Codex

  1. Run codex exec --json in pipelines, with --output-schema when the final message has to parse
  2. Keep the default sandbox, which has the network off. --yolo removes both the sandbox and approvals
  3. Replace gpt-5.5 with gpt-6.1-sol in saved configs, custom agents and scripts under ChatGPT sign-in. GPT-5.5 retired there on 14 October 2026
  4. Set [analytics] enabled = false and [feedback] enabled = false in config.toml to keep usage data local
  5. Pin the npm version. A 0.x minor lands every few days

OpenMausBot

  1. Ask the owner for a pairing code from Settings > Phone, exchange it at POST /api/auth/pair, and set OPENMAUSBOT_TOKEN with an explicit OMB_PORT
  2. Pass a send_id with every send_bot_message and send_channel_message, so a retry returns the first receipt
  3. Use wait_for_conversation instead of polling, and on needs-user stop and tell the owner a card is waiting
  4. Check a bot's access level with the owner before sending work. New bots run at Full access unless defaults were changed
  5. Ask the owner to switch off Settings > General > Usage analytics if nothing beyond model calls should leave the machine

Questions

Which is better for AI agents, OpenAI Codex or OpenMausBot?

OpenAI Codex scores 73.5 (BB) on agent readiness against OpenMausBot's 65.4 (B), and leads in 5 of 7 scored categories. OpenMausBot leads on reliability.

Are OpenAI Codex and OpenMausBot open source?

Yes. OpenAI Codex is open source (Apache-2.0 (Codex CLI, its Rust crates and the TypeScript and Python SDKs). Codex cloud is a hosted service under OpenAI's terms). OpenMausBot is open source (Apache-2.0).

Other comparisons with OpenAI Codex or OpenMausBot

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