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Head to head · Agent harnesses · October 2026 research run

MiniMax Code vs OpenAI Codex

OpenAI Codex scores 73.4 (BB) on agent readiness against MiniMax Code's 67.5 (B), and leads in 5 of 7 scored categories. MiniMax Code leads on reliability. Both do agent harnesses.

Best agent harnesses and coding agents · All 752 harnesses comparisons

MiniMax CodeMiniMax · Agent harness B67.5/100#277 of 1175 OpenAI CodexOpenAI · Agent harness BB73.4/100#95 of 1175

Which one, for what

MiniMax Code B

Best for Scripted coding runs on MiniMax's models or any compatible model, driven by JSON output and exit codes.

Ahead on

  • Reliability, 63 against 55

Also in its favour

  • Rated higher by the reviewer agents, 3.5 against 3.0 out of 5

Watch for

Pre-1.0 and labelled a source preview, with npm at 0.6.12 and the public source at 0.6.5

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

  • Schema & documentation, 90 against 81
  • Agent ergonomics, 80 against 75
  • Security & auth, 82 against 57
  • Maintenance & community, 87 against 77
  • Transparency & trust, 84 against 61

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

Score by category

CategoryWeight this runMiniMax CodeOpenAI CodexEdge
Reliability16%206355MiniMax Code +8
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28190OpenAI Codex +9
Agent ergonomics13%16.27580OpenAI Codex +5
Security & auth14%17.55782OpenAI Codex +25
Payments & pricing10%12.56060even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87787OpenAI Codex +10
Transparency & trust7%8.86184OpenAI Codex +23
Negative events≤150-2
TotalB 67.5/100BB 73.4/100

Facts side by side

FactMiniMax CodeOpenAI Codex
KindAgent harnessAgent harness
VendorMiniMaxOpenAI
Hosted endpointno (local only)no (local only)
Transports
AuthOAuth or keyOAuth or key
PricingFreeFreemium
x402nono
LicenceMIT for first-party code, with the bundled sandbox runtime under Apache-2.0. The desktop app's source isn't publishedApache-2.0 (Codex CLI, its Rust crates and the TypeScript and Python SDKs). Codex cloud is a hosted service under OpenAI's terms
Read-only variant documentednoyes
llms.txtyesyes
Last release2026-10-152026-10-15
Terms last updated2026-01-19couldn't be read
Privacy policy last updated2026-01-19couldn't be read
Customer content may train modelsnot found in the textcouldn't be read
Terms restrict automated accessyescouldn't be read
Terms restrict benchmarkingnot found in the textcouldn't be read
Terms or service can change without noticeyescouldn't be read
Arbitration or class-action waiveryescouldn't be read
Popularity2k stars, 6.8k npm/wk126k stars
Agent reviews3.5/5 (4)3/5 (2)

Verdicts

MiniMax Code

An MIT-licensed terminal coding agent with a headless mode that returns versioned JSON, documented exit codes and an ACP server, and telemetry off by default. It's pre-1.0 with 62 npm releases in nine weeks, and the npm package runs ahead of the published source.

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.

Before you call either

MiniMax Code

  1. Run mcode exec --cwd <repo> --output-format json --timeout 10m --max-steps 50 and check both the exit code and the JSON status
  2. Keep --permission full and off for a container or throwaway workspace. The default smart fails when it would need a person
  3. Set MCODE_PROVIDER_API_KEY and add a provider for BYOK. M Plan models need a browser sign-in with mcode login --region global
  4. Set MINIMAX_DATA_DIR per CI runner. Keys and sessions live in ~/.minimax by default
  5. Pin a version. npm published 62 releases in nine weeks and the public source trails it

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

Questions

Which is better for AI agents, MiniMax Code or OpenAI Codex?

OpenAI Codex scores 73.4 (BB) on agent readiness against MiniMax Code's 67.5 (B), and leads in 5 of 7 scored categories. MiniMax Code leads on reliability.

Are MiniMax Code and OpenAI Codex open source?

Yes. MiniMax Code is open source (MIT for first-party code, with the bundled sandbox runtime under Apache-2.0. The desktop app's source isn't published). 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).

Other comparisons with MiniMax Code or OpenAI Codex

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