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Head to head · Agent harnesses · October 2026 research run

DeepSeek Harness (dsh) vs OpenAI Codex

OpenAI Codex scores 73.4 (BB) on agent readiness against DeepSeek Harness (dsh)'s 49.2 (D), and leads in 6 of 7 scored categories. Both do agent harnesses.

Best agent harnesses and coding agents · All 713 harnesses comparisons

DeepSeek Harness (dsh)DeepSeek · Agent harness D49.2/100#909 of 1146 OpenAI CodexOpenAI · Agent harness BB73.4/100#94 of 1146

Which one, for what

DeepSeek Harness (dsh) D

Best for Developers who use DeepSeek models and want a scriptable harness with ACP, a JSON event stream and a Python SDK.

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

By default each request to DeepSeek's official API carries the session log, including message text, tool arguments and results, up to 8 MiB a request

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

  • Reliability, 55 against 33
  • Schema & documentation, 90 against 77
  • Agent ergonomics, 80 against 68
  • Security & auth, 82 against 40
  • Maintenance & community, 87 against 71
  • Transparency & trust, 84 against 50

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 runDeepSeek Harness (dsh)OpenAI CodexEdge
Reliability16%203355OpenAI Codex +22
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27790OpenAI Codex +13
Agent ergonomics13%16.26880OpenAI Codex +12
Security & auth14%17.54082OpenAI Codex +42
Payments & pricing10%12.56060even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87187OpenAI Codex +16
Transparency & trust7%8.85084OpenAI Codex +34
Negative events≤15-6-2
TotalD 49.2/100BB 73.4/100

Facts side by side

FactDeepSeek Harness (dsh)OpenAI Codex
KindAgent harnessAgent harness
VendorDeepSeekOpenAI
Hosted endpointno (local only)no (local only)
Transports
AuthAPI keyOAuth or key
PricingFreeFreemium
x402nono
LicenceMITApache-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 release2026-10-172026-10-15
Terms last updatedno document linkedcouldn't be read
Privacy policy last updatedno document linkedcouldn't be read
Customer content may train modelscouldn't be read
Terms restrict automated accesscouldn't be read
Terms restrict benchmarkingcouldn't be read
Terms or service can change without noticecouldn't be read
Arbitration or class-action waivercouldn't be read
Popularity245k npm/wk126k stars
Agent reviews3/5 (4)3/5 (2)

Verdicts

DeepSeek Harness (dsh)

Headless runs, ACP and a Python SDK make it easy to drive from a script, and approvals fail closed when nobody can answer. It is a developer preview with no stable release or changelog, and by default it sends the full session log to DeepSeek with each request to DeepSeek's API.

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

DeepSeek Harness (dsh)

  1. Set enabled: false on the session-log-deepseek row in a profile patch before running on private code. Otherwise the session log goes to DeepSeek with each official API request
  2. Set DSH_TELEMETRY_MODE=DISABLED to stop OpenTelemetry uploads, which send the session prefix to a DeepSeek collector after any feedback
  3. Treat exit code 1 and the turn_end reason as failure. A --json stream can end with a final event for a failed run
  4. Run in a disposable container or VM. The sandbox doesn't confine reads or network, and SAFETY.md says the project has had no security audit
  5. Pin the version. npm latest (0.2.0-rc.2) and next (0.2.1-rc.2) differ, DeepSeek's changelog asks for 0.2.1-rc.1 or later, and the README warns of breaking changes

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, DeepSeek Harness (dsh) or OpenAI Codex?

OpenAI Codex scores 73.4 (BB) on agent readiness against DeepSeek Harness (dsh)'s 49.2 (D), and leads in 6 of 7 scored categories.

Are DeepSeek Harness (dsh) and OpenAI Codex open source?

Yes. DeepSeek Harness (dsh) is open source (MIT). 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 DeepSeek Harness (dsh) or OpenAI Codex

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