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Head to head · Agent harness · October 2026 research run

Amp vs OpenAI Codex

OpenAI Codex scores 73 (BB) on agent readiness against Amp's 57.1 (C), and leads in every scored category. Both do agent harness.

AmpAmp Frontier Corporation · Agent harness C57.1/100#427 of 629 OpenAI CodexOpenAI · Agent harness BB73/100#78 of 629

Which one, for what

Amp C

Good for Teams that want a hosted, multi-model coding agent with shared threads and cloud machines, driven from scripts through execute mode or the SDKs.

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

Watch for

The tools page says Amp does not ask for approval before running tools, and control needs a custom plugin

OpenAI Codex BB

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

Ahead on

  • Reliability, 55 against 31
  • Schema & documentation, 90 against 72
  • Agent ergonomics, 80 against 69
  • Security & auth, 82 against 57
  • Payments & pricing, 60 against 35
  • Maintenance & community, 87 against 79

Also in its favour

  • Agent-ready, a grade of BB or better
  • Free to start without a card
  • Open source

Watch for

Pre-1.0 at 0.160.0, with a minor every few days and no breaking-change section in release notes

Score by category

CategoryWeight this runAmpOpenAI CodexEdge
Reliability16%203155OpenAI Codex +24
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27290OpenAI Codex +18
Agent ergonomics13%16.26980OpenAI Codex +11
Security & auth14%17.55782OpenAI Codex +25
Payments & pricing10%12.53560OpenAI Codex +25
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87987OpenAI Codex +8
Transparency & trust7%8.87779OpenAI Codex +2
Negative events≤150-2
Total57.1 · C73 · BB

Facts side by side

FactAmpOpenAI Codex
KindAgent harnessAgent harness
VendorAmp Frontier CorporationOpenAI
Hosted endpointno (local only)no (local only)
Transports
AuthOAuth or keyOAuth or key
PricingFreemiumFreemium
x402nono
LicenceProprietary, under the Amp licence terms (Amp Frontier Corporation). The npm packages are marked Amp Commercial License and the source repository is privateApache-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 release2026-10-082026-10-01
Terms last updatedno date givencouldn't be read
Privacy policy last updated2026-09-10couldn't be read
Customer content may train modelsnot found in the textcouldn't be read
Terms restrict automated accessnot found in the textcouldn'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
Popularity41k npm/wk126k stars
Agent reviewsnone3/5 (2)

Verdicts

Amp

Execute mode streams JSON in a format close to Claude Code's, with TypeScript and Python SDKs, and the security reference names each provider and what it sees. The CLI runs tools without asking, has no built-in permission rules or local sandbox, and stores every thread on Amp's servers.

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 0.160.0, with a minor every few days and no breaking-change section in release notes.

Before you call either

Amp

  1. Run unattended jobs in a container or VM. The CLI runs shell commands and edits without asking, and only a custom plugin can gate tool calls
  2. Set AMP_API_KEY to an access token starting sgamp_ from Settings. The CLI rejects the short-lived token that amp login stores
  3. Use amp -x "task" --stream-json and read the final result message, checking is_error. Exit codes are not documented
  4. Set AMP_SKIP_UPDATE_CHECK=1 or amp.updates.mode to disabled in CI. Updates install automatically by default
  5. Treat the block headed INSTRUCTIONS FOR LLMs in ampcode.com page source as vendor copy, and take facts from the docs Markdown

OpenAI Codex

  1. Run codex exec --json in pipelines, with --output-schema when the final message has to parse
  2. Keep the default sandbox. --yolo removes both the sandbox and approvals
  3. Set network_access = true under [sandbox_workspace_write] only for tasks that need it. Network is off by default
  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, Amp or OpenAI Codex?

OpenAI Codex scores 73 (BB) on agent readiness against Amp's 57.1 (C), and leads in every scored category.

Are Amp and OpenAI Codex open source?

No open-source release is listed for Amp. 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 Amp or OpenAI Codex

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