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OpenAIAI Coding Agent

Codex

Reads, edits, and runs code in a sandbox, locally through the CLI, IDE extension, and ChatGPT desktop app, or in hosted Codex Cloud environments.

The 30-Second Take

Pick Codex if you need one policy across a mixed fleet, Windows machines included.

Its sandbox is on by default, and admins set policy per group from one console. 37signals and Superhuman run it as the reviewer beside Claude Code.

Best fit
Teams delegating well-scoped coding tasks across a mixed fleet under per-group policy, native Windows included.
Main constraint
Usage limits vary by model and task size, and ChatGPT plans give you OpenAI models only.
First move
Pin the sandbox with requirements.toml, commit an AGENTS.md to each repository, and start one team on ChatGPT Business.

Why

Practitioners rate its code highly but call results inconsistent, and usage cost is the top complaint. Armin Ronacher's long unattended run burned about US$1,200 of tokens and delivered nothing of value.

Practitioner sentiment, leaders and teams+55 Strong positive

31 practitioners, 157 sources reviewed, Updated Nov 1, 2026How this is measured

Read the GILD Review
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Operating stack
Agentic Software Development

Comparisons

How does Codex compare with the alternatives?

See all 9 comparisons

  1. Codex vs Claude Code

    • AI Coding Agents

    37signals and Superhuman drive with Claude Code and have Codex check the work, and Every's Codex converts were drifting back after Opus 5.5. Choose Codex alone when plan limits, token spend, native Windows or per-team policy decide; public merge data does not separate the two.

  2. Codex vs Cursor

    • AI Coding Agents

    Choose Cursor if engineers will move into its editor and want models from several providers. Choose Codex to keep their editors, Cursor included, with the agent bundled into ChatGPT plans.

  3. Codex vs GitHub Copilot

    • AI Coding Agents

    Choose Copilot to keep agent work and its budgets inside GitHub, where it can also run the Codex agent. Choose Codex through ChatGPT for the desktop app and Codex Cloud on OpenAI's current models.

Operator Insights

What are engineering leaders learning from deploying Codex?

See all 16 operator accounts

Buying and deployment

What engineering leaders should verify before a broader rollout.

Sourced from Codex documentation

How you buy it

US$20

A month in ChatGPT Plus. Business is US$25 per user monthly, or US$20 billed annually.

Source 1, OpenAI, Pricing: Pricing

Details

Codex comes with ChatGPT plans. Plus US$20 per month; Pro US$100, US$200, or US$500 per month; Business US$25 per user per month billed monthly, or US$20 billed annually for 2+ users, with Premium seats at US$125, or US$100 billed annually, for five times Standard usage and no five-hour limit; Enterprise through OpenAI sales. Pro 200 subscriptions now carry a lower allowance than before; earlier subscribers kept the old one for a grace period that has ended. Free, and Go at US$8 per month, get Codex in the desktop app on GPT-6 Luna as it rolls out.

Cost drivers

15 to 160 messages

Local messages per five hours on Plus and Business. Pro has no five-hour limit.

Source 1, OpenAI, Pricing: PricingSource 5, OpenAI, OpenAI API pricing: OpenAI API pricingSource 6, developers.openai.com, GPT-6.1 Sol model page: GPT-6.1 Sol model page

Details

Local messages and cloud chats share plan limits, which vary by model. Plus and Business estimate 15 to 160 local messages per five hours on GPT-6.1 Sol, and Pro has no five-hour limit. Past the limit, ChatGPT credits extend usage. With an API key, gpt-6.1-sol costs US$2 input, US$0.10 cached input, and US$10 output per million tokens. Prompts over 272,000 input tokens bill at 2x input and 1.5x output for the whole request.

Where it runs

App, CLI, IDE, cloud

The desktop app, the CLI, editor extensions, and cloud tasks from GitHub, Slack, or Linear.

Source 4, OpenAI, Codex Cloud: Codex CloudSource 7, learn.chatgpt.com, Codex in your IDE: Codex in your IDE

Details

The ChatGPT desktop app, with Windows and Linux desktop apps, the Codex CLI, and an IDE extension for VS Code, Cursor, and Windsurf. Codex Cloud tasks start from the web, mobile, or desktop app, with GitHub, Slack, and Linear integrations.

What to verify

Sign-in route

ChatGPT sign-in follows workspace rules. An API key has no cloud features.

Source 2, OpenAI, Authentication: AuthenticationSource 3, OpenAI, Agent approvals & security: Agent approvals & securitySource 8, OpenAI, Enterprise admin setup: Enterprise admin setupSource 9, GitHub, Codex CLI 0.164.0 release (Oct 23, 2026): Codex CLI 0.164.0 release (Oct 23, 2026)

Details

The sign-in route: ChatGPT sign-in follows workspace RBAC and retention, and Codex cloud requires ChatGPT sign-in, so an API key covers local work only. Check sandbox and network defaults, and that Codex Cloud stays off on Enterprise until an admin enables it. Windows fleets behind an authenticating corporate proxy, or with enterprise MCP servers, need Codex CLI 0.164.0 (Oct 23, 2026) or later. That release adds Negotiate/NTLM proxy sign-in and enterprise MCP authentication.

Signals

What is the current evidence saying about Codex?

A source-linked read of what engineering leaders, teams, and builders report about Codex.

Whose sources count

Practitioner sentiment, leaders and teams

+55 Strong positive net

of 33 sources that take a side, each author counted once.

How this figure is made

7 more state no overall view and cast no vote.

Current sentiment

Positive, mixed and negative sources

The score counts them as 19 positive, 10 mixed and 2 negative votes, one per author.

Teams praise the code Codex writes in 7 of the 8 sources that discuss it, and the day-to-day experience in 8 of 14. Their cost complaints are surprise bills on team plans: credit use that spikes overnight past monthly caps, and overage billed above API rates. Quesma could not turn off fast mode for the whole organization.

Use a task pilot to measure accepted work and review time.

Evidence field. All 157 sources, one mark each.

Arrange by

Each mark is one source: positive, mixed, negative, no opinion stated, or documentation (not counted).

By sentiment, Engineering leaders and teams. Every source GILD read, grouped as the field draws it.
GroupSourcesPositiveMixedNegativeNo opinion stated and not counted in the scoreDocumentation, checked and not counted
Positive21210000
Mixed10010000
Negative200200
Not counted11000110
Documentation21000021
Outside this group9240341080
Every source GILD read, by the quarter it was published, as the field's time axis counts it. Documentation is dated by the day it was checked.
QuarterSources
Q2 20258
Q3 20259
Q4 202520
Q1 202621
Q2 202630
Q3 202639
Q4 20269
Documentation, checked21

By sentiment

21 documentation pages check facts and are not counted; 92 sit outside this group.

Hover a mark for a quick look, click it or press Enter to open its source.Tap a mark to open its source, then step to its neighbors with Previous and Next.

What practitioners praise

Top praise of 2. Each mark is a source on it; filled marks praise it.

  1. Developer Experience8 of 14 sources on it praise it

Most common concerns

Top concern of 3. Each mark is a source on it; filled marks raise it.

  1. Usage Limits / Cost7 of 13 sources on it raise it as a concern
All 157 sources behind these findings
  1. 3 days left before pro accounts get halvedZealousideal-Alps-71, Reddit r/codex poster on the US$500 Pro plan (self-described: Solo, 8 concurrent tasks across several projects), Reddit post, published Oct 28, 2026
  2. Severe weekly allowance regression: GPT-6 Astra High/Fast exhausts weekly quota in one dayAnton Kozheltsev, GitHub user on ChatGPT Prolite (self-described: ZITADEL staging upgrade and migration check, Codex desktop on macOS), GitHub issue on openai/codex, published Oct 19, 2026
  3. Comment on: Codex Desktop continuously generates Crashpad pending dumpsCountSessine, Hacker News commenter (self-described: Developer using Astra at work), Hacker News comment, published Oct 18, 2026
  4. GitHub issue: credits added separately from the weekly allowanceA Codex Desktop user and ChatGPT subscriber, GitHub openai/codex (self-described: Codex Desktop on a ChatGPT plan), GitHub issue, published Oct 16, 2026
  5. Are Harnesses Worth the Cost?Naresh Jain, founder of Specmatic (Ten-run experiment building an API service with Kafka events against contract tests), Article, martinfowler.com (Exploring Gen AI series), published Oct 13, 2026
  6. Comment on: Gemini 4 Argoniforgotmypasswo, Hacker News commenter (self-described: Engineering manager on an enterprise OpenAI plan), Hacker News comment, published Oct 13, 2026
  7. OverviewOpenAI (Official), Product documentation, checked Oct 12, 2026
  8. PricingOpenAI (Official), Product documentation, checked Oct 12, 2026
  9. ModelsOpenAI (Official), Product documentation, checked Oct 12, 2026
  10. AuthenticationOpenAI (Official), Product documentation, checked Oct 12, 2026
  11. Codex CLIOpenAI (Official), Product documentation, checked Oct 12, 2026
  12. IDE extensionOpenAI (Official), Product documentation, checked Oct 12, 2026
  13. ChatGPT desktop appOpenAI (Official), Product documentation, checked Oct 12, 2026
  14. Codex CloudOpenAI (Official), Product documentation, checked Oct 12, 2026
  15. Cloud environmentsOpenAI (Official), Product documentation, checked Oct 12, 2026
  16. Agent approvals & securityOpenAI (Official), Product documentation, checked Oct 12, 2026
  17. SandboxingOpenAI (Official), Product documentation, checked Oct 12, 2026
  18. Custom instructions with AGENTS.mdOpenAI (Official), Product documentation, checked Oct 12, 2026
  19. Review GitHub pull requests with CodexOpenAI (Official), Product documentation, checked Oct 12, 2026
  20. Non-interactive modeOpenAI (Official), Product documentation, checked Oct 12, 2026
  21. Codex GitHub ActionOpenAI (Official), Product documentation, checked Oct 12, 2026
  22. Use Codex in LinearOpenAI (Official), Product documentation, checked Oct 12, 2026
  23. Use ChatGPT in SlackOpenAI (Official), Product documentation, checked Oct 12, 2026
  24. Admin rollout guideOpenAI (Official), Product documentation, checked Oct 12, 2026
  25. Managed configurationOpenAI (Official), Product documentation, checked Oct 12, 2026
  26. GovernanceOpenAI (Official), Product documentation, checked Oct 12, 2026
  27. Open sourceOpenAI (Official), Product documentation, checked Oct 12, 2026
  28. Comment on: Incident with Git Operations, Pull Requests and Actions - Resolvedaleqs, Hacker News commenter (self-described: uses Codex alongside Claude Code), Hacker News comment, published Oct 7, 2026
  29. Why Engineers Are Switching to CodexJayson DeLancey, Semgrep (self-described: Semgrep's own engineering team; the post also announces Semgrep Guardian support for Codex), Company blog post, Semgrep, published Oct 6, 2026
  30. Get Into Agentic Development From the Shallow EndNick Kilpatrick, software developer at Atomic Object (Atomic Object consultant on a mobile app project with simulator testing), Company blog post, Atomic Object (Atomic Spin), published Oct 1, 2026
  31. Codex Cloud, and a Week of Work Before Getting Out of BedFelipe Coimbra, Venture Architect (self-described: Solo projects; queues Codex Cloud work from a phone and reviews the results later), Personal blog post, felipe.ai, published Sep 30, 2026
  32. Comment on: GPT 6.1 Sol: Near-Astra intelligence for a fifth of the pricesreekanth850, Hacker News commenter (self-described: Three-person team on a large C# codebase, Codex in VS Code), Hacker News comment, published Sep 30, 2026
  33. Merged, Not Measured: An Empirical Study of Performance Issues Fixed by Coding AgentsZhenyu Qi and co-authors, software engineering researchers (self-described: Agent performance fixes in public repositories, AIDev dataset), Independent study, arXiv, published Sep 29, 2026
  34. We Let Claude Code and Codex Race Human Researchers - Elie Bakouch, Prime IntellectElie Bakouch, research engineer at Prime Intellect (self-described: Prime Intellect, optimizer speedrun experiments on the company GPU cluster), Conference talk, AI Engineer (YouTube), published Sep 26, 2026
  35. Alexander Stolle - From Intentional Sprawl to a Deliberate Stack: Rolling Out CodexAlexander Stolle, Director Data & AI at XING (self-described: XING, company-wide consolidation on ChatGPT Enterprise and Codex), Conference talk, Agentic Hamburg (YouTube), published Sep 23, 2026
  36. Comment on: GPT-6 Sol and LunaHuppie, Hacker News commenter (self-described: Own projects; Codex reviews commits made with Claude Code), Hacker News comment, published Sep 22, 2026
  37. Every: Vibe Check, Opus 5.5 Is Pulling Our Codex Converts Back to ClaudeKatie Parrott, staff writer, Every (self-described: Every staff across evals, design and leadership), Organization write-up, published Sep 22, 2026
  38. Auditing in the age of (good enough) AIFredrik Dahlgren, Principal Security Engineer at Trail of Bits (Trail of Bits audit team preparing a Miden VM security review), Company engineering blog post, Trail of Bits, published Sep 18, 2026
  39. Codex Cloud/Web has compounding reliability, observability, and workflow problems that make long-running tasks difficult to trustinsightlabs38, OpenAI Developer Community user (self-described: Development work in Codex Cloud on ChatGPT Plus), Forum post, published Sep 13, 2026
  40. Comment on: Cognition launches new SWE-2 model, Rivaling Fable 5.1 and GPT-Astrahightrix, Hacker News commenter (self-described: Company with enterprise seats for Devin, Claude and Codex), Hacker News comment, published Sep 10, 2026
  41. Comment on: I-have-ADHD: A skill to stop coding agents from burying the answeriforgotmypasswo, choosing their company's primary AI provider (self-described: Company evaluating a switch of its primary AI provider), Hacker News comment, published Sep 9, 2026
  42. Review: Codex Tools for Improving AccessibilityRiley Collins, software developer at Atomic Object (Atomic Object, sole developer on a client project while one arm was in a cast), Company blog post, Atomic Object (Atomic Spin), published Sep 8, 2026
  43. Astra for Coding: Why Are We Doing This Again?Armin Ronacher, developer (self-described: Solo weekend experiment running an unattended agent 'software factory' on a CPython fork, plus regular programming), Personal blog post, lucumr.pocoo.org (Armin Ronacher's Thoughts and Writings), published Sep 7, 2026
  44. The Codex 5-Hour Limit Is Making It Practically UnusableJessica Doering, developer (self-described: Solo, adding a feature to their own editor app), dev.to post, DEV Community, published Aug 30, 2026
  45. OpenAI Codex pricing: the US$270 PR a US$200/month sub covers dailyJacek Migdal, Quesma (self-described: Quesma, company on OpenAI Business ChatGPT & Codex seats; teammates on ChatGPT Pro 20x), Company blog post, Quesma Blog, published Aug 28, 2026
  46. Lex Fridman Podcast #501: DHH on the future of programming and agentic engineeringDHH, CTO, 37signals (self-described: 37signals and Omarchy, his own agent work), Podcast episode with publisher transcript, published Aug 26, 2026
  47. Let Codex review draft PRs before they are ready for human reviewDan Masquelier, engineer on a team using Codex Cloud code review (self-described: Team keeping pull requests in draft while bots review them), GitHub issue on openai/codex, published Aug 25, 2026
  48. Lets talk about Codex (why i switched)Chris Raroque, independent app developer (self-described: Solo, their own iOS and productivity apps), Video, YouTube, published Aug 24, 2026
  49. Comment on: GPT 5.6 Sol 20% price reductionThePhysicist, Hacker News commenter (self-described: Own UI redesign), Hacker News comment, published Aug 22, 2026
  50. Comment on: GPT 5.6 Sol 20% price reductionreturnInfinity, Hacker News commenter (self-described: Company with unlimited Codex and Claude access), Hacker News comment, published Aug 22, 2026
  51. Comment on: Anthropic appears to be A/B testing reduced effort levels in Claude Codershnotsecure, Hacker News commenter (self-described: Developer approved for ChatGPT Pro at work), Hacker News comment, published Aug 22, 2026
  52. Quick impressions: A week of using Codex more than ClaudeLucian Ghinda, Ruby and Rails developer (self-described: Solo, own Ruby and Rails projects; week-long side-by-side use), Personal newsletter post, All about coding, published Aug 21, 2026
  53. How Superhuman Scaled AI Coding Agents Across Their Entire Eng OrgYaroslav (Yarik), tech lead for the coding-agent rollout, Superhuman (self-described: Superhuman, formerly Grammarly, engineering organization), Conference talk video, published Aug 18, 2026
  54. Codex credits consumed ~38,000 to 39,000 overnight with zero tasks issued: recurring bug, cap not enforced, no warning givenchang-kr, GitHub user in an organization workspace (self-described: Company workspace with organization-set monthly credit caps, VS Code extension), GitHub issue on openai/codex, published Aug 13, 2026
  55. How I Rebuilt My Development Workstation for Agentic WorkBrian May, software developer at Atomic Object (Atomic Object consultant running several agent threads across client work), Company blog post, Atomic Object (Atomic Spin), published Aug 8, 2026
  56. What's the Best Coding Agent? 2026 EditionTim Sehn, CEO of DoltHub (Over 1,500 agent pull requests on DoltLite since May 1, about six hours a day), Company engineering blog post, DoltHub Blog, published Aug 5, 2026
  57. Comment on: Google fixed more Chrome bugs in June than over the past two years, thanks to AIndriscoll, Hacker News commenter (self-described: Engineering team owning production services, using Slack, PagerDuty and Grafana), Hacker News comment, published Jul 31, 2026
  58. Comment on: Using an open model feels surprisingly goodsafety1st, Hacker News commenter (self-described: Team that uses both Codex and Claude, with human-reviewed delivery), Hacker News comment, published Jul 28, 2026
  59. XDA Developers: I cancelled Claude after 6 months of daily useAnurag Singh, tech journalist, XDA Developers (self-described: His own coding projects, moved to the US$20 ChatGPT Plus plan), Practitioner write-up, published Jul 27, 2026
  60. Comment on: What is happening to jobs? Separating AI hype from realitysuzzer99, tech lead at a very small shop (self-described: Very small shop; large internal project with a team of about eight), Hacker News comment, published Jul 26, 2026
  61. GPT-5.6 often serializes independent Code Mode calls; explicit batching reduced weighted usage by 27 to 45%Deleted GitHub account (self-described: Large proprietary work codebase on Business and a personal app on Pro), GitHub issue on openai/codex, published Jul 24, 2026
  62. Comment on: Fable 5 vs. GPT-5.6 Sol on an NP-Hard Problem: Does /goal help?sreekanth850, Hacker News commenter (self-described: Three-person team selling to local government, 400,000-line repository), Hacker News comment, published Jul 18, 2026
  63. Codex is technically better than Claude Code, but I stopped using it for one specific reasonMahnoor Faisal, tech writer at XDA Developers (self-described: Solo, building apps with coding agents), First-person review column, XDA Developers, published Jul 16, 2026
  64. Parlance Labs: automated error analysis on 100 production tracesAntaripa Saha and Hamel Husain, evaluation practitioners, Parlance Labs (self-described: 100 masked production traces from an apartment-leasing assistant), Practitioner write-up, published Jul 11, 2026
  65. Perceived regression in Codex quality and higher token consumption with GPT-5.6boss-ccc, GitHub user (self-described: Day-to-day coding in Codex), GitHub issue on openai/codex, published Jul 10, 2026
  66. Comment on: GPT-5.6clutter55561, Hacker News commenter (self-described: Developer who plans and codes with Claude and reviews with Codex), Hacker News comment, published Jul 9, 2026
  67. Codex vs Claude Code: Which Is the Better Background Agent? (2026)Rogerio Chaves, Co-founder and CTO at LangWatch (LangWatch, lean engineering team running a fleet of scheduled background agents), Company engineering blog post, LangWatch, published Jul 8, 2026
  68. How I run autonomous coding agents from my phone with OpenAI Symphony + LinearAlessio Fanelli, founder of Kernel Labs (self-described: Side projects, including tools for their trading card shop, run on a cloud VPS), Podcast episode, How I AI (YouTube), published Jul 6, 2026
  69. Comment on: Senior SWE-Bench: open-source benchmark that assesses agents as senior engineerssaberience, engineer and Hacker News commenter, self-described, Hacker News comment, published Jul 3, 2026
  70. GPT-5.5 Codex reasoning-token clustering at 516/1034/1552 may be leading to degraded performance on complex tasksvguptaa45, GitHub user (self-described: 390,195 response records from 865 of their own Codex sessions), GitHub issue on openai/codex, published Jun 27, 2026
  71. Comment on: U.S. government will decide who gets to use GPT-5.6vitally3643, Hacker News commenter (self-described: Company weighing local models against its Codex spend), Hacker News comment, published Jun 26, 2026
  72. Latent Space: Matei Zaharia of Databricks at Data + AI Summit 2026Matei Zaharia, co-founder, Databricks (self-described: Databricks developer infrastructure), Podcast episode with publisher transcript, published Jun 24, 2026
  73. Codex (gpt-5.5, Plus plan): rate-limit cost per token jumped ~10-20x since June 16, draining the 5h budget in 2-3 promptsMihnea Peteu, solo developer (GitHub profile) (self-described: Solo, Codex desktop on Windows 11), GitHub issue on openai/codex, published Jun 18, 2026
  74. Codex SQLite feedback logs can write ~640 TB/year and rapidly consume SSD enduranceRui Fan, Apache Flink PMC member (GitHub profile) (self-described: Long-running local Codex use), GitHub issue on openai/codex, published Jun 14, 2026
  75. Regression: encrypted MultiAgentV2 messages remove readable task audit trailIgnat Remizov, CTO at Zolvat (GitHub profile) (self-described: Fintech, Codex CLI with MultiAgentV2 subagents), GitHub issue on openai/codex, published Jun 13, 2026
  76. Grit: rewriting Git in Rust with agentsScott Chacon, co-founder of GitButler (GitButler, months-long port of Git to a Rust library run through several coding agents), Company blog post, GitButler (Butler's Log), published Jun 9, 2026
  77. Comment on: Anthropic surpasses OpenAI to become most valuable AI startupamazingamazing, Hacker News commenter (self-described: Developer and a colleague comparing Claude Code and Codex on real pull requests), Hacker News comment, published May 30, 2026
  78. Comment on: Corporate America Is Starting to Ration AI as Cost Skyrocketsninkendo, Hacker News commenter (self-described: Team service with a Postgres-backed CI pipeline), Hacker News comment, published May 30, 2026
  79. Comment on: Anthropic raises $65B in Series H funding at $965B post-money valuationtoraway, Hacker News commenter (self-described: Engineer who recommends the company's AI coding subscriptions), Hacker News comment, published May 29, 2026
  80. Codex Is ExcellentClaire Morrison and Katie Fifer, Technically Curious (self-described: Two co-authors using Codex for personal coding projects and business work), Newsletter post, Technically Curious (Substack), published May 27, 2026
  81. I let Codex run for 6 hours. Here's what happened.Claire Vo, founder of ChatPRD and host of How I AI (self-described: ChatPRD codebase plus personal email and Linear cleanup), Podcast episode, How I AI (YouTube), published May 27, 2026
  82. How I code with AI changed a lotTheo Browne (t3.gg), developer who builds T3 Code (self-described: Solo build of their Lakebed project over five days), Video, YouTube, published May 27, 2026
  83. Comment on: Outsourcing plus local AI will soon become more economical vs. frontier labsz2, Hacker News commenter (self-described: Company on ChatGPT Business with a small share of staff using Codex), Hacker News comment, published May 26, 2026
  84. Significant model quality regression in codex-5-5 (xhigh): Instructions not followed, repeated regressions, affects both CLI and IDEAndrés Alvarez, Full Stack Developer at Learnware Cloud (GitHub profile) (self-described: Feature work with a detailed AGENTS.md, Codex CLI and VS Code extension), GitHub issue on openai/codex, published May 26, 2026
  85. Comment on: Using AI to write better code more slowlyjillesvangurp, Hacker News commenter (self-described: Resource-constrained company), Hacker News comment, published May 26, 2026
  86. Why Are Agentic Pull Requests Merged or Rejected? An Empirical StudySien Reeve O. Peralta and co-authors, software engineering researchers (self-described: 9,799 human-reviewed agent pull requests, 717 inspected by hand), Independent study, arXiv, published May 21, 2026
  87. Comment on: AI subscriptions are a ticking time bomb for enterprisesubmeta, Hacker News commenter (self-described: Employee at a company that rolled out ChatGPT with Codex), Hacker News comment, published May 17, 2026
  88. Comment on: Codex is now in the ChatGPT mobile appsuperfrank, Hacker News commenter (self-described: Personal projects (Codex); Claude at work), Hacker News comment, published May 15, 2026
  89. Comment on: Claude for Small Businessjillesvangurp, developer at a company that helps small teams adopt agentic AI (self-described: Small company; onboarding its non-developer CEO to Codex for website, inbox, sales and accounting work), Hacker News comment, published May 14, 2026
  90. Claude Code vs ChatGPT Codex: Two Official Agents, One Choice You Don't Have to MakeKen Imoto, engineer at Propel-Lab (self-described: Own projects; ran both agents side by side for a month), dev.to post, DEV Community, published May 14, 2026
  91. Transcript: 'Why We Switched From Claude Code to Codex'Austin Tedesco, head of growth at Every (self-described: Every, growth and knowledge work plus occasional product PRs), Podcast episode (published transcript), Every (AI & I podcast), published May 6, 2026
  92. Comment on: Claude.ai and API unavailable [fixed]CompoundEyes, Hacker News commenter (self-described: Company with unlimited Anthropic and OpenAI model access), Hacker News comment, published Apr 30, 2026
  93. How I Use OpenAI Codex (Real Workflow)Owain Lewis, developer (self-described: Solo, their own project tracked in Linear), Video, YouTube, published Apr 25, 2026
  94. OpenAI's New GPT-5.5 Powers Codex on NVIDIA Infrastructure, and NVIDIA Is Already Putting It to WorkJustin Boitano, vice president and general manager of enterprise computing at NVIDIA (self-described: NVIDIA, over 10,000 employees across functions using Codex; per-employee cloud VMs), Company blog post, NVIDIA Blog, published Apr 23, 2026
  95. Latent Space: Shopify with CTO Mikhail ParakhinMikhail Parakhin, CTO, Shopify (self-described: Shopify, every employee chooses their coding tool), Podcast episode with publisher transcript, published Apr 22, 2026
  96. Dueling Agents: Claude and CodexTim Sehn, CEO of DoltHub (Building DoltLite, a SQLite fork in C, with agents in parallel terminals), Company engineering blog post, DoltHub Blog, published Apr 22, 2026
  97. I switched from Claude Code to Codex for a week, and the trade-offs surprised meMahnoor Faisal, tech writer at XDA Developers (self-described: Solo, building tools for their own workflow), First-person review column, XDA Developers, published Apr 21, 2026
  98. Comment on: Claude Opus 4.7trueno, Hacker News commenter (self-described: Works with a coworker; their current toolset is Claude), Hacker News comment, published Apr 16, 2026
  99. How we made the Angular Compiler faster using AILong Yinan, software engineer at VoidZero (VoidZero Oxc team, two-month Rust port of the Angular compiler), Company engineering blog post, VoidZero, published Apr 10, 2026
  100. GPT 5.4 is a big step for CodexNathan Lambert, ML researcher (self-described: Solo, smaller projects, data analysis and research tasks), Newsletter, Interconnects AI (Substack), published Mar 18, 2026
  101. Burning tokens very fastcyooi, GitHub user on a Business plan (self-described: Business plan, VS Code extension), GitHub issue on openai/codex, published Mar 13, 2026
  102. AGENTS.md is silently truncated and instructions near the end ignoredBeehive Innovations, makers of 2Do and BusyCal (GitHub organization account) (self-described: App maker with a large AGENTS.md, Pro plan on macOS), GitHub issue on openai/codex, published Mar 3, 2026
  103. Comment on: Claude becomes number one app on the U.S. App Storeben_w, Hacker News commenter (self-described: European software engineer, mainly Swift, ObjC and Java), Hacker News comment, published Mar 2, 2026
  104. OpenAI Codex Review 2026 - Updated from Daily UseZachary Proser, Applied AI at WorkOS (self-described: Personal projects and apps Proser maintains on the WorkOS Applied AI team), Personal blog post, zackproser.com, published Mar 2, 2026
  105. Comment on: Ask HN: Who has seen productivity increases from AISomeone1234, Hacker News commenter (self-described: Team rewriting a legacy 1990s RAD application into React), Hacker News comment, published Feb 24, 2026
  106. Hackathon Spotlight: AI-Assisted Jira Workflows and One-Shot Fixes with Kotlin Koog and OpenAI CodexMatthias Tamegger and Lukas Knoch-Girstmair, engineers at Bitmovin (self-described: Bitmovin company-wide hackathon; Jira-ticket-to-pull-request one-shot fix workflow running Codex non-interactively in Docker), Engineering blog post, Bitmovin blog, published Feb 23, 2026
  107. Codex App Worktrees: A Practical WorkflowThiago Temple, developer (self-described: Solo, their own web app monorepo), Video, YouTube, published Feb 23, 2026
  108. Comment on: How I use Claude Code: Separation of planning and executionraw_anon_1111, Hacker News commenter (self-described: Consultant with a US$800 monthly company Claude allowance), Hacker News comment, published Feb 22, 2026
  109. When Coding Tools Compete: Claude Code vs. Codex (Real Usage After 2 Months)Pawel Jozefiak, independent builder (self-described: Solo, auditing their own 2-month-old agent codebase), Newsletter post, Digital Thoughts (thoughts.jock.pl, Substack), published Feb 16, 2026
  110. Claude Opus 4.6 vs GPT-5.3 Codex: Which is the better software engineer?Claire Vo, founder of ChatPRD and host of How I AI (self-described: ChatPRD marketing site and core application), Podcast episode, How I AI (YouTube), published Feb 11, 2026
  111. I Tried OpenAI's New Codex Agent. Here are my First Impressions (It's Really Good)Dan Vega, Java developer (self-described: Solo, a Java test project and their personal website), Personal blog post, danvega.dev, published Feb 5, 2026
  112. Trying out the Codex appMatt Crouch, developer (self-described: Their personal blog codebase and a work front end monorepo), Personal blog post, mattcrouch.net (Matt Crouch's Blog), published Feb 4, 2026
  113. Quality of GPT-5.2 xhigh's work has massively degraded and appears to just route to GPT-5.2 Codexkhoek, Codex CLI user on the Pro plan (self-described: GitHub issue on openai/codex, Pro plan), GitHub issue, published Feb 3, 2026
  114. Comment on: Qwen3-Coder-NextUehreka, Hacker News commenter (self-described: Work (ChatGPT Enterprise) plus a personal Claude Max subscription), Hacker News comment, published Feb 3, 2026
  115. Vibe Check: We Tested OpenAI's New Codex AppDan Shipper, co-founder and CEO of Every, with staff writer Katie Parrott (self-described: Every team Reach Test with its engineering lead and the general managers of Monologue and Cora), Newsletter, Every, published Feb 2, 2026
  116. Subagent feature: Launching concurrent subagents instantly drains entire Pro plan usage quotaAdrian Holt, CTO at FloodWaive (GitHub profile) (self-described: Pro plan, VS Code on Ubuntu), GitHub issue on openai/codex, published Jan 23, 2026
  117. Where Do AI Coding Agents Fail? An Empirical Study of Failed Agentic Pull Requests in GitHubRamtin Ehsani and co-authors, software engineering researchers (self-described: 33,596 agent pull requests in public GitHub repositories), Independent study, arXiv, published Jan 21, 2026
  118. Lenny's Podcast: The non-technical PM's guide to building with CursorZevi Arnovitz, product manager, Meta (self-described: His own projects), Podcast episode with publisher transcript, published Jan 18, 2026
  119. Full Story of Brex’s AI Hail MaryJames Reggio, CTO at Brex (Brex engineering, where employees choose among several licensed coding tools), Podcast episode show notes and transcript, Latent Space, published Jan 17, 2026
  120. Terminal-Bench: Benchmarking Agents on Hard, Realistic Tasks in Command Line InterfacesTerminal-Bench authors (self-described: Benchmark of hard command-line tasks, agents run by the benchmark team), Independent benchmark, arXiv (Terminal-Bench), published Jan 17, 2026
  121. Why I’m Sold on AI for Code ReviewsKelsey Brennan, software developer at Atomic Object (Atomic Object client project team with a Django backend and shared Cursor rules), Company blog post, Atomic Object (Atomic Spin), published Dec 30, 2025
  122. Comment on: The 70% AI productivity myth: why most companies aren't seeing the gainsorwin, Hacker News commenter (self-described: Senior engineer on a team using Sonnet 4.5 and Codex 5.1), Hacker News comment, published Dec 30, 2025
  123. A Year Of VibesArmin Ronacher, developer (self-described: Their own coding at a new company, reviewed with agents locally), Personal blog post, lucumr.pocoo.org (Armin Ronacher's Thoughts and Writings), published Dec 22, 2025
  124. Codex vs. Claude Code (Today)Joe Fabisevich, indie developer and Plinky creator (self-described: Solo client and personal projects; Codex for coding and Claude Code for utility tasks), Personal blog post, build.ms, published Dec 22, 2025
  125. Comment on: Your job is to deliver code you have proven to worktunesmith, director-level engineering manager (self-described: Leads a team of direct reports; a bug the team had attributed to an external vendor), Hacker News comment, published Dec 19, 2025
  126. I ported JustHTML from Python to JavaScript with Codex CLI and GPT-5.2 in 4.5 hoursSimon Willison, independent developer (self-described: Solo side experiment: porting an open source HTML5 parser), Personal blog post, simonwillison.net, published Dec 15, 2025
  127. The Ultimate Guide to ChatGPT Codex: OpenAI's Claude Code KillerCarl Vellotti, creator of AI tutorials for product managers (self-described: A PM workspace built for the episode and a personal side project), Podcast episode (show notes), Product Growth (Aakash Gupta), published Dec 8, 2025
  128. AI Engineer: Hacking Subagents Into Codex CLIBrian John, principal full-stack engineer, AI enablement for R&D, BetterUp (self-described: BetterUp R&D AI enablement), Conference talk video, published Nov 24, 2025
  129. Comment on: Building more with GPT-5.1-Codex-MaxJaiden333, startup founder and engineer (self-described: Startup, own feature work), Hacker News comment, published Nov 20, 2025
  130. Comment on: Building more with GPT-5.1-Codex-Maxjohnfn, Hacker News commenter, self-described, Hacker News comment, published Nov 19, 2025
  131. Pro plan: hit 5-hour limit twice (in 2h and 1.5h) and nearly exhausted weekly cap in 1 day after today's updateMax Zhadobin, OpenAI Developer Community user (self-described: OpenAI Developer Community post, Pro plan), Forum post, published Nov 2, 2025
  132. Comment on: I've been loving Claude Code on the webwahnfrieden, Hacker News commenter (self-described: Team that uses Codex as its main coding agent), Hacker News comment, published Oct 28, 2025
  133. Comment on: Claude Code vs. Codex: I built a sentiment dashboard from Reddit commentsextr, Hacker News commenter (self-described: Enterprise developer who uses Claude Code and Codex), Hacker News comment, published Oct 17, 2025
  134. Experiences with GPT-5-CodexWayne Joubert, guest author on John D. Cook's blog (self-described: Their own Python code, Codex extension inside Cursor), Blog post (guest author), johndcook.com (John D. Cook's blog), published Oct 16, 2025
  135. Just Talk To It - the no-bs Way of Agentic EngineeringPeter Steinberger, independent developer (self-described: Solo, own projects; several Codex CLI sessions in one folder), Personal blog post, steipete.me, published Oct 14, 2025
  136. Comment on: Two things LLM coding agents are still bad atrossant, Hacker News commenter (self-described: Neuroscience researcher and engineer at the International Brain Laboratory and UCL), Hacker News comment, published Oct 9, 2025
  137. Dual Wielding Codex and Claude CodeChris Ellis, engineering team lead at XtendOps (self-described: Pivot of a multi-tenant product to single tenant under deadline, working inside Cursor), Newsletter post, Engineered Intelligence (Substack), published Oct 8, 2025
  138. Embracing the parallel coding agent lifestyleSimon Willison, independent developer (self-described: Solo open source work, several agents in separate checkouts), Personal blog post, simonwillison.net, published Oct 5, 2025
  139. Claude Code vs Codex CLI: Head to HeadMatt Wigdahl, independent software developer (self-described: Solo, controlled side-by-side rebuild of the same React and TypeScript specification), Substack post, The Anything Interface, published Oct 3, 2025
  140. Comment on: Unix philosophy and filesystem access makes Claude Code amazingdudeinhawaii, Hacker News commenter (self-described: Large codebases with dozens of interconnected tools and projects), Hacker News comment, published Oct 1, 2025
  141. Comment on: Claude Sonnet 4.5iagooar, Hacker News commenter (self-described: Own web application of about 200k lines of code), Hacker News comment, published Sep 29, 2025
  142. Codex vs Claude Code: which is the better AI coding agent?Steve Sewell, co-founder and CEO of Builder.io (self-described: Builder.io dev team; Codex also built into Builder.io for designers and PMs), Company blog post, Builder.io blog, published Sep 28, 2025
  143. How I Used Codex to Ship Nearly 80 Pull Requests in Two Daystom-takeru, full-stack engineer (self-described: Solo, personal subscription-style product repository), dev.to post, DEV Community, published Sep 27, 2025
  144. Claude Code vs Codex CLIRaveesh, independent builder (self-described: Solo, a fairly mature personal project), Newsletter post, raveesh.substack.com (Substack), published Sep 22, 2025
  145. GPT 5 - Codex is a fantastic AI model for coding, but...GosuCoder, independent developer (self-described: Their own codebase plus side-by-side test prompts), Video, YouTube, published Sep 19, 2025
  146. AI coding: plateauing but also acceleratingAlex Ghiculescu, co-founder of Tanda (Tanda engineering, comparing Codex cloud tasks with Claude Code), Newsletter post, Alex Ghiculescu (Substack), published Aug 18, 2025
  147. Testing AI coding agents (2025): Cursor vs. Claude, OpenAI, and GeminiMitch Alderson, Render (self-described: Render engineering, vibe-coding task and tasks in a production Go repository), Independent benchmark, Render engineering blog, published Aug 12, 2025
  148. Comment on: Ask HN: How much of OpenAI code is written by AI?ianpurton, Hacker News commenter, self-described, Hacker News comment, published Jul 14, 2025
  149. Comment on: Building a Personal AI Factorydgunay, Hacker News commenter (self-described: Finance company, Go codebase of several hundred thousand lines serving six-figure B2C users), Hacker News comment, published Jul 2, 2025
  150. Comment on: Building Effective AI Agents0x457, Hacker News commenter, self-described, Hacker News comment, published Jun 17, 2025
  151. Comment on: OpenAI Codex hands-on reviewrmonvfer, Hacker News commenter (self-described: Software engineer in Spain building Agentmode), Hacker News comment, published May 20, 2025
  152. OpenAI's Codex: A review after a dozen AI generated PRsAntoine Finkelstein, co-founder of Hunter (self-described: Own production application), Personal blog post, antoine.fi, published May 19, 2025
  153. OpenAI Codex Review: Is It Worth It in 2025?Zachary Proser, Applied AI at WorkOS (self-described: Own repositories, first days of the Codex cloud at its May 2025 launch), Personal blog post, zackproser.com, published May 18, 2025
  154. Improving our Java SDK with Codex by OpenAIRyan Cox, Senior Director of Infrastructure and Security at Temporal (self-described: Temporal SDK and server repositories; engineers across the company), Engineering blog post, Temporal blog, published May 17, 2025
  155. Comment on the Hacker News launch thread for Codex (May 2025)johnjwang, Hacker News commenter testing Codex with their team at Assembled (self-described: Assembled, engineering team in the Codex alpha test), Hacker News comment, published May 16, 2025
  156. Vibe Check: Codex, OpenAI's New Coding AgentDan Shipper, co-founder and CEO of Every (self-described: Every; tested with Kieran Klaassen, Cora general manager, on Cora's Rails codebase), Newsletter, Every, published May 16, 2025
  157. Comment on: Show HN: Memex is a Claude Code alternative built on Rust+Tauri for vibe codinguyzeqzer, Hacker News commenter (self-described: Company that routes model access through LiteLLM), Hacker News comment, published Apr 29, 2025

Apr 2025 to Oct 2026.

136 sources from practitioners, by month and sentiment.

The full readExplore all Codex Signals8 praise themes, 6 concerns, 5 points of agreement and 3 disagreements across all three groups, with all 157 sources open to inspect.

Where It Fits

Where does Codex belong in the stack?

Open Where It Fits: the Stack Field and the full map

Codex is Core across Build, supports Plan and Validate, and touches Ship and Operate.

Business area
Product & Engineering
Function
Software Development
Operating stack
Agentic Software Development
Primary role
Local & Cloud Coding Agent
Codex beside the rest of its stackThe Stack Field, every product on every layer
FootprintCodex across the Agentic Software Development stack. Bar height is its role on each layer.

  1. Plan

    1. Work planning: Supports

      Work planning, supports. Codex can plan a change before editing, split larger work across subagents, and take tasks from Linear issues; planning stays in the team's tracker.

  2. Build

    1. Codebase context: Core

      Codebase context, core. Codex inspects the repository and reads layered AGENTS.md files before any work, and Codex Cloud environments keep repositories and dependencies ready across tasks.

    2. Coding: Core

      Coding, core. Codex's primary role is coding implementation: writing and changing repository code from the CLI, IDE extension, desktop app, or cloud task.

    3. Agent runtime: Core

      Agent runtime, core. The Codex CLI, the IDE extension for VS Code-compatible editors, and the ChatGPT desktop app are where developers steer, review, and accept agent work.

    4. Tool execution: Core

      Tool execution, core. Codex runs commands inside an OS-enforced sandbox with an approval policy, calls MCP tools, and lets rules allow, prompt, or forbid specific command prefixes.

  3. Validate

    1. Debugging: Supports

      Debugging, supports. Codex can reproduce and investigate failures using repository context and command output, locally or in a cloud task.

    2. Testing: Supports

      Testing, supports. Codex can write and run tests inside its sandbox or cloud environment, but it does not replace dedicated testing infrastructure.

    3. Code review: Supports

      Code review, supports. Codex reviews GitHub pull requests on request or automatically, flagging P0 and P1 issues, and /review checks local changes. Final review ownership stays with the team.

    4. Application security: Touches

      Application security, touches. Codex Security scans connected GitHub repositories on Enterprise plans; application security stays on the team's own platform.

  4. Ship

    1. Source control: Touches

      Source control, touches. Codex works in Git worktrees and can commit or open pull requests; Git stays the system of record.

    2. CI/CD: Touches

      CI/CD, touches. codex exec and the Codex GitHub Action run Codex in CI jobs; delivery stays in the team's CI/CD.

  5. Operate

    1. Observability: Touches

      Observability, touches. Codex can help investigate production issues when given the relevant context, but it does not provide observability itself.

Market mapThe layers Codex covers, and who else owns each one.

  1. Codebase context & intelligence

    CoreBuild

  2. Coding & implementation

    CoreBuild

  3. Agent interface & developer runtime

    CoreBuild

  4. Tool execution & integrations

    CoreBuild

  5. Work planning & task decomposition

    SupportsPlan

7 more layers on the full map. Core, Supports and Touches describe coverage. They say nothing about quality.

Models

Which models run in Codex?

The current releases GILD tracks that public sources record running in Codex. Each model's page charts its public benchmark scores.

  1. Gemini 3.8 FlashA Gemini Flash release for long-horizon software engineering, agents, and enterprise workflows.Gemini FlashBenchmarks
  2. GLM-5.2Z.ai's flagship model for long-horizon tasks, reading text only, with a 1M-token context window and 128K output tokens. API model glm-5.2 at US$1.40 per million input tokens and US$4.40 per million output tokens; also on Google Cloud, Databricks (which lists it as a legacy model) and in Cursor.GLMBenchmarks
  3. GLM-5.3Z.ai's flagship open-weight model for coding and agentic work, with a 1M-token context window, on the Z.ai API and also served by Mistral AI and OpenRouter. Weights under the GLM-5.3 License.GLMBenchmarks
  4. GPT-5.4OpenAI's GPT-5.4 model for coding and professional work, with text and image input. API model gpt-5.4 (snapshot gpt-5.4-2026-03-05) at US$2.50 per million input tokens and US$15 per million output tokens, with a 1,050,000-token context window; prompts over 272K input tokens cost more. Also in Cursor; GitHub Copilot dropped it on October 19, 2026.GPT-5Benchmarks
  5. GPT-5.5OpenAI's GPT-5.5 flagship model for coding and complex professional work, with text and image input. API model gpt-5.5 (snapshot gpt-5.5-2026-04-23) at US$5 per million input tokens and US$30 per million output tokens, with a 1,050,000-token context window; also in Cursor. It left GitHub Copilot on October 19, 2026 and Codex for ChatGPT sign-in on October 14, 2026.GPT-5Benchmarks
  6. GPT-5.6 LunaOpenAI's GPT-5.6 model for cost-sensitive, high-volume workloads, with text and image input. API model gpt-5.6-luna at US$0.20 per million input tokens and US$1.20 per million output tokens, with a 1,050,000-token context window; also in GitHub Copilot and Cursor.GPT LunaBenchmarks
  7. GPT-5.6 SolOpenAI's GPT-5.6 flagship model for complex professional work, with text and image input. API model gpt-5.6-sol at US$4 per million input tokens and US$20 per million output tokens, with a 1,050,000-token context window and 128,000 output tokens; also in GitHub Copilot and Cursor.GPT SolBenchmarks
  8. GPT-5.6 TerraOpenAI's GPT-5.6 model that balances intelligence and cost, with text and image input. API model gpt-5.6-terra at US$2 per million input tokens and US$12 per million output tokens, with a 1,050,000-token context window; also in GitHub Copilot and Cursor.GPT TerraBenchmarks
  9. GPT-6.1 SolOpenAI's newer Sol model, close to GPT-6 Astra on complex work at a lower cost. On OpenAI's own OSWorld 2.1 computer-use run (offline set) it scores 78%, 2.9 points under GPT-6 Astra at about a seventh of the cost per task. API model gpt-6.1-sol, with a 1,050,000-token context on the OpenAI API; Microsoft Foundry caps input at 922,000 tokens.GPT SolBenchmarks
  10. GPT-6.1 TerraOpenAI's fast, efficient GPT-6.1 model for visual reasoning, computer use and writing, at US$1 per million input tokens and US$5 per million output tokens. Artificial Analysis scores it 51 on its Intelligence Index at US$0.96 per task, and OpenAI's own OSWorld 2.1 computer-use run (offline set) puts it at 74.2%, 3.8 points under GPT-6.1 Sol. API model gpt-6.1-terra, with a 1,050,000-token context and 128,000 output tokens on the OpenAI API.GPT TerraBenchmarks
  11. GPT-6 AstraOpenAI's highest-capability GPT-6 release for complex end-to-end work.GPT AstraBenchmarks
  12. GPT-6 LunaOpenAI's most efficient GPT-6 model, for focused, high-volume tasks. API model gpt-6-luna, with a 1,050,000-token context on the OpenAI API; Microsoft Foundry caps input at 922,000 tokens.GPT LunaBenchmarks
  13. gpt-oss-120bOpenAI's largest open-weight model, 117B parameters with 5.1B active, with a 131,072-token context window. Weights under the Apache 2.0 license; OpenAI lists no API price for it, so it runs on your own hardware or a host's.gpt-ossBenchmarks
  14. Grok 4.6xAI's Grok release for coding, agentic tasks and knowledge work, which xAI's release notes credit to SpaceXSI. API model grok-4.6 with a 500K-token context window at US$2 per million input tokens and US$6 per million output tokens below 200K prompt tokens, twice that above; also on Amazon Bedrock, Google Cloud and Microsoft Foundry (preview), and in GitHub Copilot and Cursor. xAI's models page points code and other text work to Grok 4.7.GrokBenchmarks
  15. Kimi K3.1 ProMoonshot AI's first K3.1 release, a post-trained Kimi K3 with a 1M-token context window and a Highspeed variant on the Kimi API. Weights under the Kimi K3.1 Pro License.Kimi K3.1Benchmarks
  16. MiMo-V2.6-ProXiaomi's flagship MiMo model, a mixture-of-experts model of about 1T parameters with 42B active and a 1M-token context. Weights under the MIT license.MiMoBenchmarks
  17. Mistral Large 4Mistral AI's flagship multimodal mixture-of-experts model, in Public Preview (v26.10) on the Mistral API and Mistral Studio since October 6, 2026, and also on OpenRouter and OpenCode Zen. Mistral has published no GA date. Its open weights followed on October 29, 2026, under the Mistral Ecosystem Open-Weight license, a modified MIT license.Mistral LargeBenchmarks

More on Codex

  1. GILD ReviewGILD's evaluation, with the buying facts
  2. Research3 pieces
  3. Guides4 guides
  4. Operator Insights16 operator accounts
  5. Where It FitsOn the Agentic Software Development stack
  6. Related Products8 products