OpenAI Codex changelog

Codex CLI 0.166.0 adds GPT-6.1 Terra to Vertex AI and Bedrock catalogs

Codex CLI 0.166.0 adds GPT-6.1 Terra to the bundled, Vertex AI, and Amazon Bedrock model catalogs.

Who is affected:

Codex users on Vertex AI or Bedrock can select GPT-6.1 Terra.

What to do:

Update to Codex CLI 0.166.0 to see the model in your catalog.

Codex CLI 0.166.0 adds transcript selection and codex doctor --network-only

Codex CLI 0.166.0 adds keyboard-driven transcript selection, codex queue --resume, clearer safety-block explanations with safer follow-up prompts, and codex doctor --network-only for network diagnostics.

Who is affected:

Codex CLI users get new terminal navigation and diagnostics features.

What to do:

Run npm install -g @openai/codex@0.166.0 to update.

OpenAI API, Codex and ChatGPT Work purchasable through Oracle Marketplace

Oracle customers in the U.S. can buy access to the OpenAI API, Codex and ChatGPT Work through Oracle Marketplace. Purchases use existing procurement processes and eligible Oracle Universal Credits.

Codex CLI 0.165.0 adds a Google Cloud Vertex AI provider

Codex CLI 0.165.0 adds a built-in Vertex AI provider set with model_provider = "gcp" and adds GPT-6.1 Terra to the model catalogs. It also turns on reasoning effort changes during a conversation by default and makes memory v2 the default for fresh profiles.

Who is affected:

Codex CLI users who want Google Cloud models or who start fresh profiles are affected.

What to do:

Run npm install -g @openai/codex@0.165.0 to update.

GPT-6.1 Terra arrives in ChatGPT Work and Codex

GPT-6.1 Terra is available in ChatGPT Work and Codex on Plus, Pro, Business, Enterprise and Edu plans. It is not available in Chat and does not support UAE inference residency.

Who is affected:

Users of Codex and ChatGPT Work on paid plans can now pick a fast model with strong image understanding and computer use.

What to do:

Choose GPT-6.1 Terra from the model list in Advanced in the ChatGPT desktop app or in ChatGPT Work on the web.

Codex CLI 0.164.0 adds /presets and inline /model arguments

Codex CLI 0.164.0 adds ten numbered /presets slots for reusable prompts and slash commands. It also lets users set model, reasoning effort, speed and permission profiles with inline /model and /permissions arguments, and enables the Amazon Bedrock setup wizard by default.

Who is affected:

Codex CLI users get faster model and permission switching and reusable prompts.

What to do:

Run npm install -g @openai/codex@0.164.0 to update.

OpenAI models and Codex coming to Google Cloud

OpenAI and Google Cloud announced OpenAI frontier models and Codex workflows in Model Garden through Google Cloud Marketplace.

GPT-5.5 retired from Codex and ChatGPT

At noon PDT (19:00 UTC) on October 14, 2026, GPT-5.5 retired from Codex for ChatGPT sign-in. Replacements are GPT-6.1 Sol on paid plans and GPT-6 Luna on Free and Go. API-key sessions are not affected.

Who is affected:

Codex and ChatGPT users and scheduled tasks that selected GPT-5.5.

Action needed:

Replace gpt-5.5 with gpt-6.1-sol in defaults, custom agents, scheduled tasks and scripts.

GPT-6.1 Sol in Codex matches Astra at 58.2% on Terminal-Bench 4.0 for about a fifth of the cost

Codex with GPT-6.1 Sol at max effort resolved 58.18% (plus or minus 3.1, 330 trials) for $634.24 total, against $3,267.18 for GPT-6 Astra at the same score. Posted October 6, 2026.

Who is affected:

Codex users deciding between GPT-6.1 Sol and GPT-6 Astra.

What to do:

Try GPT-6.1 Sol first for terminal tasks.

MarginLab Codex tracker shows GPT-6 Sol pass rates falling while its baseline is still being collected

MarginLab's Codex tracker (GPT-6 Sol at high effort, from September 24, 2026) showed 54% on the latest day (50 tasks), 59% over 7 days (350 tasks) and 79% over 30 days (1,450 tasks). The page marks 1-day (-29.4%) and 7-day (-24.9%) changes as statistically significant but says degradation detection is paused while the new baseline is built.

Who is affected:

Codex CLI users on GPT-6 Sol at high effort.

What to do:

Treat the drop as provisional and compare GPT-6.1 Sol on your own tasks.

GPT-6.1 Sol becomes the default model in the Codex CLI catalog

Codex CLI 0.159.1 added GPT-6.1 Sol as the default model in the bundled catalog and the Amazon Bedrock Mantle and Runtime catalogs.

Who is affected:

Codex CLI users who have not pinned a model.

What to do:

Pin a model in your Codex config if you need the previous default.

GPT-6.1 Sol arrives in Codex and ChatGPT Work

GPT-6.1 Sol rolled out to Codex and ChatGPT Work for Plus, Pro, Business, Enterprise and Edu. Free and Go were not included at launch.

Who is affected:

Codex and ChatGPT Work users.

What to do:

Try gpt-6.1-sol for long-running work.

New ChatGPT Pro 500 plan at $500 a month

OpenAI announced a Pro 500 plan at $500 a month with its highest included usage and Ultrafast access in ChatGPT Work and Codex.

Who is affected:

Heavy Codex and ChatGPT Work users.

What to do:

Compare Pro 500 against Pro 200 plus credits.

OpenAI fixes an image encoding bug that degraded GPT-6 Sol and Luna image understanding

OpenAI's API changelog says a bug in image encoding degraded image understanding in GPT-6 Sol and GPT-6 Luna, and the fix improves visual tasks in the API and Codex, including computer use.

Who is affected:

Apps and Codex sessions that sent image inputs or used computer use with GPT-6 Sol or GPT-6 Luna after their September 22 release.

What to do:

Rerun evaluations and retry workflows that used image inputs with GPT-6 Sol or GPT-6 Luna.

GPT-6 Sol and Luna roll out in Codex and ChatGPT Work

GPT-6 Sol and GPT-6 Luna rolled out to Codex and ChatGPT Work for Plus, Pro, Business, Enterprise and Edu at lower token prices than GPT-5.6. Free and Go get Luna in the desktop app. They are not available in ChatGPT Chat.

Who is affected:

Codex and ChatGPT Work users.

What to do:

Pick gpt-6-sol or gpt-6-luna. Enterprise admins must enable them.

GPT-5.3-Codex-Spark research preview retired

GPT-5.3-Codex-Spark was deprecated on September 14, 2026 and is no longer available in the ChatGPT desktop app, Codex CLI or IDE extension.

Who is affected:

Codex users and scripts that select gpt-5.3-codex-spark.

Action needed:

Switch to a recommended model. Use Fast mode for speed.

GPT-5.5 to retire from ChatGPT, ChatGPT Work and Codex on October 14

OpenAI announced GPT-5.5 would retire from ChatGPT, ChatGPT Work and Codex on all plans on October 14, 2026. The API is not affected.

Who is affected:

ChatGPT and Codex users and admins who select GPT-5.5.

Action needed:

Update workspace defaults, saved settings, custom agents and scripts that select gpt-5.5.

codex mcp-server command removed

The codex mcp-server command and the standalone codex-mcp-server binary were removed after deprecation on August 24, 2026. Connecting to external MCP servers through codex mcp still works.

Who is affected:

Integrations that launch Codex as an MCP server.

Action needed:

Move integrations to the Codex app server before upgrading Codex.

GPT-6 Astra in Codex scores 58.2% on Terminal-Bench 4.0

Codex with GPT-6 Astra at max effort resolved 58.18% (plus or minus 2.8, 330 trials, $3,267.18 total cost). Xhigh and high scored 57.88% and medium 54.24%.

GPT-5.4 and GPT-5.4 mini retired from Codex

gpt-5.4 and gpt-5.4-mini retired from Codex with ChatGPT sign-in on August 31, 2026. The Codex models page now lists gpt-6-sol and gpt-6-luna as replacements.

Who is affected:

Codex users signed in with ChatGPT.

Action needed:

Replace gpt-5.4 with gpt-6-sol and gpt-5.4-mini with gpt-6-luna.

Five-hour usage limit returns for Plus in Codex and ChatGPT Work

OpenAI said the five-hour usage limit returns for Plus subscribers in Codex and ChatGPT Work from August 25, after several weeks with only a weekly cap. Pro $100 and Pro $200 stay without the five-hour limit for now.

Who is affected:

ChatGPT Plus users who run Codex or Work.

Action needed:

Spread heavy Codex sessions across five-hour windows or buy credits.

Premium seats on ChatGPT Business with 5x usage and no five-hour limit

ChatGPT Business added premium seats with 5x more usage and no five-hour usage limit.

Who is affected:

ChatGPT Business workspaces.

What to do:

Admins: decide which members need premium seats.

GPT-5.4 and GPT-5.4 mini leave Codex on August 31

GPT-5.4 and GPT-5.4 mini will no longer be available in Codex for ChatGPT sign-in from August 31, 2026. They stay on the API. Replacements named were GPT-5.6 Terra and GPT-5.6 Luna.

Who is affected:

Codex users signed in with ChatGPT who use GPT-5.4 or GPT-5.4 mini.

Action needed:

Update workspace defaults, saved settings and scheduled tasks before August 31.

Codex moves into the ChatGPT desktop app

Codex became part of the ChatGPT desktop app on macOS and Windows. Existing Codex app users keep their projects and settings.

Who is affected:

Codex desktop app users.

What to do:

Update the app. Settings carry over.

Codex users report GPT-5.5 reasoning tokens clustering at 516, linked to weaker answers

A GitHub issue analyzing Codex token metadata from February 1 to June 27, 2026 found gpt-5.5 responses landing disproportionately at exactly 516 reasoning tokens, consistent with a reasoning-budget threshold. The author says it does not prove truncation. The thread drew 372 points and 152 comments.

Who is affected:

Codex users running gpt-5.5 on complex tasks.

What to do:

No action needed. GPT-5.5 retired from Codex with ChatGPT sign-in on October 14, 2026.

OpenAI fixes Codex bug that burned usage limits too fast

OpenAI's Codex lead said auto-review and subagents sometimes ran more often than intended or retried too aggressively, draining usage limits. Fixes were deployed and limits were reset for all users.

Who is affected:

Codex users who hit usage limits early in late June 2026.

What to do:

No action needed. Limits were reset.

OpenAI finds abuse systems wrongly rate-limited some Codex accounts

OpenAI's status page investigated reports of Codex usage limits depleting faster than expected from June 26 and said some were caused by its abuse and fraud prevention systems incorrectly rate limiting certain accounts. It was resolved June 29, 2026.

Codex adds banked rate-limit resets for Plus and Pro

Codex added rate-limit reset banking for Plus and Pro users, with one free reset at launch and more earned through referrals during a promotion.

GPT-5.3-Codex and GPT-5.2 deprecated in Codex

GPT-5.3-Codex and GPT-5.2 are no longer user-selectable in Codex for ChatGPT sign-in. API-key workflows are not affected.

Who is affected:

Codex users signed in with ChatGPT who used these models.

Action needed:

Switch to GPT-5.5, GPT-5.4 or GPT-5.4 mini.

OpenAI models, Codex and Managed Agents on AWS

OpenAI announced its GPT models, Codex and Managed Agents on AWS.

GPT-5.5 available in Codex and recommended for most tasks

GPT-5.5 became available in Codex as the recommended choice for most Codex tasks once it appears in the model picker.

Who is affected:

Codex users.

What to do:

Select gpt-5.5 in Codex.

Codex drops GPT-5.2-Codex, GPT-5.1-Codex models and GPT-5 for ChatGPT sign-in

From April 7 the Codex model picker stopped showing gpt-5.2-codex, gpt-5.1-codex-mini, gpt-5.1-codex-max, gpt-5.1-codex, gpt-5.1 and gpt-5, and they were removed for ChatGPT sign-in on April 14.

Who is affected:

Codex users signed in with ChatGPT who selected these models.

Action needed:

Switch to gpt-5.4 or another listed model, or use an API key.

Codex pricing moves to API token usage instead of per-message

OpenAI published a Codex rate card that ties Codex credit usage to API token usage rather than a per-message estimate. The Hacker News thread drew 211 points and 193 comments. The OpenAI help page blocks automated access, so details beyond the headline were not verified.

Who is affected:

ChatGPT plan users who buy Codex credits.

What to do:

Check the Codex rate card before buying credits.

Codex adds pay-as-you-go pricing for Business and Enterprise

OpenAI added pay-as-you-go Codex pricing for ChatGPT Business and Enterprise.

OpenAI publishes its Codex degradation investigation and finds smaller issues, not one large cause

After public reports that Codex performed worse around the gpt-5-codex launch on September 15, 2025, the Codex team investigated full time, removed over 60 feature flags, and reported a combination of behavior shifts (such as compaction) and smaller concrete issues rather than one large regression.

Who is affected:

Codex CLI and cloud users who saw weaker results in September and October 2025.

What to do:

Update the Codex CLI and start new conversations for targeted tasks instead of relying on repeated compaction.

Codex SDK released with Codex general availability

OpenAI released the Codex SDK for TypeScript when Codex became generally available. It lets developers run the same agent that powers the Codex CLI inside their own tools and workflows.