Codex

Name: Codex
Brand: OpenAI

Codex is an autonomous software engineering agent developed by OpenAI, released in May 2025 as a research preview. The system operates both in the cloud and locally on a user's machine, supporting parallel execution of multiple coding tasks simultaneously.

The cloud version of Codex runs each task in an isolated container with the user's GitHub repository loaded. The agent can write new features, fix bugs, run tests, perform code refactoring, and propose pull requests for human review. Each task runs independently, allowing multiple projects to be delegated at once.

The local version is available as Codex CLI — an open-source command-line tool (Apache 2.0 license) that runs on macOS, Linux, and experimentally on Windows. The CLI runs the agent directly on the user's machine inside a sandbox, where it can read files, execute commands, and make code changes while keeping data under local control.

Codex is also available as an extension for popular IDEs, enabling work with the agent without leaving the code editor. GitHub integration allows the agent to be invoked directly from pull request comments by tagging @codex.

The system is powered by models from the Codex family — specifically codex-1 (an o3 variant optimized for software engineering), GPT-5-Codex, GPT-5.2-Codex, GPT-5.3-Codex, and GPT-5.4 as the default model from March 2026. The models were trained using reinforcement learning on real coding tasks to produce code that closely matches the style and preferences of human developers.

Access to Codex is included in paid ChatGPT plans: Plus, Pro, Business, Enterprise, and Edu. There is no separate Codex-only subscription.

Web appCLIIDE extensionAPIMobile appConnected Apps / IntegracjeFreemiumPaidSeat-basedEnterpriseUsage-based

Released 16 May 2025Updated 18 Apr 2026Global · Global

Visit website API documentation

Overview

System type

Input

TextImageDocumentsStructured data

Output

CodeTextStructured dataSummaries

Access & Pricing

PUBLIC

Access channels

Web app

Access via web browser with no installation required.

CLI

Access via command-line interface.

IDE extension

Plugin for an IDE (VS Code, JetBrains, etc.).

API

Programmatic access via REST or WebSocket API.

Mobile app

Native app for iOS or Android.

Connected Apps / Integracje

Access via integrations with external applications and platforms.

Availability scope

Global

Dostępny w ramach płatnych planów ChatGPT: Plus ($20/mies.), Pro ($100/mies. lub $200/mies.), Business ($25/użytkownika/mies.), Enterprise (ceny negocjowane), Edu. Dostęp przez interfejs web (chatgpt.com/codex), CLI (macOS, Linux, Windows eksperymentalnie), rozszerzenie IDE oraz API. Codex CLI jest open source (licencja Apache-2.0). Chmurowe zadania Codex wymagają repozytoriów hostowanych na GitHub. Funkcja Computer Use niedostępna w EOG, UK i Szwajcarii.

Subscription model

FreemiumPaidSeat-basedEnterpriseUsage-based

Pricing

Updated 18 Apr 2026Official pricing

Codex is included in paid ChatGPT subscriptions. From April 2, 2026, billing is token-based (credits per million tokens). Plans: Plus $20/mo., Pro $100/mo. (5× limit vs. Plus), Pro $200/mo. (20× limit vs. Plus), Business $25/user/mo., Enterprise (custom pricing). API access via key is billed at standard OpenAI API rates.

CategoryPlanUnitInputCachedOutput

ChatGPT Plus

Monthly subscription. Limited Codex usage quota, reset on a recurring basis. Access via CLI, web, and IDE extension.

standardflat$20——

ChatGPT Pro ($100)

5× higher Codex limit than Plus. Access to GPT-5.3-Codex-Spark (research preview). Introduced April 2026.

standardflat$100——

ChatGPT Pro ($200)

20× higher Codex limit than Plus. For intensive, parallel projects.

standardflat$200——

ChatGPT Business

$25/user/month. Standard or usage-based Codex seats. Additional workspace credits available for purchase.

APIother$25——

ChatGPT Enterprise

Prices are negotiated individually. Shared credit pool for organizations. SCIM, EKM, RBAC, audit logs.

Enterpriseother———

Capabilities

10 capabilities

Reasoning & Planning

Agency & Action

Communication & Multimodality

Task Specialization

Integrations

System tools

Ecosystem

Available on platforms

OpenAI API

Security & Enterprise

Security source

Audit Logs

Available in Enterprise plans through the Compliance API.

Compliance Controls

GDPR, CCPA, HIPAA, FERPA. A Data Processing Addendum is available for Enterprise customers.

CMEK

Enterprise Key Management (EKM) for eligible customers.

Data Residency

Available in regions: USA, Europe, UK, Japan, Canada, South Korea, Singapore, Australia, India, UAE.

Encryption Controls

TLS in transit, AES-256 at rest.

Enterprise Access

SCIM, SAML SSO, MFA, RBAC, domain verification, user analytics.

OpenAI holds SOC 2 Type 2, ISO/IEC 27001:2022, 27017, 27018, and 27701 certifications. Data is encrypted with TLS in transit and AES-256 at rest. Model training on organizational data is disabled by default under Enterprise, Business, and Edu plans.

Notes

Upd. 18 Apr 2026

Codex cloud runs tasks in isolated containers. Codex CLI operates locally — code remains on the user's machine. GPT-5.3-Codex is classified as a high-capability model in cybersecurity under the Preparedness Framework — additional safeguards and the Trusted Access for Cyber program have been implemented.