The OpenAI Developers plugin helps you build AI applications and agents in Codex with OpenAI Platform access and OpenAI API setup guidance. Adaptations for Claude Code and Cursor bundle the portable developer skills and public OpenAI Docs MCP server without the Codex-specific Platform connector. The Codex plugin works together with the OpenAI Docs Skill that comes bundled with your Codex install.
It includes:
- OpenAI API Platform: connect Codex to the OpenAI API Platform.
- OpenAI Docs MCP: use current OpenAI documentation from Claude Code or Cursor.
- API key setup: create, save, and connect a project API key from Codex, or
get guided local
OPENAI_API_KEYsetup in Claude Code and Cursor. - Agents SDK: build and deploy OpenAI Agents SDK apps from an idea, a repo, or a prior Codex thread.
- Troubleshooting: identify common OpenAI API failures and route you to the right next step.
Get started with Codex
If you are new to Codex, start here before installing the plugin:
- Download the Codex app for macOS or Windows.
- Follow the Codex quickstart to sign in, choose a project, and send your first message.
Install the plugin
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Open Codex
Start Codex from your terminal:
codex -
Open the plugin browser
Run:
/plugins -
Install the plugin
Search for OpenAI Developers, open it, and select
Install plugin. -
Complete any setup prompts
If Codex asks you to connect the bundled OpenAI Platform app, complete that setup so the plugin can create project API keys when needed.
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Start a new thread
Open a new thread before using the plugin for the first time.
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Open the plugin settings
In the Claude app, open Settings, then select Plugins.
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Add the marketplace
Select Add in the top-right corner, then choose Add Marketplace. In the modal, select Add from a repository.
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Add the repository
Enter
https://github.com/openai/openai-developers-for-claudeand select Sync. Do not append a.gitsuffix. -
Install the plugin
When OpenAI Developers appears, open it and select Install.
-
Add the plugin marketplace
In Claude Code, run:
/plugin marketplace add openai/openai-developers-for-claude -
Install the plugin
Run:
/plugin install openai-developers@openai-developers -
Start a new session
Start a new Claude Code session before using the plugin for the first time.
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Open the plugin settings
In Cursor, open Settings, then select Plugins.
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Add the repository
Paste
https://github.com/openai/openai-developers-for-cursorinto the plugin search box. -
Install the plugin
When OpenAI Developers appears, open it and select Install.
Use the plugin
After installation, start building with your coding agent. Codex can use the plugin automatically when the task calls for OpenAI Platform interactions, such as creating API keys or troubleshooting API issues. Claude Code and Cursor can use the plugin’s skills and bundled Docs MCP server for OpenAI API, model, Agents SDK, and ChatGPT Apps guidance.
The plugin is useful when you want your coding agent to:
- build an app or agent that uses the OpenAI API
- set up OpenAI API access for the app you are building
- diagnose common OpenAI API errors and explain the next step.
Sample prompts
Build a new app
Build an app with the Responses API
Create a campaign studio that turns a brief into polished copy and generated visual directions.
Build an agent with the Agents SDK
Create a launch-planning agent with a frontend, useful tools, and observability hooks.
Build a realtime audio app
Make a voice-first worldbuilding companion with low-latency audio interactions.
Improve an existing app
Upgrade to the latest model
Create a no-code-change plan to modernize model/API usage while preserving behavior.
Optimize my API implementation
Create a no-code-change optimization plan for quality, latency, reliability, and cost.
Migrate from Responses API to Agents SDK
Create a no-code-change migration plan for whether and how to move to the Agents SDK.