How to integrate Gemini MCP with Codex

Connect Codex to Gemini MCP. Summarize this research article in 100 words, generate a creative image of a futuristic city, and more using natural language, with authentication handled for you.

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Gemini is Google's multimodal AI platform for generating text, video, and rich chat completions. It's a one-stop shop for advanced AI content creation and intelligent automation.

8 Tools

Introduction

Codex is one of the most popular coding harnesses out there. And MCP makes the experience even better. With the Gemini MCP integration, Codex can generate text, create images with Nano Banana, produce videos with Veo, embed content, and count tokens, all without leaving the terminal or the app, whichever you prefer.

For exact tool slugs and parameter tables, see the tool catalog in the Composio docs.

Also integrate Gemini with

Why use Composio?

Apart from a managed and hosted MCP server, you will get:

  • CodeAct: A dedicated workbench that allows GPT to write its code to handle complex tool chaining. Reduces to-and-fro with LLMs for frequent tool calling.
  • Large tool responses: Handle them to minimise context rot.
  • Dynamic just-in-time access to 20,000 tools across 1700+ other Apps for cross-app workflows. It loads the tools you need, so GPTs aren't overwhelmed by tools you don't need.

How to install Gemini MCP in Codex

Run the setup command

Run this command in your terminal to add the Composio MCP server to Codex.

Terminal

It will initiate the authentication in a browser window, authorize Codex to access your Composio account.

Composio authentication page

(Optional) Authenticate with OAuth

To authenticate manually, run the login command to open a browser window and authorize Codex to access your Composio account.

bash
codex mcp login composio

Verify the connection

Run codex mcp list to confirm Composio appears as a registered MCP server.

bash
codex mcp list

Codex App

Codex App follows the same approach as VS Code.

  1. Click ⚙️ on the bottom left → MCP Servers → + Add servers → Streamable HTTP:
  2. Fill the header and Key fields with { "x-consumer-api-key" = "ck_*******" }.
  3. The Key is the Composio API key, that you can find on dashboard.composio.dev
  4. Click on Authenticate and authorize Codex to your Composio account and you're all set.
Codex App MCP setup
  1. Restart and verify if it's there in .codex/config.toml
bash
[mcp_servers.composio]
url = "https://connect.composio.dev/mcp"
http_headers = { "x-consumer-api-key" = "ck_*******" }

Try it

Ask Codex for a Gemini task. The first time, Composio asks you to connect your Gemini account.

For example, ask it to:

  • "Summarize this research article in 100 words"
  • "Generate a creative image of a futuristic city"
  • "Create a 30-second video based on this script"

What is the Gemini MCP server, and what's possible with it?

The Gemini MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Gemini account. It provides structured and secure access to Gemini's multimodal AI features, so your agent can generate text, images, and videos, analyze content, and manage model resources on your behalf.

  • Text and content generation: Instruct your agent to create high-quality, customized text using Gemini's advanced generative models—great for brainstorming, drafting, or summarizing information.
  • Creative image and video generation: Ask the agent to generate original images or high-quality videos from text prompts using Gemini 2.5 Flash and Veo models, with fine control over style and format.
  • Embedding and semantic analysis: Let your agent transform any text into rich semantic embeddings for similarity search, clustering, or classification tasks.
  • Model discovery and optimization: Have the agent list available Gemini and Veo models, check their capabilities, and select the best fit for your project or workflow.
  • Efficient resource management: Enable the agent to track video generation operations, download final assets, and optimize prompt inputs by counting tokens—all without manual intervention.

Conclusion

You've successfully integrated Gemini with Codex using Composio's MCP server. Now you can interact with Gemini directly from your terminal, VS Code, or the Codex App using natural language commands.

Key benefits of this setup:

  • Seamless integration across CLI, VS Code, and standalone app
  • Natural language commands for Gemini operations
  • Managed authentication through Composio
  • Access to 20,000+ tools across 1700+ apps for cross-app workflows
  • CodeAct workbench for complex tool chaining

Next steps:

  • Try asking Codex to perform various Gemini operations
  • Explore cross-app workflows by connecting more toolkits
  • Build automation scripts that leverage Codex's AI capabilities
TOOLS

Supported Tools

Every Gemini action and event your agent gets out of the box.

Count Tokens (Gemini)

Counts the number of tokens in text using Gemini tokenization.

Embed Content (Gemini)

Generates text embeddings using Gemini embedding models.

Generate Content (Gemini)

Generates text content or speech audio from prompts using Gemini models.

Generate Image (Nano Banana)

Generates a downloadable image from a text prompt, defaulting to Nano Banana 2 Lite on managed connections and Gemini 3 Pro Image Preview on other connections.

Generate Videos

Starts an MP4 video generation from a text prompt with Gemini Omni 1.

Get Video Generation Status

Checks a Gemini Omni Flash video generation started by GEMINI_GENERATE_VIDEOS once, without waiting.

List Models (Gemini API)

Lists available Gemini models with their capabilities and limits.

Wait and Download Video

Waits up to about 45 seconds for a Gemini Omni Flash video started by GEMINI_GENERATE_VIDEOS and returns the MP4 when ready.

FAQ

Frequently asked questions

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