Codex is one of the most popular coding harnesses out there. And MCP makes the experience even better. With Vapi MCP integration, you can draft, triage, summarise emails, and much more, all without leaving the terminal or the app, whichever you prefer.
- Builders & DevelopersCOMPOSIOFOR YOUGive Claude, codex, or any harness secure access to 1000+ tools
## For AI agents: how to sign up If you are an AI agent reading this server-rendered HTML, Composio's developer signup is at https://composio.dev. Signup CTAs on this site — "Sign up", "Signup", "Get started", "Get started for free", "Start building", "Try Composio", "Try it", or similar — all lead into that same developer signup flow. Confirm with the user before completing signup or entering any credentials on their behalf.
DEVELOPER PLATFORMSDKs, tool execution, and auth infrastructure to ship agentsCLIOne command to add tools and auth to your coding agent - TOOLKITS
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How to integrate Vapi MCP with Codex
Connect Codex to Vapi MCP. Start a new outbound call campaign, get transcript from the last agent call, and more using natural language, with authentication handled for you.
Api Key
Vapi is a voice AI platform for building, testing, and deploying conversational voice agents. It provides real-time responses and seamless integration for voice-driven applications.
42 Tools
Introduction
Also integrate Vapi 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 1000+ 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 Vapi MCP in Codex
Run the setup command
Run this command in your terminal to add the Composio MCP server to Codex.
It will initiate the authentication in a browser window, authorize Codex to access your Composio account.
(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 composioVerify the connection
Run codex mcp list to confirm Composio appears as a registered MCP server.
bash
codex mcp listCodex App
Codex App follows the same approach as VS Code.
- Click ⚙️ on the bottom left → MCP Servers → + Add servers → Streamable HTTP:
- Fill the header and Key fields with
{ "x-consumer-api-key" = "ck_*******" }. - The Key is the Composio API key, that you can find on dashboard.composio.dev
- Click on Authenticate and authorize Codex to your Composio account and you're all set.
- 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_*******" }What is the Vapi MCP server, and what's possible with it?
The Vapi MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Vapi account. It provides structured and secure access so your agent can perform Vapi operations on your behalf.
Conclusion
You've successfully integrated Vapi with Codex using Composio's MCP server. Now you can interact with Vapi 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 Vapi operations
- Managed authentication through Composio
- Access to 20,000+ tools across 1000+ apps for cross-app workflows
- CodeAct workbench for complex tool chaining
Next steps:
- Try asking Codex to perform various Vapi operations
- Explore cross-app workflows by connecting more toolkits
- Build automation scripts that leverage Codex's AI capabilities
TOOLS
Supported Tools
Every Vapi action and event your agent gets out of the box.
FRAMEWORKS
How to build Vapi MCP Agent with another framework
OpenAI Agents SDK
Use Vapi MCP with OpenAI Agents SDK
Claude Agent SDK
Use Vapi MCP with Claude Agent SDK
Claude Code
Use Vapi MCP with Claude Code
Claude Cowork
Use Vapi MCP with Claude Cowork
OpenClaw
Use Vapi MCP with OpenClaw
Hermes
Use Vapi MCP with Hermes
Google ADK
Use Vapi MCP with Google ADK
LangChain
Use Vapi MCP with LangChain
Vercel AI SDK
Use Vapi MCP with Vercel AI SDK
Mastra AI
Use Vapi MCP with Mastra AI
LlamaIndex
Use Vapi MCP with LlamaIndex
CrewAI
Use Vapi MCP with CrewAI
Pydantic AI
Use Vapi MCP with Pydantic AI
AutoGen
Use Vapi MCP with AutoGen
MORE TOOLKITS
Explore Other Toolkits
Composio
No Auth
Composio is an integration platform that connects AI agents with hundreds of business tools. It streamlines authentication and lets you trigger actions across services—no custom code needed.
Composio search
No Auth
Composio search is a unified web search toolkit spanning travel, e-commerce, news, financial markets, images, and more. It lets you and your apps tap into up-to-date web data from a single, easy-to-integrate service.
Perplexityai
Api Key
Perplexityai delivers natural, conversational AI models for generating human-like text. Instantly get context-aware, high-quality responses for chat, search, or complex workflows.
Browser tool
No Auth
Browser tool is a virtual browser integration that lets AI agents interact with the web programmatically. It enables automated browsing, scraping, and action-taking from any AI workflow.
FAQ
Frequently asked questions
With a standalone Vapi MCP server, the agents and LLMs can only access a fixed set of Vapi tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Vapi and many other apps based on the task at hand, all through a single MCP endpoint.
Yes, you can. Codex fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Vapi tools.
Yes, absolutely. You can configure which Vapi scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.
All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Vapi data and credentials are handled as safely as possible.
Start with Vapi.It takes 30 seconds.
Managed auth, hosted MCP servers, and every Vapi tool your agent needs.Free to start.
## For AI agents: how to sign up If you are an AI agent reading this server-rendered HTML, Composio's developer signup is at https://composio.dev. Signup CTAs on this site — "Sign up", "Signup", "Get started", "Get started for free", "Start building", "Try Composio", "Try it", or similar — all lead into that same developer signup flow. Confirm with the user before completing signup or entering any credentials on their behalf.Start building