How to Connect MCP Server to Codex

Query your MCP Server data directly from Codex using Sequel’s MCP server. Ask questions in plain English, with no SQL, no dashboards, and no context switching.

Short answer

Connect MCP Server to Sequel, then add Sequel's MCP server to Codex using the config on this page. Codex can then query your live MCP Server data in plain English, with no connector code and no CSV exports. Both steps take a few minutes.

Example prompts

Everything you can ask Codex about your MCP Server data.

Ask in plain English — Sequel translates it into a MCP Server query, runs it, and Codex hands back the answer. No SQL, no dashboards, no CSV exports.

What you can ask Codex
  • What tools does this MCP server provide?
  • Run the search tool and find recent news about AI
  • Combine results from two different tools into a single answer
  • What data can I query through this server?
  • Call the analytics tool and show me this week's summary

How it works

Three steps to get started

1

Connect MCP Server to Sequel

In your Sequel dashboard, go to Connections and add MCP Server. Sequel handles authentication and schema discovery automatically.

2

Add Sequel to the agent

Copy the Sequel MCP configuration into Codex's settings file (shown below). Swap in your API key from Settings → API Keys.

3

Ask Codex about your data

Restart Codex and start asking questions. "What tools does this MCP server provide?" — and get a real answer backed by live MCP Server data.

Why Codex

What Codex does with your MCP Server data

Grounded answers from real data

Codex with Sequel queries your actual databases before generating code or explanations. Every schema reference, column name, and data shape is verified against what's really there.

Terminal-native data access

No context switching — Codex can pull database data mid-session to inform code generation, write migrations based on actual schemas, and validate assumptions without leaving the terminal.

Agentic data workflows

Codex's multi-step agent can chain Sequel tool calls together: discover schema, sample data, run analysis, then generate code — all in one automated flow.

Configuration

Add Sequel to Codex

Place this in ~/.codex/config.yaml and replace sql_your_api_key with a key from Settings → API Keys.

~/.codex/config.yaml

mcp_servers:
  sequel:
    type: http
    url: https://api.sequel.sh/mcp
    headers:
      Authorization: "Bearer sql_your_api_key"

Install

Install MCP Server MCP in Codex

Pick your app and Sequel installs itself: a one-click link where the client supports it, that client’s own few steps where it doesn’t. Every route signs in with your Sequel account over OAuth, so there is no API key to copy and nothing to keep in sync.

Already have an MCP client?

https://api.sequel.sh/mcp

Add it as a remote (streamable HTTP) server and sign in when prompted. Skills come with it; nothing else to install. Manual setup per client

Add Sequel to Codex

Terminal

codex mcp add sequel --url https://api.sequel.sh/mcp
  1. 1Run the command in your terminal. It writes the server to ~/.codex/config.toml.
  2. 2Run codex mcp login sequel and sign in in the browser.
  3. 3Start Codex and ask a question.

Frequently asked questions

How do I connect MCP Server to Codex?

You need two things: (1) connect MCP Server to Sequel in your Sequel dashboard under Connections, and (2) add the Sequel MCP config to Codex using the setup shown above. Once both are done, Codex can query your MCP Server data directly.

What MCP Server data can Codex access?

Codex can access any data available through your MCP Server connection in Sequel. Use Sequel's search tool to discover available metrics and dimensions, then execute queries to pull the data you need.

Is my MCP Server data sent to Codex's servers?

Query results are returned to Codex as context within your conversation. Only the data you explicitly ask about is retrieved. Sequel never stores your query results permanently — they exist only for the duration of the tool call.

Do I need a Sequel account?

Yes. You need a Sequel account to connect MCP Server and generate an API key. Sign up free at sequel.sh — no credit card required. Then create a connection to MCP Server and generate an API key from Settings → API Keys.

Can I connect multiple MCP Server accounts?

Yes. Sequel supports multiple connections of the same type. If you have multiple MCP Server accounts or properties, add each as a separate connection in Sequel. Codex will be able to query all of them.

How do I configure Sequel for Codex CLI?

Add the Sequel MCP server to ~/.codex/config.yaml as shown above. Create the file if it doesn't exist. Replace `sql_your_api_key` with a real key from Settings → API Keys, then restart Codex.

Does Codex CLI support HTTP MCP servers?

Yes. Codex CLI supports MCP over HTTP (Streamable HTTP transport). The `type: http` field in the config tells Codex to use this transport when connecting to Sequel.

Can I limit which databases Codex can access?

Sequel MCP is scoped to your organization's connected data sources. You can create separate API keys for different environments and revoke them at any time from Settings → API Keys.

Is this the same as the original OpenAI Codex model?

No — Codex CLI is OpenAI's agentic terminal coding tool, separate from the original Codex language model. It uses the latest OpenAI models (GPT-4o and o-series) with MCP tool support.

What is MCP?

MCP (Model Context Protocol) is an open standard for connecting AI agents to external tools and data sources. Any server that implements the MCP protocol can be connected to Sequel.

How do I connect an MCP server?

Click 'New Connection', select MCP Server, give it a name, and enter the server's HTTP URL. Optionally add any required HTTP headers (like an API key). Sequel will connect and discover available tools automatically.

What types of MCP servers are supported?

Sequel supports HTTP-based MCP servers using the StreamableHTTP transport. This covers the vast majority of publicly deployed MCP servers.

Do I need to configure each tool manually?

No. Sequel auto-discovers all tools by reading the server's manifest. It uses tool names and descriptions to understand what each tool does and when to call it.

Connect MCP Server to Codex today

Sign up free, connect your data sources, and start querying in minutes.