Setup guide · Codex

Connect Conxt to Codex in four steps.

OpenAI’s Codex desktop app supports Streamable HTTP MCP. Generate a key, set one environment variable, and paste two values into Codex’s MCP settings. It takes about two minutes.

Generate your API key

One key works in every tool you connect. It’s copied to your clipboard the moment it’s created.

Set the environment variable

The Codex app doesn’t inherit variables from a new shell session, so set CONXT_API_KEY at the user level where Codex can find it on launch.

PowerShell

[Environment]::SetEnvironmentVariable("CONXT_API_KEY", "<your-api-key>", "User")

Generate your key in step 1 and it’s filled in here.

Add Conxt to Codex

In the Codex app, open Plugins → Add custom MCP, choose Streamable HTTP, and paste these two values.

URL

https://mcp.conxt.dev/mcp/

Bearer token env var

CONXT_API_KEY

Leave Headers and Headers from environment variables empty. The bearer token field handles authentication.

Finish step 2 first.

Test it in Codex

Open a new Codex chat and send this prompt. Codex should answer from your Conxt memory.

Test prompt

Using Conxt, what are my coding rules?

Finish step 3 first.

Using Cursor, Windsurf, Claude Code or Claude Desktop? The same key works there too.

Connect another tool