---
title: Connect Codex
description: Configure Phasoric in Codex, authenticate with OAuth, and retrieve the project brief behind a coding task.
slug: mcp-codex
path: /mcp-codex
section: MCP setup
availability: supported
nav_order: 6.4
canonical_url: https://developers.phasoric.com/mcp-codex
markdown_url: https://developers.phasoric.com/mcp-codex.md
mirror_url: https://phasoric.com/developers/mcp-codex
---
# Connect Codex to Phasoric

First [prepare an accessible Phasoric vault](https://developers.phasoric.com/mcp-client-setup). Use the Codex installation on the machine or host where the task runs.

## Add and authenticate

1. Add the server with the Codex CLI:

```bash
codex mcp add phasoric --url https://phasoric.com/api/mcp
codex mcp login phasoric
codex mcp list
```

2. Complete Phasoric sign-in in the browser and review consent. Approve continued access if offered.
3. Start a new Codex task using that host's configuration. Ask it to list your Phasoric vaults and read the project brief before changing code.

For configuration-based setup, merge this entry into your existing Codex configuration rather than replacing the file:

```toml
[mcp_servers.phasoric]
url = "https://phasoric.com/api/mcp"
```

OAuth login is separate from adding the URL. If an existing entry uses a manual bearer-token environment variable, choose which authentication method to retain; do not leave a missing environment-variable credential in place and assume OAuth will override it. See [Codex's official MCP documentation](https://developers.openai.com/codex/mcp) for current configuration and credential precedence.

## Use the brief in a coding task

```text
Read the implementation brief in my Phasoric Vault. Summarize its constraints
and acceptance criteria, then inspect this repository before making changes.
Keep the source note path in your explanation.
```

Phasoric supplies permitted knowledge. Codex performs repository work using its own workspace permissions; MCP access does not grant repository or deployment authority. After reviewing the implementation, ask for a proposed decision-note update and approve it separately if you want it written back.

A configured URL is not proof of authenticated access. Confirm `list_vaults` and a note read, and use the [shared troubleshooting guide](https://developers.phasoric.com/mcp-client-setup) if either fails.