Codex CLI

Requires Codex CLI 0.147.0 or later.

Setup with your assistant

Copy this prompt into Codex CLI. It guides the MCP setup, sign-in, and connection check.

Set up Valency in Codex CLI. Add the connection, complete sign-in, and verify the tools work.Copy prompt✓   Now paste it into your assistant

Prefer to set it up yourself?

Already connected? Run codex mcp list. If valency is listed, skip the add command and verify it with a real list_sources tool call. If not, check codex plugin list too: a previously installed Valency plugin may already provide the MCP connection. Use that connection instead of adding a duplicate.

1. Add Valency from a terminal if it is absent:

   codex mcp add valency --url https://mcp.valency.io/

   This saves the connection for future Codex CLI sessions.

2. Complete one browser sign-in. If the add command opens Valency sign-in, finish it and wait for the command to succeed. Only if sign-in did not start or finish, run:

   codex mcp login valency

   A Valency account is created automatically on first sign-in. You do not need an API token, client ID, or secret, and your Valency email does not have to match your ChatGPT email.

3. Start a new Codex CLI session so it loads the connection, then ask it to call list_sources on the MCP server named valency. A returned source list confirms it works. Seeing Valency in codex mcp list or /mcp only confirms configuration. An account-wide codex_apps/valency result does not verify this CLI connection.

4. Ask (more prompt ideas):

   Use Valency to search for papers about quantum computing

What success looks like

You see paper results in your terminal, with sources you can inspect.

Troubleshooting

Sign-in fails with "Authorization server response missing required issuer"? Your Codex CLI is too old. Run codex --version to check: versions 0.143.0 through 0.146.x cannot finish Valency sign-in, even after you approve it in the browser. Run codex update (or upgrade through npm or Homebrew) to get 0.147.0 or later, then run codex mcp login valency.

Need to sign in again? Run codex mcp login valency, complete browser sign-in, then retry list_sources.

Tools don't appear? Run codex mcp get valency to check the saved server, then start a new Codex CLI session. MCP tools may not load into a session that was already open when you added the server.

Need to start over with a direct connection? Run codex mcp remove valency, then follow the add and sign-in steps above. This removes the directly configured server; a Valency plugin, if you have one, is managed separately.

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Need help?

If something isn't working, check Troubleshooting for common fixes. See the FAQ for general questions, or report an issue if you're still stuck.