Connect Codex

Connect Siglata to Codex with one command and sign in.

To connect Siglata to Codex, run codex mcp add siglata --url https://www.siglata.com/v1/mcp in the terminal and sign in to your Siglata account in the browser the command opens. The Codex CLI, the IDE extension and the ChatGPT desktop app use the same ~/.codex/config.toml, so one connection covers them all.

Steps

1. In the terminal, run:

   codex mcp add siglata --url https://www.siglata.com/v1/mcp

2. The command opens sign-in in the browser. Sign in to Siglata and approve access.

3. Open a new Codex session, or resume the conversation. Codex loads MCP servers when a session starts.

Rather have Codex do it? Paste Set up Siglata: https://www.siglata.com/en-US/SKILL.md into the conversation. Codex asks to run the command outside the sandbox, because it writes ~/.codex/config.toml and uses the network. It also saves the siglata skill in .codex/skills/siglata in your user folder (on Mac and Windows), so later conversations look in Siglata first.

Siglata’s skills come through the connection (see Siglata’s skills).

Each person does this setup. Workspace admins can restrict the available MCP servers with an allowlist in requirements.toml. Codex’s connection is separate from ChatGPT on the web, which uses remote MCP tools supplied through plugins, not Codex’s config.toml.

Approvals

Codex reads the tools’ annotations: read tools such as list, sql and document_search run without an approval prompt; write tools such as sheet_write, move and trash change files, folders, sharing or members, and Codex asks before each call. Keep the default. Do not set default_tools_approval_mode = "approve" on the siglata server: that also lets writes run without asking.

Uploading Files

To upload a file, the agent runs a curl that sends the bytes to Siglata’s upload link. Codex’s default sandbox has no network, so Codex asks you to approve that command on every upload. Approve it with Yes, proceed. The command carries a one-time token, so the don’t-ask-again option does not cover the next upload.

To upload without approvals, turn on sandbox network once in ~/.codex/config.toml:

[sandbox_workspace_write]
network_access = true

This opens the network to every sandboxed command, not only to Siglata.

Done

Setup is complete when your agent authenticates with Siglata. Keep working in the agent and add files when you need them.

Troubleshooting

• Sign-in stuck or wrong organization. Run codex mcp login siglata and pick the right organization.
• No tools. Open a new session. codex mcp list should show siglata.

Common questions

Do I need a paid ChatGPT plan to use Siglata in Codex?

No. As of October 2026, OpenAI includes Codex in every ChatGPT plan, Free and Go included, with usage limits that vary by plan.

Does the Codex connection work in ChatGPT on the web?

No. ChatGPT on the web uses a custom MCP server plugin, set up separately. See Connect ChatGPT.

Why does Codex ask for approval on every file upload?

The upload runs a curl, and Codex’s default sandbox has no network. Approve the command on each upload, or turn on the sandbox network as described in Uploading files.