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Public Signal Labs

Setup guide

Use Public Signal in Codex

Add Instagram research to your Codex coding workflow.

Connection address (MCP URL)

https://publicsignallabs.com/mcp

This address is public and is not a secret. You never need to open it in a browser: your app pastes it in during setup.

Before you start

For people already using the Codex IDE extension or CLI. This is separate from ChatGPT on the web.

  • A working Codex IDE extension or CLI, or a ChatGPT Desktop build that exposes Settings → MCP servers. This guide does not cover installing those apps.
  • Your model-provider sign-in for Codex, which is separate from Public Signal authorization: you will sign in twice, once per service.
  • A Public Signal account whose credits you want research to use.
  • A computer with a browser for the sign-in step.

Effort: About 10 minutes. Take it one step at a time; nothing here runs research or spends credits until you send the first request yourself.

Steps

  1. Choose your setup path

    IDE extension users follow step 2 and skip step 3. CLI users follow step 3 and skip step 2. Both end at the same Public Signal browser sign-in.

    This client is Codex, not ChatGPT on the web: the ChatGPT Developer-mode steps do not apply here.

    ChatGPT Desktop with a local Codex host: open Settings → MCP servers → Add server, name it public-signal, choose Streamable HTTP, and paste the connection address from this guide. Save, select Restart, then select Authenticate beside the server and approve Public Signal sign-in. Type /mcp in the composer to view connected servers. Skip steps 2–3 and continue at step 4. This is separate from ChatGPT's web Developer-mode setup.

    You should now see: You know which app-specific setup path you are following.

  2. IDE: add the server and authenticate

    In the Codex IDE extension, select the settings gear, open MCP servers, and choose Add server. Select Streamable HTTP, name the server public-signal, paste the connection address from this guide, and save. Select Restart extension, then choose Authenticate beside the server.

    A browser opens for Public Signal sign-in. Use the account whose credits you want, review the request, and approve it.

    You should now see: Codex lists Public Signal as an authenticated server.

  3. CLI: register the server and sign in

    Run the two commands below in your terminal, one at a time. The first saves the server; the second starts browser sign-in. Review and approve access using the Public Signal account whose credits you want to use.

    Keep your model-provider sign-in and billing separate in your mind from the Public Signal approval: they are two different accounts.

    Codex setup commands

    codex mcp add public-signal --url https://publicsignallabs.com/mcp
codex mcp login public-signal

    You should now see: The CLI reports the Public Signal server as authenticated.

  4. Confirm the tools, then try one lookup

    In the CLI, run codex mcp list, then use /mcp inside your Codex session to inspect the available tools. In the IDE, check the MCP server's status. Once connected, send the bounded first request from this guide. Live research uses Public Signal credits.

    You should now see: You receive a short profile summary with a source link.

Your first request

Copy the request below and send it in your app when you are ready. It asks for exactly one profile, so you can confirm the connection without starting a large search. Running it uses Public Signal credits, and your app may have its own usage charges.

First request (copy, then send in your app)

Using Public Signal, look up the public Instagram profile @natgeo. Summarize its bio and follower count, and include its profile link. Use only one profile lookup; do not fetch follower lists or expand the research.

Keep it switched on

  • Enable the Public Signal server in each workspace or session where you want research.
  • The documented ChatGPT Desktop, Codex CLI, and IDE extension share configuration for the same local Codex host. This does not synchronize ChatGPT web connections or promise support in every Desktop version.

Next, bring your own campaign brief and ask for a small evidence-backed shortlist. Build your first creator shortlist walks through that.

If something goes wrong

  • Authenticate does nothing: Allow the browser handoff and complete the sign-in there, then return to the IDE. If no browser opens, check that a default browser is set and retry the Authenticate step.
  • It keeps asking me to sign in: You may be mixing up the two sign-ins. Complete the Codex provider sign-in first, then the Public Signal approval with the account whose credits you want.
  • I connected it, but nothing happens: Confirm the server is enabled for the current workspace or session and its tools are listed, then retry the bounded first request.

Still stuck? Get connection help covers the common cases across every app, or write to support@publicsignallabs.com.

Remove the connection

  • In the IDE, remove the server from MCP settings. For the CLI, remove the [mcp_servers.public-signal] section from ~/.codex/config.toml, leaving other server sections intact.
  • Also use the client's logout or clear-authentication control where available. Removing configuration alone does not establish revocation; contact support if needed. Disconnecting does not restore used credits.

Good to know

  • Signing in lets your app use Public Signal on your behalf. Your Public Signal password is not shared with the app.
  • Research uses your Public Signal credits. Your AI app may have its own plan or usage charges, and hosted-agent chats also consume credits for model inference.
  • Public Signal uses browser sign-in, not API keys or manually pasted access tokens. Use automatic registration where offered; do not invent a client ID or secret.
  • Prefer to skip setup entirely? Open the agent and research here instead.