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Public Signal Labs

Setup guide

Use Public Signal in Gemini CLI

Run Instagram research from your terminal with Gemini CLI.

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 Gemini CLI who are comfortable with a terminal. This is a technical guide.

  • Gemini CLI installed and working. This guide does not cover installing it.
  • Comfort editing a JSON-style MCP configuration and running slash commands in the terminal.
  • A Public Signal account whose credits you want research to use.
  • Note the boundary: this guide is for Gemini CLI, the terminal application. Ordinary Gemini chats on the web are a different product and are not covered here.

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. Add Public Signal to the MCP configuration

    In a terminal outside Gemini CLI, run the command below. It adds a server named public-signal using HTTP. If you edit ~/.gemini/settings.json instead, its mcpServers.public-signal entry must use httpUrl, not url: url selects the older SSE transport. Keep existing configuration entries.

    Do not add API keys or tokens: Public Signal signs you in through a browser.

    Gemini CLI setup command

    gemini mcp add --transport http public-signal https://publicsignallabs.com/mcp

    You should now see: Your configuration contains a Public Signal server entry.

  2. Authenticate from inside Gemini CLI

    Start Gemini CLI with gemini, then enter the slash command below inside that session, not in your operating system's shell. A browser opens: sign in with your Public Signal account, review the request, and approve it.

    Gemini authentication command

    /mcp auth public-signal

    You should now see: Gemini CLI reports the server as authenticated.

  3. List the tools, then try one lookup

    Enter /mcp inside Gemini CLI to confirm Public Signal and its tools appear. Then send the bounded first request from this guide when you are ready. 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

  • MCP servers attach per session: if the tools are missing after a restart, re-check the server list before re-adding anything.
  • Keep the server entry enabled while you want to use its tools.

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

  • Authentication never completes: Complete the browser sign-in fully and return to the terminal. If no browser opened, check that a default browser is set and run the auth command again.
  • The tools do not appear: Confirm the server URL matches this guide exactly and the entry is enabled, then re-run authentication and list the tools again.
  • I connected it, but nothing happens: Verify the server is attached in the current session and retry the bounded first request rather than a broad autonomous task.

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

Remove the connection

  • Run gemini mcp remove public-signal in your terminal. If you need to clear saved local credentials, remove only this server's entry from ~/.gemini/mcp-oauth-tokens.json, leaving other servers' credentials intact.
  • Deleting local credentials does not by itself revoke copies already issued. Contact support if you need help revoking access. 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.