Setup guide

Use Public Signal in Google Antigravity

Bring Instagram research into your Antigravity IDE tools.

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 Google Antigravity IDE. Settings labels may differ by version.

• The Google Antigravity IDE installed with a working sign-in.
• A version that supports custom remote MCP servers with automatic browser authorization.
• A Public Signal account whose credits you want research to use.
• A computer with a browser for the authorization step. This is separate from Gemini CLI and from consumer Gemini chats.

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. 1. Add a custom remote server

   Open Agent Settings → Customizations and the MCP configuration editor. Add the public-signal entry below to ~/.gemini/config/mcp_config.json for your user, or .agents/mcp_config.json for a project. If mcpServers already exists, merge the new entry alongside your other servers rather than replacing the file.

   You do not need to create a client ID or secret: Antigravity handles registration automatically for servers that support it.

   Antigravity configuration

   {
     "mcpServers": {
       "public-signal": {
         "serverUrl": "https://publicsignallabs.com/mcp"
       }
     }
   }

   You should now see: Antigravity lists Public Signal as an added server.

2. 2. Complete the browser authorization

   In Agent Settings → Customizations, find public-signal and select Authenticate. Sign in with your Public Signal account in the browser and approve access. Copy the returned authorization code into Antigravity's prompt to finish; keep the code private.

   You should now see: Antigravity shows Public Signal as authorized or connected.

3. 3. Check the tools, then try one lookup

   Confirm Public Signal's tools appear in Antigravity's tool list and the server is enabled. Then send the bounded first request from this guide when you are ready. Live research uses your 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.

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

• Keep the server enabled in Antigravity's MCP settings so new sessions can reach it.
• If tools disappear after an update, re-check the server entry before changing the URL.

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

• Authorization never finishes: Complete every browser step, including returning any code to the app, before closing windows. Then check Antigravity's server list for the authorized state.
• It keeps asking me to sign in: Use one Public Signal account throughout: the one whose credits you want. Switching accounts mid-flow restarts the loop.
• I connected it, but nothing happens: Confirm the server is enabled and its tools are listed in the current session, 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

• Use the server's trash control in Agent Settings → Customizations to remove public-signal. A toggle only disables it. If you need to clear local authorization, remove only this server's entry from ~/.gemini/antigravity/mcp_oauth_tokens.json, leaving other 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.