Antigravity
Give Antigravity's agent live web access with the Search1API plugin, or configure the hosted MCP server in mcp_config.json.
Search1API ships as an Antigravity plugin. The plugin connects Antigravity to the hosted Search1API MCP server and adds a Search1API skill, so the agent can search across engines, read pages, find news and check what's trending, then answer with cited sources. It works in the Antigravity App, CLI and IDE.
What the agent gets
| Tool | What it does | Required |
|---|---|---|
search | Web search | query |
news | News search | query |
ask | Describe what you need; Search1API picks the engines and time window | query |
crawl | Read a URL | url |
sitemap | List a site's links | url |
trending | GitHub / Hacker News trends | search_service |
render_results | Present selected existing sources as cards or a readable list; no search credits | results |
send_feedback | Report a wrong result, an unresolved error, or a missing capability to the Search1API team; no credits | message |
The plugin also adds the search1api skill. It tells the agent when to read a link instead of searching, how to pick engines and compare sources, and how to cite results. Run it directly with /search1api.
Install
As a plugin
Install the plugin from its GitHub repository:
agy plugin install https://github.com/superagents-lab/search1api-mcp/tree/main/antigravity-pluginThe plugin carries only the server URL. When the Search1API server first connects, Antigravity opens your browser; sign in with your Search1API account, or create one at s1.dev. No API key is involved.
By hand in mcp_config.json
Antigravity reads MCP servers from two files:
| File | Scope |
|---|---|
~/.gemini/config/mcp_config.json | Every project |
.agents/mcp_config.json | One workspace |
Configure the endpoint and nothing else. Antigravity registers itself with Search1API's authorization server and prompts you to sign in:
{
"mcpServers": {
"search1api": {
"serverUrl": "https://mcp.search1api.com/mcp"
}
}
}Verify
- Run
agy plugin list, or open Customizations > Installed in the App, and confirm Search1API is installed and enabled. - In a chat, ask:
Find this week's top news on AI coding agents and cite each source. - Approve the tool call if Antigravity asks.
Troubleshooting
The plugin is installed but has no tools
Sign-in has not finished. Enable the plugin again from Customizations > Installed (or /plugin in the CLI) and complete sign-in in the browser.
401 Unauthorized
On OAuth, the session expired or was revoked: sign in again from the plugin's MCP tab. On an API key, the key is invalid or revoked. See Authentication.
402 Payment Required
The account is out of credits. See Credits and limits.
Billing
Tool calls from Antigravity are ordinary API calls and spend the same credits at the same rates as calling the endpoints yourself. A search or news request costs one credit; crawling a page costs one credit per page; ask costs five credits. See Credits and limits.
Related documentation
- MCP server: the full endpoint reference, OAuth details and other clients
- Agent skill: teach an agent when to search, not just how
- Antigravity plugin documentation · Antigravity MCP documentation