On-demand built-in tools

Use builtin_tools to enable AIVAX built-in tools for a direct request without creating a gateway:

{
    "model": "@google/gemini-3.8-flash",
    "prompt": "Search for recent news about electric vehicles.",
    "stream": true,
    "builtin_tools": {
        "tools": [
            "WebSearch"
        ],
        "options": {
            "web_search_mode": "full",
            "web_search_max_results": 5
        }
    }
}

Built-in tools include DateTime, WebSearch, AdvancedWebUsage (disabled; returns an unavailable response; see Changelogs), OpenUrl, Code, Request, Remember, GenerateWebPage, GenerateDocument, XPostsSearch, and ImageGeneration.

DateTime exposes get_date_time, a no-argument tool returning the current date, time, English weekday, time zone, UTC offset, and ISO 8601 timestamp. It uses the gateway time zone (default America/Sao_Paulo); send time_zone with an IANA identifier to override it for one request. This setting is independent of the user’s browser time zone. See Current Date and Time for configuration and output examples.

On-demand tools are suitable for occasional calls, prototypes, and integrations that do not need a persistent gateway. If the same application always uses the same tools, prefer configuring them in an AI Gateway so the policy is centralized.

Combine with a gateway #

When model is a gateway, builtin_tools adds tools to the ones the gateway already enables; it does not remove gateway tools. options applies to the tools of this request. Public API keys cannot send builtin_tools.

Built-in tools are server-side tools: their calls appear as servertool events while streaming and are not returned as messages. Reuse the conversation_token so later turns keep their results; see Server-side context. Each tool is billed according to its own rates; see Built-in tools pricing.