Windmill AI Agents

An agent, as the Agents page lists it, is a saved LLM with its own system prompt, tools and memory, stored as a resource of type ai_agent. It is built once and used in several places: it is run from its own page (a chat, or a run form), a flow's AI agent step links to it by path, and it can be shared in Slack channels from its page. Build a standalone agent when the user wants an assistant they talk to or reuse. Build a flow when the agent is one step of a larger process.

File Format

An agent is a resource file like any other, {path}.resource.yaml (or .resource.json), with resource_type: ai_agent.

Structure

{
  "resource_type": "ai_agent",
  "description": "Answers support questions from the product docs",
  "value": {
    "provider": { "kind": "openai", "resource": "$res:f/ai_providers/openai", "model": "gpt-4o" },
    "system_prompt": "You are the support assistant for Acme. Answer from the docs; say so when they don't cover a question.",
    "memory": { "kind": "compaction" },
    "output_type": "text",
    "tools": [
      {
        "id": "search_docs",
        "summary": "search_documentation",
        "description": "Search the product documentation. Use it whenever the user asks how a feature works.",
        "value": {
          "tool_type": "flowmodule",
          "type": "script",
          "path": "f/support/search_docs",
          "input_transforms": {
            "query": { "type": "ai" },
            "index": { "type": "static", "value": "product_docs" }
          }
        }
      }
    ]
  }
}

The agent's own settings are plain values, not the input_transforms an agent step in a flow uses: each is fixed when the agent is saved. Only a tool's arguments keep input_transforms (see Tools). $res: and $var: references inside it are resolved at run time.