Tools

CUGA agents call tools. You can attach them three ways:

Python functions (SDK)

Pass LangChain tools directly to CugaAgent:

from cuga import CugaAgent
from langchain_core.tools import tool

@tool
def get_accounts(limit: int = 10) -> str:
    """List CRM accounts."""
    return f"Found {limit} accounts"

agent = CugaAgent(tools=[get_accounts])

For advanced wiring (custom discovery, lazy loading), see Tool provider.

OpenAPI

Register an OpenAPI service in the tools registry config (mcp_servers.yaml by default):

services:
  - crm:
      url: "http://localhost:8007/openapi.json"
      description: "CRM API"

Then either:

• SDK — start the registry (cuga start registry) and point the agent at it, or
• Server / demo — use a preset that already includes the app (cuga start demo_crm)

Override the config file:

export MCP_SERVERS_FILE="/path/to/mcp_servers.yaml"

OpenAPI auth (API keys, OAuth) is configured in the same YAML. See the agent repo’s registry examples for api_overrides and include filters.

MCP servers

Connect to any MCP server — STDIO for local dev, HTTP/SSE for production:

mcpServers:
  github:
    command: "npx"
    args: ["-y", "@modelcontextprotocol/server-github"]
  docs:
    url: "http://localhost:8112/sse"

Three common setups:

1. Existing server — add command + args (STDIO) or url (HTTP)
2. Local STDIO server — run your own Python/Node MCP process
3. HTTP server — expose tools over SSE (recommended for remote access)

Registry (server mode)

When you run CUGA as a server, the tools registry loads OpenAPI + MCP from YAML and serves tools to the agent.

cuga start registry
# default: http://127.0.0.1:8001

Useful endpoints: GET /applications, POST /functions/call, POST /functions/onboard.

The Manage UI (cuga start manager) edits the same tool list as a draft before you publish.

Next steps

• CugaAgent — attach tools in Python
• CLI presets — demos that ship with sample apps
• Task modes — API-only, web, or hybrid
• Settings reference — registry ports and tool limits