> ## Documentation Index
> Fetch the complete documentation index at: https://docs.usefused.com/llms.txt
> Use this file to discover all available pages before exploring further.

# SubAgent framework behavior

> Choose portable graph composition, recursive ADK discovery, or an advanced child target.

Use explicit graph nodes when the multi-agent flow must move between ADK and LangGraph.

| Need                       | Use                                         |
| -------------------------- | ------------------------------------------- |
| Portable multi-agent flow  | Explicit root graph nodes                   |
| Recursive folder discovery | ADK folder SubAgents                        |
| Nested LangGraph agents    | Root graph topology                         |
| Native child target        | `Agent.advanced(...)` as a node or SubAgent |

## Portable composition

A portable graph names the SubAgent as a node. Harnest lowers the same topology to the selected framework.

| Benefit               | Result                                   |
| --------------------- | ---------------------------------------- |
| Explicit routing      | The graph shows when each child runs     |
| Framework portability | No recursive discovery dependency        |
| Testability           | Unit tests can target the compiled graph |

## Native children

An `Agent.advanced(...)` wrapper can appear as a managed SubAgent or graph node.

| Constraint          | Rule                                                   |
| ------------------- | ------------------------------------------------------ |
| Root adapters       | Embedded targets cannot use root input/output adapters |
| ADK target          | Must be `BaseAgent`, not `App`                         |
| ADK name            | Wrapper name must match the native agent name          |
| Native capabilities | Framework-owned and migrated manually                  |

<Note>
  A nested LangGraph `Agent` cannot consume a discovered sibling `subagents/` folder. Express that topology in the root graph.
</Note>

<Card title="ADK and LangGraph" icon="arrows-rotate" href="/harnest/runtime/adk-and-langgraph">
  Review the complete managed and advanced portability boundary.
</Card>