Module subagent_node 

Sub-agent nodes — the graph node that delegates to a harness agent (a model-driven agent loop) resolved by name from a CapabilityRegistry.

Where crate::graph::subgraph embeds an entire [CompiledGraph] as a node, this module embeds a harness agent as a node: a graph step hands its work to a registered, independently-observable agent and folds the agent’s answer back into the parent graph state.

The pieces:

• SubAgentNode binds an agent ComponentId to an InputMapper (parent State → SubAgentInput), an OutputMapper (SubAgentOutput → parent Update), and a SubAgentPolicy.
• subagent_node lowers a SubAgentNode + a registry into an ordinary graph node [Handler]: it resolves the agent by name, creates a distinct child run_id that preserves the run tree’s root_run_id and is parented to the enclosing graph run, applies timeout/retry/budget policy, maps the child output into the parent update, records the child run (with its usage) onto the parent execution rollup, and forwards the child run’s harness events onto the node’s event sink.
• HarnessSubAgent adapts a harness SubAgent into a registry-storable HarnessAgent.

See [types] for the data definitions and test.rs for focused tests.

Structs

HarnessSubAgent

Adapts a harness SubAgent into a registry-storable HarnessAgent.

SubAgentBudget

An optional cap on the work a single sub-agent invocation may perform.

SubAgentInput

The structured input a SubAgentNode hands to a delegated agent.

SubAgentNode

A graph node that delegates to a harness agent resolved by name.

SubAgentOutput

The structured output a delegated agent returns to its SubAgentNode.

SubAgentPolicy

Timeout, retry, and budget policy applied around a sub-agent invocation.

Traits

HarnessAgent

A harness agent invocable by name from a graph node.

Functions

subagent_node

Lowers a SubAgentNode plus a capability registry into a graph node [Handler].

Type Aliases

InputMapper

Maps parent graph State into the SubAgentInput a delegated agent runs over.

OutputMapper

Maps a delegated agent’s SubAgentOutput into the parent graph Update merged through the graph reducer.