Struct Resolver 

pub struct Resolver { /* private fields */ }

A named async value source whose inputs come from State and whose result lands back in State under {name}:result (or {name}:error).

Resolver is the async sibling of the deterministic Recognizer: both are inputs from State → value. A Resolver generalizes call_agent from “a sub-agent” to any async source — a sub-agent (Resolver::agent) or a system fetch / tool call / MCP request (Resolver::fetch) — under one result convention, so a Flow step can complete on it via Guard::resolved regardless of where the value came from.

Implementations

impl Resolver

pub fn agent(name: impl Into<String>, agent: Arc<dyn TextAgent>) -> Resolver

Resolve by running a sub-agent. Its String output becomes the result.

pub fn fetch<F, Fut>(name: impl Into<String>, f: F) -> Resolver

where F: Fn(State) -> Fut + Send + Sync + 'static, Fut: Future<Output = Result<Value, String>> + Send + 'static,

Resolve by running an async closure over a clone of State — the seam for an HTTP fetch, a tool call, or an MCP request. The closure returns Ok(value) on success or Err(message) to record an error.

pub fn llm( name: impl Into<String>, llm: Arc<dyn BaseLlm>, prompt: impl Into<String>, ) -> Resolver

Resolve by running a one-shot OOB LLM over a State-interpolated prompt ({key} placeholders). The completion text becomes the result.

pub fn name(&self) -> &str

The resolver’s name (the {name}:result prefix it writes).

pub async fn resolve(&self, state: &State) -> Result<Value, String>

Resolve synchronously (AgentMode::Call): await the source, write its value to {name}:result (or its error to {name}:error), record its provenance under state_meta:{name}:result, and return it.

pub fn dispatch(self, state: State)

Resolve detached (AgentMode::Dispatch): spawn the resolution on the runtime and return immediately. The conversation does not wait; consumers observe completion reactively via {name}:result.