umao_agents

Caution

This crate now compiles to wasm32-wasip1, but Delegate nodes still rely on outbound A2A HTTP access at runtime. For Spin-based deployments, the component manifest must allow those targets via allowed_outbound_hosts.

Note

External dependency — this crate depends on umao_core and umao_executor from the separate umao-rs repository via relative path deps (../../../umao-rs/crates/...). The UMAO crates must be available locally for compilation.

Crate: umao_agents · Path: crates/umao_agents Description (Cargo.toml): UMAO coordination for promptfleet A2A agents — AsyncNodeExecutor backed by agent_sdk.

Specification lineage

This crate is the downstream application of a three-layer stack:

Layer	Project	License
Specification	UMAO spec	Community Specification License 1.0
Reference impl	umao-rs	Apache 2.0
Application	umao_agents (this crate)	Apache 2.0

promptfleet-agents is listed as a reference implementation in the UMAO specification.

For conceptual background see UMAO Orchestration.

Role

Bridges the vendor-neutral UMAO orchestration engine with the promptfleet agent SDK. Provides PromptFleetExecutor — an AsyncNodeExecutor implementation that dispatches UMAO graph Delegate nodes to real A2A agents via agent_sdk::A2aClient. Non-delegate CFB types (Select, Aggregate, Monitor, FlowControl) use deterministic responses from umao_core.

Feature flags

From crates/umao_agents/Cargo.toml:

No feature flags declared.

Dependencies (notable)

Dependency	Role
umao_core	UMAO graph IR, error types, deterministic node responses
umao_executor	AsyncNodeExecutor trait and orchestrator runtime
agent_sdk (feature: a2a-client)	A2aClient for dispatching to real A2A agents

Public API (from src/lib.rs)

• PromptFleetExecutor — main struct; implements AsyncNodeExecutor from umao_executor
  • new() — create empty executor
  • register(name, endpoint) — register an agent by name → endpoint URL
  • from_agents(iter) — build from an iterator of (String, String) pairs
  • Implements Default

Re-exports:

• umao_core — full re-export of the UMAO core crate
• umao_executor — full re-export of the UMAO executor crate

CFB type dispatch

PromptFleetExecutor handles all UMAO CfbType variants:

CfbType	Behavior
Delegate	Routes to registered A2A agent via A2aClient::send_message
Select	Deterministic response via umao_core::deterministic
Aggregate	Combines all input port values into a formatted summary
Monitor	Deterministic response via umao_core::deterministic
FlowControl	Deterministic response via umao_core::deterministic

Example sketch

use umao_agents::PromptFleetExecutor;
use umao_executor::orchestrator;

let mut executor = PromptFleetExecutor::new();
executor.register("researcher", "http://localhost:3001");
executor.register("synthesizer", "http://localhost:3002");

// Load a UMAO graph and execute
// let result = orchestrator::execute_async(&graph, &executor, None).await;

Full API reference: cargo doc -p umao_agents --no-deps