hcom is an open-source agent orchestration harness developed by aannoo in Rust. It is built to coordinate, route, and manage multi-agent processes and native subagents, featuring deep lifecycle handling for AI systems like Claude subagents. Operating in developer terminal and multi-agent backend workflows, hcom acts as an execution harness that correlates agent calls, intercepts execution hooks (such as SubagentStart and SubagentStop), and serializes agent states. It guarantees deterministic routing, persistent task ownership, and structured relay communication across parallel subagent instances. Unlike superficial agent wrappers, hcom focuses on low-level correctness, race-condition mitigation, and concurrency control. It uses transactional allocations and transient stop-claim concurrency guards to prevent duplicate hook registrations from dropping message deliveries, while enforcing cascading teardowns across deeply nested subagent hierarchies. hcom is an open-source project hosted on GitHub under active development with versioned releases distributed via the Cargo ecosystem.
Tags: agent harness, ai agent, cli, coding agent, terminal