MA2H FAQ
Common questions about the MA2H protocol. The spec is authoritative where this page summarises.
What is MA2H?
MA2H (Multi-agent to Human) is an open, vendor- and runtime-neutral protocol (v0.6 draft, Apache-2.0, stewarded by Autonomy) that standardises how a fleet of autonomous agents coordinates with a human. Agents in any runtime send messages to one central Hub where a human handles everything from one place. Read the spec.
What are the three MA2H verbs?
notify keeps a human informed and expects no response; ask is a decision the human must make before the agent proceeds, with a structured answer routed back and signed; task is a manual action the human performs out-of-band, with an optional completion signal.
How can a coding agent (Claude Code, Codex, Cursor, CI, cron) ask me for approval and wait?
The agent POSTs an ask to the Hub and can exit. When you answer, the signed Response routes back to the originating agent by push webhook or pull polling, so approvals survive the agent process ending (the ephemeral agent resume pattern, spec §2.1).
Is there an MA2H hub I can use today?
Yes. OH HAI is a universal inbox for agent fleets that implements an MA2H hub, with web and iOS apps where you answer agents' notify, ask and task messages.
How is MA2H different from A2A?
A2A is for peer agent-to-agent task handoff. MA2H is for the many-agents → one-human → one-durable-hub shape: the inbox and decision loop. It is not a chatbot protocol, BPM engine, messaging app or UI framework.
Can a human send instructions to an agent?
Yes. Since v0.4, human→agent directives are delivered through a durable per-agent mailbox; every mailbox entry is signed, and the agent verifies and dedupes before acting.
Can agents message each other through MA2H?
Since v0.5 there is a hub-mediated inter-agent leg for one account's agents, with sessions (agent:<id>#<session>) and delivery honesty — terminal bounced and expired states. It is account-opt-in and account-scoped.
How does MA2H keep answers trustworthy?
Every pushed Response is signed (RFC 8785 JCS + detached signature) and agents verify, dedupe and act at most once. Agent state is AEAD-sealed and the Hub never holds the key; the actor is Hub-attested and resolver authorisation is fail-closed.
What changed in v0.6?
v0.6 is a corrective release scoped to the ask contract. See the v0.6 spec, changelog and migration guide.
Is there a reference implementation, schema and test suite?
Yes: a TypeScript reference implementation, JSON Schemas and conformance vectors live in the repository.
What license is MA2H under, and who stewards it?
Apache-2.0, stewarded by Autonomy, which also stewards Issuegraph and builds Descant and OH HAI.