human_input

human_input

A relay that turns one ARCP human.input.request into a fan-out across phone, email, and Slack — and resolves on the first valid response, cancelling the rest.

Before ARCP

Two patterns in the wild: (a) the agent embeds Slack/Twilio/SES clients directly and reinvents response parsing for each; (b) the agent posts to a single channel and dies waiting if nobody's watching. Neither lets a runtime block a job until a human answers without writing a custom dispatcher.

With ARCP

client.on("human.input.request", (env) => {
  void fanOut(client, env);
});

// inside fanOut:
const winner = await Promise.race([
  Promise.any(channelPromises),
  new Promise((r) => setTimeout(() => r(null), timeoutMs)),
]);
await client.send(buildEnvelope({
  ..., type: "human.input.response",
  optional: { correlation_id: request.id },
  payload: { value: won.value, responded_by: won.dest, ... },
}));

The runtime treats the answer as a typed reply to the original request and unblocks whichever job was waiting (RFC §12.4).

ARCP primitives

• human.input.request / human.input.response / human.input.cancelled — RFC §12.1, §12.4.
• Multi-channel resolution rule (resolve on first; cancel the rest) — §12.3.
• expires_at deadline → DEADLINE_EXCEEDED cancellation — §12.4.

File tour

• main.ts — opens session, dispatches each inbound HITL request. fanOut is the file. First-wins resolution, loser-channel cancellation, deadline handling.
• channels.ts — per-destination adapters; stubbed.

Variations

• Replace first-wins with a quorum policy (negotiated as an extension on human.input.request.payload).
• Honor default (§12.4): synthesize a response when the deadline expires instead of cancelling.
• Use human.choice.request for multi-option pickers; the relay pattern is identical.