Remote channels

Agent Runtime may run across local processes, remote services, browser extensions, IDEs, mobile clients, or workflow workers. The standard does not prescribe transport, but remote channels must preserve identity, permission, recovery, and event semantics.

Channel identity

A channel SHOULD include:

Field	Meaning
channel_id	Stable channel id.
transport	websocket, sse, json_rpc, grpc, http_json, stdio, in_process, or custom.
peer_role	client, host, worker, remote_runtime, peer_agent, or tool_server.
account_ref	Host account or tenant reference.
capabilities	Streaming, resume, permissions, files, artifacts, task delegation, or custom flags.
last_seen_at	Latest heartbeat or event time.
resume_token_ref	Optional recovery token reference.
native_protocol	Optional peer protocol, such as a2a, mcp, json_rpc, or custom.

Remote session ingress

Remote input SHOULD enter as a control-plane action, not write directly to transcript state:

1. Authenticate or enroll the channel.
2. Resolve session, thread, task, and workspace scope.
3. Submit a turn, create a task, append remote input, or link a peer task.
4. Emit channel events.
5. Persist read models, native ids, and recovery cursors.

A2A alignment

When the peer speaks Agent2Agent Protocol, the runtime SHOULD treat A2A as the peer transport and interaction contract while keeping Agent Runtime as the internal execution truth.

A2A concept	Runtime mapping
Agent Card	Peer capability snapshot, routing input, channel.capabilities, and optional agent_card_ref.
SendMessage / SendStreamingMessage	submit_turn, create_task, append_task_progress, and channel events depending on scope.
A2A taskId / contextId	remote_task_ref linked to local task_id, parent_task_id, subagent_id, or channel_id.
A2A Task state	Normalized task status plus native_status; do not collapse retries or local attempts.
Message	Remote input, clarification, status, or task interaction; do not treat messages as durable task outputs.
Artifact / TaskArtifactUpdateEvent	Artifact refs, artifact.changed, and produced/consumed artifact task graph edges.
Streaming / subscribe / push notifications	channel.connected, channel.message, task.progress, task.completed, channel.resumed, ack, cursor, and snapshot repair facts.
In-task authorization	action.required, permission.requested, channel.permission_forwarded, and channel.permission_returned.

A runtime MAY expose an A2A adapter, but the adapter must preserve both identities: the local runtime task_id and the remote A2A taskId / contextId.

Remote permission bridge

Remote permission decisions must record:

• which peer requested permission.
• which tool, process, action, or peer task the request applies to.
• which side made the final decision.
• the response, timeout, policy deny, or auth failure source.
• whether the decision is channel-scoped.

Remote approvals should not be flattened into normal user messages.

Event classes

Event	When emitted
channel.connected	A peer becomes reachable.
channel.disconnected	A peer disconnects or misses heartbeat.
channel.resumed	A peer resumes with cursor or token.
channel.message	Non-turn channel message, protocol notice, or status.
channel.permission_forwarded	Permission request is forwarded across a channel.
channel.permission_returned	Remote or local permission decision returns.
channel.peer_task.linked	A remote peer task is linked to a local task or subagent.
channel.peer_task.updated	Remote peer task state changes.

Recovery

Reconnect SHOULD load a snapshot first, then continue from the last acknowledged sequence. If replay is unavailable, the runtime must emit snapshot repair facts and mark the gap.

Remote task recovery SHOULD distinguish:

• remote session still running.
• remote session idle but not completed.
• remote peer task waiting for input or authorization.
• remote peer task completed but local delivery not reconciled.
• remote session archived or missing.
• auth or network temporarily unavailable.

These states should not all appear as failed.

Anti-patterns

• Writing remote messages directly to UI without entering the runtime event stream.
• Treating A2A taskId as the local task_id and losing the peer boundary.
• Using A2A messages as durable outputs instead of artifact refs.
• Replaying from the beginning after reconnect and duplicating turns or peer tasks.
• Approving remote permissions privately in the host or browser without evidence facts.
• Marking a running peer task as completed because the channel disconnected.