every.channel/evolution/proposals/ECP-0066-iroh-control-protocol.md

ECP-0066: iroh-Gossip Control Protocol For Hybrid MoQ Discovery

Status: Implemented

Decision

Add a first-party control protocol carried over iroh-gossip to advertise stream availability across multiple transport paths:

• MoQ relay (WebTransport URL + broadcast name + track),
• iroh direct (EndpointAddr + broadcast name + track).

ec-node will expose:

1. control-announce: publish control announcements to an iroh gossip topic.
2. control-listen: subscribe to the topic and print announcements.
3. Optional integration in wt-publish to announce relay-published streams via the same control topic.

Motivation

We currently have two transport worlds:

• relay-centric (wt-publish),
• direct iroh (moq-publish / moq-subscribe).

Discovery is fragmented. A shared iroh control channel makes transport selection explicit and allows consumers to discover either path (or both) from one substrate.

Scope

In scope:

• New control protocol data types in ec-core.
• New ControlGossip helper in ec-iroh.
• New CLI surfaces in ec-node for announce/listen.
• Optional relay announcement from wt-publish.

Out of scope:

• Policy engine for automatic best-path selection.
• Security policy beyond existing iroh/gossip trust boundaries.
• Replacing existing catalog gossip immediately (coexist first).

Alternatives considered

• Keep relay and direct discovery completely separate. Rejected because it forces duplicated consumer logic.
• Replace existing catalog gossip in one cutover. Rejected because additive coexistence is safer for rollout.

Rollout / Reversibility

• Additive and reversible: removing control commands and topic does not affect existing media paths.
• Existing MoQ publish/subscribe flows continue unchanged.