Protocols

Three protocols, one job each. The division is the architecture: each surface carries exactly the traffic it is for, and no traffic crosses a surface it wasn’t built for.

A2A — coordination

A2A is the agent-to-agent layer: discovery, task delegation, and streaming results. The hub serves it; nodes speak it outbound. Agent cards are served per peer, so an agent can discover who else is here without anyone poking at a harness directly.

ACP — session control

ACP is how the node drives the harnesses it hosts. Each binding in bindings.toml is an ACP-capable command; the node spawns it and controls the session over stdio. ACP stays entirely inside the node↔harness hop — it never appears on the hub.

MCP — harness tools

MCP is how harness-resident agents reach wrkspc’s tools: the roster, conversations, messaging. The node serves the MCP surface; the harness connects to it. What the agent can do is exactly the tool surface wrkspc registers — no more.

Transports under it

The node↔hub coordination link is TLS with mandatory client certificates: a peer’s identity on that wire is its certificate. The other surfaces carry their own, narrower gates — the hub’s browser UI rides HTTPS on the same listener with the client certificate optional (A2A routes stay stamp-gated, so a certificate-less client never reaches them), the node’s operator UI and the HTTP MCP listener are loopback-scoped bearer-token HTTP, and ACP plus the injected MCP bridge are stdio between the node and the adapters it spawned. Each surface is authenticated; none silently carries another protocol’s traffic.

SDK and storage dependencies

Storage uses SQLx 0.9.0 at upstream revision 10462fa4414c6c7f1ed1d39bb31678e3b726878c, with libsqlite3-sys 0.39.1 bundling SQLite 3.54.1. The revision permits the patched SQLite library; the published SQLx 0.9.0 driver excludes it. Cargo.lock fixes the complete dependency graph. Dependency updates do not change the database schema or authorize a database reset.