dpskh/dsh-a2a

One package, one entry plugin. Mounting @dpskh/a2a 0.3 provides the realtime A2A mesh: the hub host (ctx.a2aHub: project registry + immutable message history over the storage domain, with an optional listening hub server that also serves the realtime WebSocket), the mesh client (ctx.a2aMesh: one WebSocket presence per joined agent with serial injection), the a2a_peers / a2a_message / a2a_history tools, and the /a2a command surface. Presence is a live socket; messages are the durable record — realtime chat on a trusted private network.

Configuration

- id: a2a
  name: '@dpskh/a2a'
  config:
    hub:                      # optional: run the mesh hub server
      host: 127.0.0.1
      port: 43123             # base bind port
      maxPort: 43223          # optional: walk up on EADDRINUSE
    mesh:                     # optional: mesh client
      project: main           # project to connect to (defaults to main)
      agentId: main           # local agent this presence belongs to
      name: main              # roster name; defaults to the agent id
      autoConnect: true       # connect when the configured agent registers
      persistConnections: false # remember each session's last connection and rejoin it
      reconnectMs: 500        # initial reconnect delay (doubles to 10 s)

The hub needs a routed storage backend: mount @deepseek-ai/dsh-storage, a backend (storage-json or storage-sqlite), and @deepseek-ai/dsh-storage-domain with the backend routed to the a2a domain. The entry plugin composes the hub host service (ctx.a2aHub), the mesh client (ctx.a2aMesh), and — when a mesh is configured — the tool and command plugins (cordis activates them by their inject dependencies). Removed 0.2 mesh fields (persistBindings, autoRejoin, pollIntervalMs, heartbeatMs, caps) are ignored for compatibility with copied 0.2 configs.

The mesh

• Hub (ctx.a2aHub): authoritative project registry and the append-only message history (per-project monotonic sequences, project-scoped messageRefs like demo:42). The optional hub server serves the project/history routes over HTTP and the realtime WebSocket at /v1/connect (protocol version 3).
• Presence: a presence exists if and only if one WebSocket is alive. Claimed roster names are unique per project; a same-named later connection is a new presence and inherits nothing. Hub restart clears every presence while the message history survives.
• Messages: immutable, idempotent by messageId (retrying the same body returns the original message; reusing the id for different content fails with MessageIdConflictError). Direct sends resolve the recipient's current presence at accept time and fail immediately when absent; project broadcasts freeze the current presence snapshot (excluding the sender) and never backfill later joiners. replyTo provides causality inside the same project history. Text and attachments share a 4 MiB decoded-content budget; up to eight attachments per message travel as base64 (gzip when it shrinks).
• Delivery: in-memory outcomes reported to the sender — delivered proves the receiving client injected the message, failed a materialization/injection error, disconnected a socket that closed before acknowledging.
• Mesh client (ctx.a2aMesh): each joined agent owns one connection (project + roster name). Inbound messages are pushed serially in hub-assigned sequence and injected into the owning agent's session (follow-up turn when idle, plain context when busy), with attachments materialized under the system temp dir. Unexpected drops auto-reconnect with backoff while the connection is desired; a rejected claim (name in use, unknown project, protocol mismatch) stops wanting the connection. a2a/presence-changed events announce local connect/disconnect; a2a/delivery events announce delivery outcomes. Disposed agents drop their presence automatically. With persistConnections, each successful connect records agentId → (project, name) in the a2a-connections settings namespace, and an agent registering with a stored record rejoins it — the GUI path, where session ids are dynamic and no static agentId is configured; an explicit disconnect forgets the record. Each membership also tracks a local conversation-activity view (idle / conversing / working, inferred from sends, deliveries, and inbound messages — no activity state crosses the hub wire) and exposes it in status() for the connection-graph animations; activity transitions emit a2a/change so the browser refreshes live.