Skip to content
This page is in English

The technical documentation is maintained in English in the app repository. The rest of this site is translated.

Architecture

DSH Mobile is a three-module Gradle project (Kotlin 2.0, Compose, Hilt).

core/           pure JVM — no Android imports
  wire/         the DeepSeek Harness web-client protocol:
                  envelopes (client-request / server-response /
                  server-request / client-response), the lenient WireJson
                  codec, RpcTransport (OkHttp), WsDownlink (downlink-only
                  WebSockets /api/events.mux + /api/events.host),
                  DshApiClient (52 typed unary methods + respond + typert
                  remotes), ConnectionLoop (readiness handshake
                  host.describe + both streams, exponential backoff)
  wire/dto/     kotlinx.serialization ports of the harness schemas
                  (sessions, host, workspace, skills, goals, settings,
                  credentials, llm, subagents, agent presets, events,
                  frames, tool views) — lenient, merge-extensible
  session/      EventFold: raw session events → ConversationSnapshot
                  (turn/step/message/tool nodes, streaming block assembly,
                  interruption marking, gap detection)
  notify/       CompletionClassifier: turn/goal/approval/question/idle
                  events with dedup keys

app/            Android UI
  connection/   HostsStore (remembered hosts + settings, DataStore),
                  DiscoveryEngine (Wi-Fi subnet sweep + host.describe
                  probe), ConnectionManager (owns the ConnectionLoop,
                  exposes mux/host frame flows), ConnectionService
                  (foreground service), KeepAliveWorker (15-min fallback)
  data/         SessionStore — the live mirror of the harness: session
                  list/workspaces/folds per session, queue/jobs/
                  projections, approvals/questions, subagent catalog
  notify/       NotificationObserver — classifier → channels, dedup,
                  deep links
  media/        AttachmentImages — LruCache + BitmapFactory decoding of
                  session attachments (no image library: the bytes arrive
                  through session.attachment, not a URL)
  ui/           theme (exact DSH design tokens + motion specs), components
                  (buttons, disclosure rows, state dots, tool cards,
                  markdown, overlays, bottom sheets, context meter),
                  screens (connect, main shell with Discord-style drawer +
                  details panel, chat, settings)

The chat surface is split by responsibility rather than living in one file:
ChatScreen (shell) · ChatTopBar (two-row chrome + Chat/Trajectory tabs) ·
ChatTranscript · ChatNodeItem · ToolRowModel (verb + cwd-relative summary) ·
Composer · Docks · TrajectoryTab · Sheet*.kt (commands, models, presets,
subagents, permission) · ChatProjections (defensive readers).

mock-harness/   Ktor implementation of the /api protocol for tests
tools/capture/  Node recorder of real harness traffic → conformance fixtures

Data flow

  1. ConnectionManager performs the readiness handshake and pumps the two WebSocket downlinks; frames fan out as SharedFlows.
  2. SessionStore folds session events into ConversationSnapshots (incremental), keeps the session/workspace registry from host frames, and merges queue/jobs/projection snapshots. Typed projection views (permissions, stats, usage, context, image limits) are derived from that snapshot rather than fetched, so they stay in lockstep with the transcript and cost no round trips. 2b. On first connect baseline() resolves a landing session (data/InitialSession.kt): the session last opened on this harness, else the most recently active one. Reconnects keep whatever was open.
  3. Screens observe StateFlows and render; user actions go back through SessionStore → DshApiClient (POST /api/<method>, /api/respond).
  4. NotificationObserver classifies frames into completion events and posts channel-notifications that deep-link into sessions.

Key invariants

  • The wire layer never crashes on unknown data: unknown keys are ignored, unknown event/frame/card types fall back to Unknown* passthroughs.
  • HTTP status is carrier-only; business failures arrive as ok: false with a typed error code (see docs/PROTOCOL.md).
  • The WebSocket streams are downlink-only — the client never sends.
  • Settings/credentials/host-native methods are loopback-only by harness design; over LAN the app surfaces them read-only (see docs/COMPATIBILITY.md).
  • Protocol baseline: harness 0.1.0-rc.8 (core.DshCore.PROTOCOL_BASELINE).
Edit on GitHub