v0.4.0

Full Changelog: 0.3.0...0.4.0

This release introduces external data hydration: an app that owns its message store can seed a conversation from it and reconcile only the unstored tail off the Ably channel, instead of replaying the whole history. The new View.loadUntil() pages back to the newest message you already hold and returns just the missing tail, so you compose [...stored, ...tail] with no duplicates. See the external hydration demo. The release also includes a number of other improvements; see the full details below.

Breaking Changes

• The agent's run.messages now returns only the messages belonging to the run, rather than all messages for the full conversation. In order to obtain the full set of messages for the conversation (for example, in order to pass it as input to the LLM) drain the run.view and access run.view.getMessages():

  // before (0.3.0): run.messages held the whole conversation after loadConversation()
  await run.loadConversation();
  const messages = run.messages;
  
  // after (0.4.0): drain run.view, then read it
  while (run.view.hasOlder()) await run.view.loadOlder();
  const messages = run.view.getMessages().map((m) => m.message);

  #223 #227 #243

• Renamed the run types onto a shared read-model: client ActiveRun → ClientRun<TMessage>, agent Run → AgentRun (both expose runId, status, error, messages). #223

• ClientRun.runId is now a synchronous string (was Promise<string>); await run.started before reading it. The agent's runId is unchanged. #223

• ClientView.send / regenerate / edit now resolve to Promise<ClientRun<TMessage>>. #223

• Removed the agent's loadConversation() (with LoadConversationOptions / maxRuns); drain run.view instead, and run.start() now awaits the new run.located. #227

• View<TMessage> is now read-only; sibling navigation and the write path move to ClientView<TInput, TMessage> (extends View). session.view / createClientView() already return ClientView, so only code naming the old View<TInput, TMessage> needs updating. #220

• Renamed BranchSelection → BranchHandle and removed selectSibling; select via branchSelection(codecMessageId).select(index). #219

• Removed the agent's RunView; run.view is now a read-only View<TMessage> (read run.view.getMessages()), and MessageNode is no longer exported. #221

• ClientView.send / edit now reject a send with more than one new message (InvalidArgument); the array form stays for the wire-only inputs that resolve one turn (e.g. parallel tool results). #213

• Removed ClientRun.optimisticCodecMessageIds; read ClientRun.inputCodecMessageId. #213

• Removed the ClientSessionOptions.messages seed; compose [...stored, ...live] yourself over the loadOlder() walk. #227

• Removed AgentSessionOptions.inputEventLookupTimeoutMs and the InputEventNotFound error code; run.located has no deadline, so race your own timeout. #227

• Removed AgentSessionOptions.onError; subscribe via session.on('error', ...). #223

New Features

• View.loadUntil(predicate) pages history back to the first message your store already holds (the seam) and returns only the messages newer than it, so you hydrate from your own store and reconcile just the unstored tail. #234
• React seed hooks for that recipe: useMessagesWithSeed (generic and Vercel) and a messages seed option on useMessageSync, which compose your stored prefix with the live channel and run the seam walk for you. #229
• View.loadOlder() returns the page it revealed (CodecMessage[], oldest-first; [] when exhausted), the building block for the seam walk. #226
• Added historyPageSize (ClientSessionOptions / AgentSessionOptions, default 100) to tune the history fetch size per round trip. #226
• The agent gains a real paginating, read-only run.view over the same View base as the client, replacing its old messages-only read. #221

Bug Fixes

• The agent no longer feeds incomplete ancestor runs (still streaming, suspended, cancelled, or errored) into the model prompt, so a dangling tool call from a concurrent or interrupted turn no longer makes the provider reject the request. #237
• Fixed a stale message left at the end of the conversation after regenerating a non-head message in a multi-message reply. #215
• Vercel: two tabs sharing a clientId no longer error with "inputs array is empty"; a tab with no new inputs waits for the other tab's run and repaints when it completes. #224
• Fixed sends intermittently failing with unable to send; channel is initialized after a rapid subscribe/unsubscribe cycle (e.g. React StrictMode in development); connect() now attaches the channel explicitly. #229