Chord's shared watch: listeners take a tagged call, { kind: "value", value, ops, retired } or
{ kind: "failed", error }; a recoverable failure keeps the watch open and the next value arrives as
[["r", value]]; WatchEnd is tagged by kind, and an aborted context ends a watch "aborted".
Durable: observers take the watch's shapes (advance(call, ctx), end(end)); onReport(report) with
report.kind and report.error, session_failed is storage_failed; subscribeCommits is observeCommits;
SessionEnd and ReportFrom are tagged by kind; FileChange is tagged and file watchers stop with
stop(ctx); CompactionFailure and CompactionStatus name their trigger (pi.live version 2 with a
migrate); the task_outdated report uses the scheduler's reasons; TaskInspection's ready is pending;
DocumentCommitChange is tagged. Stored formats are unchanged.
Breaking change: defineDoc and defineDocFamily now require an explicit checkpointWhen predicate; no default is supplied. Set policies on built-in documents, examples, tests, and triage state, and document the required API.
Nested tool calls: ToolExecutionApi.executeTool() runs another tool as its own pi.tool task owned by the caller,
keyed for replay-safe reattachment. Results for programs live in the caller's NestedResultDoc until it settles;
pi.live.nestedTools shows each call with the arguments it runs with and a summary. TaskOptions.abandonOnRestart
aborts work its creator awaited only in memory before it runs again after a restart.
Structured output: structuredOutputSchema and structuredOutput, validated; a tool without a schema gives programs its
bounded output (one text as a string, one image as itself, else the list). ToolExecutionResult.content is now output.
callers and modelTools decide who may call a tool.
Storage errors: any error a Storage method throws fails the Session, which closes itself; later calls and waits reject
with SessionFailed, watches end with session_failed, and Session.closed settles. Nothing retries in the Harness.
StorageRejected is removed; StorageRequestError marks invalid reads that fail only their call. Listener and onReport
errors are contained and reported.
Also updates scripts/issues/triage.ts and the vacation experiment for the content -> output rename.
Tasks name their owner (conversation or task); a task waits on other tasks with a waiting state (failFast or allSettled) and runtime.outcomes(); a task that finishes while owned work is live holds completing until it drains; abort handlers run bottom-up; only live owners cascade. The generation owns its tool tasks and waits for them in a tools phase, replacing pi.post-tools and after. Adds Conversation.abort({ background: true }), example 24 (checkout with payments), and reworks example 23 into persistent subagents.
Adds defineTask, registry-resolved phase handlers, and a scheduler that
decides every task transition in one callback on the Session line:
reservation with migration, dependencies, precedence rules in a step
before each phase, handover to replaced definitions, direct-task abort
(mark, signal, join, fresh abort invocation), orphaning of blocked tasks,
open reconciliation, and close that joins invocations without writing
outcomes. runtime.commit() callbacks return the typed next state; Tx no
longer exposes setTask. Adds Harness.resume, getTask, waitForTask,
abortTask, and task-aware waitForIdle; RegistryReader.subscribe wakes
the scheduler.
