feat(core): add durable compaction barrier (#35371)

packages/schema/src/session-event.ts

@@ -436,6 +436,16 @@ export const RetryScheduled = Event.durable({
 export type RetryScheduled = typeof RetryScheduled.Type
 
 export namespace Compaction {
+  export const Admitted = Event.durable({
+    type: "session.compaction.admitted",
+    ...options,
+    schema: {
+      ...Base,
+      inputID: SessionMessage.ID,
+    },
+  })
+  export type Admitted = typeof Admitted.Type
+
   export const Started = Event.durable({
     type: "session.compaction.started",
     ...options,
@@ -466,6 +476,13 @@ export namespace Compaction {
     },
   })
   export type Ended = typeof Ended.Type
+
+  export const Failed = Event.durable({
+    type: "session.compaction.failed",
+    ...options,
+    schema: Base,
+  })
+  export type Failed = typeof Failed.Type
 }
 
 export namespace RevertEvent {
@@ -517,9 +534,11 @@ export const Definitions = Event.inventory(
   Tool.Success,
   Tool.Failed,
   RetryScheduled,
+  Compaction.Admitted,
   Compaction.Started,
   Compaction.Delta,
   Compaction.Ended,
+  Compaction.Failed,
   RevertEvent.Staged,
   RevertEvent.Cleared,
   RevertEvent.Committed,

packages/schema/src/session-input.ts

@@ -21,3 +21,22 @@ export const Admitted = Schema.Struct({
   timeCreated: DateTimeUtcFromMillis,
   promotedSeq: NonNegativeInt.pipe(optional),
 }).annotate({ identifier: "SessionInput.Admitted" })
+
+export interface PromptEntry extends Schema.Schema.Type<typeof PromptEntry> {}
+export const PromptEntry = Schema.Struct({
+  type: Schema.Literal("prompt"),
+  ...Admitted.fields,
+}).annotate({ identifier: "SessionInput.PromptEntry" })
+
+export interface Compaction extends Schema.Schema.Type<typeof Compaction> {}
+export const Compaction = Schema.Struct({
+  type: Schema.Literal("compaction"),
+  admittedSeq: NonNegativeInt,
+  id: SessionMessage.ID,
+  sessionID: SessionID,
+  timeCreated: DateTimeUtcFromMillis,
+  handledSeq: NonNegativeInt.pipe(optional),
+}).annotate({ identifier: "SessionInput.Compaction" })
+
+export const Entry = Schema.Union([PromptEntry, Compaction]).pipe(Schema.toTaggedUnion("type"))
+export type Entry = typeof Entry.Type

packages/schema/src/session-message.ts

@@ -210,6 +210,7 @@ export const Assistant = Schema.Struct({
 export interface Compaction extends Schema.Schema.Type<typeof Compaction> {}
 export const Compaction = Schema.Struct({
   type: Schema.Literal("compaction"),
+  status: Schema.Literals(["queued", "running", "completed", "failed"]),
   reason: Schema.Literals(["auto", "manual"]),
   summary: Schema.String,
   recent: Schema.String,