refactor(core): simplify session input promotion (#33443)

packages/core/src/database/migration.gen.ts

@@ -39,5 +39,6 @@ export const migrations = (
     import("./migration/20260612174303_project_dir_strategy"),
     import("./migration/20260622142730_simplify_session_context_epoch"),
     import("./migration/20260622170816_reset_v2_session_state"),
+    import("./migration/20260622202450_simplify_session_input"),
   ])
 ).map((module) => module.default) satisfies DatabaseMigration.Migration[]

packages/core/src/database/migration/20260622202450_simplify_session_input.ts

@@ -0,0 +1,17 @@
+import { Effect } from "effect"
+import type { DatabaseMigration } from "../migration"
+
+export default {
+  id: "20260622202450_simplify_session_input",
+  up(tx) {
+    return Effect.gen(function* () {
+      yield* tx.run(`DELETE FROM \`session_context_epoch\`;`)
+      yield* tx.run(`DELETE FROM \`session_input\`;`)
+      yield* tx.run(`DELETE FROM \`session_message\`;`)
+      yield* tx.run(`DELETE FROM \`event\`;`)
+      yield* tx.run(`DELETE FROM \`event_sequence\`;`)
+      yield* tx.run(`UPDATE \`session\` SET \`workspace_id\` = NULL WHERE \`workspace_id\` IS NOT NULL;`)
+      yield* tx.run(`DELETE FROM \`workspace\`;`)
+    })
+  },
+} satisfies DatabaseMigration.Migration

packages/core/src/event.ts

@@ -46,6 +46,19 @@ export type Payload<D extends Definition = Definition> = {
 export type Subscriber<D extends Definition = Definition> = (event: Payload<D>) => Effect.Effect<void>
 export type Unsubscribe = Effect.Effect<void>
 
+export const latestSequence = Effect.fn("EventV2.latestSequence")(function* (
+  db: Database.Interface["db"],
+  aggregateID: string,
+) {
+  const row = yield* db
+    .select({ seq: EventSequenceTable.seq })
+    .from(EventSequenceTable)
+    .where(eq(EventSequenceTable.aggregate_id, aggregateID))
+    .get()
+    .pipe(Effect.orDie)
+  return row?.seq ?? -1
+})
+
 export type SerializedEvent = {
   readonly id: ID
   readonly type: string

packages/core/src/session/context-epoch.ts

@@ -64,7 +64,7 @@ const prepareOnce = Effect.fnUntraced(function* (
     return { baseline: stored.baseline, baselineSeq: stored.baseline_seq }
   }
   if (result._tag === "ReplacementReady") {
-    const baselineSeq = replacementSeq ?? (yield* SessionInput.latestSeq(db, sessionID))
+    const baselineSeq = replacementSeq ?? (yield* EventV2.latestSequence(db, sessionID))
     yield* replace(db, sessionID, baselineSeq, result.generation)
     return { baseline: result.generation.baseline, baselineSeq }
   }
@@ -124,7 +124,7 @@ const insert = Effect.fnUntraced(function* (
   sessionID: SessionSchema.ID,
   generation: SystemContext.Generation,
 ) {
-  const baselineSeq = yield* SessionInput.latestSeq(db, sessionID)
+  const baselineSeq = yield* EventV2.latestSequence(db, sessionID)
   yield* db
     .insert(SessionContextEpochTable)
     .values({

packages/core/src/session/event.ts

@@ -25,6 +25,12 @@ const Base = {
   timestamp: V2Schema.DateTimeUtcFromMillis,
   sessionID: SessionSchema.ID,
 }
+const PromptFields = {
+  ...Base,
+  messageID: SessionMessageID.ID,
+  prompt: Prompt,
+  delivery: Schema.Literals(["steer", "queue"]),
+}
 
 const options = {
   durable: {
@@ -83,40 +89,16 @@ export type Moved = typeof Moved.Type
 export const Prompted = EventV2.define({
   type: "session.next.prompted",
   ...options,
-  schema: {
-    ...Base,
-    messageID: SessionMessageID.ID,
-    prompt: Prompt,
-    delivery: Schema.Literals(["steer", "queue"]),
-  },
+  schema: PromptFields,
 })
 export type Prompted = typeof Prompted.Type
 
-export namespace PromptLifecycle {
-  export const Admitted = EventV2.define({
-    type: "session.next.prompt.admitted",
-    ...options,
-    schema: {
-      ...Base,
-      messageID: SessionMessageID.ID,
-      prompt: Prompt,
-      delivery: Schema.Literals(["steer", "queue"]),
-    },
-  })
-  export type Admitted = typeof Admitted.Type
-
-  export const Promoted = EventV2.define({
-    type: "session.next.prompt.promoted",
-    ...options,
-    schema: {
-      ...Base,
-      messageID: SessionMessageID.ID,
-      prompt: Prompt,
-      timeCreated: V2Schema.DateTimeUtcFromMillis,
-    },
-  })
-  export type Promoted = typeof Promoted.Type
-}
+export const PromptAdmitted = EventV2.define({
+  type: "session.next.prompt.admitted",
+  ...options,
+  schema: PromptFields,
+})
+export type PromptAdmitted = typeof PromptAdmitted.Type
 
 export const ContextUpdated = EventV2.define({
   type: "session.next.context.updated",
@@ -455,8 +437,7 @@ const DurableDefinitions = [
   ModelSwitched,
   Moved,
   Prompted,
-  PromptLifecycle.Admitted,
-  PromptLifecycle.Promoted,
+  PromptAdmitted,
   ContextUpdated,
   Synthetic,
   Shell.Started,

packages/core/src/session/input.ts

@@ -4,7 +4,6 @@ import { and, asc, eq, isNull, lte } from "drizzle-orm"
 import { DateTime, Effect, Schema } from "effect"
 import type { Database } from "../database/database"
 import type { EventV2 } from "../event"
-import { EventSequenceTable } from "../event/sql"
 import { NonNegativeInt } from "../schema"
 import { V2Schema } from "../v2-schema"
 import { SessionEvent } from "./event"
@@ -65,7 +64,7 @@ export const admit = Effect.fn("SessionInput.admit")(function* (
   if (existing !== undefined) return existing
   const timestamp = yield* DateTime.now
   return yield* events
-    .publish(SessionEvent.PromptLifecycle.Admitted, {
+    .publish(SessionEvent.PromptAdmitted, {
       messageID: input.id,
       sessionID: input.sessionID,
       timestamp,
@@ -93,19 +92,6 @@ export const admit = Effect.fn("SessionInput.admit")(function* (
     )
 })
 
-export const latestSeq = Effect.fn("SessionInput.latestSeq")(function* (
-  db: DatabaseService,
-  sessionID: SessionSchema.ID,
-) {
-  const row = yield* db
-    .select({ seq: EventSequenceTable.seq })
-    .from(EventSequenceTable)
-    .where(eq(EventSequenceTable.aggregate_id, sessionID))
-    .get()
-    .pipe(Effect.orDie)
-  return row?.seq ?? -1
-})
-
 export const projectAdmitted = Effect.fn("SessionInput.projectAdmitted")(function* (
   db: DatabaseService,
   input: {
@@ -117,6 +103,13 @@ export const projectAdmitted = Effect.fn("SessionInput.projectAdmitted")(functio
     readonly timeCreated: DateTime.Utc
   },
 ) {
+  const message = yield* db
+    .select({ id: SessionMessageTable.id })
+    .from(SessionMessageTable)
+    .where(eq(SessionMessageTable.id, input.id))
+    .get()
+    .pipe(Effect.orDie)
+  if (message !== undefined) return yield* Effect.die(new LifecycleConflict({ id: input.id }))
   const stored = yield* db
     .insert(SessionInputTable)
     .values({
@@ -134,12 +127,13 @@ export const projectAdmitted = Effect.fn("SessionInput.projectAdmitted")(functio
   if (!stored) return yield* Effect.die(new LifecycleConflict({ id: input.id }))
 })
 
-export const projectPromoted = Effect.fn("SessionInput.projectPromoted")(function* (
+export const projectPrompted = Effect.fn("SessionInput.projectPrompted")(function* (
   db: DatabaseService,
   input: {
     readonly id: SessionMessage.ID
     readonly sessionID: SessionSchema.ID
     readonly prompt: Prompt
+    readonly delivery: Delivery
     readonly timeCreated: DateTime.Utc
     readonly promotedSeq: number
   },
@@ -157,14 +151,32 @@ export const projectPromoted = Effect.fn("SessionInput.projectPromoted")(functio
     .returning()
     .get()
     .pipe(Effect.orDie)
-  if (!updated) return yield* Effect.die(new LifecycleConflict({ id: input.id }))
-  const stored = fromRow(updated)
-  if (
-    !matchesPrompt(stored, input) ||
-    DateTime.toEpochMillis(stored.timeCreated) !== DateTime.toEpochMillis(input.timeCreated)
-  )
-    return yield* Effect.die(new LifecycleConflict({ id: input.id }))
-  return toMessage(stored)
+  if (updated) {
+    const stored = fromRow(updated)
+    if (!matchesProjection(stored, input)) return yield* Effect.die(new LifecycleConflict({ id: input.id }))
+    return
+  }
+
+  const stored = yield* find(db, input.id)
+  if (stored) {
+    if (!matchesProjection(stored, input) || stored.promotedSeq !== input.promotedSeq)
+      return yield* Effect.die(new LifecycleConflict({ id: input.id }))
+    return
+  }
+
+  yield* db
+    .insert(SessionInputTable)
+    .values({
+      id: input.id,
+      session_id: input.sessionID,
+      prompt: encodePrompt(input.prompt),
+      delivery: input.delivery,
+      admitted_seq: input.promotedSeq,
+      promoted_seq: input.promotedSeq,
+      time_created: DateTime.toEpochMillis(input.timeCreated),
+    })
+    .run()
+    .pipe(Effect.orDie)
 })
 
 export const hasPending = Effect.fn("SessionInput.hasPending")(function* (
@@ -201,35 +213,17 @@ const matchesPrompt = (input: Admitted, expected: { readonly sessionID: SessionS
   input.sessionID === expected.sessionID &&
   JSON.stringify(encodePrompt(input.prompt)) === JSON.stringify(encodePrompt(expected.prompt))
 
-export const projectLegacyPrompted = Effect.fn("SessionInput.projectLegacyPrompted")(function* (
-  db: DatabaseService,
-  input: {
-    readonly id: SessionMessage.ID
+const matchesProjection = (
+  input: Admitted,
+  expected: {
     readonly sessionID: SessionSchema.ID
     readonly prompt: Prompt
     readonly delivery: Delivery
     readonly timeCreated: DateTime.Utc
-    readonly promotedSeq: number
   },
-) {
-  const inserted = yield* db
-    .insert(SessionInputTable)
-    .values({
-      id: input.id,
-      session_id: input.sessionID,
-      admitted_seq: input.promotedSeq,
-      prompt: encodePrompt(input.prompt),
-      delivery: input.delivery,
-      promoted_seq: input.promotedSeq,
-      time_created: DateTime.toEpochMillis(input.timeCreated),
-    })
-    .onConflictDoNothing()
-    .returning()
-    .get()
-    .pipe(Effect.orDie)
-  if (!inserted) return yield* Effect.die("Prompt projection conflicts with admitted input")
-  return fromRow(inserted)
-})
+) =>
+  equivalent(input, expected) &&
+  DateTime.toEpochMillis(input.timeCreated) === DateTime.toEpochMillis(expected.timeCreated)
 
 const publish = Effect.fn("SessionInput.publish")(function* (
   db: DatabaseService,
@@ -238,18 +232,19 @@ const publish = Effect.fn("SessionInput.publish")(function* (
   rows: ReadonlyArray<typeof SessionInputTable.$inferSelect>,
 ) {
   for (const row of rows) {
+    const id = SessionMessage.ID.make(row.id)
     yield* events
-      .publish(SessionEvent.PromptLifecycle.Promoted, {
+      .publish(SessionEvent.Prompted, {
         sessionID,
-        timestamp: yield* DateTime.now,
-        messageID: SessionMessage.ID.make(row.id),
+        timestamp: DateTime.makeUnsafe(row.time_created),
+        messageID: id,
         prompt: decodePrompt(row.prompt),
-        timeCreated: DateTime.makeUnsafe(row.time_created),
+        delivery: row.delivery,
       })
       .pipe(
         Effect.catchDefect((defect) =>
           defect instanceof LifecycleConflict
-            ? find(db, SessionMessage.ID.make(row.id)).pipe(
+            ? find(db, id).pipe(
                 Effect.flatMap((stored) => (stored?.promotedSeq === undefined ? Effect.die(defect) : Effect.void)),
               )
             : Effect.die(defect),
@@ -303,13 +298,3 @@ export const promoteNextQueued = Effect.fn("SessionInput.promoteNextQueued")(fun
     .pipe(Effect.orDie)
   return row === undefined ? false : yield* publish(db, events, sessionID, [row]).pipe(Effect.as(true))
 })
-
-const toMessage = (input: Admitted) =>
-  new SessionMessage.User({
-    id: input.id,
-    type: "user",
-    text: input.prompt.text,
-    files: input.prompt.files,
-    agents: input.prompt.agents,
-    time: { created: input.timeCreated },
-  })

packages/core/src/session/message-updater.ts

@@ -137,7 +137,6 @@ export function update(adapter: Adapter, event: SessionEvent.Event) {
         )
       },
       "session.next.prompt.admitted": () => Effect.void,
-      "session.next.prompt.promoted": () => Effect.void,
       "session.next.context.updated": (event) =>
         adapter.appendMessage(
           new SessionMessage.System({

packages/core/src/session/projector.ts

@@ -21,7 +21,6 @@ type DatabaseService = Database.Interface["db"]
 const decodeMessage = Schema.decodeUnknownSync(SessionMessage.Message)
 const encodeMessage = Schema.encodeSync(SessionMessage.Message)
 
-class PromptAlreadyProjected extends Error {}
 export class SessionAlreadyProjected extends Error {}
 
 type Usage = {
@@ -350,27 +349,19 @@ export const layer = Layer.effectDiscard(
     )
     yield* events.project(SessionEvent.Prompted, (event) =>
       Effect.gen(function* () {
-        const messageID = event.data.messageID
-        const existing = yield* db
-          .select({ id: SessionMessageTable.id })
-          .from(SessionMessageTable)
-          .where(eq(SessionMessageTable.id, messageID))
-          .get()
-          .pipe(Effect.orDie)
-        if (existing) return yield* Effect.die(new PromptAlreadyProjected())
-        yield* run(db, event)
         if (event.durable === undefined) return yield* Effect.die("Durable Session event is missing aggregate sequence")
-        yield* SessionInput.projectLegacyPrompted(db, {
-          id: messageID,
+        yield* SessionInput.projectPrompted(db, {
+          id: event.data.messageID,
           sessionID: event.data.sessionID,
           prompt: event.data.prompt,
           delivery: event.data.delivery,
           timeCreated: event.data.timestamp,
           promotedSeq: event.durable.seq,
         })
+        yield* run(db, event)
       }),
     )
-    yield* events.project(SessionEvent.PromptLifecycle.Admitted, (event) =>
+    yield* events.project(SessionEvent.PromptAdmitted, (event) =>
       Effect.gen(function* () {
         if (event.durable === undefined) return yield* Effect.die("Durable Session event is missing aggregate sequence")
         yield* SessionInput.projectAdmitted(db, {
@@ -383,22 +374,6 @@ export const layer = Layer.effectDiscard(
         })
       }),
     )
-    yield* events.project(SessionEvent.PromptLifecycle.Promoted, (event) =>
-      Effect.gen(function* () {
-        if (event.durable === undefined) return yield* Effect.die("Durable Session event is missing aggregate sequence")
-        yield* insertMessage(
-          db,
-          event,
-          yield* SessionInput.projectPromoted(db, {
-            id: event.data.messageID,
-            sessionID: event.data.sessionID,
-            prompt: event.data.prompt,
-            timeCreated: event.data.timeCreated,
-            promotedSeq: event.durable.seq,
-          }),
-        )
-      }),
-    )
     yield* events.project(SessionEvent.ContextUpdated, (event) => run(db, event))
     yield* events.project(SessionEvent.Synthetic, (event) => run(db, event))
     yield* events.project(SessionEvent.Shell.Started, (event) => run(db, event))

packages/core/src/session/runner/llm.ts

@@ -176,7 +176,7 @@ export const layer = Layer.effect(
       const toolFibers = yield* FiberSet.make<void, ToolOutputStore.Error>()
       let needsContinuation = false
       if (promotion) {
-        const cutoff = yield* SessionInput.latestSeq(db, session.id)
+        const cutoff = yield* EventV2.latestSequence(db, session.id)
         if (promotion === "steer") yield* SessionInput.promoteSteers(db, events, session.id, cutoff)
         if (promotion === "queue") {
           yield* SessionInput.promoteNextQueued(db, events, session.id)