refactor(core): normalize step event versions

packages/core/src/session/event.ts

@@ -32,12 +32,6 @@ const options = {
     version: 1,
   },
 } as const
-const stepSettlementOptions = {
-  durable: {
-    aggregate: "sessionID",
-    version: 2,
-  },
-} as const
 
 export const UnknownError = Schema.Struct({
   type: Schema.Literal("unknown"),
@@ -181,7 +175,7 @@ export namespace Step {
 
   export const Ended = EventV2.define({
     type: "session.next.step.ended",
-    ...stepSettlementOptions,
+    ...options,
     schema: {
       ...Base,
       assistantMessageID: SessionMessageID.ID,
@@ -203,7 +197,7 @@ export namespace Step {
 
   export const Failed = EventV2.define({
     type: "session.next.step.failed",
-    ...stepSettlementOptions,
+    ...options,
     schema: {
       ...Base,
       assistantMessageID: SessionMessageID.ID,

packages/core/test/session-projector.test.ts

@@ -41,6 +41,55 @@ const assistantRow = (
 }
 
 describe("SessionProjector", () => {
+  it.effect("stores step settlement events as version 1", () =>
+    Effect.gen(function* () {
+      const { db } = yield* Database.Service
+      yield* db
+        .insert(ProjectTable)
+        .values({ id: Project.ID.global, worktree: AbsolutePath.make("/project"), sandboxes: [] })
+        .run()
+        .pipe(Effect.orDie)
+      yield* db
+        .insert(SessionTable)
+        .values({
+          id: sessionID,
+          project_id: Project.ID.global,
+          slug: "test",
+          directory: "/project",
+          title: "test",
+          version: "test",
+        })
+        .run()
+        .pipe(Effect.orDie)
+
+      const events = yield* EventV2.Service
+      const assistantMessageID = SessionMessage.ID.make("msg_assistant")
+      yield* events.publish(SessionEvent.Step.Ended, {
+        sessionID,
+        assistantMessageID,
+        timestamp: created,
+        finish: "stop",
+        cost: 0,
+        tokens: { input: 0, output: 0, reasoning: 0, cache: { read: 0, write: 0 } },
+      })
+      yield* events.publish(SessionEvent.Step.Failed, {
+        sessionID,
+        assistantMessageID,
+        timestamp: created,
+        error: { type: "unknown", message: "failed" },
+      })
+
+      expect(
+        (yield* db
+          .select({ type: EventTable.type })
+          .from(EventTable)
+          .where(eq(EventTable.aggregate_id, sessionID))
+          .orderBy(EventTable.seq)
+          .all()).map((event) => event.type),
+      ).toEqual(["session.next.step.ended.1", "session.next.step.failed.1"])
+    }),
+  )
+
   it.effect("orders projected messages and context by durable aggregate sequence", () =>
     Effect.gen(function* () {
       const { db } = yield* Database.Service

packages/core/test/session-runner-recorded.test.ts

@@ -180,7 +180,7 @@ describe("SessionRunnerLLM recorded", () => {
         "session.next.step.started.1",
         "session.next.text.started.1",
         "session.next.text.ended.1",
-        "session.next.step.ended.2",
+        "session.next.step.ended.1",
       ])
     }),
   )

packages/sdk/js/src/v2/gen/types.gen.ts

@@ -3334,7 +3334,7 @@ export type SyncEventSessionNextStepEnded = {
   type: "sync"
   id: string
   syncEvent: {
-    type: "session.next.step.ended.2"
+    type: "session.next.step.ended.1"
     id: string
     seq: number
     aggregateID: string
@@ -3362,7 +3362,7 @@ export type SyncEventSessionNextStepFailed = {
   type: "sync"
   id: string
   syncEvent: {
-    type: "session.next.step.failed.2"
+    type: "session.next.step.failed.1"
     id: string
     seq: number
     aggregateID: string

packages/sdk/openapi.json

@@ -24782,7 +24782,7 @@
             "properties": {
               "type": {
                 "type": "string",
-                "enum": ["session.next.step.ended.2"]
+                "enum": ["session.next.step.ended.1"]
               },
               "id": {
                 "type": "string",
@@ -24874,7 +24874,7 @@
             "properties": {
               "type": {
                 "type": "string",
-                "enum": ["session.next.step.failed.2"]
+                "enum": ["session.next.step.failed.1"]
               },
               "id": {
                 "type": "string",

specs/v2/schema-changelog.md

@@ -3,6 +3,7 @@
 ## 2026-06-22: Reset Unpublished Compaction Event
 
 - Replace the unpublished `session.next.compaction.ended.1` payload with the current checkpoint payload and remove its legacy decoder.
+- Reset the current `session.next.step.ended` and `session.next.step.failed` payloads to version `1` now that incompatible experimental history has been discarded.
 - Reset experimental events, sequences, Session inputs, projected Session messages, Context Epochs, synchronized workspace rows, and Session workspace links.
 - Preserve canonical V1 `session`, `message`, and `part` rows.
 
@@ -96,11 +97,11 @@ Compatibility:
 - Existing generated Session and Event IDs retain their current prefixes and generation behavior.
 - Deterministic constructors are additive internal helpers; public ID schemas remain strings with their existing prefixes.
 
-### Durable Step Settlement Ownership
+### Earlier Durable Step Settlement Ownership
 
 Affected schema:
 
-- `session.next.step.ended` and `session.next.step.failed` synchronized event version `2`.
+- Earlier experimental `session.next.step.ended` and `session.next.step.failed` synchronized event version `2`.
 
 Change:
 
@@ -112,7 +113,7 @@ Reason:
 
 Compatibility:
 
-- Step settlement uses synchronized event version `2` because the durable payload changed.
+- The payload originally used synchronized event version `2`; the June 22 reset later made the current payload version `1`.
 
 ### Durable Session Input Inbox