diff --git a/packages/opencode/src/control-plane/workspace.ts b/packages/opencode/src/control-plane/workspace.ts
index 00353dcca3..e7e65f8901 100644
--- a/packages/opencode/src/control-plane/workspace.ts
+++ b/packages/opencode/src/control-plane/workspace.ts
@@ -641,7 +641,7 @@ export const layer = Layer.effect(
 
             // "claim" this session so any future events coming from
             // the old workspace are ignored
-            SyncEvent.claim(input.sessionID, input.workspaceID ?? previous.projectID)
+            yield* sync.claim(input.sessionID, input.workspaceID ?? previous.projectID)
           }
         }
 
diff --git a/packages/opencode/src/sync/index.ts b/packages/opencode/src/sync/index.ts
index 931f5e84c8..5c29101b6c 100644
--- a/packages/opencode/src/sync/index.ts
+++ b/packages/opencode/src/sync/index.ts
@@ -10,7 +10,6 @@ import { EventID } from "./schema"
 import { Flag } from "@opencode-ai/core/flag/flag"
 import { Context, Effect, Layer, Schema as EffectSchema } from "effect"
 import type { DeepMutable } from "@opencode-ai/core/schema"
-import { makeRuntime } from "@/effect/run-service"
 import { serviceUse } from "@/effect/service-use"
 import { InstanceState } from "@/effect/instance-state"
 
@@ -63,6 +62,7 @@ export interface Interface {
     options?: { publish: boolean; ownerID?: string },
   ) => Effect.Effect<string | undefined>
   readonly remove: (aggregateID: string) => Effect.Effect<void>
+  readonly claim: (aggregateID: string, ownerID: string) => Effect.Effect<void>
 }
 
 export class Service extends Context.Service<Service, Interface>()("@opencode/SyncEvent") {}
@@ -175,11 +175,24 @@ export const layer = Layer.effect(Service)(
       })
     })
 
+    const claim: Interface["claim"] = Effect.fn("SyncEvent.claim")((aggregateID, ownerID) =>
+      Effect.sync(() =>
+        Database.use((db) =>
+          db
+            .update(EventSequenceTable)
+            .set({ owner_id: ownerID })
+            .where(eq(EventSequenceTable.aggregate_id, aggregateID))
+            .run(),
+        ),
+      ),
+    )
+
     return Service.of({
       run,
       replay,
       replayAll,
       remove,
+      claim,
     })
   }),
 )
@@ -188,8 +201,6 @@ export const defaultLayer = layer
 
 export const use = serviceUse(Service)
 
-const runtime = makeRuntime(Service, defaultLayer)
-
 export const registry = new Map<string, Definition>()
 let projectors: Map<Definition, ProjectorFunc> | undefined
 const versions = new Map<string, number>()
@@ -336,32 +347,6 @@ function process<Def extends Definition>(
   })
 }
 
-export function replay(event: SerializedEvent, options?: { publish: boolean; ownerID?: string }) {
-  return runtime.runSync((sync) => sync.replay(event, options))
-}
-
-export function replayAll(events: SerializedEvent[], options?: { publish: boolean; ownerID?: string }) {
-  return runtime.runSync((sync) => sync.replayAll(events, options))
-}
-
-export function run<Def extends Definition>(def: Def, data: Event<Def>["data"], options?: { publish?: boolean }) {
-  return runtime.runSync((sync) => sync.run(def, data, options))
-}
-
-export function remove(aggregateID: string) {
-  return runtime.runSync((sync) => sync.remove(aggregateID))
-}
-
-export function claim(aggregateID: string, ownerID: string) {
-  Database.use((db) =>
-    db
-      .update(EventSequenceTable)
-      .set({ owner_id: ownerID })
-      .where(eq(EventSequenceTable.aggregate_id, aggregateID))
-      .run(),
-  )
-}
-
 export function effectPayloads() {
   return registry
     .entries()
diff --git a/packages/opencode/test/sync/index.test.ts b/packages/opencode/test/sync/index.test.ts
index 0986b39044..10f593a571 100644
--- a/packages/opencode/test/sync/index.test.ts
+++ b/packages/opencode/test/sync/index.test.ts
@@ -4,7 +4,7 @@ import { Effect, Layer, Schema } from "effect"
 import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
 import { Bus } from "../../src/bus"
 import { SyncEvent } from "../../src/sync"
-import { Database } from "@/storage/db"
+import { Database, eq } from "@/storage/db"
 import { EventSequenceTable, EventTable } from "../../src/sync/event.sql"
 import { MessageID } from "../../src/session/schema"
 import { Flag } from "@opencode-ai/core/flag/flag"
@@ -323,5 +323,28 @@ describe("SyncEvent", () => {
         }),
       ),
     )
+
+    it.live(
+      "claim updates the event sequence owner",
+      provideTmpdirInstance(() =>
+        Effect.gen(function* () {
+          const { Created } = setup()
+          const id = MessageID.ascending()
+
+          yield* SyncEvent.use.run(Created, { id, name: "claimed" }, { publish: false })
+          yield* SyncEvent.use.claim(id, "owner-1")
+          yield* SyncEvent.use.claim(id, "owner-2")
+
+          const row = Database.use((db) =>
+            db
+              .select({ seq: EventSequenceTable.seq, ownerID: EventSequenceTable.owner_id })
+              .from(EventSequenceTable)
+              .where(eq(EventSequenceTable.aggregate_id, id))
+              .get(),
+          )
+          expect(row).toEqual({ seq: 0, ownerID: "owner-2" })
+        }),
+      ),
+    )
   })
 })