fix(session): use typed message reads in tools (#27280)

packages/opencode/src/share/share-next.ts

@@ -272,7 +272,7 @@ export const layer = Layer.effect(
       log.info("full sync", { sessionID })
       const info = yield* session.get(sessionID)
       const diffs = yield* session.diff(sessionID)
-      const messages = yield* Effect.sync(() => Array.from(MessageV2.stream(sessionID)))
+      const messages = yield* session.messages({ sessionID })
       const models = yield* Effect.forEach(
         Array.from(
           new Map(

packages/opencode/src/tool/plan.ts

@@ -6,16 +6,9 @@ import { Session } from "@/session/session"
 import { MessageV2 } from "../session/message-v2"
 import { Provider } from "@/provider/provider"
 import { InstanceState } from "@/effect/instance-state"
-import { type SessionID, MessageID, PartID } from "../session/schema"
+import { MessageID, PartID } from "../session/schema"
 import EXIT_DESCRIPTION from "./plan-exit.txt"
 
-function getLastModel(sessionID: SessionID) {
-  for (const item of MessageV2.stream(sessionID)) {
-    if (item.info.role === "user" && item.info.model) return item.info.model
-  }
-  return undefined
-}
-
 export const Parameters = Schema.Struct({})
 
 export const PlanExitTool = Tool.define(
@@ -51,7 +44,10 @@ export const PlanExitTool = Tool.define(
 
           if (answers[0]?.[0] === "No") yield* new Question.RejectedError()
 
-          const model = getLastModel(ctx.sessionID) ?? (yield* provider.defaultModel())
+          const messages = yield* session.messages({ sessionID: ctx.sessionID }).pipe(Effect.orDie)
+          const lastUser = messages.findLast((item) => item.info.role === "user" && item.info.model)
+          const model =
+            lastUser?.info.role === "user" && lastUser.info.model ? lastUser.info.model : yield* provider.defaultModel()
 
           const msg: MessageV2.User = {
             id: MessageID.ascending(),

packages/opencode/src/tool/task.ts

@@ -86,7 +86,7 @@ export const TaskTool = Tool.define(
           ],
         }))
 
-      const msg = yield* Effect.sync(() => MessageV2.get({ sessionID: ctx.sessionID, messageID: ctx.messageID }))
+      const msg = yield* MessageV2.getEffect({ sessionID: ctx.sessionID, messageID: ctx.messageID }).pipe(Effect.orDie)
       if (msg.info.role !== "assistant") return yield* Effect.fail(new Error("Not an assistant message"))
 
       const model = next.model ?? {