diff --git a/packages/opencode/src/cli/cmd/stats.ts b/packages/opencode/src/cli/cmd/stats.ts
index 3dadea9dd0..7dc1822605 100644
--- a/packages/opencode/src/cli/cmd/stats.ts
+++ b/packages/opencode/src/cli/cmd/stats.ts
@@ -1,6 +1,7 @@
 import { Effect } from "effect"
 import { effectCmd } from "../effect-cmd"
 import { Session } from "@/session/session"
+import { NotFoundError } from "@/storage/storage"
 import { Database } from "@/storage/db"
 import { SessionTable } from "../../session/session.sql"
 import { Project } from "@/project/project"
@@ -162,7 +163,9 @@ const aggregateSessionStats = Effect.fn("Cli.stats.aggregate")(function* (
     filteredSessions,
     (session) =>
       Effect.gen(function* () {
-        const messages = yield* svc.messages({ sessionID: session.id })
+        const messages = yield* svc.messages({ sessionID: session.id }).pipe(
+          Effect.catchIf(NotFoundError.isInstance, () => Effect.succeed([])),
+        )
 
         const sessionCost = session.cost ?? 0
         const sessionTokens = session.tokens ?? { input: 0, output: 0, reasoning: 0, cache: { read: 0, write: 0 } }
diff --git a/packages/opencode/src/server/routes/instance/httpapi/handlers/session.ts b/packages/opencode/src/server/routes/instance/httpapi/handlers/session.ts
index 80bff42bc1..ebd0fcd4d8 100644
--- a/packages/opencode/src/server/routes/instance/httpapi/handlers/session.ts
+++ b/packages/opencode/src/server/routes/instance/httpapi/handlers/session.ts
@@ -101,7 +101,7 @@ export const sessionHandlers = HttpApiBuilder.group(InstanceHttpApi, "session",
       }
       yield* SessionError.mapStorageNotFound(session.get(ctx.params.sessionID))
       if (ctx.query.limit === undefined || ctx.query.limit === 0) {
-        return yield* session.messages({ sessionID: ctx.params.sessionID })
+        return yield* SessionError.mapStorageNotFound(session.messages({ sessionID: ctx.params.sessionID }))
       }
 
       const page = yield* SessionError.mapStorageNotFound(
@@ -250,7 +250,7 @@ export const sessionHandlers = HttpApiBuilder.group(InstanceHttpApi, "session",
       payload: typeof SummarizePayload.Type
     }) {
       yield* revertSvc.cleanup(yield* SessionError.mapStorageNotFound(session.get(ctx.params.sessionID)))
-      const messages = yield* session.messages({ sessionID: ctx.params.sessionID })
+      const messages = yield* SessionError.mapStorageNotFound(session.messages({ sessionID: ctx.params.sessionID }))
       const defaultAgent = yield* agentSvc.defaultAgent()
       const currentAgent = messages.findLast((message) => message.info.role === "user")?.info.agent ?? defaultAgent
 
diff --git a/packages/opencode/src/session/compaction.ts b/packages/opencode/src/session/compaction.ts
index 4eafbdf749..f3c160fe73 100644
--- a/packages/opencode/src/session/compaction.ts
+++ b/packages/opencode/src/session/compaction.ts
@@ -565,7 +565,9 @@ export const layer: Layer.Layer<
       if (processor.message.error) return "stop"
       if (result === "continue") {
         const summary = summaryText(
-          (yield* session.messages({ sessionID: input.sessionID })).find((item) => item.info.id === msg.id) ?? {
+          (yield* session.messages({ sessionID: input.sessionID }).pipe(Effect.orDie)).find(
+            (item) => item.info.id === msg.id,
+          ) ?? {
             info: msg,
             parts: [],
           },
diff --git a/packages/opencode/src/session/prompt.ts b/packages/opencode/src/session/prompt.ts
index b89561d5d1..8656050faf 100644
--- a/packages/opencode/src/session/prompt.ts
+++ b/packages/opencode/src/session/prompt.ts
@@ -1077,7 +1077,9 @@ NOTE: At any point in time through this workflow you should feel free to ask the
           ...(current.model.variant && current.model.variant !== "default" ? { variant: current.model.variant } : {}),
         }
       }
-      const match = yield* sessions.findMessage(sessionID, (m) => m.info.role === "user" && !!m.info.model)
+      const match = yield* sessions
+        .findMessage(sessionID, (m) => m.info.role === "user" && !!m.info.model)
+        .pipe(Effect.orDie)
       if (Option.isSome(match) && match.value.info.role === "user") return match.value.info.model
       return yield* provider.defaultModel()
     })
@@ -1615,9 +1617,9 @@ NOTE: At any point in time through this workflow you should feel free to ask the
     )
 
     const lastAssistant = Effect.fnUntraced(function* (sessionID: SessionID) {
-      const match = yield* sessions.findMessage(sessionID, (m) => m.info.role !== "user")
+      const match = yield* sessions.findMessage(sessionID, (m) => m.info.role !== "user").pipe(Effect.orDie)
       if (Option.isSome(match)) return match.value
-      const msgs = yield* sessions.messages({ sessionID, limit: 1 })
+      const msgs = yield* sessions.messages({ sessionID, limit: 1 }).pipe(Effect.orDie)
       if (msgs.length > 0) return msgs[0]
       throw new Error("Impossible")
     })
diff --git a/packages/opencode/src/session/revert.ts b/packages/opencode/src/session/revert.ts
index ef9089c949..8ba7b265b9 100644
--- a/packages/opencode/src/session/revert.ts
+++ b/packages/opencode/src/session/revert.ts
@@ -40,7 +40,7 @@ export const layer = Layer.effect(
 
     const revert = Effect.fn("SessionRevert.revert")(function* (input: RevertInput) {
       yield* state.assertNotBusy(input.sessionID)
-      const all = yield* sessions.messages({ sessionID: input.sessionID })
+      const all = yield* sessions.messages({ sessionID: input.sessionID }).pipe(Effect.orDie)
       let lastUser: MessageV2.User | undefined
       const session = yield* sessions.get(input.sessionID).pipe(Effect.orDie)
 
@@ -103,7 +103,7 @@ export const layer = Layer.effect(
     const cleanup = Effect.fn("SessionRevert.cleanup")(function* (session: Session.Info) {
       if (!session.revert) return
       const sessionID = session.id
-      const msgs = yield* sessions.messages({ sessionID })
+      const msgs = yield* sessions.messages({ sessionID }).pipe(Effect.orDie)
       const messageID = session.revert.messageID
       const remove = [] as MessageV2.WithParts[]
       let target: MessageV2.WithParts | undefined
diff --git a/packages/opencode/src/session/session.ts b/packages/opencode/src/session/session.ts
index 0913b85687..d82b2369e1 100644
--- a/packages/opencode/src/session/session.ts
+++ b/packages/opencode/src/session/session.ts
@@ -474,7 +474,7 @@ export interface Interface {
   readonly clearRevert: (sessionID: SessionID) => Effect.Effect<void>
   readonly setSummary: (input: { sessionID: SessionID; summary: Info["summary"] }) => Effect.Effect<void>
   readonly diff: (sessionID: SessionID) => Effect.Effect<Snapshot.FileDiff[]>
-  readonly messages: (input: { sessionID: SessionID; limit?: number }) => Effect.Effect<MessageV2.WithParts[]>
+  readonly messages: (input: { sessionID: SessionID; limit?: number }) => Effect.Effect<MessageV2.WithParts[], NotFound>
   readonly children: (parentID: SessionID) => Effect.Effect<Info[]>
   readonly remove: (sessionID: SessionID) => Effect.Effect<void, NotFound>
   readonly updateMessage: <T extends MessageV2.Info>(msg: T) => Effect.Effect<T>
@@ -497,7 +497,7 @@ export interface Interface {
   readonly findMessage: (
     sessionID: SessionID,
     predicate: (msg: MessageV2.WithParts) => boolean,
-  ) => Effect.Effect<Option.Option<MessageV2.WithParts>>
+  ) => Effect.Effect<Option.Option<MessageV2.WithParts>, NotFound>
 }
 
 export class Service extends Context.Service<Service, Interface>()("@opencode/Session") {}
@@ -757,11 +757,25 @@ export const layer: Layer.Layer<Service, never, Bus.Service | Storage.Service |
         .pipe(Effect.orElseSucceed((): Snapshot.FileDiff[] => []))
     })
 
-    const messages = Effect.fn("Session.messages")(function* (input: { sessionID: SessionID; limit?: number }) {
+    const messages: Interface["messages"] = Effect.fn("Session.messages")(function* (input) {
       if (input.limit) {
-        return MessageV2.page({ sessionID: input.sessionID, limit: input.limit }).items
+        return (yield* MessageV2.pageEffect({ sessionID: input.sessionID, limit: input.limit })).items
       }
-      return Array.from(MessageV2.stream(input.sessionID)).reverse()
+
+      const size = 50
+      const result = [] as MessageV2.WithParts[]
+      let before: string | undefined
+      while (true) {
+        const page = yield* MessageV2.pageEffect({ sessionID: input.sessionID, limit: size, before })
+        if (page.items.length === 0) break
+        for (let i = page.items.length - 1; i >= 0; i--) {
+          const item = page.items[i]
+          if (item) result.push(item)
+        }
+        if (!page.more || !page.cursor) break
+        before = page.cursor
+      }
+      return result.reverse()
     })
 
     const removeMessage = Effect.fn("Session.removeMessage")(function* (input: {
@@ -799,12 +813,18 @@ export const layer: Layer.Layer<Service, never, Bus.Service | Storage.Service |
     })
 
     /** Finds the first message matching the predicate, searching newest-first. */
-    const findMessage = Effect.fn("Session.findMessage")(function* (
-      sessionID: SessionID,
-      predicate: (msg: MessageV2.WithParts) => boolean,
-    ) {
-      for (const item of MessageV2.stream(sessionID)) {
-        if (predicate(item)) return Option.some(item)
+    const findMessage: Interface["findMessage"] = Effect.fn("Session.findMessage")(function* (sessionID, predicate) {
+      const size = 50
+      let before: string | undefined
+      while (true) {
+        const page = yield* MessageV2.pageEffect({ sessionID, limit: size, before })
+        if (page.items.length === 0) break
+        for (let i = page.items.length - 1; i >= 0; i--) {
+          const item = page.items[i]
+          if (item && predicate(item)) return Option.some(item)
+        }
+        if (!page.more || !page.cursor) break
+        before = page.cursor
       }
       return Option.none<MessageV2.WithParts>()
     })
diff --git a/packages/opencode/src/session/summary.ts b/packages/opencode/src/session/summary.ts
index c03fc32695..aa4b8719bc 100644
--- a/packages/opencode/src/session/summary.ts
+++ b/packages/opencode/src/session/summary.ts
@@ -102,7 +102,7 @@ export const layer = Layer.effect(
       sessionID: SessionID
       messageID: MessageID
     }) {
-      const all = yield* sessions.messages({ sessionID: input.sessionID })
+      const all = yield* sessions.messages({ sessionID: input.sessionID }).pipe(Effect.orDie)
       if (!all.length) return
 
       const diffs = yield* computeDiff({ messages: all })
diff --git a/packages/opencode/test/server/httpapi-exercise/runner.ts b/packages/opencode/test/server/httpapi-exercise/runner.ts
index bc246dbeda..7ab5ccf990 100644
--- a/packages/opencode/test/server/httpapi-exercise/runner.ts
+++ b/packages/opencode/test/server/httpapi-exercise/runner.ts
@@ -168,7 +168,8 @@ function withContext<A, E>(
               )
               return { info, part }
             }),
-          messages: (sessionID) => run(modules.Session.Service.use((svc) => svc.messages({ sessionID }))),
+          messages: (sessionID) =>
+            run(modules.Session.Service.use((svc) => svc.messages({ sessionID }).pipe(Effect.orDie))),
           todos: (sessionID, todos) => run(modules.Todo.Service.use((svc) => svc.update({ sessionID, todos }))),
           worktree: (input) => run(modules.Worktree.Service.use((svc) => svc.create(input))),
           worktreeRemove: (directory) =>
diff --git a/packages/opencode/test/session/messages-pagination.test.ts b/packages/opencode/test/session/messages-pagination.test.ts
index 8332bb9b3d..247f95d280 100644
--- a/packages/opencode/test/session/messages-pagination.test.ts
+++ b/packages/opencode/test/session/messages-pagination.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, test } from "bun:test"
-import { Effect } from "effect"
+import { Effect, Option } from "effect"
 import { Session as SessionNs } from "@/session/session"
 import { MessageV2 } from "../../src/session/message-v2"
 import { MessageID, PartID, type SessionID } from "../../src/session/schema"
@@ -582,6 +582,50 @@ describe("MessageV2.get", () => {
   )
 })
 
+describe("Session.messages", () => {
+  it.instance("returns all messages in chronological order across pages", () =>
+    withSession(({ session, sessionID }) =>
+      Effect.gen(function* () {
+        const ids = yield* fill(sessionID, 55)
+        const result = yield* session.messages({ sessionID })
+        expect(result.map((item) => item.info.id)).toEqual(ids)
+      }),
+    ),
+  )
+
+  it.instance("fails with NotFoundError for non-existent session", () =>
+    Effect.gen(function* () {
+      const session = yield* SessionNs.Service
+      const fake = "non-existent-session" as SessionID
+      const error = yield* Effect.flip(session.messages({ sessionID: fake }))
+      expect(error).toBeInstanceOf(NotFoundError)
+      expect(error.message).toBe(`Session not found: ${fake}`)
+    }),
+  )
+})
+
+describe("Session.findMessage", () => {
+  it.instance("searches newest-first", () =>
+    withSession(({ session, sessionID }) =>
+      Effect.gen(function* () {
+        const ids = yield* fill(sessionID, 3)
+        const result = yield* session.findMessage(sessionID, () => true)
+        expect(Option.isSome(result) ? result.value.info.id : undefined).toBe(ids.at(-1))
+      }),
+    ),
+  )
+
+  it.instance("fails with NotFoundError for non-existent session", () =>
+    Effect.gen(function* () {
+      const session = yield* SessionNs.Service
+      const fake = "non-existent-session" as SessionID
+      const error = yield* Effect.flip(session.findMessage(fake, () => true))
+      expect(error).toBeInstanceOf(NotFoundError)
+      expect(error.message).toBe(`Session not found: ${fake}`)
+    }),
+  )
+})
+
 describe("MessageV2.filterCompacted", () => {
   it.instance("returns all messages when no compaction", () =>
     withSession(({ sessionID }) =>