diff --git a/packages/effect-codex-app-server/src/protocol.ts b/packages/effect-codex-app-server/src/protocol.ts
index 17bfaed2b64c..e87f5e9d8ae4 100644
--- a/packages/effect-codex-app-server/src/protocol.ts
+++ b/packages/effect-codex-app-server/src/protocol.ts
@@ -157,7 +157,6 @@ export const makeCodexAppServerPatchedProtocol = Effect.fn("makeCodexAppServerPa
     const incomingRequests = yield* Queue.unbounded<CodexAppServerIncomingRequest>();
     const pending = yield* Ref.make(new Map<string, CodexAppServerPendingRequest>());
     const nextRequestId = yield* Ref.make(1);
-    const remainder = yield* Ref.make("");
     const terminationHandled = yield* Ref.make(false);
 
     const logProtocol = (event: CodexAppServerProtocolLogEvent) => {
@@ -353,31 +352,18 @@ export const makeCodexAppServerPatchedProtocol = Effect.fn("makeCodexAppServerPa
 
     yield* options.stdio.stdin.pipe(
       Stream.decodeText(),
-      Stream.runForEach((chunk) =>
-        Ref.modify(remainder, (current) => {
-          const combined = current + chunk;
-          const lines = combined.split("\n");
-          const nextRemainder = lines.pop() ?? "";
-          return [lines.map((line) => line.replace(/\r$/, "")), nextRemainder] as const;
-        }).pipe(Effect.flatMap((lines) => Effect.forEach(lines, handleLine, { discard: true }))),
-      ),
+      Stream.splitLines,
+      Stream.runForEach(handleLine),
       Effect.matchEffect({
         onFailure: (error) =>
           handleTermination(() =>
             Effect.succeed(normalizeIncomingError(error, "read-input-stream")),
           ),
         onSuccess: () =>
-          Ref.get(remainder).pipe(
-            Effect.flatMap((line) => (line.trim().length === 0 ? Effect.void : handleLine(line))),
-            Effect.matchEffect({
-              onFailure: (error) => handleTermination(() => Effect.succeed(error)),
-              onSuccess: () =>
-                handleTermination(
-                  () =>
-                    options.terminationError ??
-                    Effect.succeed(new CodexError.CodexAppServerInputStreamEndedError({})),
-                ),
-            }),
+          handleTermination(
+            () =>
+              options.terminationError ??
+              Effect.succeed(new CodexError.CodexAppServerInputStreamEndedError({})),
           ),
       }),
       Effect.forkScoped,