diff --git a/packages/js-sdk/src/sandbox/commands/commandHandle.ts b/packages/js-sdk/src/sandbox/commands/commandHandle.ts
index 67852a900c..c7175cac44 100644
--- a/packages/js-sdk/src/sandbox/commands/commandHandle.ts
+++ b/packages/js-sdk/src/sandbox/commands/commandHandle.ts
@@ -84,8 +84,10 @@ export class CommandHandle
     Omit<CommandResult, 'exitCode' | 'error'>,
     Partial<Pick<CommandResult, 'exitCode' | 'error'>>
 {
-  private _stdout = ''
-  private _stderr = ''
+  private _stdoutChunks: string[] = []
+  private _stderrChunks: string[] = []
+  private _stdoutCached?: string
+  private _stderrCached?: string
 
   private result?: CommandResult
   private iterationError?: Error
@@ -130,14 +132,20 @@ export class CommandHandle
    * Command execution stderr output.
    */
   get stderr() {
-    return this._stderr
+    if (this._stderrCached === undefined) {
+      this._stderrCached = this._stderrChunks.join('')
+    }
+    return this._stderrCached
   }
 
   /**
    * Command execution stdout output.
    */
   get stdout() {
-    return this._stdout
+    if (this._stdoutCached === undefined) {
+      this._stdoutCached = this._stdoutChunks.join('')
+    }
+    return this._stdoutCached
   }
 
   /**
@@ -196,12 +204,14 @@ export class CommandHandle
           switch (e.value.output.case) {
             case 'stdout':
               out = new TextDecoder().decode(e.value.output.value)
-              this._stdout += out
+              this._stdoutChunks.push(out)
+              this._stdoutCached = undefined
               yield [out as Stdout, null, null]
               break
             case 'stderr':
               out = new TextDecoder().decode(e.value.output.value)
-              this._stderr += out
+              this._stderrChunks.push(out)
+              this._stderrCached = undefined
               yield [null, out as Stderr, null]
               break
             case 'pty':
diff --git a/packages/python-sdk/e2b/sandbox_async/commands/command_handle.py b/packages/python-sdk/e2b/sandbox_async/commands/command_handle.py
index dfe34e8383..fe63ef0f9c 100644
--- a/packages/python-sdk/e2b/sandbox_async/commands/command_handle.py
+++ b/packages/python-sdk/e2b/sandbox_async/commands/command_handle.py
@@ -41,14 +41,18 @@ def stdout(self):
         """
         Command stdout output.
         """
-        return self._stdout
+        if self._stdout_cached is None:
+            self._stdout_cached = "".join(self._stdout_chunks)
+        return self._stdout_cached
 
     @property
     def stderr(self):
         """
         Command stderr output.
         """
-        return self._stderr
+        if self._stderr_cached is None:
+            self._stderr_cached = "".join(self._stderr_chunks)
+        return self._stderr_cached
 
     @property
     def error(self):
@@ -87,8 +91,10 @@ def __init__(
         self._handle_kill = handle_kill
         self._events = events
 
-        self._stdout: str = ""
-        self._stderr: str = ""
+        self._stdout_chunks: list[str] = []
+        self._stderr_chunks: list[str] = []
+        self._stdout_cached: Optional[str] = None
+        self._stderr_cached: Optional[str] = None
 
         self._on_stdout = on_stdout
         self._on_stderr = on_stderr
@@ -113,18 +119,20 @@ async def _iterate_events(
             if event.event.HasField("data"):
                 if event.event.data.stdout:
                     out = event.event.data.stdout.decode("utf-8", "replace")
-                    self._stdout += out
+                    self._stdout_chunks.append(out)
+                    self._stdout_cached = None
                     yield out, None, None
                 if event.event.data.stderr:
                     out = event.event.data.stderr.decode("utf-8", "replace")
-                    self._stderr += out
+                    self._stderr_chunks.append(out)
+                    self._stderr_cached = None
                     yield None, out, None
                 if event.event.data.pty:
                     yield None, None, event.event.data.pty
             if event.event.HasField("end"):
                 self._result = CommandResult(
-                    stdout=self._stdout,
-                    stderr=self._stderr,
+                    stdout="".join(self._stdout_chunks),
+                    stderr="".join(self._stderr_chunks),
                     exit_code=event.event.end.exit_code,
                     error=event.event.end.error,
                 )
@@ -176,8 +184,8 @@ async def wait(self) -> CommandResult:
 
         if self._result.exit_code != 0:
             raise CommandExitException(
-                stdout=self._stdout,
-                stderr=self._stderr,
+                stdout=self._result.stdout,
+                stderr=self._result.stderr,
                 exit_code=self._result.exit_code,
                 error=self._result.error,
             )
diff --git a/packages/python-sdk/e2b/sandbox_sync/commands/command_handle.py b/packages/python-sdk/e2b/sandbox_sync/commands/command_handle.py
index a58a613e02..b2416d2eee 100644
--- a/packages/python-sdk/e2b/sandbox_sync/commands/command_handle.py
+++ b/packages/python-sdk/e2b/sandbox_sync/commands/command_handle.py
@@ -37,8 +37,8 @@ def __init__(
         self._handle_kill = handle_kill
         self._events = events
 
-        self._stdout: str = ""
-        self._stderr: str = ""
+        self._stdout_chunks: list[str] = []
+        self._stderr_chunks: list[str] = []
 
         self._result: Optional[CommandResult] = None
         self._iteration_exception: Optional[Exception] = None
@@ -67,18 +67,18 @@ def _handle_events(
                 if event.event.HasField("data"):
                     if event.event.data.stdout:
                         out = event.event.data.stdout.decode("utf-8", "replace")
-                        self._stdout += out
+                        self._stdout_chunks.append(out)
                         yield out, None, None
                     if event.event.data.stderr:
                         out = event.event.data.stderr.decode("utf-8", "replace")
-                        self._stderr += out
+                        self._stderr_chunks.append(out)
                         yield None, out, None
                     if event.event.data.pty:
                         yield None, None, event.event.data.pty
                 if event.event.HasField("end"):
                     self._result = CommandResult(
-                        stdout=self._stdout,
-                        stderr=self._stderr,
+                        stdout="".join(self._stdout_chunks),
+                        stderr="".join(self._stderr_chunks),
                         exit_code=event.event.end.exit_code,
                         error=event.event.end.error,
                     )
@@ -131,8 +131,8 @@ def wait(
 
         if self._result.exit_code != 0:
             raise CommandExitException(
-                stdout=self._stdout,
-                stderr=self._stderr,
+                stdout=self._result.stdout,
+                stderr=self._result.stderr,
                 exit_code=self._result.exit_code,
                 error=self._result.error,
             )