Add two adk run options:

--replay : a json file that contains the initial session state and user queries, adk run will create a new session based on the state and run the user queries against the session. Users cannot continue to interact with agent.

--resume : a json file that contains the previously saved session (by --save_session option), adk run will replay this session and then user can continue to interact with the agent.
PiperOrigin-RevId: 752923403

src/google/adk/cli/cli.py

@@ -39,12 +39,12 @@ class InputFile(BaseModel):
 
 async def run_input_file(
     app_name: str,
+    user_id: str,
     root_agent: LlmAgent,
     artifact_service: BaseArtifactService,
-    session: Session,
     session_service: BaseSessionService,
     input_path: str,
-) -> None:
+) -> Session:
   runner = Runner(
       app_name=app_name,
       agent=root_agent,
@@ -55,9 +55,11 @@ async def run_input_file(
     input_file = InputFile.model_validate_json(f.read())
   input_file.state['_time'] = datetime.now()
 
-  session.state = input_file.state
+  session = session_service.create_session(
+      app_name=app_name, user_id=user_id, state=input_file.state
+  )
   for query in input_file.queries:
-    click.echo(f'user: {query}')
+    click.echo(f'[user]: {query}')
     content = types.Content(role='user', parts=[types.Part(text=query)])
     async for event in runner.run_async(
         user_id=session.user_id, session_id=session.id, new_message=content
@@ -65,23 +67,23 @@ async def run_input_file(
       if event.content and event.content.parts:
         if text := ''.join(part.text or '' for part in event.content.parts):
           click.echo(f'[{event.author}]: {text}')
+  return session
 
 
 async def run_interactively(
-    app_name: str,
     root_agent: LlmAgent,
     artifact_service: BaseArtifactService,
     session: Session,
     session_service: BaseSessionService,
 ) -> None:
   runner = Runner(
-      app_name=app_name,
+      app_name=session.app_name,
       agent=root_agent,
       artifact_service=artifact_service,
       session_service=session_service,
   )
   while True:
-    query = input('user: ')
+    query = input('[user]: ')
     if not query or not query.strip():
       continue
     if query == 'exit':
@@ -100,7 +102,8 @@ async def run_cli(
     *,
     agent_parent_dir: str,
     agent_folder_name: str,
-    json_file_path: Optional[str] = None,
+    input_file: Optional[str] = None,
+    saved_session_file: Optional[str] = None,
     save_session: bool,
 ) -> None:
   """Runs an interactive CLI for a certain agent.
@@ -109,8 +112,11 @@ async def run_cli(
     agent_parent_dir: str, the absolute path of the parent folder of the agent
       folder.
     agent_folder_name: str, the name of the agent folder.
-    json_file_path: Optional[str], the absolute path to the json file, either
-      *.input.json or *.session.json.
+    input_file: Optional[str], the absolute path to the json file that contains
+      the initial session state and user queries, exclusive with
+      saved_session_file.
+    saved_session_file: Optional[str], the absolute path to the json file that
+      contains a previously saved session, exclusive with input_file.
     save_session: bool, whether to save the session on exit.
   """
   if agent_parent_dir not in sys.path:
@@ -118,46 +124,50 @@ async def run_cli(
 
   artifact_service = InMemoryArtifactService()
   session_service = InMemorySessionService()
-  session = session_service.create_session(
-      app_name=agent_folder_name, user_id='test_user'
-  )
 
   agent_module_path = os.path.join(agent_parent_dir, agent_folder_name)
   agent_module = importlib.import_module(agent_folder_name)
+  user_id = 'test_user'
+  session = session_service.create_session(
+      app_name=agent_folder_name, user_id=user_id
+  )
   root_agent = agent_module.agent.root_agent
   envs.load_dotenv_for_agent(agent_folder_name, agent_parent_dir)
-  if json_file_path:
-    if json_file_path.endswith('.input.json'):
-      await run_input_file(
+  if input_file:
+    session = await run_input_file(
         app_name=agent_folder_name,
+        user_id=user_id,
         root_agent=root_agent,
         artifact_service=artifact_service,
-          session=session,
         session_service=session_service,
-          input_path=json_file_path,
+        input_path=input_file,
     )
-    elif json_file_path.endswith('.session.json'):
-      with open(json_file_path, 'r') as f:
-        session = Session.model_validate_json(f.read())
-      for content in session.get_contents():
-        if content.role == 'user':
-          print('user: ', content.parts[0].text)
+  elif saved_session_file:
+
+    loaded_session = None
+    with open(saved_session_file, 'r') as f:
+      loaded_session = Session.model_validate_json(f.read())
+
+    if loaded_session:
+      for event in loaded_session.events:
+        session_service.append_event(session, event)
+        content = event.content
+        if not content or not content.parts or not content.parts[0].text:
+          continue
+        if event.author == 'user':
+          click.echo(f'[user]: {content.parts[0].text}')
         else:
-          print(content.parts[0].text)
+          click.echo(f'[{event.author}]: {content.parts[0].text}')
+
     await run_interactively(
-          agent_folder_name,
         root_agent,
         artifact_service,
         session,
         session_service,
     )
   else:
-      print(f'Unsupported file type: {json_file_path}')
-      exit(1)
-  else:
-    print(f'Running agent {root_agent.name}, type exit to exit.')
+    click.echo(f'Running agent {root_agent.name}, type exit to exit.')
     await run_interactively(
-        agent_folder_name,
         root_agent,
         artifact_service,
         session,
@@ -165,9 +175,6 @@ async def run_cli(
     )
 
   if save_session:
-    if json_file_path:
-      session_path = json_file_path.replace('.input.json', '.session.json')
-    else:
     session_id = input('Session ID to save: ')
     session_path = f'{agent_module_path}/{session_id}.session.json'
 

src/google/adk/cli/cli_tools_click.py

@@ -96,6 +96,23 @@ def cli_create_cmd(
   )
 
 
+def validate_exclusive(ctx, param, value):
+  # Store the validated parameters in the context
+  if not hasattr(ctx, "exclusive_opts"):
+    ctx.exclusive_opts = {}
+
+  # If this option has a value and we've already seen another exclusive option
+  if value is not None and any(ctx.exclusive_opts.values()):
+    exclusive_opt = next(key for key, val in ctx.exclusive_opts.items() if val)
+    raise click.UsageError(
+        f"Options '{param.name}' and '{exclusive_opt}' cannot be set together."
+    )
+
+  # Record this option's value
+  ctx.exclusive_opts[param.name] = value is not None
+  return value
+
+
 @main.command("run")
 @click.option(
     "--save_session",
@@ -105,13 +122,43 @@ def cli_create_cmd(
     default=False,
     help="Optional. Whether to save the session to a json file on exit.",
 )
+@click.option(
+    "--replay",
+    type=click.Path(
+        exists=True, dir_okay=False, file_okay=True, resolve_path=True
+    ),
+    help=(
+        "The json file that contains the initial state of the session and user"
+        " queries. A new session will be created using this state. And user"
+        " queries are run againt the newly created session. Users cannot"
+        " continue to interact with the agent."
+    ),
+    callback=validate_exclusive,
+)
+@click.option(
+    "--resume",
+    type=click.Path(
+        exists=True, dir_okay=False, file_okay=True, resolve_path=True
+    ),
+    help=(
+        "The json file that contains a previously saved session (by"
+        "--save_session option). The previous session will be re-displayed. And"
+        " user can continue to interact with the agent."
+    ),
+    callback=validate_exclusive,
+)
 @click.argument(
     "agent",
     type=click.Path(
         exists=True, dir_okay=True, file_okay=False, resolve_path=True
     ),
 )
-def cli_run(agent: str, save_session: bool):
+def cli_run(
+    agent: str,
+    save_session: bool,
+    replay: Optional[str],
+    resume: Optional[str],
+):
   """Runs an interactive CLI for a certain agent.
 
   AGENT: The path to the agent source code folder.
@@ -129,6 +176,8 @@ def cli_run(agent: str, save_session: bool):
       run_cli(
           agent_parent_dir=agent_parent_folder,
           agent_folder_name=agent_folder_name,
+          input_file=replay,
+          saved_session_file=resume,
           save_session=save_session,
       )
   )