fix: defer load_model() to first invocation for Container build compatibility

In Container builds, the Python module loads at container startup before
any request context exists. API-key-based providers use @requires_api_key
which needs a workload access token only available within request context,
causing ValueError at import time.

Defer load_model() using lazy initialization in all affected templates:
- Strands: get_or_create_agent() singleton
- LangChain/LangGraph: get_or_create_model() singleton
- Google ADK / OpenAI Agents: ensure_credentials_loaded() guard

Author: tejaskash

src/assets/__tests__/__snapshots__/assets.snapshot.test.ts.snap

@@ -1555,12 +1555,18 @@ def add_numbers(a: int, b: int) -> int:
     return a + b
 
 
-# Set environment variables for model authentication
-load_model()
-
 # Get MCP Toolset
 mcp_toolset = [get_streamable_http_mcp_client()]
 
+_credentials_loaded = False
+
+def ensure_credentials_loaded():
+    global _credentials_loaded
+    if not _credentials_loaded:
+        load_model()
+        _credentials_loaded = True
+
+
 # Agent Definition
 agent = Agent(
     model=MODEL_ID,
@@ -1573,6 +1579,7 @@ agent = Agent(
 
 # Session and Runner
 async def setup_session_and_runner(user_id, session_id):
+    ensure_credentials_loaded()
     session_service = InMemorySessionService()
     session = await session_service.create_session(
         app_name=APP_NAME, user_id=user_id, session_id=session_id
@@ -1808,8 +1815,13 @@ from mcp_client.client import get_streamable_http_mcp_client
 app = BedrockAgentCoreApp()
 log = app.logger
 
-# Instantiate model
-llm = load_model()
+_llm = None
+
+def get_or_create_model():
+    global _llm
+    if _llm is None:
+        _llm = load_model()
+    return _llm
 
 
 # Define a simple function tool
@@ -1834,7 +1846,7 @@ async def invoke(payload, context):
     mcp_tools = await mcp_client.get_tools()
 
     # Define the agent using create_react_agent
-    graph = create_react_agent(llm, tools=mcp_tools + tools)
+    graph = create_react_agent(get_or_create_model(), tools=mcp_tools + tools)
 
     # Process the user prompt
     prompt = payload.get("prompt", "What can you help me with?")
@@ -2139,12 +2151,17 @@ from mcp_client.client import get_streamable_http_mcp_client
 app = BedrockAgentCoreApp()
 log = app.logger
 
-# Set environment variables for model authentication
-load_model()
-
 # Get MCP Server
 mcp_server = get_streamable_http_mcp_client()
 
+_credentials_loaded = False
+
+def ensure_credentials_loaded():
+    global _credentials_loaded
+    if not _credentials_loaded:
+        load_model()
+        _credentials_loaded = True
+
 
 # Define a simple function tool
 @function_tool
@@ -2155,6 +2172,7 @@ def add_numbers(a: int, b: int) -> int:
 
 # Define the agent execution
 async def main(query):
+    ensure_credentials_loaded()
     try:
         async with mcp_server as server:
             active_servers = [server] if server else []
@@ -2406,14 +2424,19 @@ def agent_factory():
     return get_or_create_agent
 get_or_create_agent = agent_factory()
 {{else}}
-# Create agent
-agent = Agent(
-    model=load_model(),
-    system_prompt="""
-        You are a helpful assistant. Use tools when appropriate.
-    """,
-    tools=tools+[mcp_client]
-)
+_agent = None
+
+def get_or_create_agent():
+    global _agent
+    if _agent is None:
+        _agent = Agent(
+            model=load_model(),
+            system_prompt="""
+                You are a helpful assistant. Use tools when appropriate.
+            """,
+            tools=tools+[mcp_client]
+        )
+    return _agent
 {{/if}}
 
 
@@ -2425,8 +2448,10 @@ async def invoke(payload, context):
     session_id = getattr(context, 'session_id', 'default-session')
     user_id = getattr(context, 'user_id', 'default-user')
     agent = get_or_create_agent(session_id, user_id)
-
+{{else}}
+    agent = get_or_create_agent()
 {{/if}}
+
     # Execute and format response
     stream = agent.stream_async(payload.get("prompt"))
 

src/assets/python/googleadk/base/main.py

@@ -22,12 +22,18 @@ def add_numbers(a: int, b: int) -> int:
     return a + b
 
 
-# Set environment variables for model authentication
-load_model()
-
 # Get MCP Toolset
 mcp_toolset = [get_streamable_http_mcp_client()]
 
+_credentials_loaded = False
+
+def ensure_credentials_loaded():
+    global _credentials_loaded
+    if not _credentials_loaded:
+        load_model()
+        _credentials_loaded = True
+
+
 # Agent Definition
 agent = Agent(
     model=MODEL_ID,
@@ -40,6 +46,7 @@ def add_numbers(a: int, b: int) -> int:
 
 # Session and Runner
 async def setup_session_and_runner(user_id, session_id):
+    ensure_credentials_loaded()
     session_service = InMemorySessionService()
     session = await session_service.create_session(
         app_name=APP_NAME, user_id=user_id, session_id=session_id

src/assets/python/langchain_langgraph/base/main.py

@@ -9,8 +9,13 @@
 app = BedrockAgentCoreApp()
 log = app.logger
 
-# Instantiate model
-llm = load_model()
+_llm = None
+
+def get_or_create_model():
+    global _llm
+    if _llm is None:
+        _llm = load_model()
+    return _llm
 
 
 # Define a simple function tool
@@ -35,7 +40,7 @@ async def invoke(payload, context):
     mcp_tools = await mcp_client.get_tools()
 
     # Define the agent using create_react_agent
-    graph = create_react_agent(llm, tools=mcp_tools + tools)
+    graph = create_react_agent(get_or_create_model(), tools=mcp_tools + tools)
 
     # Process the user prompt
     prompt = payload.get("prompt", "What can you help me with?")

src/assets/python/openaiagents/base/main.py

@@ -7,12 +7,17 @@
 app = BedrockAgentCoreApp()
 log = app.logger
 
-# Set environment variables for model authentication
-load_model()
-
 # Get MCP Server
 mcp_server = get_streamable_http_mcp_client()
 
+_credentials_loaded = False
+
+def ensure_credentials_loaded():
+    global _credentials_loaded
+    if not _credentials_loaded:
+        load_model()
+        _credentials_loaded = True
+
 
 # Define a simple function tool
 @function_tool
@@ -23,6 +28,7 @@ def add_numbers(a: int, b: int) -> int:
 
 # Define the agent execution
 async def main(query):
+    ensure_credentials_loaded()
     try:
         async with mcp_server as server:
             active_servers = [server] if server else []

src/assets/python/strands/base/main.py

@@ -42,14 +42,19 @@ def get_or_create_agent(session_id, user_id):
     return get_or_create_agent
 get_or_create_agent = agent_factory()
 {{else}}
-# Create agent
-agent = Agent(
-    model=load_model(),
-    system_prompt="""
-        You are a helpful assistant. Use tools when appropriate.
-    """,
-    tools=tools+[mcp_client]
-)
+_agent = None
+
+def get_or_create_agent():
+    global _agent
+    if _agent is None:
+        _agent = Agent(
+            model=load_model(),
+            system_prompt="""
+                You are a helpful assistant. Use tools when appropriate.
+            """,
+            tools=tools+[mcp_client]
+        )
+    return _agent
 {{/if}}
 
 
@@ -61,8 +66,10 @@ async def invoke(payload, context):
     session_id = getattr(context, 'session_id', 'default-session')
     user_id = getattr(context, 'user_id', 'default-user')
     agent = get_or_create_agent(session_id, user_id)
-
+{{else}}
+    agent = get_or_create_agent()
 {{/if}}
+
     # Execute and format response
     stream = agent.stream_async(payload.get("prompt"))