feat: add session filesystem storage support (#893)

Adds --session-storage-mount-path to agentcore create and agentcore add agent,
wiring the mount path through schema, CLI flags, TUI wizard, template rendering,
and CDK mapping. File tools (file_read, file_write, list_files) with path traversal
protection are scaffolded into all 8 framework templates when storage is configured.
Fixes A2A sessionId not being forwarded to InvokeAgentRuntimeCommand. Validation
is centralised in SessionStorageSchema with no regex duplication across validators
or TUI.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: padmak30

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

@@ -1,3 +1,4 @@
+import os
 from google.adk.agents import Agent
 from google.adk.a2a.executor.a2a_agent_executor import A2aAgentExecutor
 from google.adk.runners import Runner
@@ -12,12 +13,71 @@ def add_numbers(a: int, b: int) -> int:
     return a + b
 
 
+tools = [add_numbers]
+
+{{#if sessionStorageMountPath}}
+SESSION_STORAGE_PATH = "{{sessionStorageMountPath}}"
+
+def _safe_resolve(path: str) -> str:
+    """Resolve path safely within the storage boundary."""
+    resolved = os.path.realpath(os.path.join(SESSION_STORAGE_PATH, path.lstrip("/")))
+    if not resolved.startswith(os.path.realpath(SESSION_STORAGE_PATH)):
+        raise ValueError(f"Path '{path}' is outside the storage boundary")
+    return resolved
+
+def file_read(path: str) -> str:
+    """Read a file from persistent storage. The path is relative to the storage root."""
+    try:
+        full_path = _safe_resolve(path)
+        with open(full_path) as f:
+            return f.read()
+    except ValueError as e:
+        return str(e)
+    except OSError as e:
+        return f"Error reading '{path}': {e.strerror}"
+
+def file_write(path: str, content: str) -> str:
+    """Write content to a file in persistent storage. The path is relative to the storage root."""
+    try:
+        full_path = _safe_resolve(path)
+        parent = os.path.dirname(full_path)
+        if parent:
+            os.makedirs(parent, exist_ok=True)
+        with open(full_path, "w") as f:
+            f.write(content)
+        return f"Written to {path}"
+    except ValueError as e:
+        return str(e)
+    except OSError as e:
+        return f"Error writing '{path}': {e.strerror}"
+
+def list_files(directory: str = "") -> str:
+    """List files in persistent storage. The directory is relative to the storage root."""
+    try:
+        target = _safe_resolve(directory)
+        entries = os.listdir(target)
+        return "\n".join(entries) if entries else "(empty directory)"
+    except ValueError as e:
+        return str(e)
+    except OSError as e:
+        return f"Error listing '{directory}': {e.strerror}"
+
+tools.extend([file_read, file_write, list_files])
+{{/if}}
+
+AGENT_INSTRUCTION = """
+You are a helpful assistant. Use tools when appropriate.
+{{#if sessionStorageMountPath}}
+You have persistent storage at {{sessionStorageMountPath}}. Use file tools to read and write files. Data persists across sessions.
+{{/if}}
+"""
+
 agent = Agent(
     model=load_model(),
     name="{{ name }}",
     description="A helpful assistant that can use tools.",
-    instruction="You are a helpful assistant. Use tools when appropriate.",
-    tools=[add_numbers],
+    instruction=AGENT_INSTRUCTION,
+    tools=tools,
 )
 
 runner = Runner(

src/assets/python/a2a/googleadk/base/main.py

@@ -1,3 +1,4 @@
+import os
 from langchain_core.tools import tool
 from langgraph.prebuilt import create_react_agent
 from opentelemetry.instrumentation.langchain import LangchainInstrumentor
@@ -18,8 +19,70 @@ def add_numbers(a: int, b: int) -> int:
     return a + b
 
 
+tools = [add_numbers]
+
+{{#if sessionStorageMountPath}}
+SESSION_STORAGE_PATH = "{{sessionStorageMountPath}}"
+
+def _safe_resolve(path: str) -> str:
+    """Resolve path safely within the storage boundary."""
+    resolved = os.path.realpath(os.path.join(SESSION_STORAGE_PATH, path.lstrip("/")))
+    if not resolved.startswith(os.path.realpath(SESSION_STORAGE_PATH)):
+        raise ValueError(f"Path '{path}' is outside the storage boundary")
+    return resolved
+
+@tool
+def file_read(path: str) -> str:
+    """Read a file from persistent storage. The path is relative to the storage root."""
+    try:
+        full_path = _safe_resolve(path)
+        with open(full_path) as f:
+            return f.read()
+    except ValueError as e:
+        return str(e)
+    except OSError as e:
+        return f"Error reading '{path}': {e.strerror}"
+
+@tool
+def file_write(path: str, content: str) -> str:
+    """Write content to a file in persistent storage. The path is relative to the storage root."""
+    try:
+        full_path = _safe_resolve(path)
+        parent = os.path.dirname(full_path)
+        if parent:
+            os.makedirs(parent, exist_ok=True)
+        with open(full_path, "w") as f:
+            f.write(content)
+        return f"Written to {path}"
+    except ValueError as e:
+        return str(e)
+    except OSError as e:
+        return f"Error writing '{path}': {e.strerror}"
+
+@tool
+def list_files(directory: str = "") -> str:
+    """List files in persistent storage. The directory is relative to the storage root."""
+    try:
+        target = _safe_resolve(directory)
+        entries = os.listdir(target)
+        return "\n".join(entries) if entries else "(empty directory)"
+    except ValueError as e:
+        return str(e)
+    except OSError as e:
+        return f"Error listing '{directory}': {e.strerror}"
+
+tools.extend([file_read, file_write, list_files])
+{{/if}}
+
+SYSTEM_PROMPT = """
+You are a helpful assistant. Use tools when appropriate.
+{{#if sessionStorageMountPath}}
+You have persistent storage at {{sessionStorageMountPath}}. Use file tools to read and write files. Data persists across sessions.
+{{/if}}
+"""
+
 model = load_model()
-graph = create_react_agent(model, tools=[add_numbers])
+graph = create_react_agent(model, tools=tools, prompt=SYSTEM_PROMPT)
 
 
 class LangGraphA2AExecutor(AgentExecutor):

src/assets/python/a2a/langchain_langgraph/base/main.py

@@ -5,6 +5,9 @@
 {{#if hasMemory}}
 from memory.session import get_memory_session_manager
 {{/if}}
+{{#if sessionStorageMountPath}}
+import os
+{{/if}}
 
 
 @tool
@@ -15,6 +18,66 @@ def add_numbers(a: int, b: int) -> int:
 
 tools = [add_numbers]
 
+{{#if sessionStorageMountPath}}
+SESSION_STORAGE_PATH = "{{sessionStorageMountPath}}"
+
+def _safe_resolve(path: str) -> str:
+    """Resolve path safely within the storage boundary."""
+    resolved = os.path.realpath(os.path.join(SESSION_STORAGE_PATH, path.lstrip("/")))
+    if not resolved.startswith(os.path.realpath(SESSION_STORAGE_PATH)):
+        raise ValueError(f"Path '{path}' is outside the storage boundary")
+    return resolved
+
+@tool
+def file_read(path: str) -> str:
+    """Read a file from persistent storage. The path is relative to the storage root."""
+    try:
+        full_path = _safe_resolve(path)
+        with open(full_path) as f:
+            return f.read()
+    except ValueError as e:
+        return str(e)
+    except OSError as e:
+        return f"Error reading '{path}': {e.strerror}"
+
+@tool
+def file_write(path: str, content: str) -> str:
+    """Write content to a file in persistent storage. The path is relative to the storage root."""
+    try:
+        full_path = _safe_resolve(path)
+        parent = os.path.dirname(full_path)
+        if parent:
+            os.makedirs(parent, exist_ok=True)
+        with open(full_path, "w") as f:
+            f.write(content)
+        return f"Written to {path}"
+    except ValueError as e:
+        return str(e)
+    except OSError as e:
+        return f"Error writing '{path}': {e.strerror}"
+
+@tool
+def list_files(directory: str = "") -> str:
+    """List files in persistent storage. The directory is relative to the storage root."""
+    try:
+        target = _safe_resolve(directory)
+        entries = os.listdir(target)
+        return "\n".join(entries) if entries else "(empty directory)"
+    except ValueError as e:
+        return str(e)
+    except OSError as e:
+        return f"Error listing '{directory}': {e.strerror}"
+
+tools.extend([file_read, file_write, list_files])
+{{/if}}
+
+SYSTEM_PROMPT = """
+You are a helpful assistant. Use tools when appropriate.
+{{#if sessionStorageMountPath}}
+You have persistent storage at {{sessionStorageMountPath}}. Use file tools to read and write files. Data persists across sessions.
+{{/if}}
+"""
+
 {{#if hasMemory}}
 def agent_factory():
     cache = {}
@@ -24,7 +87,7 @@ def get_or_create_agent(session_id, user_id):
             cache[key] = Agent(
                 model=load_model(),
                 session_manager=get_memory_session_manager(session_id, user_id),
-                system_prompt="You are a helpful assistant. Use tools when appropriate.",
+                system_prompt=SYSTEM_PROMPT,
                 tools=tools,
             )
         return cache[key]
@@ -35,7 +98,7 @@ def get_or_create_agent(session_id, user_id):
 {{else}}
 agent = Agent(
     model=load_model(),
-    system_prompt="You are a helpful assistant. Use tools when appropriate.",
+    system_prompt=SYSTEM_PROMPT,
     tools=tools,
 )
 {{/if}}

src/assets/python/a2a/strands/base/main.py

@@ -22,6 +22,66 @@ def add_numbers(a: int, b: int) -> int:
 # Define a collection of tools used by the model
 tools = [add_numbers_tool]
 
+{{#if sessionStorageMountPath}}
+SESSION_STORAGE_PATH = "{{sessionStorageMountPath}}"
+
+def _safe_resolve(path: str) -> str:
+    """Resolve path safely within the storage boundary."""
+    resolved = os.path.realpath(os.path.join(SESSION_STORAGE_PATH, path.lstrip("/")))
+    if not resolved.startswith(os.path.realpath(SESSION_STORAGE_PATH)):
+        raise ValueError(f"Path '{path}' is outside the storage boundary")
+    return resolved
+
+def file_read(path: str) -> str:
+    """Read a file from persistent storage. The path is relative to the storage root."""
+    try:
+        full_path = _safe_resolve(path)
+        with open(full_path) as f:
+            return f.read()
+    except ValueError as e:
+        return str(e)
+    except OSError as e:
+        return f"Error reading '{path}': {e.strerror}"
+
+def file_write(path: str, content: str) -> str:
+    """Write content to a file in persistent storage. The path is relative to the storage root."""
+    try:
+        full_path = _safe_resolve(path)
+        parent = os.path.dirname(full_path)
+        if parent:
+            os.makedirs(parent, exist_ok=True)
+        with open(full_path, "w") as f:
+            f.write(content)
+        return f"Written to {path}"
+    except ValueError as e:
+        return str(e)
+    except OSError as e:
+        return f"Error writing '{path}': {e.strerror}"
+
+def list_files(directory: str = "") -> str:
+    """List files in persistent storage. The directory is relative to the storage root."""
+    try:
+        target = _safe_resolve(directory)
+        entries = os.listdir(target)
+        return "\n".join(entries) if entries else "(empty directory)"
+    except ValueError as e:
+        return str(e)
+    except OSError as e:
+        return f"Error listing '{directory}': {e.strerror}"
+
+tools.extend([
+    FunctionTool(file_read, description="Read a file from persistent storage. The path is relative to the storage root."),
+    FunctionTool(file_write, description="Write content to a file in persistent storage. The path is relative to the storage root."),
+    FunctionTool(list_files, description="List files in persistent storage. The directory is relative to the storage root."),
+])
+{{/if}}
+
+SYSTEM_MESSAGE = """
+You are a helpful assistant. Use tools when appropriate.
+{{#if sessionStorageMountPath}}
+You have persistent storage at {{sessionStorageMountPath}}. Use file tools to read and write files. Data persists across sessions.
+{{/if}}
+"""
 
 @app.entrypoint
 async def invoke(payload, context):
@@ -35,7 +95,7 @@ async def invoke(payload, context):
         name="{{ name }}",
         model_client=load_model(),
         tools=tools + mcp_tools,
-        system_message="You are a helpful assistant. Use tools when appropriate.",
+        system_message=SYSTEM_MESSAGE,
     )
 
     # Process the user prompt