diff --git a/agent_builder/tools.py b/agent_builder/tools.py
index 8d90f3e..ac7572c 100644
--- a/agent_builder/tools.py
+++ b/agent_builder/tools.py
@@ -259,13 +259,9 @@ def build_tools(ctx: ToolContext) -> list[Any]:
         written: list[dict[str, Any]] = []
         for path, content in files.items():
             key = prefix + path
-            s3.put_object(
-                Bucket=bucket,
-                Key=key,
-                Body=content.encode("utf-8"),
-                ContentType="text/plain; charset=utf-8",
-            )
-            written.append({"path": key, "size": len(content)})
+            encoded = content.encode("utf-8")
+            store.put(key, encoded, "text/plain; charset=utf-8")
+            written.append({"path": key, "size": len(encoded)})
         return json.dumps({
             "ok": True,
             "agent": name,
diff --git a/tests/test_template_init.py b/tests/test_template_init.py
index 574dbfa..a11f9ea 100644
--- a/tests/test_template_init.py
+++ b/tests/test_template_init.py
@@ -1,9 +1,11 @@
 from __future__ import annotations
 
 import io
+import json
 import tarfile
 import unittest
 
+from agent_builder.config import Settings
 from agent_builder.tools import (
     _BUILDER_STATE_FILE,
     _BUILDER_INTERNAL_PREFIX,
@@ -14,6 +16,8 @@ from agent_builder.tools import (
     _render_a2a_init_template,
     _render_skill_md,
     _tarball_workspace_dir,
+    ToolContext,
+    build_tools,
 )
 
 
@@ -205,6 +209,30 @@ class TemplateInitTests(unittest.TestCase):
             ],
         )
 
+    def test_init_agent_template_writes_through_workspace_store(self) -> None:
+        workspace = _FakeWorkspace()
+        tools = build_tools(
+            ToolContext(
+                bucket="bucket",
+                settings=_settings(),
+                workspace=workspace,
+            )
+        )
+
+        init = _tool_by_name(tools, "init_agent_template")
+        result = json.loads(
+            init.invoke({
+                "name": "website-scraper",
+                "description": "Browser scraper",
+                "frontend": "none",
+            })
+        )
+
+        self.assertTrue(result["ok"])
+        self.assertIn("agents/website-scraper/agent.py", workspace.objects)
+        self.assertIn("agents/website-scraper/a2a.yaml", workspace.objects)
+        self.assertIn("agents/website-scraper/requirements.txt", workspace.objects)
+
 
 def _tarball(files: dict[str, str]) -> bytes:
     buf = io.BytesIO()
@@ -259,3 +287,44 @@ class _FakePaginator:
                 ]
             }
         ]
+
+
+class _FakeWorkspace:
+    def __init__(self) -> None:
+        self.objects: dict[str, bytes] = {}
+
+    def iter_paths(self) -> list[str]:
+        return sorted(self.objects)
+
+    def read_bytes(self, key: str) -> bytes:
+        return self.objects[key]
+
+    def write_bytes(self, key: str, body: bytes) -> None:
+        self.objects[key] = bytes(body)
+
+    def delete_path(self, key: str) -> None:
+        self.objects.pop(key, None)
+
+
+def _tool_by_name(tools: list[object], name: str) -> object:
+    for tool in tools:
+        if getattr(tool, "name", None) == name:
+            return tool
+    raise AssertionError(f"tool not found: {name}")
+
+
+def _settings() -> Settings:
+    return Settings(
+        sandbox_url="http://sandbox.test",
+        sandbox_timeout_s=1,
+        sandbox_token=None,
+        deploy_wait_timeout_s=1,
+        litellm_url="http://litellm.test",
+        litellm_key="",
+        litellm_model="gpt-test",
+        cp_url="http://cp.test",
+        minio_endpoint="http://minio.test",
+        minio_access_key="key",
+        minio_secret_key="secret",
+        image="python:3.11-slim",
+    )