diff --git a/application/agents/tools/code_executor.py b/application/agents/tools/code_executor.py
index 2c597301..3520230e 100644
--- a/application/agents/tools/code_executor.py
+++ b/application/agents/tools/code_executor.py
@@ -77,9 +77,11 @@ class CodeExecutorTool(Tool):
             {
                 "name": "run_code",
                 "description": (
-                    "Execute code in a sandboxed, stateful session bound to this conversation. "
+                    "Execute Python in a sandboxed, stateful session bound to this conversation. "
                     "Files written by the code are captured as downloadable artifacts; only a "
-                    "compact summary (output tail + artifact references) is returned, never raw bytes."
+                    "compact summary (output tail + artifact references) is returned, never raw bytes. "
+                    "Each call is capped at ~60s of wall-clock; for longer work, start it in the "
+                    "background and poll with additional run_code calls (use persist=true to keep state)."
                 ),
                 "active": True,
                 "require_approval": self._require_approval,
@@ -88,16 +90,8 @@ class CodeExecutorTool(Tool):
                     "properties": {
                         "code": {
                             "type": "string",
-                            "description": "Source code to execute in the session.",
-                        },
-                        "language": {
-                            "type": "string",
-                            "description": "Programming language (default: python).",
-                        },
-                        "libraries": {
-                            "type": "array",
-                            "items": {"type": "string"},
-                            "description": "Packages to ensure are installed before running.",
+                            "description": "Python source to execute in the session. Install packages from "
+                            "within the code itself (e.g. subprocess pip install) if needed.",
                         },
                         "inputs": {
                             "type": "array",
@@ -106,10 +100,6 @@ class CodeExecutorTool(Tool):
                             "ref like `A1` returned by a previous artifact action, a full artifact id, or "
                             "the name/id of a file the user attached to this conversation.",
                         },
-                        "timeout": {
-                            "type": "integer",
-                            "description": "Wall-clock timeout in seconds for this execution.",
-                        },
                         "ttl": {
                             "type": "integer",
                             "description": "Keep-alive lifetime (seconds) for the session; clamped by SANDBOX_MAX_TTL.",
@@ -133,21 +123,9 @@ class CodeExecutorTool(Tool):
         ]
 
     def get_config_requirements(self) -> Dict[str, Any]:
-        """Return configuration requirements (approval gate + backend selection)."""
-        return {
-            "require_approval": {
-                "type": "boolean",
-                "label": "Require approval",
-                "description": "Pause for human approval before each code execution.",
-                "required": False,
-            },
-            "sandbox_backend": {
-                "type": "string",
-                "label": "Sandbox backend",
-                "description": "Code-execution backend (defaults to the SANDBOX_BACKEND setting).",
-                "required": False,
-            },
-        }
+        """Return configuration requirements (none; approval is an action-level flag,
+        and the sandbox backend is a deployment-level setting)."""
+        return {}
 
     def get_artifact_id(self, action_name: str, **kwargs: Any) -> Optional[str]:
         """Return the primary produced artifact id so the UI artifact rail lights up."""
@@ -184,7 +162,7 @@ class CodeExecutorTool(Tool):
 
         should_capture = kwargs.get("capture_artifacts", True)
         ttl = self._coerce_int(kwargs.get("ttl"))
-        timeout = self._resolve_timeout(kwargs.get("timeout"))
+        timeout = self._exec_timeout()
         inputs = kwargs.get("inputs") or []
 
         manager = SandboxCreator.get_manager()
@@ -356,11 +334,21 @@ class CodeExecutorTool(Tool):
         if stderr_tail:
             payload["stderr_tail"] = stderr_tail
         if not result.ok:
-            payload["error"] = (
-                f"{result.error_name}: {result.error_value}"
-                if result.error_name
-                else (result.error_value or "execution error")
-            )
+            if self._is_timeout(result):
+                cap = int(self._exec_timeout())
+                payload["error"] = (
+                    f"Execution timed out. Each run_code call is capped at {cap}s and the limit "
+                    "cannot be raised. For long-running work, start it in the background (e.g. launch a "
+                    "subprocess or `nohup ... &` and write progress to a file) and return immediately, "
+                    "then poll with additional run_code calls to check on it. Pass persist=true (or a "
+                    "ttl) so the background process and its files survive between calls."
+                )
+            else:
+                payload["error"] = (
+                    f"{result.error_name}: {result.error_value}"
+                    if result.error_name
+                    else (result.error_value or "execution error")
+                )
         if inputs_loaded:
             payload["inputs_loaded"] = inputs_loaded
         return payload
@@ -387,13 +375,16 @@ class CodeExecutorTool(Tool):
             return None
         return parsed if parsed > 0 else None
 
-    def _resolve_timeout(self, requested: Any) -> float:
-        """Return the stricter of the requested timeout and the sandbox's default cap."""
-        cap = float(getattr(settings, "SANDBOX_EXEC_TIMEOUT", 60))
-        parsed = self._coerce_int(requested)
-        if parsed is None:
-            return cap
-        return float(min(parsed, cap))
+    @staticmethod
+    def _exec_timeout() -> float:
+        """Return the fixed per-run wall-clock cap (SANDBOX_EXEC_TIMEOUT; not caller-adjustable)."""
+        return float(getattr(settings, "SANDBOX_EXEC_TIMEOUT", 60))
+
+    @staticmethod
+    def _is_timeout(result: ExecResult) -> bool:
+        """True when a failed exec looks like a wall-clock timeout (any backend's naming/message)."""
+        blob = f"{result.error_name or ''} {result.error_value or ''}".lower()
+        return "timeout" in blob or "timed out" in blob
 
     @staticmethod
     def _keep_alive(persist: Any, ttl: Optional[int]) -> bool:
diff --git a/application/core/settings.py b/application/core/settings.py
index 3acb9a24..58288c25 100644
--- a/application/core/settings.py
+++ b/application/core/settings.py
@@ -373,7 +373,7 @@ class Settings(BaseSettings):
     DAYTONA_API_KEY: Optional[str] = None  # Daytona Cloud API key (secret)
     DAYTONA_API_URL: Optional[str] = None  # override Daytona API base URL, if self-targeting
     DAYTONA_TARGET: Optional[str] = None  # Daytona region/target, e.g. "us"
-    DAYTONA_SNAPSHOT: Optional[str] = None  # snapshot/image id to create sandboxes from
+    DAYTONA_SNAPSHOT: Optional[str] = None  # image for new sandboxes; render libs via scripts/build_daytona_snapshot.py
     DAYTONA_LANGUAGE: str = "python"  # default runtime language for created sandboxes
     DAYTONA_AUTO_STOP_INTERVAL: int = 15  # minutes idle before Daytona auto-stops a sandbox (0 disables)
     DAYTONA_AUTO_DELETE_INTERVAL: int = 60  # minutes after stop before Daytona auto-deletes (-1 disables)
diff --git a/deployment/sandbox/README.md b/deployment/sandbox/README.md
index fe6f1040..1200ba34 100644
--- a/deployment/sandbox/README.md
+++ b/deployment/sandbox/README.md
@@ -109,6 +109,31 @@ app chooses it). The same applies to k8s: `SANDBOX_KERNEL_NAME=docsgpt-python`
 is set on the `docsgpt-api` and `docsgpt-worker` deployments in
 `deployment/k8s/deployments/docsgpt-deploy.yaml`.
 
+## Artifact rendering on Daytona (snapshot)
+
+The `artifact` tool renders `presentation` / `document` / `spreadsheet` / `pdf`
+specs by running a fixed renderer **inside the sandbox** that imports
+`python-pptx`, `python-docx`, `openpyxl`, and `reportlab` (HTML/markdown need no
+library). The self-hosted Jupyter runner inherits these from the backend venv,
+but Daytona's default snapshot is a plain Python image — so under
+`SANDBOX_BACKEND=daytona` those renders fail with `render failed: ExecutionError`
+(a `ModuleNotFoundError` raised inside the sandbox). HTML/markdown still work.
+
+Bake the libraries into a Daytona snapshot once, then point `DAYTONA_SNAPSHOT`
+at it:
+
+```bash
+# Reads DAYTONA_API_KEY / DAYTONA_API_URL / DAYTONA_TARGET from .env:
+python scripts/build_daytona_snapshot.py        # builds "docsgpt-artifacts-py312"
+# then in .env:
+#   DAYTONA_SNAPSHOT=docsgpt-artifacts-py312
+```
+
+The snapshot lives in **your** Daytona account, so each deployment builds its
+own — the script is idempotent and skips if the name already exists. Keep the
+pins in `scripts/build_daytona_snapshot.py` in sync with the backend venv so the
+Daytona render output matches the Jupyter-backend output.
+
 ## Document reading (parsing worker — not the sandbox)
 
 Document reading no longer runs in this sandbox. The `read_document` tool and the
diff --git a/frontend/src/conversation/ConversationBubble.tsx b/frontend/src/conversation/ConversationBubble.tsx
index 48e8e0df..03b025fc 100644
--- a/frontend/src/conversation/ConversationBubble.tsx
+++ b/frontend/src/conversation/ConversationBubble.tsx
@@ -131,6 +131,11 @@ const ConversationBubble = forwardRef<
 
   const formatToolName = (toolName: string | undefined): string => {
     if (!toolName) return '';
+    // Display-name overrides for tools whose label differs from the formatted key.
+    const overrides: Record<string, string> = {
+      artifact_generator: 'Artifact',
+    };
+    if (overrides[toolName]) return overrides[toolName];
     return toolName
       .split('_')
       .map((word) => word.charAt(0).toUpperCase() + word.slice(1).toLowerCase())
@@ -691,9 +696,9 @@ const ConversationBubble = forwardRef<
           </div>
         )}
         {message && (
-          <div className="my-2 ml-2 flex flex-wrap justify-start gap-y-2">
+          <div className="my-2 ml-2 flex flex-wrap justify-start gap-2">
             {type === 'ERROR' ? (
-              <div className="relative mr-2 block items-center justify-center">
+              <div className="relative block items-center justify-center">
                 <div>{retryBtn}</div>
               </div>
             ) : (
@@ -702,7 +707,7 @@ const ConversationBubble = forwardRef<
                   completedArtifactCalls.map((artifactCall, artifactIndex) => (
                     <div
                       key={artifactCall.call_id ?? artifactIndex}
-                      className="relative mr-2 flex items-center justify-center"
+                      className="relative flex items-center justify-center"
                     >
                       <Button
                         type="button"
@@ -743,11 +748,11 @@ const ConversationBubble = forwardRef<
                   ))}
                 {!isStreaming && (
                   <>
-                    <div className="relative mr-2 block items-center justify-center">
+                    <div className="relative block items-center justify-center">
                       <CopyButton textToCopy={message} />
                     </div>
                     {research && message && (
-                      <div className="relative mr-2 block items-center justify-center">
+                      <div className="relative block items-center justify-center">
                         <Button
                           type="button"
                           variant="ghost"
@@ -782,12 +787,12 @@ const ConversationBubble = forwardRef<
                         </Button>
                       </div>
                     )}
-                    <div className="relative mr-2 block items-center justify-center">
+                    <div className="relative block items-center justify-center">
                       <SpeakButton text={message} />
                     </div>
                     {handleFeedback && (
                       <>
-                        <div className="relative mr-2 flex items-center justify-center">
+                        <div className="relative flex items-center justify-center">
                           <Button
                             type="button"
                             variant="ghost"
@@ -810,7 +815,7 @@ const ConversationBubble = forwardRef<
                           </Button>
                         </div>
 
-                        <div className="relative mr-2 flex items-center justify-center">
+                        <div className="relative flex items-center justify-center">
                           <Button
                             type="button"
                             variant="ghost"
diff --git a/scripts/build_daytona_snapshot.py b/scripts/build_daytona_snapshot.py
new file mode 100644
index 00000000..0f628e31
--- /dev/null
+++ b/scripts/build_daytona_snapshot.py
@@ -0,0 +1,108 @@
+"""Build a Daytona snapshot preloaded with the artifact-render libraries.
+
+The Daytona managed sandbox backend (``SANDBOX_BACKEND=daytona``) creates each
+session from a snapshot. The default snapshot is a plain Python image, so the
+``artifact`` tool's renderers — which ``import`` ``python-pptx`` / ``python-docx``
+/ ``openpyxl`` / ``reportlab`` inside the sandbox — fail with
+``render failed: ExecutionError``. This script bakes those libraries into a
+snapshot once; point ``DAYTONA_SNAPSHOT`` at its name to fix rendering on Daytona.
+
+Usage::
+
+    # Reads DAYTONA_API_KEY / DAYTONA_API_URL / DAYTONA_TARGET from .env (settings):
+    python scripts/build_daytona_snapshot.py
+    python scripts/build_daytona_snapshot.py --name docsgpt-artifacts-py312 --python 3.12
+
+Then set in .env::
+
+    DAYTONA_SNAPSHOT=docsgpt-artifacts-py312
+
+Keep the pins in sync with the backend venv (python-pptx / openpyxl / lxml /
+pillow are in application/requirements.txt; python-docx and reportlab arrive
+transitively) so the Daytona render output matches the Jupyter-backend output.
+"""
+
+from __future__ import annotations
+
+import argparse
+import sys
+
+# Render libraries imported by the artifact tool's renderers, pinned to the
+# versions installed in the backend venv as of this writing.
+RENDER_PINS = [
+    "python-pptx==1.0.2",
+    "python-docx==1.2.0",
+    "openpyxl==3.1.5",
+    "reportlab==4.5.1",
+    "lxml==6.0.2",
+    "pillow==11.3.0",
+]
+
+DEFAULT_NAME = "docsgpt-artifacts-py312"
+DEFAULT_PYTHON = "3.12"
+
+
+def _parse_args(argv: list[str]) -> argparse.Namespace:
+    """Parse CLI arguments for the snapshot name and Python series."""
+    parser = argparse.ArgumentParser(description=__doc__.splitlines()[0])
+    parser.add_argument("--name", default=DEFAULT_NAME, help="snapshot name (default: %(default)s)")
+    parser.add_argument("--python", default=DEFAULT_PYTHON, help="Python series, e.g. 3.12")
+    parser.add_argument(
+        "--force", action="store_true", help="rebuild even if a snapshot with that name exists"
+    )
+    return parser.parse_args(argv)
+
+
+def main(argv: list[str]) -> int:
+    """Build (or skip) the snapshot and print the value to set as DAYTONA_SNAPSHOT."""
+    args = _parse_args(argv)
+
+    from application.core.settings import settings
+
+    if not settings.DAYTONA_API_KEY:
+        print("DAYTONA_API_KEY is not set (check .env).", file=sys.stderr)
+        return 2
+
+    from daytona import (
+        CreateSnapshotParams,
+        Daytona,
+        DaytonaConfig,
+        DaytonaConflictError,
+        Image,
+    )
+
+    cfg: dict[str, object] = {"api_key": settings.DAYTONA_API_KEY}
+    if settings.DAYTONA_API_URL:
+        cfg["api_url"] = settings.DAYTONA_API_URL
+    if settings.DAYTONA_TARGET:
+        cfg["target"] = settings.DAYTONA_TARGET
+    client = Daytona(DaytonaConfig(**cfg))
+
+    if not args.force:
+        try:
+            existing = client.snapshot.get(args.name)
+            print(f"snapshot {args.name!r} already exists (state={getattr(existing, 'state', '?')}).")
+            print(f"set DAYTONA_SNAPSHOT={args.name}")
+            return 0
+        except Exception as exc:  # noqa: BLE001 - "not found" is the happy path; build it
+            if type(exc).__name__ != "DaytonaNotFoundError" and "not found" not in str(exc).lower():
+                print(f"warning: get({args.name!r}) probe: {type(exc).__name__}: {exc}", file=sys.stderr)
+
+    image = Image.debian_slim(args.python).pip_install(RENDER_PINS)
+    print(f"building snapshot {args.name!r} (python {args.python}) with: {', '.join(RENDER_PINS)}")
+    print("--- build logs ---")
+    try:
+        snap = client.snapshot.create(
+            CreateSnapshotParams(name=args.name, image=image), on_logs=print, timeout=600
+        )
+    except DaytonaConflictError:
+        print(f"snapshot {args.name!r} already exists (conflict) — reuse it or pass --force a new name.")
+        return 0
+    print("--- created ---")
+    print(f"name={getattr(snap, 'name', args.name)} state={getattr(snap, 'state', '?')}")
+    print(f"\nNow set in .env:\n    DAYTONA_SNAPSHOT={args.name}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main(sys.argv[1:]))
diff --git a/tests/test_code_executor_tool.py b/tests/test_code_executor_tool.py
index 2101a31f..7aabc475 100644
--- a/tests/test_code_executor_tool.py
+++ b/tests/test_code_executor_tool.py
@@ -108,12 +108,12 @@ def test_shape_payload_ok_with_artifacts():
 def test_shape_payload_error_carries_clean_message_no_hang():
     tool = _tool()
     result = ExecResult(
-        status="error", error_name="TimeoutError",
-        error_value="execution exceeded 1.0s", exit_code=-1,
+        status="error", error_name="RuntimeError",
+        error_value="kernel reset mid-run", exit_code=-1,
     )
     payload = tool._shape_payload(result, artifacts=[], inputs_loaded=[])
     assert payload["status"] == "error"
-    assert payload["error"] == "TimeoutError: execution exceeded 1.0s"
+    assert payload["error"] == "RuntimeError: kernel reset mid-run"
     assert payload["artifacts"] == []
 
 
@@ -148,16 +148,37 @@ def test_resolve_session_id_sanitizes_disallowed_chars():
     assert re.fullmatch(r"[A-Za-z0-9_-]+", sid)
 
 
-def test_resolve_timeout_picks_the_stricter_cap(monkeypatch):
+def test_exec_timeout_is_a_fixed_uncapped_value(monkeypatch):
+    from application.core import settings as settings_module
+
+    # The per-run wall-clock cap is fixed from settings; callers cannot pass one.
+    monkeypatch.setattr(settings_module.settings, "SANDBOX_EXEC_TIMEOUT", 60, raising=False)
+    assert CodeExecutorTool._exec_timeout() == 60.0
+    monkeypatch.setattr(settings_module.settings, "SANDBOX_EXEC_TIMEOUT", 90, raising=False)
+    assert CodeExecutorTool._exec_timeout() == 90.0
+    # The action schema no longer advertises language/libraries/timeout.
+    props = _tool().get_actions_metadata()[0]["parameters"]["properties"]
+    assert "timeout" not in props and "language" not in props and "libraries" not in props
+
+
+def test_is_timeout_detects_any_backend_naming():
+    assert CodeExecutorTool._is_timeout(ExecResult(error_name="TimeoutError", error_value="x"))
+    assert CodeExecutorTool._is_timeout(ExecResult(error_name="DaytonaTimeoutError"))
+    assert CodeExecutorTool._is_timeout(ExecResult(error_value="process timed out"))
+    assert not CodeExecutorTool._is_timeout(ExecResult(error_name="ValueError", error_value="boom"))
+
+
+def test_timeout_result_guides_backgrounding(monkeypatch):
     from application.core import settings as settings_module
 
     monkeypatch.setattr(settings_module.settings, "SANDBOX_EXEC_TIMEOUT", 60, raising=False)
     tool = _tool()
-    assert tool._resolve_timeout(10) == 10.0  # under the cap
-    assert tool._resolve_timeout(999) == 60.0  # clamped to cap
-    assert tool._resolve_timeout(None) == 60.0  # default
-    assert tool._resolve_timeout("bad") == 60.0  # invalid -> default
-    assert tool._resolve_timeout(-5) == 60.0  # non-positive -> default
+    timed_out = ExecResult(status="error", error_name="TimeoutError", error_value="execution exceeded 60s")
+    err = tool._shape_payload(timed_out, [], [])["error"]
+    assert "60s" in err and "background" in err.lower() and "poll" in err.lower()
+    # A non-timeout failure keeps the raw name/value.
+    crashed = ExecResult(status="error", error_name="ValueError", error_value="boom")
+    assert tool._shape_payload(crashed, [], [])["error"] == "ValueError: boom"
 
 
 def test_coerce_int_and_keep_alive():
@@ -187,10 +208,11 @@ def test_run_code_metadata_reflects_require_approval():
     assert ungated.preview_decision("other", {}) == (True, False)
 
 
-def test_config_requirements_expose_approval_and_backend():
-    reqs = CodeExecutorTool({}, user_id="u").get_config_requirements()
-    assert "require_approval" in reqs
-    assert "sandbox_backend" in reqs
+def test_config_requirements_is_empty():
+    # Approval is an action-level flag (see test_run_code_metadata_reflects_require_approval)
+    # and the sandbox backend is a deployment-level setting, so the tool advertises no
+    # user-configurable requirements.
+    assert CodeExecutorTool({}, user_id="u").get_config_requirements() == {}
 
 
 def test_execute_action_rejects_unknown_action_and_missing_code():