Skip to content

ref(mcp): Inline _prepare_handler_data() #6758

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
alexander-alderman-webb wants to merge 2 commits into from
+43 −73
Draft

ref(mcp): Inline _prepare_handler_data() #6758

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
247f5d4
ref(mcp): Use middleware when available
alexander-alderman-webb Jul 6, 2026
ebf64d3
ref(mcp): Inline _prepare_handler_data
alexander-alderman-webb Jul 6, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
116 changes: 43 additions & 73 deletions sentry_sdk/integrations/mcp.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -457,50 +457,6 @@
return handler_name, arguments


def _prepare_handler_data(
handler_type: str,
original_args: "tuple[Any, ...]",
original_kwargs: "Optional[dict[str, Any]]" = None,
params: "Optional[Any]" = None,
) -> "tuple[str, dict[str, Any], str, str, str, Optional[str]]":
"""
Prepare common handler data for both v1 and v2 MCP SDK.

Args:
handler_type: "tool", "prompt", or "resource"
original_args: Original positional args (v1 path)
original_kwargs: Original keyword args (v1 path)
params: Typed params object from v2 ServerRequestContext path

Returns:
Tuple of (handler_name, arguments, span_data_key, span_name, mcp_method_name, result_data_key)
"""
if params is not None:
handler_name, arguments = _extract_handler_data_from_params(
handler_type, params
)
elif _is_v2_context(original_args):
handler_name = "unknown"
arguments = {}
else:
handler_name, arguments = _extract_handler_data_from_args(
handler_type, original_args, original_kwargs
)

span_data_key, span_name, mcp_method_name, result_data_key = _get_span_config(
handler_type, handler_name
)

return (
handler_name,
arguments,
span_data_key,
span_name,
mcp_method_name,
result_data_key,
)


async def _tool_handler_wrapper(
func: "Callable[..., Awaitable[Union[CallToolResult, InputRequiredResult]]]",
original_args: "tuple[Any, ...]",
Expand Down Expand Up @@ -530,16 +486,20 @@
and isinstance(original_args[0], ServerRequestContext)
):
ctx = original_args[0]
params = original_args[1] if len(original_args) > 1 else None
if len(original_args) > 1:
params = original_args[1]
handler_name, arguments = _extract_handler_data_from_params("tool", params)
else:
handler_name = "unknown"
arguments = {}
else:
handler_name, arguments = _extract_handler_data_from_args(
"tool", original_args, original_kwargs
)

(
handler_name,
arguments,
span_data_key,
span_name,
mcp_method_name,
result_data_key,
) = _prepare_handler_data("tool", original_args, original_kwargs, params=params)
span_data_key, span_name, mcp_method_name, result_data_key = _get_span_config(
"tool", handler_name
)

scopes = _get_active_http_scopes(ctx=ctx)

Expand Down Expand Up @@ -641,23 +601,27 @@

# Detect v1 vs v2: MCP SDK v2 passes (ServerRequestContext, params) to handlers
ctx: "Optional[Any]" = None
params: "Optional[Any]" = None
if (
ServerRequestContext is not None
and original_args
and isinstance(original_args[0], ServerRequestContext)
):
ctx = original_args[0]
params = original_args[1] if len(original_args) > 1 else None
if len(original_args) > 1:
handler_name, arguments = _extract_handler_data_from_params(
"prompt", original_args[1]
)
else:
handler_name = "unknown"
arguments = {}
else:
handler_name, arguments = _extract_handler_data_from_args(
"prompt", original_args, original_kwargs

Check warning on line 619 in sentry_sdk/integrations/mcp.py

View check run for this annotation

@sentry/warden / warden: find-bugs

`handler_name` used before assignment in `_extract_handler_data_from_args` for prompt type 

If `original_args` is empty and `original_kwargs` has no `"name"` key, `handler_name` is never assigned but is referenced in `arguments = {"name": handler_name, ...}`, raising `UnboundLocalError` at runtime.
Comment thread
alexander-alderman-webb marked this conversation as resolved.
)

(
handler_name,
arguments,
span_data_key,
span_name,
mcp_method_name,
result_data_key,
) = _prepare_handler_data("prompt", original_args, original_kwargs, params=params)
span_data_key, span_name, mcp_method_name, result_data_key = _get_span_config(
"prompt", handler_name
)

scopes = _get_active_http_scopes(ctx=ctx)

Expand Down Expand Up @@ -764,16 +728,22 @@
and isinstance(original_args[0], ServerRequestContext)
):
ctx = original_args[0]
params = original_args[1] if len(original_args) > 1 else None

(
handler_name,
arguments,
span_data_key,
span_name,
mcp_method_name,
result_data_key,
) = _prepare_handler_data("resource", original_args, original_kwargs, params=params)
if len(original_args) > 1:
params = original_args[1]
handler_name, arguments = _extract_handler_data_from_params(
"resource", params
)
else:
handler_name = "unknown"
arguments = {}
else:
handler_name, arguments = _extract_handler_data_from_args(
"resource", original_args, original_kwargs
)

span_data_key, span_name, mcp_method_name, result_data_key = _get_span_config(
"resource", handler_name
)

scopes = _get_active_http_scopes(ctx=ctx)

Expand Down
Loading