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Handle progress notifications from long-running server operations.
2.3.5
MCP servers can report progress during long-running operations. The client can receive these updates through a progress handler.
from fastmcp import Client
async def my_progress_handler(
progress: float,
total: float | None,
message: str | None
) -> None:
if total is not None:
percentage = (progress / total) * 100
print(f"Progress: {percentage:.1f}% - {message or ''}")
else:
print(f"Progress: {progress} - {message or ''}")
client = Client(
"my_mcp_server.py",
progress_handler=my_progress_handler
)
async with client:
# Override with specific progress handler for this call
result = await client.call_tool(
"long_running_task",
{"param": "value"},
progress_handler=my_progress_handler
)