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Fix task polling blocking the Run button #1134

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Fix task polling blocking the Run button #1134

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196 changes: 95 additions & 101 deletions client/src/App.tsx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -997,6 +997,92 @@ const App = () => {
cacheToolOutputSchemas(response.tools);
};

const pollTaskInBackground = async (
taskId: string,
pollInterval: number,
initialResponseMeta: Record<string, unknown> | undefined,
) => {
setIsPollingTask(true);
let taskCompleted = false;

while (!taskCompleted) {
try {
await new Promise((resolve) => setTimeout(resolve, pollInterval));

const taskStatus = await sendMCPRequest(
{
method: "tasks/get",
params: { taskId },
},
GetTaskResultSchema,
);

if (
taskStatus.status === "completed" ||
taskStatus.status === "failed" ||
taskStatus.status === "cancelled"
) {
taskCompleted = true;
console.log(
`Polling complete for task ${taskId}: ${taskStatus.status}`,
);

if (taskStatus.status === "completed") {
console.log(`Fetching result for task ${taskId}`);
const result = await sendMCPRequest(
{
method: "tasks/result",
params: { taskId },
},
CompatibilityCallToolResultSchema,
);
console.log(`Result received for task ${taskId}:`, result);
setToolResult(result as CompatibilityCallToolResult);
} else {
setToolResult({
content: [
{
type: "text",
text: `Task ${taskStatus.status}: ${taskStatus.statusMessage || "No additional information"}`,
},
],
isError: true,
});
}
void listTasks();
} else {
setToolResult({
content: [
{
type: "text",
text: `Task status: ${taskStatus.status}${taskStatus.statusMessage ? ` - ${taskStatus.statusMessage}` : ""}. Polling...`,
},
],
_meta: {
...(initialResponseMeta || {}),
"io.modelcontextprotocol/related-task": { taskId },
},
});
void listTasks();
}
} catch (pollingError) {
console.error("Error polling task status:", pollingError);
setToolResult({
content: [
{
type: "text",
text: `Error polling task status: ${pollingError instanceof Error ? pollingError.message : String(pollingError)}`,
},
],
isError: true,
});
taskCompleted = true;
}
}

setIsPollingTask(false);
};

const callTool = async (
name: string,
params: Record<string, unknown>,
Expand Down Expand Up @@ -1061,16 +1147,14 @@ const App = () => {
if (runAsTask && isTaskResult(response)) {
const taskId = response.task.taskId;
const pollInterval = response.task.pollInterval;
// Set polling state BEFORE setting tool result for proper UI update
setIsPollingTask(true);
// Safely extract any _meta from the original response (if present)
const initialResponseMeta =
response &&
typeof response === "object" &&
"_meta" in (response as Record<string, unknown>)
? ((response as { _meta?: Record<string, unknown> })._meta ?? {})
: undefined;
let latestToolResult: CompatibilityCallToolResult = {
const initialTaskResult: CompatibilityCallToolResult = {
content: [
{
type: "text",
Expand All @@ -1082,107 +1166,17 @@ const App = () => {
"io.modelcontextprotocol/related-task": { taskId },
},
};
setToolResult(latestToolResult);
setToolResult(initialTaskResult);

// Polling loop
let taskCompleted = false;
while (!taskCompleted) {
try {
// Wait for 1 second before polling
await new Promise((resolve) => setTimeout(resolve, pollInterval));
// Poll in the background so the UI remains interactive.
// This allows users to run other tool calls while a task is
// being polled, matching the MCP specification's intent for
// concurrent task operations.
void pollTaskInBackground(taskId, pollInterval, initialResponseMeta);

const taskStatus = await sendMCPRequest(
{
method: "tasks/get",
params: { taskId },
},
GetTaskResultSchema,
);

if (
taskStatus.status === "completed" ||
taskStatus.status === "failed" ||
taskStatus.status === "cancelled"
) {
taskCompleted = true;
console.log(
`Polling complete for task ${taskId}: ${taskStatus.status}`,
);

if (taskStatus.status === "completed") {
console.log(`Fetching result for task ${taskId}`);
const result = await sendMCPRequest(
{
method: "tasks/result",
params: { taskId },
},
CompatibilityCallToolResultSchema,
);
console.log(`Result received for task ${taskId}:`, result);
latestToolResult = result as CompatibilityCallToolResult;
setToolResult(latestToolResult);

// Refresh tasks list to show completed state
void listTasks();
} else {
latestToolResult = {
content: [
{
type: "text",
text: `Task ${taskStatus.status}: ${taskStatus.statusMessage || "No additional information"}`,
},
],
isError: true,
};
setToolResult(latestToolResult);
// Refresh tasks list to show failed/cancelled state
void listTasks();
}
} else {
// Update status message while polling
// Safely extract any _meta from the original response (if present)
const pollingResponseMeta =
response &&
typeof response === "object" &&
"_meta" in (response as Record<string, unknown>)
? ((response as { _meta?: Record<string, unknown> })._meta ??
{})
: undefined;
latestToolResult = {
content: [
{
type: "text",
text: `Task status: ${taskStatus.status}${taskStatus.statusMessage ? ` - ${taskStatus.statusMessage}` : ""}. Polling...`,
},
],
_meta: {
...(pollingResponseMeta || {}),
"io.modelcontextprotocol/related-task": { taskId },
},
};
setToolResult(latestToolResult);
// Refresh tasks list to show progress
void listTasks();
}
} catch (pollingError) {
console.error("Error polling task status:", pollingError);
latestToolResult = {
content: [
{
type: "text",
text: `Error polling task status: ${pollingError instanceof Error ? pollingError.message : String(pollingError)}`,
},
],
isError: true,
};
setToolResult(latestToolResult);
taskCompleted = true;
}
}
setIsPollingTask(false);
// Clear any validation errors since tool execution completed
// Clear any validation errors since tool execution started
setErrors((prev) => ({ ...prev, tools: null }));
return latestToolResult;
return initialTaskResult;
} else {
const directResult = response as CompatibilityCallToolResult;
setToolResult(directResult);
Expand Down
5 changes: 2 additions & 3 deletions client/src/components/ToolsTab.tsx
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Original file line number Diff line number Diff line change
Expand Up @@ -836,17 +836,16 @@ const ToolsTab = ({
}}
disabled={
isToolRunning ||
isPollingTask ||
hasValidationErrors ||
hasReservedMetadataEntry ||
hasInvalidMetaPrefixEntry ||
hasInvalidMetaNameEntry
}
>
{isToolRunning || isPollingTask ? (
{isToolRunning ? (
<>
<Loader2 className="w-4 h-4 mr-2 animate-spin" />
{isPollingTask ? "Polling Task..." : "Running..."}
Running...
</>
) : (
<>
Expand Down