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feat: add streaming methods for elicitation and sampling (#1210)

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Co-authored-by: Konstantin Konstantinov <KKonstantinov@users.noreply.github.com>
This commit is contained in:
Luca Chang 2026-02-11 07:14:58 -08:00 • committed by GitHub
commit 91f6a277c4
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1 changed files with 882 additions and 17 deletions
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64
examples/client/src/simpleStreamableHttp.ts
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@ -14,6 +14,7 @@ import {
Client,
getDisplayName,
GetPromptResultSchema,
InMemoryTaskStore,
ListPromptsResultSchema,
ListResourcesResultSchema,
ListToolsResultSchema,
@ -65,6 +66,7 @@ function printHelp(): void {
console.log(' greet [name] - Call the greet tool');
console.log(' multi-greet [name] - Call the multi-greet tool with notifications');
console.log(' collect-info [type] - Test form elicitation with collect-user-info tool (contact/preferences/feedback)');
console.log(' collect-info-task [type] - Test bidirectional task support (server+client tasks) with elicitation');
console.log(' start-notifications [interval] [count] - Start periodic notifications');
console.log(' run-notifications-tool-with-resumability [interval] [count] - Run notification tool with resumability');
console.log(' list-prompts - List available prompts');
@ -140,6 +142,11 @@ function commandLoop(): void {
break;
}
case 'collect-info-task': {
await callCollectInfoWithTask(args[1] || 'contact');
break;
}
case 'start-notifications': {
const interval = args[1] ? Number.parseInt(args[1], 10) : 2000;
const count = args[2] ? Number.parseInt(args[2], 10) : 10;
@ -249,7 +256,10 @@ async function connect(url?: string): Promise<void> {
console.log(`Connecting to ${serverUrl}...`);
try {
// Create a new client with form elicitation capability
// Create task store for client-side task support
const clientTaskStore = new InMemoryTaskStore();
// Create a new client with form elicitation capability and task support
client = new Client(
{
name: 'example-client',
@ -259,25 +269,49 @@ async function connect(url?: string): Promise<void> {
capabilities: {
elicitation: {
form: {}
},
tasks: {
requests: {
elicitation: {
create: {}
}
}
}
}
},
taskStore: clientTaskStore
}
);
client.onerror = error => {
console.error('\u001B[31mClient error:', error, '\u001B[0m');
};
// Set up elicitation request handler with proper validation
client.setRequestHandler('elicitation/create', async request => {
// Set up elicitation request handler with proper validation and task support
client.setRequestHandler('elicitation/create', async (request, extra) => {
if (request.params.mode !== 'form') {
throw new ProtocolError(ProtocolErrorCode.InvalidParams, `Unsupported elicitation mode: ${request.params.mode}`);
}
console.log('\n🔔 Elicitation (form) Request Received:');
console.log(`Message: ${request.params.message}`);
console.log(`Related Task: ${request.params._meta?.[RELATED_TASK_META_KEY]?.taskId}`);
console.log(`Task Creation Requested: ${request.params.task ? 'yes' : 'no'}`);
console.log('Requested Schema:');
console.log(JSON.stringify(request.params.requestedSchema, null, 2));
// Helper to return result, optionally creating a task if requested
const returnResult = async (result: {
action: 'accept' | 'decline' | 'cancel';
content?: Record<string, string | number | boolean | string[]>;
}) => {
if (request.params.task && extra.task?.store) {
// Create a task and store the result
const task = await extra.task.store.createTask({ ttl: extra.task.requestedTtl });
await extra.task.store.storeTaskResult(task.taskId, 'completed', result);
console.log(`📋 Created client-side task: ${task.taskId}`);
return { task };
}
return result;
};
const schema = request.params.requestedSchema;
const properties = schema.properties;
const required = schema.required || [];
@ -411,7 +445,7 @@ async function connect(url?: string): Promise<void> {
}
if (inputCancelled) {
return { action: 'cancel' };
return returnResult({ action: 'cancel' });
}
// If we didn't complete all fields due to an error, try again
@ -424,7 +458,7 @@ async function connect(url?: string): Promise<void> {
continue;
} else {
console.log('Maximum attempts reached. Declining request.');
return { action: 'decline' };
return returnResult({ action: 'decline' });
}
}
@ -443,7 +477,7 @@ async function connect(url?: string): Promise<void> {
continue;
} else {
console.log('Maximum attempts reached. Declining request.');
return { action: 'decline' };
return returnResult({ action: 'decline' });
}
}
@ -460,14 +494,14 @@ async function connect(url?: string): Promise<void> {
switch (confirmAnswer) {
case 'yes':
case 'y': {
return {
return returnResult({
action: 'accept',
content
};
});
}
case 'cancel':
case 'c': {
return { action: 'cancel' };
return returnResult({ action: 'cancel' });
}
case 'no':
case 'n': {
@ -475,7 +509,7 @@ async function connect(url?: string): Promise<void> {
console.log('Please re-enter the information...');
continue;
} else {
return { action: 'decline' };
return returnResult({ action: 'decline' });
}
break;
@ -485,7 +519,7 @@ async function connect(url?: string): Promise<void> {
}
console.log('Maximum attempts reached. Declining request.');
return { action: 'decline' };
return returnResult({ action: 'decline' });
});
transport = new StreamableHTTPClientTransport(new URL(serverUrl), {
@ -699,6 +733,12 @@ async function callCollectInfoTool(infoType: string): Promise<void> {
await callTool('collect-user-info', { infoType });
}
async function callCollectInfoWithTask(infoType: string): Promise<void> {
console.log(`\n🔄 Testing bidirectional task support with collect-user-info-task tool (${infoType})...`);
console.log('This will create a task on the server, which will elicit input and create a task on the client.\n');
await callToolTask('collect-user-info-task', { infoType });
}
async function startNotifications(interval: number, count: number): Promise<void> {
console.log(`Starting notification stream: interval=${interval}ms, count=${count || 'unlimited'}`);
await callTool('start-notification-stream', { interval, count });