import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { ElicitResultSchema } from "@modelcontextprotocol/sdk/types.js";
import { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
// Tool configuration
const name = "trigger-elicitation-request";
const config = {
title: "Trigger Elicitation Request Tool",
description: "Trigger a Request from the Server for User Elicitation",
inputSchema: {},
};
/**
* Registers the 'trigger-elicitation-request' tool.
*
* If the client does not support the elicitation capability, the tool is not registered.
*
* The registered tool sends an elicitation request for the user to provide information
* based on a pre-defined schema of fields including text inputs, booleans, numbers,
* email, dates, enums of various types, etc. It uses validation and handles multiple
* possible outcomes from the user's response, such as acceptance with content, decline,
* or cancellation of the dialog. The process also ensures parsing and validating
* the elicitation input arguments at runtime.
*
* The elicitation dialog response is returned, formatted into a structured result,
* which contains both user-submitted input data (if provided) and debugging information,
* including raw results.
*
* @param {McpServer} server - TThe McpServer instance where the tool will be registered.
*/
export const registerTriggerElicitationRequestTool = (server: McpServer) => {
// Does the client support elicitation?
const clientCapabilities = server.server.getClientCapabilities() || {};
const clientSupportsElicitation: boolean =
clientCapabilities.elicitation !== undefined;
// If so, register tool
if (clientSupportsElicitation) {
server.registerTool(
name,
config,
async (args, extra): Promise<CallToolResult> => {
const elicitationResult = await extra.sendRequest(
{
method: "elicitation/create",
params: {
message: "Please provide inputs for the following fields:",
requestedSchema: {
type: "object",
properties: {
name: {
title: "String",
type: "string",
description: "Your full, legal name",
},
check: {
title: "Boolean",
type: "boolean",
description: "Agree to the terms and conditions",
},
firstLine: {
title: "String with default",
type: "string",
description: "Favorite first line of a story",
default: "It was a dark and stormy night.",
},
email: {
title: "String with email format",
type: "string",
format: "email",
description:
"Your email address (will be verified, and never shared with anyone else)",
},
homepage: {
type: "string",
format: "uri",
title: "String with uri format",
description: "Portfolio / personal website",
},
birthdate: {
title: "String with date format",
type: "string",
format: "date",
description: "Your date of birth",
},
integer: {
title: "Integer",
type: "integer",
description:
"Your favorite integer (do not give us your phone number, pin, or other sensitive info)",
minimum: 1,
maximum: 100,
default: 42,
},
number: {
title: "Number in range 1-1000",
type: "number",
description: "Favorite number (there are no wrong answers)",
minimum: 0,
maximum: 1000,
default: 3.14,
},
untitledSingleSelectEnum: {
type: "string",
title: "Untitled Single Select Enum",
description: "Choose your favorite friend",
enum: [
"Monica",
"Rachel",
"Joey",
"Chandler",
"Ross",
"Phoebe",
],
default: "Monica",
},
untitledMultipleSelectEnum: {
type: "array",
title: "Untitled Multiple Select Enum",
description: "Choose your favorite instruments",
minItems: 1,
maxItems: 3,
items: {
type: "string",
enum: ["Guitar", "Piano", "Violin", "Drums", "Bass"],
},
default: ["Guitar"],
},
titledSingleSelectEnum: {
type: "string",
title: "Titled Single Select Enum",
description: "Choose your favorite hero",
oneOf: [
{ const: "hero-1", title: "Superman" },
{ const: "hero-2", title: "Green Lantern" },
{ const: "hero-3", title: "Wonder Woman" },
],
default: "hero-1",
},
titledMultipleSelectEnum: {
type: "array",
title: "Titled Multiple Select Enum",
description: "Choose your favorite types of fish",
minItems: 1,
maxItems: 3,
items: {
anyOf: [
{ const: "fish-1", title: "Tuna" },
{ const: "fish-2", title: "Salmon" },
{ const: "fish-3", title: "Trout" },
],
},
default: ["fish-1"],
},
legacyTitledEnum: {
type: "string",
title: "Legacy Titled Single Select Enum",
description: "Choose your favorite type of pet",
enum: ["pet-1", "pet-2", "pet-3", "pet-4", "pet-5"],
enumNames: ["Cats", "Dogs", "Birds", "Fish", "Reptiles"],
default: "pet-1",
},
},
required: ["name"],
},
},
},
ElicitResultSchema,
{ timeout: 10 * 60 * 1000 /* 10 minutes */ }
);
// Handle different response actions
const content: CallToolResult["content"] = [];
if (
elicitationResult.action === "accept" &&
elicitationResult.content
) {
content.push({
type: "text",
text: `✅ User provided the requested information!`,
});
// Only access elicitationResult.content when action is accept
const userData = elicitationResult.content;
const lines = [];
if (userData.name) lines.push(`- Name: ${userData.name}`);
if (userData.check !== undefined)
lines.push(`- Agreed to terms: ${userData.check}`);
if (userData.color) lines.push(`- Favorite Color: ${userData.color}`);
if (userData.email) lines.push(`- Email: ${userData.email}`);
if (userData.homepage) lines.push(`- Homepage: ${userData.homepage}`);
if (userData.birthdate)
lines.push(`- Birthdate: ${userData.birthdate}`);
if (userData.integer !== undefined)
lines.push(`- Favorite Integer: ${userData.integer}`);
if (userData.number !== undefined)
lines.push(`- Favorite Number: ${userData.number}`);
if (userData.petType) lines.push(`- Pet Type: ${userData.petType}`);
content.push({
type: "text",
text: `User inputs:\n${lines.join("\n")}`,
});
} else if (elicitationResult.action === "decline") {
content.push({
type: "text",
text: `❌ User declined to provide the requested information.`,
});
} else if (elicitationResult.action === "cancel") {
content.push({
type: "text",
text: `⚠️ User cancelled the elicitation dialog.`,
});
}
// Include raw result for debugging
content.push({
type: "text",
text: `\nRaw result: ${JSON.stringify(elicitationResult, null, 2)}`,
});
return { content };
}
);
}
};
