Elicitation

import { stdin, stdout } from "node:process";
import { createInterface } from "node:readline/promises";
import {
  acceptWithDefaults,
  MCPClient,
  type OnElicitationCallback,
} from "@mcp-use/client";

const onElicitation: OnElicitationCallback = async (params) => {
  if (params.mode === "url") {
    // The tool call continues as soon as this returns, so accept only after
    // the user has finished the external flow.
    console.log(`Visit: ${params.url}`);
    const prompt = createInterface({ input: stdin, output: stdout });
    await prompt.question("Press Enter after you finish in the browser. ");
    prompt.close();
    return { action: "accept" };
  }
  // Form mode — collect fields from params.requestedSchema
  return acceptWithDefaults(params);
};

const client = new MCPClient(
  { mcpServers: { demo: { url: "http://localhost:3000/mcp" } } },
  { onElicitation },
);

import { useMcp, type ElicitResult } from "@mcp-use/client/react";

const mcp = useMcp({
  url: "http://localhost:3000/mcp",
  onElicitation: async (params): Promise<ElicitResult> => {
    if (params.mode === "url") {
      window.open(params.url, "_blank", "noopener");
      // The tool call continues as soon as this resolves, so accept only
      // after the user confirms they finished the external flow.
      const finished = window.confirm(
        `${params.message}\n\nSelect OK after you finish in the new tab.`
      );
      return { action: finished ? "accept" : "cancel" };
    }
    const content: NonNullable<ElicitResult["content"]> = {};
    for (const [name, field] of Object.entries(
      params.requestedSchema.properties
    )) {
      if (field.default !== undefined) content[name] = field.default;
    }
    return { action: "accept", content };
  },
});