Memory for Vercel AI SDK agents

• Which value is current. Harny stores dated memories, so a changed value with a newer timestamp becomes the current value and the earlier one stays answerable by date.
• When a fact happened. Harny records a timestamp for each memory, so recall can filter by when something happened.
• One person's memory. Harny keeps each person's memory separate from others. Calls made with a person's key are scoped to that person.

The Harny MCP server is at https://api.harny.ai/v1/mcp/mcp (Streamable HTTP). The header key belongs to one person (fsk_), so the tools the agent calls read and write only that person's memory.

import { generateText } from "ai";
import { createMCPClient } from "@ai-sdk/mcp";

export async function ask(question: string, userKey: string) {
  const harny = await createMCPClient({
    transport: {
      type: "http",
      url: "https://api.harny.ai/v1/mcp/mcp",
      // the signed-in person's key, set by your application
      headers: { Authorization: `Bearer ${userKey}` },
    },
  });
  try {
    const { text } = await generateText({
      model, // the model you already use with the AI SDK
      tools: await harny.tools(),
      prompt: question,
    });
    return text;
  } finally {
    await harny.close();
  }
}

The server lists the tools your key may call. A person's key (starts with fsk_) reaches the memory tools for that person only.

• assemble_context recalls ranked context for the person whose key you hold.
• ingest_text writes a note or fact into that person's memory.
• describe is available with any key.

• Use the AI SDK's own state for the work of the current run, such as the messages and tool results in the session.
• Add Harny when the agent needs memory that lasts across sessions, keeps dates, and shows which fact is current for a person.