Vercel AI SDK Memory, RAG & Chat History with Redis
Add long-term memory, RAG, and chat history to the Vercel AI SDK with Upstash Redis — drop-in tools for generateText and streamText, no separate vector database.
Upstash AgentKit builds AI agents on Upstash Redis: memory,
conversation history, caching, and RAG, with no separate vector database. The semantic features run on
Upstash Redis Search and its $smart fuzzy operator.
@upstash/agentkit-ai-sdk is the Vercel AI SDK adapter — drop-ins for
generateText / streamText. redis defaults to Redis.fromEnv(), so you import only from this
package.
| Import | Feature |
|---|---|
createChatHistory | Durable chat history on Redis Search — save, list, and $smart-search a user's transcripts. |
createMemoryTools | recall_memory + save_memory tools so the model reads and writes long-term memory. |
createSearchTools | search / aggregate / count tools over a Redis Search index (this is how you do RAG). |
createRateLimit | A configured Upstash Ratelimit to call before the model. |
cachedTools | Memoize a map of AI SDK tools' results in Redis. |
npm install @upstash/agentkit-ai-sdk @upstash/redis aiAgentKit reads UPSTASH_REDIS_REST_URL / UPSTASH_REDIS_REST_TOKEN from the environment by default.
Pass your own @upstash/redis client as redis to any helper to override.
How to store chat history with the AI SDK
A Redis-backed ChatHistory<UIMessage>, the durable source of truth for your conversations. userId
comes from your auth session; chatId is the useChat id that the client posts. Save the full
transcript from your route's onFinish:
// app/api/chat/route.tsimport { convertToModelMessages, createUIMessageStreamResponse, streamText, toUIMessageStream } from "ai";import { createChatHistory } from "@upstash/agentkit-ai-sdk";const history = createChatHistory();export async function POST(req: Request) { const userId = await getSessionUserId(req); // your auth session, never a client-sent id const { id: chatId, messages } = await req.json(); // useChat posts its chat id + the full transcript const result = streamText({ model, messages: convertToModelMessages(messages) }); return createUIMessageStreamResponse({ stream: toUIMessageStream({ stream: result.stream, originalMessages: messages, onFinish: ({ messages }) => history.saveChat({ userId, sessionId: chatId, messages, title: "New chat" }), }), });}To load a chat, take chatId from the page route and userId from the session, then seed useChat:
const chat = await history.getChat({ userId, sessionId: chatId }); // full transcript, or nullconst chats = await history.listChats({ userId, limit: 50 }); // summaries, no messagesconst hits = await history.searchChats({ userId, query: "headphones", target: "both", limit: 20 });// client: useChat({ id: chatId, messages: chat?.messages ?? [] })Config and how it's stored
createChatHistory({ redis, // optional: defaults to Redis.fromEnv() prefix: "agentkit:chat", // optional: base key prefix indexName: "agentkit_chat", // optional: index name (defaults to the prefix) ttlSeconds: 60 * 60 * 24 * 30, // optional: per-chat TTL (default: no expiry)});Each chat is one JSON doc at agentkit:chat:<userId>:<sessionId> (keyed per user, so two users
can't collide on a sessionId), indexed over userId + sessionId (filters) and userMessages +
modelMessages ($smart fuzzy text); the raw messages array rides along unindexed. saveChat
overwrites the whole array (no delta merge) — useChat sends the full conversation. Other
methods: getChat / deleteChat ({ userId, sessionId }), listChats / searchChats
({ userId }).
Security — userId is the tenant boundary
Every method takes a single object; userId is required, non-empty, and may not contain :.
Derive it from a verified server-side auth source — the subject/user id from your auth provider
(Clerk, Auth.js/NextAuth, Supabase Auth, Auth0, …) — and never from a client-supplied header,
query param, or body (read it from the session in your route). A chat can't be read or
overwritten under a different userId.
How to add agent memory with the AI SDK
recall_memory and save_memory tools so the model reads and writes its own long-term memory.
import { createMemoryTools } from "@upstash/agentkit-ai-sdk";import { generateText, stepCountIs } from "ai";const tools = createMemoryTools({ userId });await generateText({ model, tools, stopWhen: stepCountIs(5), prompt: "What do you know about me?" });Options and the userId tenant boundary
userId(required) — a string, or(input, options) => string.redis— defaults toRedis.fromEnv().topK— max memoriesrecallreturns.minScore— BM25 relevance floor.recallToolName/saveToolName— override the tool names.
userId is the only tenant boundary (required, non-empty, no :). Derive it from a verified
server-side auth source (Clerk, Auth.js/NextAuth, Supabase Auth, Auth0, …) — never a
client-supplied value. Memories are stored at agentkit:memory:<userId>:<id>.
How to add RAG with the AI SDK
search / aggregate / count tools over an Upstash Redis Search index; the model-facing
descriptions are generated from your schema.
import { s } from "@upstash/redis";import { createSearchTools } from "@upstash/agentkit-ai-sdk";import { generateText, stepCountIs } from "ai";const schema = s.object({ name: s.string(), age: s.number(), city: s.string().noTokenize() });const tools = createSearchTools({ schema, indexName: "users" });await generateText({ model, tools, stopWhen: stepCountIs(5), prompt: "How many users named Ada live in London?" });Options
schema(required) — built withsfrom@upstash/redis.redis— defaults toRedis.fromEnv().indexName— defaults to"agentkit:search".prefix— key prefix for indexed JSON docs (defaults to"<indexName>:").defaultLimit— default page size forsearch(10).
The index is created (and waitIndexing-ed) reactively on first use — no setup step.
How to add rate limiting with the AI SDK
A configured Upstash Ratelimit. Call .limit(identifier) before
the model and short-circuit when over the limit.
import { createRateLimit, Ratelimit } from "@upstash/agentkit-ai-sdk";const ratelimit = createRateLimit({ limiter: Ratelimit.slidingWindow(20, "1 m") });const { success } = await ratelimit.limit(userId);if (!success) throw new Error("rate limited"); // or return a 429 from your routeOptions
limiter(required) — e.g.Ratelimit.slidingWindow(20, "1 m")orfixedWindow(...).redis— defaults toRedis.fromEnv().prefix— base key prefix; keys are<prefix>:<identifier>(defaultagentkit:rateLimit).
There's no model wrapper. Pass a per-user identifier to .limit() to throttle per user.
How to cache tools with the AI SDK
Memoize a map of AI SDK tools' results in Redis. Each tool is cached under its map key, scoped to
userId.
import { z } from "zod";import { generateText, tool } from "ai";import { cachedTools } from "@upstash/agentkit-ai-sdk";const tools = cachedTools( { getWeather: tool({ description: "Get the weather for a city", inputSchema: z.object({ city: z.string() }), execute: async ({ city }) => fetchWeather(city), }), }, { userId },);await generateText({ model, tools, prompt: "What's the weather in Paris?" });Options
Pass tools built with the AI SDK's tool() (so each keeps full input/output inference). Second arg:
userId(required) — a string, or(input, options) => string; scopes every entry to this user.redis— defaults toRedis.fromEnv().ttlSeconds— default per-result TTL for every tool.
Cache keys are agentkit:toolCache:<userId>:<toolName>:<hash-of-input> — the toolName is the map
key, so you never pass a name yourself.
How to put it all together with the AI SDK
A single streamText route can wire every feature: rate limit first, then memory, search, and cached
tools, persisting the whole conversation in onFinish:
// app/api/chat/route.tsimport { openai } from "@ai-sdk/openai";import { convertToModelMessages, createUIMessageStreamResponse, streamText, stepCountIs, toUIMessageStream, tool, type UIMessage,} from "ai";import { z } from "zod";import { s, Redis } from "@upstash/redis";import { Ratelimit, cachedTools, createChatHistory, createMemoryTools, createRateLimit, createSearchTools,} from "@upstash/agentkit-ai-sdk";export async function POST(req: Request) { const { id, messages } = (await req.json()) as { id: string; messages: UIMessage[] }; const redis = Redis.fromEnv(); // Derive this from your verified auth session in production (Clerk, Auth.js, …), never a client value. const userId = "user-123"; // 1. Rate limit (by user) before any model work. const ratelimit = createRateLimit({ redis, limiter: Ratelimit.slidingWindow(30, "1 m") }); const { success } = await ratelimit.limit(userId); if (!success) return new Response("Rate limited", { status: 429 }); // 2. Memory, search, and cached tools — all scoped to this user. const tools = { ...createMemoryTools({ redis, userId }), ...createSearchTools({ schema: s.object({ title: s.string(), author: s.string() }), redis, indexName: "books" }), ...cachedTools( { convert_price: tool({ description: "Convert a USD price to another currency.", inputSchema: z.object({ usd: z.number(), currency: z.string() }), execute: async ({ usd, currency }) => ({ currency, amount: usd * 0.92 }), }), }, { userId, redis }, ), }; const result = streamText({ model: openai("gpt-5.4-mini"), messages: await convertToModelMessages(messages), tools, stopWhen: stepCountIs(5), }); // 3. Persist the whole conversation when the stream finishes. const history = createChatHistory({ redis }); return createUIMessageStreamResponse({ stream: toUIMessageStream({ stream: result.stream, originalMessages: messages, onFinish: ({ messages }) => history.saveChat({ userId, sessionId: id, messages, title: "New chat" }), }), });}A complete, runnable Next.js demo (useChat UI, chat sidebar with fuzzy search, inline tool calls)
lives in examples/ai-sdk-demo.