In-Memory Storage

InMemoryStorage is the simplest storage driver. It keeps all data in a JavaScript Map—no external dependencies, no disk I/O. Data is lost when the process restarts. Use it for development, testing, or ephemeral workloads.

When to Use

Development

Fast iteration. No database setup required.

Testing

Isolated tests. No shared state between runs.

Demos

Quick prototypes. No infrastructure needed.

Not for Production

Data is lost on restart. Use Sqlite, Postgres, or MongoDB for persistence.

Installation

No additional packages required. InMemoryStorage is included in @agentium/core.

Usage

import { InMemoryStorage } from "@agentium/core";

const storage = new InMemoryStorage();

// No initialize() needed—ready to use immediately
await storage.set("namespace", "key", { foo: "bar" });
const value = await storage.get<{ foo: string }>("namespace", "key");
console.log(value); // { foo: "bar" }

const items = await storage.list("namespace", "k");
console.log(items); // [{ key: "key", value: { foo: "bar" } }]

await storage.delete("namespace", "key");
await storage.close();

With Agent

When you don’t provide a storage option, Agentium defaults to InMemoryStorage:

import { Agent, openai } from "@agentium/core";

// Explicit (same as default)
const agent = new Agent({
  name: "Assistant",
  model: openai("gpt-4o"),
  storage: new InMemoryStorage(),
});

// Implicit—InMemoryStorage is used automatically
const agent2 = new Agent({
  name: "Assistant",
  model: openai("gpt-4o"),
});

With Memory

import { Agent, Memory, InMemoryStorage, openai } from "@agentium/core";

const storage = new InMemoryStorage();
const memory = new Memory({
  storage,
  maxShortTermMessages: 50,
  enableLongTerm: false,
});

const agent = new Agent({
  name: "Assistant",
  model: openai("gpt-4o"),
  memory,
});

// Session data lives in memory until process exits
await agent.run("Hello!", { sessionId: "user-123" });

Limitations

Limitation	Description
No persistence	All data is lost when the Node.js process exits.
Single process	Not shared across multiple server instances.
Memory bound	Large datasets consume RAM.
No backup	No built-in snapshot or export.

API Reference

Method	Signature	Description
`get`	`get<T>(namespace, key) => Promise<T \| null>`	Get value by key.
`set`	`set<T>(namespace, key, value) => Promise<void>`	Store value (JSON-serialized).
`delete`	`delete(namespace, key) => Promise<void>`	Remove key.
`list`	`list<T>(namespace, prefix?) => Promise<Array<{key, value}>>`	List keys, optionally with prefix.
`close`	`close() => Promise<void>`	Clears the in-memory store.

​In-Memory Storage

​When to Use

Development

Testing

Demos

Not for Production

​Installation

​Usage

​With Agent

​With Memory

​Limitations

​API Reference