memory

const memory: object

Type Declaration

compaction

compaction: (config?) => Middleware = memoryCompaction

Context window management with compaction strategies.

Creates a memory.compaction() middleware that manages the context window.

Automatically compacts messages before each LLM call when the token count exceeds the configured limit. Only modifies ModelContext.messages — SessionContext.history is never touched.

Five strategies from gentlest to most aggressive:

• clear-tool-results: Replace old tool results with placeholder
• truncate (default): Drop oldest messages
• window: Keep last N messages
• summarize: LLM summarizes old messages
• hybrid: Summarize old + keep recent verbatim

Parameters

config?

CompactionConfig

Working memory configuration

Returns

Middleware

Middleware that manages context window

Example

// Simple truncation (default, zero cost)
agent.use(memory.compaction({ maxTokens: 8192 }))

// Hybrid (best quality, one LLM call)
agent.use(memory.compaction({
  maxTokens: 8192,
  strategy: "hybrid",
  summaryModel: "anthropic/claude-haiku-4-5",
  keepRecentMessages: 10,
}))

store

store: (config) => Middleware = memoryStore

Session persistence to external stores.

Creates a memory.store() middleware for session persistence.

Loads session on creation, saves after each turn. Falls back to in-memory on backend failure — user-facing functionality is never blocked.

Parameters

config

MemoryStoreConfig

SessionStore backend and options

Returns

Middleware

Middleware

Example

import { memory } from "agent-express"
import { sqliteStore } from "@agent-express/session-sqlite"

agent.use(memory.store({ backend: sqliteStore({ path: "./sessions.db" }) }))