adk-memory

Semantic memory and search for Rust Agent Development Kit (ADK-Rust) agents.

Overview

adk-memory provides long-term memory capabilities for the Rust Agent Development Kit (ADK-Rust):

• InMemoryMemoryService - Simple in-memory memory storage
• SqliteMemoryService - SQLite-backed persistence (sqlite-memory feature)
• PostgresMemoryService - PostgreSQL + pgvector persistence (database-memory feature)
• MongoMemoryService - MongoDB-backed persistence (mongodb-memory feature)
• Neo4jMemoryService - Neo4j-backed persistence (neo4j-memory feature)
• RedisMemoryService - Redis-backed persistence (redis-memory feature)
• MemoryService - Trait for custom storage backends
• Semantic Search - Query memories by content similarity
• Schema Migrations - Versioned, forward-only migrations for all database backends

Installation

[dependencies]
adk-memory = "0.4"

Or use the meta-crate:

[dependencies]
adk-rust = { version = "0.4", features = ["memory"] }

Quick Start

use adk_memory::{InMemoryMemoryService, MemoryService, MemoryEntry, SearchRequest};
use adk_core::Content;
use chrono::Utc;

let service = InMemoryMemoryService::new();

let entries = vec![
    MemoryEntry {
        content: Content::new("user").with_text("User prefers dark mode"),
        author: "system".to_string(),
        timestamp: Utc::now(),
    },
];

service.add_session("my_app", "user_123", "session_456", entries).await?;

let response = service.search(SearchRequest {
    query: "what theme does the user like?".to_string(),
    user_id: "user_123".to_string(),
    app_name: "my_app".to_string(),
}).await?;

for memory in response.memories {
    println!("Found: {:?}", memory.content);
}

Feature Flags

# SQLite
adk-memory = { version = "0.4", features = ["sqlite-memory"] }

# PostgreSQL + pgvector
adk-memory = { version = "0.4", features = ["database-memory"] }

Schema Migrations

All database backends (SQLite, PostgreSQL, MongoDB, Neo4j) include a versioned migration system. Migrations are forward-only, idempotent, and tracked in a _schema_migrations registry table.

use adk_memory::SqliteMemoryService;

let service = SqliteMemoryService::new("sqlite:memory.db").await?;

// Run all pending migrations
service.migrate().await?;

// Check current schema version
let version = service.schema_version().await?;
println!("Schema version: {version}");

MemoryService Trait

#[async_trait]
pub trait MemoryService: Send + Sync {
    async fn add_session(
        &self,
        app_name: &str,
        user_id: &str,
        session_id: &str,
        entries: Vec<MemoryEntry>,
    ) -> Result<()>;
    
    async fn search(&self, req: SearchRequest) -> Result<SearchResponse>;
}

Related Crates

• adk-rust - Meta-crate with all components
• adk-core - Core Memory trait
• adk-runner - Memory injection during execution
• adk-rag - RAG pipeline with vector stores

License

Apache-2.0

Part of ADK-Rust

This crate is part of the ADK-Rust framework for building AI agents in Rust.