Built on Tablestore, Memory Storage provides serverless memory writes, automatic extraction, and semantic retrieval for AI agents. It supports data isolation for millions of tenants and memory reuse across sessions.
What is Memory Storage
Memory Storage is a managed memory service built on Tablestore for AI agents. You write conversations or text to a memory store. The service retains original messages and extracts searchable long-term memories. In later conversations, the agent recalls relevant memories through natural language queries to produce more coherent, context-aware responses.
AI agents need to handle continuous conversations, cross-session preferences, user profiles, and historical facts. Relying only on the context window leads to higher token costs, lost history, and context interference. Building memory extraction, storage, and retrieval from scratch requires LLM calls, vector search, full-text search, data isolation, and auditing. Memory Storage packages these capabilities into a unified memory store interface. Integrate through an SDK, the CLI, or agent plugins without building the extraction and retrieval pipeline yourself.
To try Memory Storage, see Quick start.
Core benefits
Serverless and ready to use
Memory Storage uses a fully managed serverless architecture. Write and retrieve memories through APIs without deploying or maintaining infrastructure. Pay only for what you use, with no charges at zero usage.
Automatic memory extraction
After you write conversations or text, the service extracts key facts and preferences into structured memories. No custom extraction or organization logic is required. Use memory-store-level extraction instructions (extractInstructions) to focus extraction on business-critical information.
File view access
Service-managed structured memories support two read modes: structured access through SDKs, the CLI, and other interfaces, or directory- and file-based access through file views.
File views expose memory data as read-only files. Applications continue to write or update source memories through structured interfaces, preventing conflicts between file operations and structured memories.
File memory
If you already have Markdown or other UTF-8 text files, or want to organize a memory directory yourself, write the files directly to a file memory store. Applications control file paths and can create, read, update, rename, and delete files, as well as query file version history.
Automatic memory consolidation (Dream)
Memory consolidation (Dream) asynchronously refines stored memories in the background. It can merge, deduplicate, and update long-term memories (memory), and extract reusable skills (skill) and structured user profiles (profile) from interaction history. Dream can generate proposals for manual confirmation or automatically apply changes that meet a confidence threshold.
Horizontal scaling
Built on Tablestore's distributed architecture, Memory Storage scales horizontally. Storage capacity theoretically has no upper limit and can support millions of tenants and tens of billions of memories.
Accurate semantic retrieval
Memory Storage combines vector search and full-text search in a hybrid retrieval mode. Natural language queries recall relevant memories. Optionally enable Rerank, similarity threshold filtering (minSimilarity), and source evidence return (includeEvidence) to improve relevance and explainability.
Lower token costs
Compared with injecting full conversation histories, Memory Storage saves about 95% of tokens with almost no loss in response quality. Retrieving only relevant memories reduces unrelated context. It also avoids O(N²) cumulative token growth from repeatedly injecting the full history and the "Lost in the Middle" performance degradation.
Multi-tenant isolation
A four-level Scope of appId, tenantId, agentId, and runId isolates data by application, tenant, agent, and session for millions of tenants.
Comparison with mem0
The following table compares Memory Storage with the open-source memory system mem0.
|
Dimension |
Memory Storage |
Open-source mem0 |
|
Deployment and maintenance |
Serverless, ready to use through APIs, with no infrastructure maintenance |
Requires deployment and maintenance of the underlying components |
|
Memory extraction |
Automatic extraction with no extra development |
Requires custom extraction logic |
|
Retrieval accuracy |
88.25% overall on LoCoMo, with strong performance in complex reasoning use cases |
64.20% overall on LoCoMo |
|
Retrieval latency |
P95 ≤ 288 ms at the scale of hundreds of millions of entries |
About four times the Tablestore latency at the same scale |
|
Storage scale |
Horizontal scaling, validated with 1.2 million tenants and more than 100 million memories |
Limited by the underlying storage solution |
|
Multi-tenant isolation |
Built-in four-level Scope support |
Requires a custom isolation scheme |
For detailed benchmark data and methodology, see Architecture and technology selection.
Use cases
Continuity across multi-turn conversations
Write historical messages to a memory store during long conversations. The service retains the original messages and extracts key facts. Later conversations retrieve only relevant memories on demand, avoiding full-history context injection.
Preference reuse across sessions
User preferences, habits, and constraints expressed across sessions are extracted into long-term memories. New sessions retrieve these memories through semantic search, maintaining consistent agent responses across different times and entry points.
Knowledge sharing across multiple agents
Using a wildcard for agentId in the four-level Scope lets multiple agents share the same user memories within a tenant. This avoids extracting and maintaining the same facts for each agent.
User profile accumulation
Continuously write user behavior, attributes, and historical facts to a memory store. The service automatically consolidates the data into structured profile units that recommendation, customer service, and marketing agents can retrieve.
Access methods
|
Method |
Use case |
Documentation |
|
Agent Storage SDK |
Access structured memory and file memory with an API key. Use AccessKey credentials to call the full Tablestore API set or upload knowledge base documents. |
|
|
Tablestore native SDK |
Call structured memory APIs from business services with AccessKey credentials |
|
|
CLI |
Local debugging, operations, and automation scripts |
|
|
Agent plugins |
Integrate memory retrieval and write-back into existing agent frameworks |
Supported regions
Memory Storage is currently available only in the China (Beijing) and China (Hangzhou) regions.
References
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For system architecture and technology selection, see Architecture and technology selection.
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To run the first example, see Quick start.