AI Memory

CrestApps.Core includes reusable memory services for applications that want an AI assistant to remember durable user facts across sessions.

What the framework provides

AddCoreAIMemory() adds the shared runtime behavior for:

• memory tool registration
• safety validation for memory writes
• semantic memory search orchestration
• preemptive memory retrieval during orchestration
• shared indexing and search helpers

builder.Services.AddCrestAppsCore(crestApps => crestApps
    .AddAISuite(ai => ai
        .AddAIMemory(memory => memory
            .AddEntityCoreStores()
        )
        .AddOpenAI()
    )
    .AddEntityCoreSqliteDataStore("Data Source=app.db")
);

What your host must provide

The framework does not assume a single persistence model. A host application is responsible for wiring the storage and search pieces that match its runtime:

• an IAIMemoryStore implementation for durable memory entries
• a persistent ISearchIndexProfileStore implementation for index profile lookup when you want saved index profiles (registered via .AddIndexingServices(indexing => indexing.AddEntityCoreStores()) or .AddYesSqlStores()). AddCoreAIServices() already supplies a null fallback store so hosts can start before a persistent store is added.
• one or more keyed IMemoryVectorSearchService implementations
• options such as AIMemoryOptions, GeneralAIOptions, and ChatInteractionMemoryOptions

Register stores directly on the AI memory builder:

Entity Framework Core (via builder):

.AddAIMemory(memory => memory
    .AddEntityCoreStores()
)

YesSql (via builder):

.AddAIMemory(memory => memory
    .AddYesSqlStores()
)

Both register the IAIMemoryStore implementation. See Data Storage for the full per-feature store reference.

Core concepts

Memory entries

A memory entry is a durable user-scoped fact:

Field	Purpose
UserId	Identifies the owner of the memory
Name	Stable key such as preferred-language
Description	Semantic summary used to improve retrieval quality
Content	The value to retain for later recall
CreatedUtc / UpdatedUtc	Lifecycle timestamps

Safety validation

Before a memory is stored, IAIMemorySafetyService can reject obviously sensitive data such as credentials, connection strings, SSNs, or payment card numbers. The framework ships with the validation pipeline; hosts decide how they surface validation failures.

User scoping

Memory tools operate on the current authenticated user. The framework resolves identity from orchestration scope or the current HTTP context so retrieval stays user-specific.

Key contracts

Contract	Purpose
IAIMemoryStore	CRUD and query access for persisted memory entries
IAIMemorySearchService	Shared semantic retrieval over memory entries
IMemoryVectorSearchService	Provider-specific vector search adapter
IAIMemorySafetyService	Validation for writes before they are stored
IPreemptiveRagHandler	Injects relevant memory context before the model responds

Built-in tools

When memory is enabled, the orchestration layer can expose these system tools:

Tool	Purpose
save_user_memory	Create or update a durable memory
search_user_memories	Find relevant memories by semantic similarity
list_user_memories	Enumerate saved memories for the current user
remove_user_memory	Delete a saved memory by name

These tools are intended for long-lived facts such as preferences, recurring projects, or roles, not for transient one-off chat state.

Typical flow

1. Register AddCoreAIMemory() with the rest of the AI runtime.
2. Provide the store, vector search, and option bindings for your host.
3. Enable memory-aware orchestration for the profiles or chat surfaces that should use it.
4. Let the orchestrator decide when to store, search, or inject memory context.

Related guidance

• Pair memory with Orchestration Overview when you want automatic recall
• Pair memory with Data Sources when you also need document or index-backed RAG