@mi8y/cap-agents-memory

CDS-backed long-term memory for LangGraph. CdsMemoryStore implements LangGraph's Store API, so facts and preferences can be shared across threads while remaining within CAP's database and tenant context.

Installation

npm install @mi8y/cap-agents-memory
cds add agent-memory

The add command creates db/agent-memory.cds with StoreItems and StoreItemFields in the plugin.langgraph.memory namespace. It never overwrites an existing generated file.

Requires @sap/cds >= 10 and @langchain/core >= 1.

Usage

import { CdsMemoryStore } from "@mi8y/cap-agents-memory";

const store = new CdsMemoryStore({ name: "support-memory" });
const graph = builder.compile({ store });

await store.put(["users", "alice"], "profile", {
  preferredTone: "concise",
  lastTopic: "travel",
});

const profile = await store.get(["users", "alice"], "profile");

name is required and becomes graphName in CDS, isolating multiple stores that share a database. Unlike checkpointers, a Store is long-lived and can be read from any graph thread.

Custom entities

The generated entities are defaults. Define your own entities by implementing the exported aspects, then pass their fully qualified names to the Store.

using { StoreItem, StoreItemField } from '@mi8y/cap-agents-memory';

namespace my.app.memory;

entity Items : StoreItem {
    fields : Composition of many Fields on fields.item = $self;
}

entity Fields : StoreItemField {
    item : Association to Items
        on item.graphName = $self.graphName
        and item.namespace = $self.namespace
        and item.id = $self.id;
    embedding : Vector(3072);
}

const store = new CdsMemoryStore({
  name: "support-memory",
  fqnStoreItemsEntity: "my.app.memory.Items",
  fqnStoreItemFieldsEntity: "my.app.memory.Fields",
});

API

new CdsMemoryStore(config);

| Option | Type | Description | | -------------------------- | ------------ | ------------------------------------------------------ | | name | string | Required store name used for isolation. | | embeddings | Embeddings | Optional LangChain embeddings implementation. | | fqnStoreItemsEntity | string | Defaults to plugin.langgraph.memory.StoreItems. | | fqnStoreItemFieldsEntity | string | Defaults to plugin.langgraph.memory.StoreItemFields. |

Supported Store operations are put, get, delete, search, listNamespaces, and batch.

Namespaces are non-empty arrays of non-empty strings. A label cannot contain . and the root langgraph namespace is reserved.

Search and filtering

search(namespacePrefix, options) supports query, filter, limit, and offset. Without embeddings, query matches stored field values. Metadata filters support direct equality and $eq, $ne, $in, and $notIn operators.

Provide embeddings to embed stored fields on put and query text on search for vector-assisted search. The generated Vector(1536) field must be changed to match the selected embedding model's dimensions.

CAP notes

• Use the Store inside CAP request handlers to inherit the active database and tenant context.
• CAP-supported SQLite, SAP HANA, and PostgreSQL adapters are supported by the CDS query implementation.
• Use a checkpointer for short-term, thread-scoped graph state; use this package for cross-thread long-term memory.

License

MIT License