What is the point of "EmbeddedJsonModel" ?

[hieubnt235]

Hello guys, I try to understand what is the different of EmbeddedJsonModel and JsonModel and when to use it, i try some example to clarify but cannot find anything.

from redis.asyncio import Redis
from uuid_extensions import uuid7
from pydantic import AnyUrl, Field, BaseModel
from aredis_om import JsonModel, EmbeddedJsonModel, Migrator, Field as RField
from aredis_om.model.model import model_registry

from typing import Literal
from uuid import UUID

redis = Redis(host='localhost',port=3333,password="ssssss")

class Message(EmbeddedJsonModel):
	role: Literal['user', 'system', 'assistant']
	content: str
	class Meta:
		database = redis

class ChatSessionData(EmbeddedJsonModel): #  change here
	id: str = RField(index=True,primary_key=True)

	messages: list[Message] = Field(default_factory=list)
	summaries: list[str] = Field(default_factory=list)
	urls: list[AnyUrl] = Field(default_factory=list,description="Addition data should be store in object storage and provide url.")
	class Meta:
		database = redis

class UserData(JsonModel):
	username:str = RField(index=True,primary_key=True)
	password:str
	chat_sessions:list[ChatSessionData] = Field(default_factory=list)
	class Meta:
		database = redis

await Migrator().run() # create all indexes

chat_id = uuid7()
chat_id_str = str(chat_id)
chat_session_data = ChatSessionData(id = chat_id_str,
                                    messages=[Message(role = "user",content = "this is content")],
                                    summaries=["sum1","sum2"],
                                    urls = ["http://example.com"])
userdata = UserData(username="xxx", password="def",token = uuid7(),chat_sessions = [chat_session_data])

await userdata.save()

In the above code, i change EmbeddedJsonModel parent class to both JsonModel and EmbeddedJsonModel. And they store object completely the same in server (monitor in RedisInsight).

Thank you.

[abrookins]

Great question! The difference between JsonModel and EmbeddedJsonModel is about how they're stored in Redis:

JsonModel

• Creates its own Redis key (e.g., UserData:username)
• Can be saved, retrieved, and queried independently
• Has its own RediSearch index (if index=True)

EmbeddedJsonModel

• Does NOT create its own Redis key
• Is stored inline within the parent JsonModel's JSON document
• Cannot be saved, retrieved, or queried independently
• Useful for nested structures that don't need their own identity

When to use each

Use EmbeddedJsonModel when:

• The nested object is always accessed through its parent
• You don't need to query the nested object independently
• The nested object doesn't have its own lifecycle

Use JsonModel when:

• The object needs its own Redis key
• You want to query it independently
• Multiple parent objects might reference the same child

Your example

In your code, Message and ChatSessionData are correctly using EmbeddedJsonModel because:

• They're always accessed through UserData
• They don't need independent storage or querying

The reason they "look the same" in RedisInsight is because both are stored as JSON - but with JsonModel, each would get its own key, while with EmbeddedJsonModel, they're nested inside the parent's JSON document.

If you changed ChatSessionData to JsonModel, you'd see separate keys for each chat session, and the UserData document would only contain references (or the data would be duplicated).

Hope this clarifies the difference!

[abrookins]

Closing as this question has been answered. See the comment above explaining the difference between JsonModel and EmbeddedJsonModel. The key distinction is that EmbeddedJsonModel is stored inline within the parent's JSON document without its own Redis key, while JsonModel gets its own key and can be queried independently.