Integrate MongoDB with Mem0

add()

The add() method extracts facts from a conversation and writes them to your collection as memory documents. If a semantically equivalent memory already exists for the entity, Mem0 updates that memory instead of creating a duplicate document.

The following example passes a conversation to the add() method and scopes the resulting memory to a specific user:

messages = [
    {"role": "user", "content": "I'm moving to Berlin next month."},
    {"role": "assistant", "content": "I'll remember that you're relocating to Berlin."},
]
result = m.add(messages, user_id="alice")
print(result)

{'results': [{'id': '...', 'memory': 'User is moving to Berlin around September 2026.', 'event': 'ADD'}]}

get()

The get() method retrieves a single memory document by its ID value without running a vector search.

The following example retrieves a memory directly by its ID:

memory = m.get(memory_id="<memory-id>")
print(memory)

{'id': '...', 'memory': 'User is moving to Berlin around September 2026.',
'hash': '...', 'metadata': None, 'score': None, 'created_at': '...',
'updated_at': '...', 'user_id': 'alice', 'attributed_to': 'user'}

The memory_id parameter is required and accepts the id value of the memory document to retrieve. If no memory with that ID exists, the get() method returns None.

search()

The search() method runs a semantic search against the MongoDB Vector Search index and returns the memories that are most relevant to a query string.

The following example searches a specific user's memories for the five most relevant results:

results = m.search(
    query="Where does Alice live?",
    filters={"user_id": "alice"},
    top_k=5,
)
for mem in results["results"]:
    print(mem["memory"], "- score:", mem["score"])

User is moving to Berlin around September 2026. - score: 0.7043201923370361

get_all()

The get_all() method returns the memory documents stored for a given entity without running a semantic search. Use this method to display an entity's full memory history.

The following example returns and prints all memories for a specific user:

all_memories = m.get_all(filters={"user_id": "alice"})
for mem in all_memories["results"]:
    print(mem["id"], mem["memory"])

<id> User is moving to Berlin around September 2026.

update()

The update() method replaces the text of an existing memory document. Mem0 recomputes the embedding from the new text and updates the document in place.

The following example replaces the text of an existing memory:

m.update(memory_id="<memory-id>", text="Alice relocated to Berlin in July 2025.")

delete()

The delete() method deletes a single memory document from your collection.

The following example deletes a memory by its ID:

m.delete(memory_id="<memory-id>")

The memory_id parameter is required and accepts the id value of the memory document to delete.

delete_all()

The delete_all() method deletes all memory documents for a given entity from your collection.

The following example deletes all memories for a specific user:

m.delete_all(user_id="alice")

history()

The history() method returns the edit history for a single memory, including each version of the text and the event type. Mem0 stores this history in a local SQLite database rather than in MongoDB. To change where Mem0 writes that database, set the history_db_path key in your configuration dictionary.

The following example retrieves and prints the edit history for a memory:

history = m.history(memory_id="<memory-id>")
for entry in history:
    print(entry["event"], entry["old_memory"], entry["new_memory"])

ADD None User is moving to Berlin around September 2026.
UPDATE User is moving to Berlin around September 2026. Alice relocated to Berlin in July 2025.

The memory_id parameter is required and accepts the id value of the memory document whose history you want to retrieve.

reset()

The reset() method performs the following actions:

• Deletes your MongoDB collection and its MongoDB Vector Search and MongoDB Search indexes

• Resets the local history database

• Recreates the collection and its indexes from scratch

Use this method to clear all memories rather than using the delete_all() method to delete them one entity at a time.

m.reset()

reset() does not accept any parameters and deletes every memory Mem0 has stored through this Memory instance.

close()

The close() method releases the local SQLite connection that Mem0 uses for the history database. This method doesn't affect your MongoDB connection.

m.close()

close() does not accept any parameters. Mem0 calls it automatically if you use the Memory instance as a context manager.