Skip to main content

How to make Neo4j read-only for an LLM

To make Neo4j read-only for an LLM, guard the Neo4j driver the LLM uses with guard(). Read mode is the default. Blocked queries raise GuardError and are never sent.

Install​

pip install neo4j-guard

Guard the driver​

Give the LLM its own driver and guard it. Other drivers are not checked, so the rest of the application can still write.

from neo4j import GraphDatabase
from neo4j_guard import GuardError, guard

driver = guard(GraphDatabase.driver("neo4j://localhost:7687", auth=("neo4j", "password")))

try:
    driver.execute_query("MERGE (p:Person {name: 'Ada'})")
except GuardError as error:
    print(error)  # MERGE is not allowed in read mode

Check what read mode allows​

Read mode
Read clauses (MATCH, RETURN, WITH, ...)Allowed
Write clauses (CREATE, MERGE, SET, ...)Blocked
Delete clauses (DELETE, DETACH DELETE)Blocked
Other clauses (LOAD CSV, USE)Blocked
Built-in functions (toUpper, count, ...)Allowed
Schema and search procedures (db.labels, db.index.vector.queryNodes, ...)Allowed
Other procedures and functions (apoc.*, dbms.*, ...)Blocked
Admin commands (SHOW USERS, CREATE INDEX, ...)Blocked