Getting Started
RedisVL is a Python library with an integrated CLI for building AI applications with Redis. This guide covers the core workflow:
- Defining an
IndexSchema - Preparing a sample dataset
- Creating a
SearchIndex - Using the
rvlCLI - Loading data into Redis
- Fetching and managing records
- Executing vector searches
- Updating an index
Prerequisites
Before you begin, ensure you have:
- Installed RedisVL:
pip install redisvl - A running Redis instance (Redis 8+ or Redis Cloud)
What You'll Learn
By the end of this guide, you will be able to:
- Create index schemas using Python dictionaries or YAML files
- Build and manage
SearchIndexobjects - Use the
rvlCLI for index management - Load data and execute vector similarity searches
- Fetch individual records and list all keys in an index
- Delete specific records by key or document ID
- Update index schemas as your application evolves
Define an IndexSchema
The IndexSchema maintains crucial index configuration and field definitions to
enable search with Redis. For ease of use, the schema can be constructed from a
python dictionary or yaml file.
Example Schema Creation
Consider a dataset with user information, including job, age, credit_score,
and a 3-dimensional user_embedding vector.
You must also decide on a Redis index name and key prefix to use for this dataset. Below are example schema definitions in both YAML and Dict format.
YAML Definition:
version: '0.1.0'
index:
name: user_simple
prefix: user_simple_docs
fields:
- name: user
type: tag
- name: credit_score
type: tag
- name: job
type: text
- name: age
type: numeric
- name: user_embedding
type: vector
attrs:
algorithm: flat
dims: 3
distance_metric: cosine
datatype: float32
Store this in a local file, such as schema.yaml, for RedisVL usage.
Python Dictionary:
schema = {
"index": {
"name": "user_simple",
"prefix": "user_simple_docs",
},
"fields": [
{"name": "user", "type": "tag"},
{"name": "credit_score", "type": "tag"},
{"name": "job", "type": "text"},
{"name": "age", "type": "numeric"},
{
"name": "user_embedding",
"type": "vector",
"attrs": {
"dims": 3,
"distance_metric": "cosine",
"algorithm": "flat",
"datatype": "float32"
}
}
]
}
Sample Dataset Preparation
Below, create a mock dataset with user, job, age, credit_score, and
user_embedding fields. The user_embedding vectors are synthetic examples
for demonstration purposes.
For more information on creating real-world embeddings, refer to this article.
import numpy as np
data = [
{
'user': 'john',
'age': 1,
'job': 'engineer',
'credit_score': 'high',
'user_embedding': np.array([0.1, 0.1, 0.5], dtype=np.float32).tobytes()
},
{
'user': 'mary',
'age': 2,
'job': 'doctor',
'credit_score': 'low',
'user_embedding': np.array([0.1, 0.1, 0.5], dtype=np.float32).tobytes()
},
{
'user': 'joe',
'age': 3,
'job': 'dentist',
'credit_score': 'medium',
'user_embedding': np.array([0.9, 0.9, 0.1], dtype=np.float32).tobytes()
}
]
The user_embedding vectors are converted to bytes using NumPy's .tobytes() method.
Create a SearchIndex
With the schema and sample dataset ready, create a SearchIndex.
Bring your own Redis connection instance
This is ideal in scenarios where you have custom settings on the connection instance or if your application will share a connection pool:
from redisvl.index import SearchIndex
from redis import Redis
client = Redis.from_url("redis://localhost:6379")
index = SearchIndex.from_dict(schema, redis_client=client, validate_on_load=True)
Let the index manage the connection instance
This is ideal for simple cases:
index = SearchIndex.from_dict(schema, redis_url="redis://localhost:6379", validate_on_load=True)
# If you don't specify a client or Redis URL, the index will attempt to
# connect to Redis at the default address "redis://localhost:6379".
Create the index
Now that we are connected to Redis, we need to run the create command.
index.create(overwrite=True)
Note that at this point, the index has no entries. Data loading follows.
Inspect with the rvl CLI
Use the rvl CLI to inspect the created index and its fields:
!rvl index info -i user_simple
Index Information:
╭──────────────────────┬──────────────────────┬──────────────────────┬──────────────────────┬──────────────────────╮
│ Index Name │ Storage Type │ Prefixes │ Index Options │ Indexing │
├──────────────────────┼──────────────────────┼──────────────────────┼──────────────────────┼──────────────────────┤
| user_simple | HASH | ['user_simple_docs'] | [] | 0 |
╰──────────────────────┴──────────────────────┴──────────────────────┴──────────────────────┴──────────────────────╯
Index Fields:
╭─────────────────┬─────────────────┬─────────────────┬─────────────────┬─────────────────┬─────────────────┬─────────────────┬─────────────────┬─────────────────┬─────────────────┬─────────────────╮
│ Name │ Attribute │ Type │ Field Option │ Option Value │ Field Option │ Option Value │ Field Option │ Option Value │ Field Option │ Option Value │
├─────────────────┼─────────────────┼─────────────────┼─────────────────┼─────────────────┼─────────────────┼─────────────────┼─────────────────┼─────────────────┼─────────────────┼─────────────────┤
│ user │ user │ TAG │ SEPARATOR │ , │ │ │ │ │ │ │
│ credit_score │ credit_score │ TAG │ SEPARATOR │ , │ │ │ │ │ │ │
│ job │ job │ TEXT │ WEIGHT │ 1 │ │ │ │ │ │ │
│ age │ age │ NUMERIC │ │ │ │ │ │ │ │ │
│ user_embedding │ user_embedding │ VECTOR │ algorithm │ FLAT │ data_type │ FLOAT32 │ dim │ 3 │ distance_metric │ COSINE │
╰─────────────────┴─────────────────┴─────────────────┴─────────────────┴─────────────────┴─────────────────┴─────────────────┴─────────────────┴─────────────────┴─────────────────┴─────────────────╯
Load Data to SearchIndex
Load the sample dataset to Redis.
Validate data entries on load
RedisVL uses pydantic validation under the hood to ensure loaded data is valid and confirms to your schema. This setting is optional and can be configured in the SearchIndex class.
keys = index.load(data)
print(keys)
['user_simple_docs:01KHKHQYX95EDQN18FG8FRMRQ5', 'user_simple_docs:01KHKHQYXC97WY4ACG1V01GEPC', 'user_simple_docs:01KHKHQYXC97WY4ACG1V01GEPD']
By default, load will create a unique Redis key as a combination of the index key prefix and a random ULID. You can also customize the key by providing direct keys or pointing to a specified id_field on load.
Load INVALID data
This will raise a SchemaValidationError if validate_on_load is set to true in the SearchIndex class.
# NBVAL_SKIP
try:
keys = index.load([{"user_embedding": True}])
except Exception as e:
print(str(e))
Schema validation failed for object at index 0. Field 'user_embedding' expects bytes (vector data), but got boolean value 'True'. If this should be a vector field, provide a list of numbers or bytes. If this should be a different field type, check your schema definition.
Object data: {
"user_embedding": true
}
Hint: Check that your data types match the schema field definitions. Use index.schema.fields to view expected field types.
Upsert the index with new data
Upsert data by using the load method again:
# Add more data
new_data = [{
'user': 'tyler',
'age': 9,
'job': 'engineer',
'credit_score': 'high',
'user_embedding': np.array([0.1, 0.3, 0.5], dtype=np.float32).tobytes()
}]
keys = index.load(new_data)
print(keys)
['user_simple_docs:01KHKHR37CD6143DNQ41G3ADNA']
Fetch and Manage Records
RedisVL provides several methods to retrieve and manage individual records in your index.
Fetch a record by ID
Use fetch() to retrieve a single record when you know its ID. The ID is the unique identifier you provided during load (via id_field) or the auto-generated ULID.
# Fetch a record by its ID (e.g., the user field value if used as id_field)
# First, let's reload data with a specific id_field
index.load(data, id_field="user")
# Now fetch by the user ID
record = index.fetch("john")
print(record)
You can also construct the full Redis key from an ID using the key() method:
# Get the full Redis key for a given ID
full_key = index.key("john")
print(f"Full Redis key: {full_key}")
| vector_distance | user | age | job | credit_score |
|---|---|---|---|---|
| 0 | john | 1 | engineer | high |
| 0 | mary | 2 | doctor | low |
| 0.0566298961639 | tyler | 9 | engineer | high |
List all keys in the index
To enumerate all keys in your index, use paginate() with a FilterQuery. This is useful for batch processing or auditing your data.
from redisvl.query import FilterQuery
from redisvl.query.filter import FilterExpression
# Create a query that matches all documents
query = FilterQuery(
filter_expression=FilterExpression("*"),
return_fields=["user", "age", "job"]
)
# Paginate through all results
for batch in index.paginate(query, page_size=10):
for doc in batch:
print(f"Key: {doc['id']}, User: {doc['user']}")
Delete specific records
Use drop_keys() to remove specific records by their full Redis key, or drop_documents() to remove by document ID.
# Delete by full Redis key
full_key = index.key("john")
deleted_count = index.drop_keys(full_key)
print(f"Deleted {deleted_count} record(s) by key")
# Delete multiple keys at once
# index.drop_keys(["key1", "key2", "key3"])
# Delete by document ID (without the prefix)
deleted_count = index.drop_documents("mary")
print(f"Deleted {deleted_count} record(s) by document ID")
# Delete multiple documents at once
# index.drop_documents(["id1", "id2", "id3"])
Note: drop_keys() expects the full Redis key (including prefix), while drop_documents() expects just the document ID.
Creating VectorQuery Objects
Next we will create a vector query object for our newly populated index. This example will use a simple vector to demonstrate how vector similarity works. Vectors in production will likely be much larger than 3 floats and often require Machine Learning models (i.e. Huggingface sentence transformers) or an embeddings API (Cohere, OpenAI). redisvl provides a set of Vectorizers to assist in vector creation.
from redisvl.query import VectorQuery
from jupyterutils import result_print
query = VectorQuery(
vector=[0.1, 0.1, 0.5],
vector_field_name="user_embedding",
return_fields=["user", "age", "job", "credit_score", "vector_distance"],
num_results=3
)
| vector_distance | user | age | job | credit_score |
|---|---|---|---|---|
| 0 | john | 1 | engineer | high |
| 0 | mary | 2 | doctor | low |
| 0.0566298961639 | tyler | 9 | engineer | high |
Note: For HNSW and SVS-VAMANA indexes, you can tune search performance using runtime parameters:
# Example with HNSW runtime parameters
query = VectorQuery(
vector=[0.1, 0.1, 0.5],
vector_field_name="user_embedding",
return_fields=["user", "age", "job"],
num_results=3,
ef_runtime=50 # Higher for better recall (HNSW only)
)
See the SVS-VAMANA guide and Advanced Queries guide for more details on runtime parameters.
Executing queries
With our VectorQuery object defined above, we can execute the query over the SearchIndex using the query method.
results = index.query(query)
result_print(results)
Using an Asynchronous Redis Client
The AsyncSearchIndex class along with an async Redis python client allows for queries, index creation, and data loading to be done asynchronously. This is the
recommended route for working with redisvl in production-like settings.
from redisvl.index import AsyncSearchIndex
from redis.asyncio import Redis
client = Redis.from_url("redis://localhost:6379")
index = AsyncSearchIndex.from_dict(schema, redis_client=client)
4
# execute the vector query async
results = await index.query(query)
result_print(results)
True
Updating a schema
In some scenarios, it makes sense to update the index schema. With Redis and redisvl, this is easy because Redis can keep the underlying data in place while you change or make updates to the index configuration.
So for our scenario, let's imagine we want to reindex this data in 2 ways:
- by using a
Tagtype forjobfield instead ofText - by using an
hnswvector index for theuser_embeddingfield instead of aflatvector index
# Modify this schema to have what we want
index.schema.remove_field("job")
index.schema.remove_field("user_embedding")
index.schema.add_fields([
{"name": "job", "type": "tag"},
{
"name": "user_embedding",
"type": "vector",
"attrs": {
"dims": 3,
"distance_metric": "cosine",
"algorithm": "hnsw",
"datatype": "float32"
}
}
])
# Run the index update but keep underlying data in place
await index.create(overwrite=True, drop=False)
# Execute the vector query async
results = await index.query(query)
result_print(results)
Check Index Stats
Use the rvl CLI to check the stats for the index:
!rvl stats -i user_simple
Next Steps
Now that you understand the basics of RedisVL, explore these related guides:
- Query and Filter Data - Learn advanced filtering with tag, numeric, text, and geo filters
- Create Embeddings with Vectorizers - Generate embeddings using OpenAI, HuggingFace, Cohere, and more
- Choose a Storage Type - Understand when to use Hash vs JSON storage
Cleanup
Use .clear() to flush all data from Redis associated with the index while leaving the index in place for future insertions.
Use .delete() to remove both the index and the underlying data.
# Clear all data from Redis associated with the index
await index.clear()
# But the index is still in place
await index.exists()
# Remove / delete the index in its entirety
await index.delete()