Redis State Store

Redis stores agent state in memory for sub-millisecond access — pair it with a SQL backend for conversation history.

This is the supported way to use Redis with PraisonAI. MemoryConfig(backend="redis") is no longer accepted — it raises a ValueError. Always attach Redis through db(state_url=...) as shown below.

from praisonaiagents import Agent, MemoryConfig
from praisonaiagents.db import db

agent = Agent(
    name="FastBot",
    instructions="You are a helpful assistant.",
    memory=MemoryConfig(
        db=db(state_url="redis://localhost:6379"),
        session_id="redis-session",
    ))
agent.start("Store my preferences in Redis")

The user updates session state; Redis serves fast reads while SQL can hold conversation history.

Quick Start

Simple Usage

pip install redis praisonai

from praisonaiagents import Agent, MemoryConfig
from praisonaiagents.db import db

agent = Agent(
    name="FastBot",
    memory=MemoryConfig(
        db=db(state_url="redis://localhost:6379"),
        session_id="session-1",
    ))
agent.start("Hello!")

With Configuration

Hybrid setup — SQL for conversations, Redis for state:

from praisonaiagents import Agent, MemoryConfig
from praisonaiagents.db import db

agent = Agent(
    name="HybridBot",
    memory=MemoryConfig(
        db=db(
            database_url="postgresql://user:pass@localhost/conversations",
            state_url="redis://localhost:6379",
        ),
        session_id="hybrid-session",
    ))
agent.start("Conversations in Postgres, state in Redis")

How It Works

Redis is a state store — fast key-value access for agent preferences and runtime data. Conversation history uses database_url separately.

Feature	Description
In-memory speed	Sub-millisecond reads and writes
TTL support	Expire keys automatically with `ttl`
Key prefix	Namespace keys with `prefix` (default `praison:`)

Configuration Options

Option	Type	Default	Description
`url`	`str`	`None`	Full Redis URL (overrides host/port/db/password)
`host`	`str`	`"localhost"`	Redis host when `url` is not set
`port`	`int`	`6379`	Redis port
`db`	`int`	`0`	Redis database number
`password`	`str`	`None`	Redis password
`prefix`	`str`	`"praison:"`	Key prefix for namespacing
`decode_responses`	`bool`	`True`	Compatibility flag (not used internally)
`socket_timeout`	`int`	`5`	Socket timeout in seconds
`max_connections`	`int`	`10`	Compatibility flag for pool size

URL formats

db(state_url="redis://localhost:6379")
db(state_url="redis://:password@host:6379/0")

Production notes

Redis is single-threaded, so a slow admin command stalls every other client on the same instance. To list many keys, call scan_prefix() instead of keys() — it walks the keyspace with a non-blocking cursor SCAN (batches of 500) so a large read never freezes agents sharing the instance.

from praisonai.persistence import create_state_store

store = create_state_store("redis", url="redis://localhost:6379")

recent = store.scan_prefix("session:")

Method	Under the hood	Safe on large keyspaces
`store.keys(pattern)`	Redis `KEYS` (O(N), blocking)	Small keyspaces only
`store.scan_prefix(prefix)`	`SCAN` cursor (batch `500`)	✅

Best Practices

Prefer scan_prefix() for large listings

scan_prefix(prefix) uses a non-blocking SCAN cursor (batch 500), so admin or garbage-collection reads on a large keyspace never stall other agents sharing the Redis instance. Reserve keys(pattern) for small keyspaces.

Pair Redis with a SQL conversation backend

Use database_url for chat history and state_url for fast ephemeral state.

Set TTL on ephemeral keys

Pass ttl when storing session-scoped data that should expire automatically.

Use a key prefix per environment

Set prefix="prod:" vs prefix="staging:" to isolate keys on a shared Redis instance.

Enable persistence for durability

Configure Redis AOF or RDB snapshots if state must survive Redis restarts.

MongoDB State Store

Document-based state with flexible schemas

Database Persistence

Overview of conversation and state backends

Getting Started

Install

Core Concepts

Guides

Features

Models

Databases

Observability

Memory

Telemetry & Analytics

Knowledge

RAG

Persistence

Tools

Other Features

Developers

Configuration

Best Practices

Getting Started (No Code)

Quick Start

How It Works

Configuration Options

URL formats

Production notes

Best Practices

MongoDB State Store

Database Persistence

​Quick Start

​How It Works

​Configuration Options

​URL formats

​Production notes

​Best Practices

​Related

MongoDB State Store

Database Persistence

Quick Start

How It Works

Configuration Options

URL formats

Production notes

Best Practices

Related