mcp-persist 0.1.1

Production-grade persistence backends for the MCP Python SDK

mcp-persist

Production-grade persistence backends for the MCP Python SDK.

The MCP SDK ships an EventStore interface but only an in-memory reference implementation. mcp-persist provides backends for real deployments where you need durability across process restarts and multi-worker environments.

Backends

Backend	Extra	Use case
RedisEventStore	redis	Multi-process / multi-worker SSE resumability

Installation

pip install "mcp-persist[redis]"

Quickstart

import redis.asyncio as aioredis
from mcp_persist import RedisEventStore
from mcp.server.streamable_http_manager import StreamableHTTPSessionManager

redis_client = aioredis.from_url("redis://localhost:6379")
store = RedisEventStore(redis_client, ttl=3600)  # 1 hour TTL

session_manager = StreamableHTTPSessionManager(
    app=mcp_server,
    event_store=store,
)

RedisEventStore

Stores MCP SSE events in Redis so clients can resume interrupted streams — even across worker restarts or load-balanced deployments.

How it works

Redis data layout:

{prefix}counter                 — atomic INCR source for monotonic event IDs
{prefix}event:{event_id}        — HASH: stream_id + serialized payload
{prefix}stream:{stream_id}      — ZSET: event IDs sorted by score for O(log N) range queries

• Atomic monotonic IDs via Redis INCR — collision-free across concurrent workers
• O(log N) replay via sorted set ZRANGEBYSCORE
• TTL support — automatic key expiry to prevent unbounded memory growth
• Multi-tenant isolation via configurable key_prefix
• Priming event handling — sentinel empty-string payloads are stored but never replayed to clients

Configuration

RedisEventStore(
    redis,                  # redis.asyncio.Redis instance
    key_prefix="mcp:",      # isolate multiple servers on one Redis instance
    ttl=3600,               # seconds; None = never expire (not recommended)
)

TTL guidance: Set ttl to at least 2× your session idle timeout. If you leave it as None, a warning is logged and events accumulate indefinitely.

Multi-tenant deployments

If multiple MCP servers share a Redis instance, use different prefixes:

store_a = RedisEventStore(redis_client, key_prefix="server-a:")
store_b = RedisEventStore(redis_client, key_prefix="server-b:")

Development

git clone https://github.com/Ar-maan05/mcp-persist
cd mcp-persist
pip install -e ".[redis,dev]"
pytest tests/

Tests use fakeredis — no external Redis server required.

License

MIT