Locking Module for Medusa: acquires and releases locks on shared resources so that only one process runs a critical section at a time, preventing race conditions such as overselling inventory. Locks are handled by Locking Module Providers: an in-memory provider is built in, and Postgres or Redis providers coordinate locks across multiple instances. It ships with @medusajs/medusa and is registered by default; use it with the acquireLockStep and releaseLockStep workflow steps, or resolve it with container.resolve(Modules.LOCKING).

At a glance

| | | | --- | --- | | Package | @medusajs/locking | | Type | Infrastructure Module | | Module key | Modules.LOCKING ("locking") | | Registered by default | Yes (in-memory provider; Redis provider on Medusa Cloud when REDIS_URL is set) |

Providers

The module accepts multiple providers. The built-in in-memory provider (in-memory) is always registered and is the default when you don't register others. Official providers:

| Package | Register with | | --- | --- | | @medusajs/locking-postgres | @medusajs/medusa/locking-postgres | | @medusajs/locking-redis | @medusajs/medusa/locking-redis |

Installation

No installation needed. The module ships with @medusajs/medusa.

Usage

import { defineConfig } from "@medusajs/framework/utils"

module.exports = defineConfig({
  // ...
  modules: [
    {
      resolve: "@medusajs/medusa/locking",
      options: {
        providers: [
          {
            resolve: "@medusajs/medusa/locking-redis",
            id: "locking-redis",
            is_default: true,
            options: {
              redisUrl: process.env.LOCKING_REDIS_URL,
            },
          },
        ],
      },
    },
  ],
})

Configuration

| Option | Type | Description | Default | | --- | --- | --- | --- | | providers | { resolve: string, id: string, is_default?: boolean, options?: Record<string, unknown> }[] | Locking providers to register. When only one provider is registered, or one sets is_default: true, it becomes the default. | [] (in-memory provider is used) |

Resources

• Locking Module
• Postgres Locking Module Provider
• Redis Locking Module Provider