---
title: From 2.0 to 2.1
description: What changed in Mercur 2.1 and how to upgrade an existing 2.0.x project.
---

# Migrating from 2.0 to 2.1

Mercur `2.1.1` is the first stable release of the 2.x line after `2.0.2`. The only required change is a package rename. Everything else is handled by `bun run medusa db:migrate`.

If you are starting fresh, follow [Installation](/getting-started/installation) instead — new projects already use the 2.1 names.

## Breaking change: `@mercurjs/core-plugin` → `@mercurjs/core`

The Medusa plugin previously published as `@mercurjs/core-plugin` is now published as **`@mercurjs/core`**. The package contents are the same; only the name changed.

This affects:

- `package.json` — installed package name
- `medusa-config.ts` — every `resolve: "@mercurjs/core-plugin/..."` value
- Any source imports in `packages/api/src/**`

### Step 1 — swap the dependency

```bash
bun remove @mercurjs/core-plugin
bun add @mercurjs/core@2.1.1
```

If you use npm/yarn/pnpm, use the equivalent commands for your package manager.

Or edit `packages/api/package.json` by hand — replace the `@mercurjs/core-plugin` entry under `dependencies` with `@mercurjs/core` at the matching version, then run your installer:

```jsonc
// before
"dependencies": {
  "@mercurjs/core-plugin": "2.0.2"
}

// after
"dependencies": {
  "@mercurjs/core": "2.1.1"
}
```

```bash
bun install
```

### Step 2 — replace strings in config and source

In `packages/api/medusa-config.ts` and anywhere under `packages/api/src/**`, replace every occurrence of `@mercurjs/core-plugin` with `@mercurjs/core`. A repo-wide find-and-replace is safe — there are no other valid uses of the old name.

```ts
// before
{
  resolve: "@mercurjs/core-plugin/modules/seller",
}

// after
{
  resolve: "@mercurjs/core/modules/seller",
}
```

```ts
// before
import { createSellerWorkflow } from "@mercurjs/core-plugin/workflows"

// after
import { createSellerWorkflow } from "@mercurjs/core/workflows"
```

The same applies to:

- `@mercurjs/core-plugin/modules/<module>`
- `@mercurjs/core-plugin/workflows`
- `@mercurjs/core-plugin/links`
- `@mercurjs/core-plugin/api`

### Step 3 — reinstall and rebuild

```bash
bun install
bun run build
```

If TypeScript still complains about `@mercurjs/core-plugin`, you missed an import. Re-run the find-and-replace.

### Step 4 — refresh installed blocks

If your project installed registry blocks (`mercurjs add reviews`, `mercurjs add requests`, etc.) on a 2.0.x version, the local copies still reference `@mercurjs/core-plugin`. Either:

- Run the same find-and-replace inside `packages/api/src/` (registry blocks live there once installed)

## Database migrations

Mercur 2.1 ships several new migrations on the `seller` module. All are non-destructive. Run:

```bash
bun run medusa db:migrate
```

## Full changelog

The complete 2.1 changelog is published with the [GitHub release](https://github.com/mercurjs/mercur/releases/tag/v2.1.1).