twenty/packages/twenty-docs/user-guide/data-model/how-tos/create-many-to-many-relations.mdx

---
title: Create Many-to-Many Relations
description: Connect records where many items on both sides can be linked together using junction objects.
---

Many-to-many relations let you connect multiple records on both sides. For example: many People can work on many Projects, and each Project can have many People.

<Warning>
**Lab Feature**: Junction relations are currently in the Lab. Enable them at **Settings → Updates → Lab** before following this guide.
</Warning>

<Note>
This feature also requires **Advanced mode** to be enabled (toggle at the bottom right of Settings).
</Note>

## When to Use Many-to-Many

Use many-to-many when both sides of a relationship can have multiple connections:

| Relationship | Example |
|-------------|---------|
| People ↔ Projects | A person works on multiple projects; a project has multiple team members |
| Companies ↔ Tags | A company can have multiple tags; a tag can apply to multiple companies |
| Products ↔ Orders | A product can be in multiple orders; an order contains multiple products |

## How It Works

Twenty uses a **junction object** pattern for many-to-many relations. A junction object sits between two objects and holds the connections:

```
People ←→ Project Assignments ←→ Projects
```

The **Project Assignments** object (junction) has:
- A relation to People (many-to-one)
- A relation to Projects (many-to-one)

When you enable the junction relation toggle, Twenty displays linked records directly instead of showing the intermediate junction records.

## Prerequisites

1. **Enable Junction Relations in Lab**: Go to **Settings → Updates → Lab** and enable **Junction Relations**
2. **Enable Advanced mode**: Toggle on **Advanced mode** at the bottom right of the Settings sidebar
3. Plan your data model:
   - Which two objects are you connecting?
   - What should the junction object be called?

## Step 1: Create the Junction Object

First, create the intermediate object that will hold the connections.

1. Go to **Settings → Data Model**
2. Click **+ New object**
3. Name it descriptively (e.g., "Project Assignment", "Team Member", "Product Order")
4. Click **Save**

<Tip>
**Naming convention**: Use a name that describes the relationship, like "Project Assignment" or "Team Membership". This makes the data model easier to understand.
</Tip>

## Step 2: Create Relations from the Junction Object

Add relation fields from the junction object to both objects you want to connect.

### First Relation (Junction → Object A)

1. Select your junction object in **Settings → Data Model**
2. Click **+ Add Field**
3. Choose **Relation** as the field type
4. Select the first object (e.g., "People")
5. Set the relation type to **Many-to-One** (many assignments can link to one person)
6. Name the fields:
   - Field on junction: e.g., "Person"
   - Field on People: e.g., "Project Assignments"
7. Click **Save**

### Second Relation (Junction → Object B)

1. Still on the junction object, click **+ Add Field**
2. Choose **Relation** as the field type
3. Select the second object (e.g., "Projects")
4. Set the relation type to **Many-to-One**
5. Name the fields:
   - Field on junction: e.g., "Project"
   - Field on Projects: e.g., "Team Members"
6. Click **Save**

## Step 3: Configure the Junction Relation Display

Now configure the source objects to display linked records directly, skipping the intermediate junction object.

1. Go to **Settings → Data Model**
2. Select the first object (e.g., "People")
3. Find the relation field pointing to the junction object (e.g., "Project Assignments")
4. Click to edit the field
5. Enable **"This is a relation to a Junction Object"**
6. Select the **Target relation** (e.g., "Project" — the field on the junction that points to the other side)
7. Click **Save**


{/* TODO: Add image
<img src="/images/user-guide/fields/junction-relation-toggle.png" style={{width:'100%'}}/>
*/}

Repeat for the other object:
1. Select "Projects" in Data Model
2. Edit the "Team Members" relation field
3. Enable the junction toggle
4. Select "Person" as the target relation
5. Save

## Result

After configuration:

- On a **Person** record, the "Project Assignments" field displays **Projects** directly (not assignment records)
- On a **Project** record, the "Team Members" field displays **People** directly

The junction object still exists and stores the connections, but the UI presents a cleaner many-to-many view.

## Example: People ↔ Projects

Here's a complete walkthrough:

### Create the Junction Object
- Name: **Project Assignment**
- Description: "Links people to projects they work on"

### Add Relations
1. **Project Assignment → People**
   - Type: Many-to-One
   - Field on Assignment: "Person"
   - Field on People: "Project Assignments"

2. **Project Assignment → Projects**
   - Type: Many-to-One
   - Field on Assignment: "Project"
   - Field on Projects: "Team Members"

### Configure Junction Display
1. On **People** object:
   - Edit "Project Assignments" field
   - Enable junction toggle
   - Target: "Project"

2. On **Projects** object:
   - Edit "Team Members" field
   - Enable junction toggle
   - Target: "Person"

### Use It
- Open a Person record → See their Projects directly
- Open a Project record → See team members directly
- Create new connections from either side

## Adding Extra Data to Connections

Since the junction object is a real object, you can add custom fields to store information about the relationship:

- **Role**: "Developer", "Designer", "Manager"
- **Start Date**: When they joined the project
- **Hours Allocated**: Weekly hours on this project

To access this data, navigate to the junction object directly or query it via the API.

## Limitations

- **CSV Import/Export**: Importing many-to-many relations directly is not supported. Import records to the junction object instead.
- **Filters**: Filtering by many-to-many relations may have limited options.

## Related

- [Relation Fields](/user-guide/data-model/capabilities/relation-fields) — relation types explained
- [Create Custom Objects](/user-guide/data-model/how-tos/create-custom-objects) — how to create objects
- [Create Relation Fields](/user-guide/data-model/how-tos/create-relation-fields) — basic relation setup