---
url: "https://vueda.dev/v3/reference/api/js/utils/columnMappings/functions/mergeColumnMappings.md"
title: "mergeColumnMappings"
---

# mergeColumnMappings

## Overview

Deep-merge custom column mappings into the defaults. Mirrors
`mergeDefaultFieldMappings`. Mutates and returns the shared `columnMappings`.

## Signature

`mergeColumnMappings(customMappings)`

### Parameters

| Name | Type | Required | Description |
| --- | --- | --- | --- |
| <span id="param-customMappings">customMappings</span> | `object` | yes | Custom mappings to merge in. |

### Returns

`The merged mappings.`

## Source

`client/lib/utils/columnMappings.js:114`