> ## Documentation Index
> Fetch the complete documentation index at: https://docs.versori.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Field Mapping

> Map fields between your connected systems in the Field Mapping tab, with AI-assisted expressions and transformation pipelines.

Field Mapping lets you map data from a source system to a destination system — matching fields, transforming values, and shaping the payload your integration sends. It runs in a dedicated **Field Mapping** tab alongside Build, Connect, and the other workspace tabs.

<Note>
  **Prerequisite:** the Build Agent only creates field mappings when the **field-mapping skill** is attached to your integration. Add it to your organisation's library and attach it when building — see [Skills](/latest/ai-tooling/skills).
</Note>

<Info>
  With the skill attached, ask the Build Agent to create field mappings for your integration and the **Field Mapping** tab appears automatically.
</Info>

## Opening the mapper

Open the **Field Mapping** tab, then pick a mapping from the dropdown at the top. The canvas shows your source fields on the left and destination fields on the right, with the mapping between them.

<Frame caption="The Field Mapping tab alongside Build, Connect, and the other workspace tabs">
  <img src="https://mintlify.s3.us-west-1.amazonaws.com/versori/images/guides/build/field-mapping-tab-001.png" alt="Workspace tab bar with the Field Mapping tab highlighted" />
</Frame>

<Frame caption="The mapper canvas, with source fields on the left and destination fields on the right">
  <img src="https://mintlify.s3.us-west-1.amazonaws.com/versori/images/guides/build/field-mapping-canvas-001.png" alt="Field mapper canvas showing source and destination field trees connected by mapping lines" />
</Frame>

## Guided walkthrough

The quickest way to learn the mapper is the built-in tour.

<Info>
  Click the eye icon<span style={{ margin: '0 0.4rem' }}><Icon icon="eye" library="lucide" /></span>next to **Field mapping** on the left to launch a guided tour that steps through every feature. The **Help** icon in the top-right opens the reference documentation.
</Info>

## Adjusting the source and destination schemas

The mapper derives its fields from sample JSON for each side. Use **Edit Source** and **Edit Destination** to change those samples in a field-tree editor — add, rename, retype, or remove fields. When you save, the mapper rebuilds the field tree and reconciles your existing mappings against it; if an edit would drop a field that a mapping still uses, you'll be warned first.

## AI assistance

Two AI helpers are available, both powered by the Build Agent with your project's context:

* **Expression AI** — describe what you want and it generates a single JSONata / JSON-formula expression for a field.
* **AI Pipeline** — generates an ordered transformation pipeline for a mapping (e.g. format a date, then uppercase).

Generated results appear in the canvas for you to review; nothing is persisted until you save.

## Saving

Click **Save DSL** to persist the mapping to your project. Your integration then uses it at runtime to transform data between the connected systems.