---
title: "Creating custom type definitions with Pathfinder"
slug: "pathfinder-custom-type-definitions"
status: "new"
updated: 2026-10-27T09:03:09Z
published: 2026-10-27T09:03:09Z
canonical: "docs.lobstersoftware.com/pathfinder-custom-type-definitions"
---

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

# Creating custom type definitions with Pathfinder

Pathfinder uses AI to generate a custom type definition from a natural-language description, an uploaded document, or both. This guide shows you how to generate, adjust, and save a type definition.

> [!NOTE]
> **NOTE:**
> 
> You can create custom type definitions with Pathfinder only through the **Build with AI** button on the **Custom type definitions** page. This button starts a specialized AI assistant for type definitions. This is not possible through the general Pathfinder chat.

## Prerequisites

Pathfinder is enabled in the system.

## Procedure

1. Go to **Orchestration > Custom type definitions**.
2. Switch to the **Pathfinder** tab and click **Build with AI**. The **Custom type definitions assistant** opens on the right.

![](https://cdn.document360.io/4be90b94-ec83-41d8-963e-962df16110d4/Images/Documentation/image-YSJWVBME.png)
3. In the assistant, specify what to generate:
  - describe the desired structure in the input field,
  - and/or use the **paperclip icon** to attach a document for Pathfinder to derive the structure from.![](https://cdn.document360.io/4be90b94-ec83-41d8-963e-962df16110d4/Images/Documentation/image-NA9WZIZJ.png)
4. Then send the prompt.

During generation, a loading status appears. You cannot edit the type definition during this time.
5. Review the result on the **Type** tab. Pathfinder derives the fields and types automatically. If needed, you can:
  - request further changes with a prompt
  - edit the type definition manually
  - use **Undo** and **Redo** to revert or reapply changes
6. Save the type definition.

## Result

Pathfinder has generated the type definition based on your input. You can see the derived entities and fields on the **Type** tab, where you can adjust or save them. Elements created by Pathfinder are marked with a dot.

![](https://cdn.document360.io/4be90b94-ec83-41d8-963e-962df16110d4/Images/Documentation/image-SDGF2U8X.png)

## Attaching files

You can attach files of the following types to the assistant:

- text files such as CSV, TXT, Markdown, and HTML,
- Excel spreadsheets (XLS, XLSX),
- structured data in JSON or XML format,
- PDF files,
- images (for example JPG, PNG, GIF, WEBP).

The following limits apply:

- a maximum of 10 MB per file,
- a maximum of 5 files per message.

Other formats are rejected, such as DOCX, ZIP, or files with no recognizable type. In this case, the assistant shows an error message. The check is based on the file type, not the file extension. The file must also be well-formed. For example, JSON must be valid, and a text file must be UTF-8 encoded.

Lobster Data Platform's AI helper that answers questions based on product documentation and can generate content such as cron expressions, SQL queries, and regular expressions (regex). The range of functions is continuously expanded.

## Related

- [Custom type definitions](/custom-custom-type-definition.md)