Quickstart: Your First LinkML Schema in 10 Minutes

This tutorial walks you through creating a small schema from scratch, connecting classes, validating your model, and exporting the YAML — all without writing a line of YAML by hand.

What you'll build: a simple bookstore schema with Book, Author, and a Genre enumeration.

1. Open the App and Start a New Project

Open the app in your browser:

Local development: pnpm dev, then visit http://localhost:5173
Live demo: https://adamlabadorf.github.io/linkml-modeler-app/app/

The splash page appears. Click New Empty Project.

The canvas opens with a single blank schema file (untitled_schema.yaml) already loaded in the Project Panel on the left.

Want to skip ahead?

Download the sample schemas and open them with Open Local Folder instead.

2. Add Your First Class

Right-click anywhere on the empty canvas and choose Add Class from the context menu.

A new node named ClassName appears. It is immediately selected, and the Properties Panel on the right shows its editable fields.

In the Name field, type Book and press Enter.
In the Description field, type A book in the bookstore catalog.

The node on the canvas updates to show the new name.

3. Add Slots (Attributes) to Book

With Book still selected in the Properties Panel, scroll down to the Attributes section. Type a name in the text field and click + Add.

Add the following attributes one at a time:

Name	Range	Notes
`isbn`	`string`	Check Identifier
`title`	`string`	Check Required
`year_published`	`integer`
`genre`	(leave as string for now)	You will change this after creating the enum

Setting range

After adding an attribute, click its row in the Properties Panel to expand it. The Range dropdown lists built-in LinkML types (string, integer, boolean, date, …) and all classes and enums defined in your schema.

4. Add the Author Class

Right-click the canvas again and choose Add Class. Name the new class Author and add these attributes:

Name	Range	Notes
`name`	`string`	Check Required
`bio`	`string`

5. Add a Genre Enumeration

Right-click the canvas and choose Add Enum. Name the new enum Genre.

In the Properties Panel, type a value name in the permissible values field and click + Add. Add these values one at a time:

fiction
non_fiction
mystery
science_fiction
biography

6. Wire Up the Genre Range

Click the Book node to select it. In the Properties Panel, find the genre attribute and change its Range to Genre (the enum you just created). The dropdown will show all available types including your new enum.

7. Add Books ↔ Author Relationship

Click the Book node. Add a new attribute named author with Range set to Author.

Now you have a cross-class reference: Book.author → Author.

8. Connect Inheritance (Optional Bonus Step)

Suppose you want a RareBook that extends Book.

Right-click the canvas → Add Class → name it RareBook.
Hover over the RareBook node until small connection handles appear on its edges.
Drag from a handle on RareBook to any handle on Book. This creates an is_a relationship — an inheritance arrow on the canvas.
In the Properties Panel you will see is_a: Book already set.

Add a condition attribute (string) to RareBook to describe its preservation state.

9. Validate Your Schema

Click ✓ Validate in the header (or press the button — it opens the Validation Panel at the bottom).

A schema with a Book.isbn marked as an identifier and a Book.title marked as required should validate cleanly. If you see any errors, the panel shows the affected element and a description — click to jump to it.

Common validation errors

A slot's range points to a class or enum that no longer exists (e.g. you renamed it).
A required identifier slot has no range set.
Circular inheritance — class A is_a B is_a A.

10. Inspect the YAML Preview

Look at the YAML Preview panel on the far right. It shows exactly what the editor would write to disk — a valid LinkML YAML document generated live from your visual model.

You should see output similar to:

yaml

id: https://example.org/untitled_schema
name: untitled_schema
prefixes:
  linkml: https://w3id.org/linkml/
default_prefix: untitled_schema
imports:
  - linkml:types
classes:
  Book:
    description: A book in the bookstore catalog
    attributes:
      isbn:
        identifier: true
        range: string
      title:
        required: true
        range: string
      year_published:
        range: integer
      genre:
        range: Genre
      author:
        range: Author
  Author:
    description: ''
    attributes:
      name:
        required: true
        range: string
      bio:
        range: string
enums:
  Genre:
    permissible_values:
      fiction: {}
      non_fiction: {}
      mystery: {}
      science_fiction: {}
      biography: {}

11. Save Your Work

Press Ctrl+S (or Cmd+S on macOS).

Because this is a new project with no save location yet, a directory picker opens. Choose (or create) a folder on your machine — for example ~/schemas/bookstore. The editor writes untitled_schema.yaml into that folder.

After saving, the ● unsaved changes badge in the header disappears.

12. Reload and Verify Round-Trip

Go to File → Open Project… in the menu bar. This closes the current project and returns to the splash page.
On the splash page, click Open Local Folder and pick the bookstore folder you saved to.
The editor re-reads the YAML, rebuilds the canvas, and your schema is restored exactly.

The YAML Preview and the canvas should match what you left — confirming that the round-trip (visual → YAML → visual) preserves your model faithfully.

What's Next?

User Guide — detailed reference for every panel and feature.
Schema Settings — click ⚙ in the header to set a real schema URI, add prefixes, or manage imports.
Multi-schema projects — download the pets + pets-base sample to see how imports: work across multiple files in one project.
Git integration — open the Git Panel at the bottom to commit your schema and track changes over time.

Sample Schemas

Download these sample schemas to explore specific LinkML features in the editor. To use them:

Download the file(s) to a local folder.
On the app splash page, click Open Local Folder and select that folder.

Beginner: Bookstore

A 3-class schema with a simple enum — a clean starting point.

Download bookstore.yaml

Covers: classes, attributes, identifier slots, required slots, enumerations, cross-class ranges.

Intermediate: Pet Registry (multi-schema import)

Two files — pets.yaml imports pets_base.yaml for a base Animal class and a HealthStatus enum.

Download pets_base.yaml · Download pets.yaml

Place both files in the same folder before opening. The editor resolves the import automatically.

Covers: multi-file projects, imports:, inherited classes, cross-schema ranges.

Advanced: Library Catalog

A realistic schema with shared slots, URI mappings, subsets, validation rules, and email pattern constraints.

Download library_catalog.yaml

Covers: named slots, slot_uri, prefixes (schema:, dcterms:), subsets, pattern, minimum_value / maximum_value, conditional rules (preconditions / postconditions).

Quickstart: Your First LinkML Schema in 10 Minutes ​

1. Open the App and Start a New Project ​

2. Add Your First Class ​

3. Add Slots (Attributes) to Book ​

4. Add the Author Class ​

5. Add a Genre Enumeration ​

6. Wire Up the Genre Range ​

7. Add Books ↔ Author Relationship ​

8. Connect Inheritance (Optional Bonus Step) ​

9. Validate Your Schema ​

10. Inspect the YAML Preview ​

11. Save Your Work ​

12. Reload and Verify Round-Trip ​

What's Next? ​

Sample Schemas ​

Beginner: Bookstore ​

Intermediate: Pet Registry (multi-schema import) ​

Advanced: Library Catalog ​