Unlayer Cloud API (2)

Welcome to the Unlayer REST API documentation. Our API enables you to programmatically access and manipulate email templates, designs, and other Unlayer resources.

The Unlayer API uses Basic Authentication. All requests require you to authenticate using a Unlayer Project API Key as the username with an empty string as the password:

curl -u YOUR_API_KEY: -X GET https://api.unlayer.com/v2/templates

All API calls must use HTTPS. Any calls made using HTTP will return an appropriate error code.

Follow these steps to get your API key:

1. Log in to the Developer Console
2. Create a Project
3. Find your API key in Project > Settings

Authorization: Basic BASE64-ENCODED-API-KEY

If you need to, you may construct and send basic auth headers yourself. To do this you need to perform the following steps:

1. Get the API Key
2. Build a string in the form of APIKey:Password where Password will always be empty. For example, if your API Key is XAyAztva4, you will just add a : at the end. XAyAztva4:
3. Base64 encode the string
4. Supply an Authorization header with content Basic followed by the encoded string. For example, the string XAyAztva4: encodes to WEF5QXp0dmE0Og== in base64. Here's how the request would look:

  curl -D- \
    -X GET \
    -H "Authorization: Basic WEF5QXp0dmE0Og==" \
    "https://api.unlayer.com/v2/templates"

All API requests will receive a standard HTTP response code.

Response Ranges

• 2xx -- Successful Request
• 4xx -- Failed Request (Client error)
• 5xx -- Failed Request (Server error)

This API is versioned. The current version is 2.0.

Manage email templates

Validate a design JSON against the Unlayer design schema. Returns { valid: true } when the payload conforms, or { valid: false, errors: [...] } with the path, message, and code of every issue when it doesn't. Always responds with HTTP 200 — valid is the source of truth.

Useful in CI, in import pipelines, and before saving — catching a schema problem before it reaches the editor produces a much better error message than letting the editor crash on render.

See Data Structures → Design object for the design shape this endpoint expects.

This endpoint lives on the v3 base URL: https://api.unlayer.com/v3. Authenticate with a Bearer token (API key with the unlayer_sk_ prefix).

Manage template folders

Convert a design JSON between Unlayer's two schema forms:

• Full — the rich representation the editor manipulates in memory. Every option, every computed default, every internal property. Verbose but lossless.
• Simple — the compact representation Unlayer stores and ships over the wire. Strips defaults and editor-only metadata, keeping the parts an external consumer needs.

Round-trip safely by passing includeConversion: true on the way out — the embedded _conversion metadata restores original values without data loss.

See Data Structures → Design object for the shape these endpoints accept and return.

These endpoints live on the v3 base URL: https://api.unlayer.com/v3. Authenticate with a Bearer token (API key with the unlayer_sk_ prefix).

You can use Unlayer's Cloud API to generate HTML, Image, PDF or ZIP file of your templates or designs.

The Cloud API helps you take care these common use-cases:

• Retrieving the HTML: This is useful if you do not store the HTML, or need to retrieve the latest HTML for a design.
• Generating a Image: This is useful to show thumbnails or previews of designs to users.
• Generating a PDF: You can use this to export a design in PDF format.
• Generating a ZIP: This will export a design as a ZIP file that will include their html and images.