Docs / Templates / Email Header template | HTML to Image API Docs

Email Header template

The email-header template renders a content image as a PNG. POST a JSON payload to the endpoint below and you receive a CDN URL in the response.

Endpoint

POST https://app.html2img.com/api/v1/templates/email-header
X-API-Key: <your-api-key>
Content-Type: application/json

Authentication uses the X-API-Key header. See the authentication docs for details on issuing and rotating keys.

Inputs

The full set of inputs the template accepts:

Name	Type	Required	Description	Example
`title`	string	Yes	Main headline shown in the image.	`The Production Hour Weekly`
`subtitle`	string	No	Secondary line of text shown below the title.	`Conversations from the people running real systems`
`issue_number`	string	No	Text value for the issue number.	`Issue #042`
`publication_date`	string	No	Text value for the publication date.	`May 6, 2026`
`background_pattern`	enum (none \| dots \| grid \| waves)	No	One of the supported background pattern values listed below.	`dots`
`accent_color`	string	No	Hex colour code for the accent.	`#7C3AED`
`background_color`	string	No	Hex colour code for the background.	`#0F172A`
`brand_logo_url`	url	No	URL of the brand logo to include in the rendered image.	`-`

Enum values

background_pattern accepts one of: none , dots , grid , waves .

Defaults

Defaults applied automatically when not overridden in the request:

Option	Default value
`width`	`1200`
`height`	`300`

Code examples

curl -X POST https://app.html2img.com/api/v1/templates/email-header \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"title":"The Production Hour Weekly","subtitle":"Conversations from the people running real systems","issue_number":"Issue #042","publication_date":"May 6, 2026","background_pattern":"dots","accent_color":"#7C3AED","background_color":"#0F172A"}'

<?php
$response = \Illuminate\Support\Facades\Http::withHeaders([
    'X-API-Key' => 'YOUR_API_KEY',
])->post('https://app.html2img.com/api/v1/templates/email-header', ['title' => 'The Production Hour Weekly', 'subtitle' => 'Conversations from the people running real systems', 'issue_number' => 'Issue #042', 'publication_date' => 'May 6, 2026', 'background_pattern' => 'dots', 'accent_color' => '#7C3AED', 'background_color' => '#0F172A']);

$url = $response->json('url');

const response = await fetch('https://app.html2img.com/api/v1/templates/email-header', {
  method: 'POST',
  headers: {
    'X-API-Key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "title": "The Production Hour Weekly",
    "subtitle": "Conversations from the people running real systems",
    "issue_number": "Issue #042",
    "publication_date": "May 6, 2026",
    "background_pattern": "dots",
    "accent_color": "#7C3AED",
    "background_color": "#0F172A"
}),
});

const { url } = await response.json();

import requests

response = requests.post(
    'https://app.html2img.com/api/v1/templates/email-header',
    headers={'X-API-Key': 'YOUR_API_KEY'},
    json={'title': 'The Production Hour Weekly', 'subtitle': 'Conversations from the people running real systems', 'issue_number': 'Issue #042', 'publication_date': 'May 6, 2026', 'background_pattern': 'dots', 'accent_color': '#7C3AED', 'background_color': '#0F172A'},
)

url = response.json()['url']

Looking for a fuller integration sketch in your language? The usage guides cover PHP, Laravel, Rails, Python, JavaScript, React and Vue.

Response

A successful render returns:

{
 "success": true,
 "id": "abc123",
 "url": "https://i.html2img.com/abc123.png",
 "credits_remaining": 1234,
 "template": "email-header"
}

The url field is a CDN URL for the rendered PNG. credits_remaining tracks your monthly quota. Shared response fields are documented in the API parameters reference.

Errors

The template endpoint returns the following error responses:

422 Validation failed

Returned when one or more inputs fail validation. The errors object lists field-specific messages.

{
 "success": false,
 "error": "validation_failed",
 "errors": {
 "title": ["The title field is required."]
 }
}

404 Template not found

Returned with {"code": "template_not_found"} if the slug is not registered. Check the template list for current slugs.

401 Unauthorised

Missing or invalid API key. See the authentication docs.

429 Too many requests

You have hit the rate limit or used your monthly credits. The pricing page covers higher-volume plans.

Related templates

Quote Card - Pull-quote cards for testimonials, reviews, and shareable quotes
Podcast Episode Card - Per-episode share cards sized for Twitter, LinkedIn, and Slack unfurls
Podcast Cover - Square cover artwork sized for Apple Podcasts, Spotify, and the major directories
Blog Featured Hero - Editorial hero images for blog posts and article pages

See the Email Header template in our gallery for sample renders and use cases.

Documentation