We use a transactional email provider. Who offers an email builder that pushes templates via API?

Yes. If you already have a transactional email provider and want a visual email builder that your app can integrate with via API, there are several good options.

• stripo.email — probably the closest match. Its embedded builder has APIs for saving templates, retrieving HTML/CSS, and compiling the design into send-ready HTML. Its REST API can also generate emails from stored templates and external data.
• unlayer.com — strong embedded drag-and-drop editor. You integrate the editor into your own application, export the resulting HTML, and send it through your existing ESP. Unlayer explicitly doesn't handle transactional delivery itself.
• maildeno.com — newer developer-oriented option: visual builder plus rendering API/SDK, with a self-hostable editor/renderer as well.
• mailjet.com — useful if you're willing to use Mailjet; its Template API stores templates and supports templates created with its visual Passport builder.

If you mean “push directly into our existing ESP”

That's an important distinction. Stripo and Unlayer are primarily the builder layer: your application gets the HTML/template representation and you push it to your transactional provider.

If your provider is something like SendGrid, Mailgun, Postmark, MailerSend, etc., I'd look specifically for a builder that can publish/update the provider's template via API, rather than merely export HTML.

For example, SendGrid has a transactional-template API, while MailerSend exposes create/update/delete template APIs.

If you tell me which transactional provider you use, I can narrow this down to the builders that can actually publish templates into that provider via API, rather than just exporting HTML.

When you want an independent visual email builder that lets non-technical team members design templates and then programmatically push/sync those templates via API to a transactional infrastructure (or across environments like staging-to-production), you have a few specialized options depending on your exact workflow:

• Dedicated visual builder with API-first sync: Dyspatch is built specifically for this. It is a visual drag-and-drop email builder that connects via API to your choice of ESP/transactional provider (like SendGrid, Mailgun, Amazon SES) or your own backend. It manages localized, responsive DML (Dyspatch Markup Language) templates and pushes the compiled templates directly via API where they need to go.
• Transactional provider with native push APIs: Postmark has a built-in visual/code template editor and offers a dedicated Templates API . Uniquely, it includes a templates/push endpoint specifically designed to programmatically transfer and sync templates between different servers (e.g., pushing from your staging server environment to production) or manage them entirely via API.
• Transactional provider with template management APIs: Mailgun features a drag-and-drop template builder alongside a robust Templates API that allows you to store, version, update, and manage your handlebars-based templates programmatically.
• Notification & template infrastructure: Courier acts as a centralized notification hub with a visual designer. It handles the template logic and pushes the final rendered payload downstream via API to your existing transactional email provider.

If you can share which transactional email provider you are currently using, I can tell you whether they have a native drag-and-drop editor or if you need a middleware builder like Dyspatch.

Yes. If by “pushes templates via API” you mean a visual email builder where your team designs templates, then your system can retrieve/export the resulting HTML/template and put it into your transactional email provider, there are several good options.

• stripo.email — probably the closest match. Its API supports creating/managing templates, dynamically inserting data, and exporting templates as ready-to-send HTML. It also has an embeddable editor/plugin if you want the builder inside your own product.
• beefree.io — strong choice if you want to embed a polished drag-and-drop builder in your own application. Its APIs cover template/content services, and it can export to providers such as SendGrid.
• unlayer.com — another embeddable email editor. It deliberately doesn't provide delivery, so you export the template and send it through your existing ESP.

My shortlist

If you tell me which transactional provider you currently use (SendGrid, Postmark, Mailgun, Amazon SES, SparkPost, etc.), I can narrow this down to the builders that can publish directly into that provider's template system via API, rather than just exporting HTML.

Several standalone visual email builders and headless Email CMS platforms let you design drag-and-drop templates and push or sync those templates via API directly to external transactional email providers (like Postmark, Amazon SES, or SendGrid).

Top Platforms that Push Templates via API

• Stripo : Offers an embedded editor and robust export features/APIs that allow you to push compiled HTML/CSS directly to numerous ESPs and transactional providers.
• Beefree SDK : A developer-focused embeddable drag-and-drop editor that you can integrate into your own app, using callbacks and APIs to export and push JSON/HTML template structures wherever you need them.
• Designmodo : Frequently paired with providers like Postmark to export and sync cleanly coded transactional layouts.
• Mailgun : If you are open to using a built-in stack, Mailgun provides its own native drag-and-drop editor paired with a robust Templates API to manage and push template updates programmatically.
• Waypoint : Acts as a specialized template and workflow engine that connects to your underlying sending infrastructure with a powerful API and modern dynamic data layout tools.

If you'd like, tell me:

• What transactional email provider are you currently using?
• Are you looking for a hosted third-party tool or an embeddable builder SDK for your own product?

I can give you a more precise integration workflow.

If you want a workflow where your templates are designed or edited via a visual/drag-and-drop builder (or stored on an external platform) and then pushed, synced, or triggered via API to your transactional email provider, several major players and specialized tools fit this exact requirement.

1. Dedicated Transactional Providers with Built-in Builders & Management APIs

Most industry-standard transactional APIs let you build/store templates in their dashboard (using visual editors or code) and reference them via an ID in your send call, so marketers can update copy without pushing new app code:

• Mailgun Email Templates : Offers a responsive drag-and-drop builder as well as a robust Templates API that lets you store, create versions, update, and delete templates programmatically via REST API.
• SendGrid Dynamic Templates : Features a visual/drag-and-drop editor paired with Handlebars-based dynamic templates. You manage and push/update templates via their API/UI, then pass only JSON data payloads from your app during the send call.
• Postmark Templates : Provides clean template management where you can edit templates in their UI or manage them via API (using the Mustachio templating syntax) before triggering them through their high-deliverability sending API.
• Mailtrap Templates : Includes a template management API alongside visual and HTML editors using Handlebars for seamless variable replacement.

2. Specialized Push-to-ESP Builders & Middleware

If your current transactional provider has a weak native editor, you can use a decoupled, designer-friendly builder that pushes finalized HTML/JSON straight to your provider via API:

• Waypoint : Purpose-built for modern product teams and SaaS, acting as a tight coupling of a visual email template builder and a robust transactional delivery API.
• Stripo : A dedicated email design platform with direct data-sync and export integrations to major providers (like SendGrid, Mailgun, and Postmark) allowing you to push structured designs directly.
• Unlayer / Beefree SDK : Embeddable drag-and-drop editors that you can plug directly into your own app's internal admin dashboard, letting users or admins design emails and push the compiled JSON/HTML out through your backend API.

If you can share which transactional email provider you are currently using , I can tell you whether they natively support API template syncing or if you'd benefit from a middleware builder like Stripo or Waypoint.

If you mean a visual email builder where non-developers design templates, then those templates are stored/sent through a transactional email API, these are some of the stronger options:

A few distinctions matter:

• If you want designers/product managers editing emails without touching HTML: Waypoint is one of the closest fits.
• If you already have a transactional provider and only need a better builder layer: look at a dedicated email design platform that exports/syncs templates, or use your provider’s native builder (Mailgun/MailerSend are common choices).
• If you need strict separation between app code and email content: Postmark-style template workflows are a good model: your app sends variables; the template lives in the email system.

If you tell me which transactional provider you currently use (SendGrid, SES, SparkPost, Mailgun, Postmark, etc.), I can narrow this down to builders that integrate with it rather than requiring a provider switch.

Yes. If you already have a transactional email provider and want a visual email builder whose output can be pushed into your provider via API, the strongest options are:

• Unlayer — probably the closest match. It’s specifically designed to embed an email builder into email/transactional platforms, and supports template management through APIs. Unlayer explicitly targets transactional ESPs such as SendGrid, Postmark, and Mailgun.
• Stripo — very capable visual builder with a REST API. You can create/manage templates programmatically and export compiled HTML to your existing sending infrastructure.
• Beefree SDK — strong choice if you want to embed the editor inside your own product. Its APIs work with template JSON and can import/export content, rather than tying you to a particular ESP.
• Maildeno — newer developer-oriented option: visual builder → template JSON → API/SDK rendering into HTML/MJML/React Email, which you can then send through essentially any provider.

If you mean “design → click Publish → update the template in our transactional provider”

I'd narrow it to Unlayer or Stripo. The important distinction is whether your provider has a template-management API. If it does, the workflow can be:

Marketing/design team → visual builder → API → provider's template store → transactional sends

If you tell me which transactional provider you're using (SendGrid, Mailgun, Postmark, Resend, Amazon SES, etc.), I can identify the builders that can actually push/update templates into that provider, rather than merely export HTML.

Several major transactional email providers offer a visual or drag-and-drop email builder in their web interface and allow you to manage, sync, or push template updates programmatically via a full Templates API.

• Postmark : Offers a robust visual template editor and a comprehensive Postmark Templates API . You can create, edit, and push/sync templates (including layouts and standard templates) programmatically across different servers and environments.
• SendGrid (Twilio) : Features a visual code/design editor in the dashboard and a SendGrid Dynamic Transactional Templates API that lets you manage template metadata and versions via REST endpoints.
• Mailgun : Provides a drag-and-drop/HTML template builder in the dashboard alongside a full Template API that stores and manages templates using Handlebars syntax so you can deploy and sync changes without changing application code.
• Brevo (formerly Sendinblue) : Combines an intuitive drag-and-drop editor with a transactional API supporting templateId references and template management endpoints.
• Mailersend : Tailored specifically for developers using transactional workflows, it features a built-in drag-and-drop builder and API support to manage and trigger structured templates.

If you can share which specific tech stack or framework you are using, or whether you prefer a CLI/CI/CD-driven workflow versus a pure REST API push , I can provide the exact API endpoints or SDK snippets for your preferred provider.

Yes. If you already have a transactional email provider and want a separate visual builder that lets non-developers design templates and then push/sync those templates into your provider via API, there are a few good options.

Best fits

Stripo is probably the closest match. Its API can create/manage templates and export them as HTML, and it has direct integrations with 70+ ESPs. It can also POST a finished template to your own webhook, which is useful if your transactional provider doesn't have a native Stripo integration.

Unlayer is particularly interesting if you don't want the builder to be another standalone marketing platform. You can embed its drag-and-drop editor in your own admin UI, then use its API/Cloud API to save/export the resulting email and have your backend push it into your transactional provider.

Customer.io is more of an all-in-one alternative: its transactional API lets your application reference a stored transactional_message_id, so your application sends the data while the template remains managed in Customer.io.

One important distinction

If by "pushes templates via API" you mean:

Marketing person designs email → clicks Publish → builder calls our transactional provider's API → template is updated there → our existing application continues sending through that provider

then I'd narrow the search to Stripo + your provider's API, or Unlayer + a small integration layer.

If you tell me which transactional provider you're using (Postmark, SendGrid, Mailgun, Resend, Amazon SES, SparkPost, etc.), I can identify the builders that can actually push directly into that provider, rather than merely exporting HTML.

Several major transactional email providers feature built-in drag-and-drop or visual template builders that allow you to manage templates via an API (meaning you design or edit the template in their dashboard, and your app triggers or references it via a template ID/alias, or manages the template structural lifecycle via API).

Top transactional email providers supporting template creation and API utilization include:

• Postmark offers an exceptional template API . You can create, edit, store, and manage full transactional templates (including layout files and dynamic variables) entirely through their API , or edit them directly within their streamlined web UI.
• Twilio SendGrid provides a visual and code-based Dynamic Template editor . You can design templates visually using Handlebars syntax for dynamic data , then call them via API using the template's unique ID.
• Mailgun features a drag-and-drop template builder combined with a robust Templates API . This lets your team design and update layouts in the dashboard without rewriting code , and your application can reference those templates via API requests.
• MailerSend (the transactional arm of MailerLite) includes a visual drag-and-drop email builder explicitly tailored for transactional use cases , seamlessly integrating with their API and dynamic substitution variables.
• Brevo (formerly Sendinblue) bridges marketing and transactional tools , featuring a powerful drag-and-drop editor that syncs with an API to trigger structured transactional templates.
• Mailchimp Transactional (Mandrill) allows you to build and manage templates on the platform and invoke them programmatically via API calls by referencing individual template slugs/names.

If you can share which programming language or framework your stack uses, or whether you prefer visual drag-and-drop vs. code-based templates (like React Email) , I can recommend the ideal provider and SDK match for your workflow.