What is a custom stack template?

A custom stack template is a reusable recipe for an application stack that your own team writes once and deploys many times. On SeaGit it lists up to 12 applications (Helm charts or Docker images), the form someone fills in to deploy it, the secrets to generate, the order to install things in, and the connection details to show afterwards. It is private to your account.

Which plans include the template builder?

Pro, Startup and Enterprise. Building a template and editing it need a paid plan, and the platform refuses a save from a Free or expired account. An account that downgrades can still delete its templates, and stacks already deployed from them keep running.

Can one template mix Helm charts and Docker images?

Yes. Each application in a template is either a Helm chart (repository, chart name, version and values) or a Docker image (registry, image, tag, port, CPU, memory, copies and a health check path). A typical template puts a database chart in the first stage and Docker services that connect to it in the next.

How do applications in a template find each other?

With values the platform fills in at deploy time. ${stack. .svc} is another application’s in-cluster service address and ${stack. .url} its public address. ${secret. } is a generated 43-character secret shared by every application that uses the same name, so a database and its clients agree on a password nobody typed.

Is this an alternative to Backstage Software Templates?

For deploying stacks, yes. Backstage’s scaffolder generates repositories and runs the actions you script, and you host and maintain the portal yourself. A SeaGit template deploys the applications directly into a Kubernetes cluster in your own AWS account, with no portal to run. If you need a service catalog and scorecards, Backstage or a hosted portal still fits that job.

Feature · Paid plans

Self-service stack templates for Kubernetes

Turn the stack your team keeps rebuilding into a template: Helm charts and Docker images, a form to fill in, secrets generated for you, and an install order that waits for the database. Anyone on the team deploys it into your own AWS account in a few clicks.

See plans Read the guide

What are stack templates on SeaGit?

A stack template is a private, reusable definition of a whole application stack that a developer builds once and the rest of the team deploys from a form. One template holds up to 12 applications, each a Helm chart or a Docker image, plus up to 40 form inputs, the secrets to generate, install stages and up to 20 connection details to show when the stack is running. Applications reach each other through values filled in at deploy time, such as ${stack.db.svc} for a database address or ${secret.db_password} for a password generated once and shared. A stage can wait until the previous one is healthy, so nothing starts before what it depends on. Templates deploy into a Kubernetes cluster in your own AWS account, the same way the ready-made RAG, Redis and database stacks do. Building templates is part of the paid plans.

How to build a stack template

1
Describe the stack
Name it, pick a category, and add up to 12 applications. Each is a Helm chart or a Docker image from Docker Hub, Amazon ECR Public, GitHub (ghcr.io) or Quay.
2
Design the form people fill in
Add up to 40 inputs: text, number, dropdown, radio buttons, yes/no or secret. Use any answer anywhere in the template as ${form.<key>}.
3
Set the install order
Group applications into stages. A stage can wait until the previous one is healthy, so a database is ready before the API that migrates it starts.
4
Wire secrets, cloud access and outputs
Generate passwords with ${secret.<name>}, give an application a new or existing IAM role, and list up to 20 connection details to show on the Stack tab once it is running.
5
Check, save, deploy
A Check panel lists every problem before you save. Saved templates appear in your Templates catalog, and anyone allowed to create applications deploys them into the environments you allow.

What can a template contain?

Helm charts with values that reference form answers, secrets and other applications.
Docker images with port, CPU, memory, copies, health check and container arguments.
Reach per application: inside the cluster only, or exposed to the internet on your domain.
Variables and secrets per application, including generated secrets nobody has to type.
Cloud access per application: none, a new IAM role with access rules, or an existing role.
Install stages that start right away or wait until the previous stage is healthy.
An outputs panel with a heading you choose: addresses, ports and secrets behind Reveal.
A Code tab with the whole template as JSON, for review or copying between accounts.

How are stack templates different from a developer portal?

Stack templates deploy the stack; a developer portal catalogues it. Backstage Software Templates, for example, render a skeleton repository, publish it and register it in a catalog, and deploying the result is left to pipelines you build behind them. A SeaGit stack template holds the running stack itself: up to 12 Helm charts and Docker images, the form, the generated secrets and the install order. A developer who has never written a values file deploys it correctly, and there is no portal to host or upgrade. What you give up is the catalog: templates do not track service ownership or score services against standards.

Looking at Backstage alternatives? See Backstage alternatives compared. Moving a multi-service app off Docker Compose? See Docker Compose alternatives for production. And see how templates compare with Render Blueprints, Railway templates and Northflank templates.

Start from a working example

The builder’s Load an example button fills in a four-application stack (a Redis cache that installs first, then an API, a worker and a dashboard that use it) that passes every check, so you can edit something that works rather than start from a blank page. The step-by-step guide walks through a database plus API template end to end. Ready-made stacks built the same way: RAG stacks, Redis and the LLM gateway. Compare plans on the plans page.

Stack templates — FAQ

What is a custom stack template?: A custom stack template is a reusable recipe for an application stack that your own team writes once and deploys many times. On SeaGit it lists up to 12 applications (Helm charts or Docker images), the form someone fills in to deploy it, the secrets to generate, the order to install things in, and the connection details to show afterwards. It is private to your account.
Which plans include the template builder?: Pro, Startup and Enterprise. Building a template and editing it need a paid plan, and the platform refuses a save from a Free or expired account. An account that downgrades can still delete its templates, and stacks already deployed from them keep running.
Can one template mix Helm charts and Docker images?: Yes. Each application in a template is either a Helm chart (repository, chart name, version and values) or a Docker image (registry, image, tag, port, CPU, memory, copies and a health check path). A typical template puts a database chart in the first stage and Docker services that connect to it in the next.
How do applications in a template find each other?: With values the platform fills in at deploy time. ${stack.<app>.svc} is another application’s in-cluster service address and ${stack.<app>.url} its public address. ${secret.<name>} is a generated 43-character secret shared by every application that uses the same name, so a database and its clients agree on a password nobody typed.
Is this an alternative to Backstage Software Templates?: For deploying stacks, yes. Backstage’s scaffolder generates repositories and runs the actions you script, and you host and maintain the portal yourself. A SeaGit template deploys the applications directly into a Kubernetes cluster in your own AWS account, with no portal to run. If you need a service catalog and scorecards, Backstage or a hosted portal still fits that job.