Build your first Jeston application

Start · First application

Purpose — Connect a page, a server handler, and a real request contract into one small vertical slice.

A first application whose behavior can be inspected from browser to server response.

Key concepts

Page

Initial HTML

API

Status and JSON

Failure

Safe error body

What to verify

Area	Expected state	Evidence
Page	Initial HTML	Useful without waiting for client work.
API	Status and JSON	Stable for callers and tests.
Failure	Safe error body	Actionable without leaking internals.

Working example

request -> Jeston runtime -> typed boundary -> observable response

Before you move on

A vertical slice exposes integration mistakes earlier than a collection of disconnected components.

Implementation notes

Engineering move	Guidance
Create the route	Give the page or API endpoint a narrow responsibility.
Validate at the edge	Reject malformed input before domain work or persistence.
Return an explicit result	Choose status, headers, and body intentionally.
Exercise the failure path	Test bad input, missing data, and a cancelled request.

Decision lens

Mode	Practical emphasis
Page	Use SSR for initial content and clear loading boundaries.
API	Keep method handling and response shapes explicit.
Test	Assert observable behavior rather than implementation details.

Start

Core

Platform

Reference

Operations

Build your first Jeston application

Build your first Jeston application

Start · First application

Key concepts

Page

API

Failure

What to verify

Working example

Before you move on

Implementation notes

Decision lens

References

​Build your first Jeston application

​Start · First application

​Key concepts

Page

API

Failure

​What to verify

​Working example

​Before you move on

​Implementation notes

​Decision lens

​Related topics

​References

Build your first Jeston application

Start · First application

Key concepts

What to verify

Working example

Before you move on

Implementation notes

Decision lens

Related topics

References