horse-minimal-api

Horse Minimal API

For focused microservices, mock APIs, or rapid prototyping, you can leverage Horse's lightweight routing and configuration DSL to build complete HTTP services in a single file with minimal boilerplate.

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1. Single-File Bootstrap Design (Delphi)

A Minimal API structures all route registrations, basic logic, and middleware imports directly within the main .dpr bootstrap file using inline anonymous procedures:

program MinimalAPI;

{$APPTYPE CONSOLE}

uses
  System.SysUtils,
  System.JSON,
  Horse,
  Horse.Jhonson;

begin
  // 1. Fluent Middleware Configuration
  THorse.Use(Jhonson);

  // 2. Inline Route Mappings
  THorse.Get('/ping',
    procedure(Req: THorseRequest; Res: THorseResponse)
    begin
      Res.Send('pong');
    end);

  THorse.Get('/hello/:name',
    procedure(Req: THorseRequest; Res: THorseResponse)
    begin
      Res.Send('Hello, ' + Req.Params.Field('name').AsString + '!');
    end);

  // 3. Fast JSON response
  THorse.Get('/status',
    procedure(Req: THorseRequest; Res: THorseResponse)
    var
      LStatus: TJSONObject;
    begin
      LStatus := TJSONObject.Create(TJSONPair.Create('status', 'online'));
      Res.Send(LStatus); // Johnson takes ownership
    end);

  // 4. Port Listening
  THorse.Listen(9000);
end.

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2. Best Practices for Minimal APIs

Although Minimal APIs promote rapid development, follow these principles to avoid "spaghetti code":

1. Extract Complex Handlers: If a route handler exceeds 25 lines of code or requires database calls, do not write it inline. Extract it to a local unit procedure.
2. Use Radix Router: Opt-in to THorse.UseRadixRouter; to ensure maximum matching speed if your API contains path parameters.
3. Keep it Focused: A Minimal API should serve a single responsibility (Microservice). If you need to manage multiple domains (e.g. Users, Products, Invoices) in the same project, migrate to modular controllers.

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3. When to Transition to MVC Architecture

Transition from a Minimal API to a structured MVC/Modular architecture when: