Delphi-spec-kit Horse Framework

Patterns for developing REST APIs with Horse framework in Delphi

install
source · Clone the upstream repo
git clone https://github.com/delphicleancode/delphi-spec-kit
Claude Code · Install into ~/.claude/skills/
T=$(mktemp -d) && git clone --depth=1 https://github.com/delphicleancode/delphi-spec-kit "$T" && mkdir -p ~/.claude/skills && cp -r "$T/.claude/skills/horse-framework" ~/.claude/skills/delphicleancode-delphi-spec-kit-horse-framework && rm -rf "$T"
manifest: .claude/skills/horse-framework/SKILL.md
source content

Horse Framework — Skill

Use this skill when creating REST APIs with the Horse framework in Delphi.

When to Use

  • When creating a new REST API project
  • When adding routes and endpoints
  • When implementing middleware (JWT, CORS, logging)
  • When integrating Horse with FireDAC

About Horse

Horse is a minimalist and performant REST framework for Delphi, inspired by Express.js (Node.js). It uses the middleware chain concept and is extremely simple to configure.

Project Structure

src/
├── MeuApp.dpr                          ← Projeto principal
├── Controllers/
│   ├── MeuApp.Controller.Customer.pas
│   ├── MeuApp.Controller.Product.pas
│   └── MeuApp.Controller.Health.pas
├── Middleware/
│   ├── MeuApp.Middleware.Auth.pas
│   ├── MeuApp.Middleware.Logger.pas
│   └── MeuApp.Middleware.CORS.pas
├── Domain/
│   ├── MeuApp.Domain.Customer.Entity.pas
│   └── MeuApp.Domain.Customer.Repository.Intf.pas
├── Application/
│   └── MeuApp.Application.Customer.Service.pas
├── Infrastructure/
│   └── MeuApp.Infra.Customer.Repository.pas
└── Config/
    └── MeuApp.Config.Server.pas

Basic Server Configuration

program MeuApp;

{$APPTYPE CONSOLE}

uses
  Horse,
  Horse.Jhonson,       //JSON middleware
  Horse.CORS,          //CORS middleware
  Horse.HandleException,
  MeuApp.Controller.Customer,
  MeuApp.Controller.Health;

begin
  THorse.Use(Jhonson);
  THorse.Use(CORS);
  THorse.Use(HandleException);

  //Register broken
  TCustomerController.RegisterRoutes;
  THealthController.RegisterRoutes;

  THorse.Listen(9000,
    procedure
    begin
      Writeln('Server running on port 9000');
    end
  );
end.

Controller Pattern

unit MeuApp.Controller.Customer;

interface

uses
  Horse,
  System.JSON;

type
  TCustomerController = class
  public
    class procedure RegisterRoutes;
  private
    class procedure GetAll(AReq: THorseRequest; ARes: THorseResponse; ANext: TProc);
    class procedure GetById(AReq: THorseRequest; ARes: THorseResponse; ANext: TProc);
    class procedure Create(AReq: THorseRequest; ARes: THorseResponse; ANext: TProc);
    class procedure Update(AReq: THorseRequest; ARes: THorseResponse; ANext: TProc);
    class procedure Delete(AReq: THorseRequest; ARes: THorseResponse; ANext: TProc);
  end;

implementation

uses
  System.SysUtils,
  MeuApp.Application.Customer.Service.Intf;

class procedure TCustomerController.RegisterRoutes;
begin
  THorse.Get('/api/customers', GetAll);
  THorse.Get('/api/customers/:id', GetById);
  THorse.Post('/api/customers', Create);
  THorse.Put('/api/customers/:id', Update);
  THorse.Delete('/api/customers/:id', Delete);
end;

class procedure TCustomerController.GetAll(
  AReq: THorseRequest; ARes: THorseResponse; ANext: TProc);
var
  LService: ICustomerService;
  LResult: TJSONArray;
begin
  LService := TServiceFactory.CreateCustomerService;
  LResult := LService.GetAllAsJSON;
  ARes.Send<TJSONArray>(LResult).Status(THTTPStatus.OK);
end;

class procedure TCustomerController.GetById(
  AReq: THorseRequest; ARes: THorseResponse; ANext: TProc);
var
  LService: ICustomerService;
  LId: Integer;
  LResult: TJSONObject;
begin
  LId := AReq.Params['id'].ToInteger;
  LService := TServiceFactory.CreateCustomerService;

  LResult := LService.GetByIdAsJSON(LId);
  if not Assigned(LResult) then
  begin
    ARes.Send('Customer not found').Status(THTTPStatus.NotFound);
    Exit;
  end;

  ARes.Send<TJSONObject>(LResult).Status(THTTPStatus.OK);
end;

class procedure TCustomerController.Create(
  AReq: THorseRequest; ARes: THorseResponse; ANext: TProc);
var
  LService: ICustomerService;
  LBody: TJSONObject;
begin
  LBody := AReq.Body<TJSONObject>;
  LService := TServiceFactory.CreateCustomerService;

  try
    LService.CreateFromJSON(LBody);
    ARes.Send('Created').Status(THTTPStatus.Created);
  except
    on E: EValidationException do
      ARes.Send(E.Message).Status(THTTPStatus.BadRequest);
    on E: EBusinessRuleException do
      ARes.Send(E.Message).Status(THTTPStatus.Conflict);
  end;
end;

Custom Middleware

unit MeuApp.Middleware.Auth;

interface

uses
  Horse;

procedure AuthMiddleware(AReq: THorseRequest; ARes: THorseResponse; ANext: TProc);

implementation

uses
  System.SysUtils,
  Horse.JWT;

procedure AuthMiddleware(AReq: THorseRequest; ARes: THorseResponse; ANext: TProc);
var
  LToken: string;
begin
  LToken := AReq.Headers['Authorization'];

  if LToken.IsEmpty then
  begin
    ARes.Send('Token not provided').Status(THTTPStatus.Unauthorized);
    Exit;
  end;

  //Validar token JWT
  if not ValidateJWTToken(LToken) then
  begin
    ARes.Send('Invalid token').Status(THTTPStatus.Unauthorized);
    Exit;
  end;

  ANext; //continue to the next handler
end;

end.

Logger Middleware

unit MeuApp.Middleware.Logger;

interface

uses
  Horse;

procedure LoggerMiddleware(AReq: THorseRequest; ARes: THorseResponse; ANext: TProc);

implementation

uses
  System.SysUtils,
  System.DateUtils;

procedure LoggerMiddleware(AReq: THorseRequest; ARes: THorseResponse; ANext: TProc);
var
  LStartTime: TDateTime;
begin
  LStartTime := Now;
  Writeln(Format('[%s] %s %s',
    [FormatDateTime('hh:nn:ss', Now),
     AReq.MethodType.ToString,
     AReq.RawWebRequest.PathInfo]));

  ANext;

  Writeln(Format('[%s] Completed in %dms',
    [FormatDateTime('hh:nn:ss', Now),
     MilliSecondsBetween(Now, LStartTime)]));
end;

end.

Conventions for Horse

AppearanceConvention
URLsKebab-case, plural:
/api/customers
,
/api/order-items
HTTP MethodsGET (list/search), POST (create), PUT (update), DELETE (remove)
Status200 OK, 201 Created, 400 Bad Request, 404 Not Found, 500 Internal
ResponseAlways JSON via
Jhonson
middleware
ControllerStatic class methods with
RegisterRoutes
MiddlewareStandalone procedures or class methods
ParametersPath:
AReq.Params['id']
, Query:
AReq.Query['search']

Horse Add-on Packages

PackageUsageBoss Installation
horse-jhonson
JSON middleware
boss install horse-jhonson
horse-cors
CORS
boss install horse-cors
horse-jwt
JWT Authentication
boss install horse-jwt
horse-basic-auth
Basic Auth
boss install horse-basic-auth
horse-handle-exception
Error handler
boss install horse-handle-exception
horse-octet-stream
Upload/download
boss install horse-octet-stream

Checklist for Horse Projects

  • Jhonson
    registered middleware for automatic JSON?
  • CORS
    registered middleware?
  • HandleException
    middleware for error handling?
  • Routes follow RESTful convention (plural, kebab-case)?
  • Controllers use Services (do not access direct repository)?
  • Guard clauses in handlers before logic?
  • Correct HTTP status in responses?
  • Integration tests with
    TRESTClient
    simulating calls?