REST API Development

When to Use This Skill

Use this skill when building REST APIs with ColdBox, including API routing, handlers, authentication, versioning, and response formatting.

Language Mode Reference

Examples use BoxLang (.bx) syntax by default. Adapt for your target language:

Concept	BoxLang (.bx)	CFML (.cfc)
Class declaration	class [extends="..."] {	component [extends="..."] {
DI annotation	@inject above property name="svc";	property name="svc" inject="svc";
View templates	.bxm suffix	.cfm / .cfml suffix
Tag prefix	<bx:if>, <bx:output>, <bx:set>	<cfif>, <cfoutput>, <cfset>

CFML Compat Mode: With BoxLang + CFML Compat module, .bx and .cfc files coexist freely. BoxLang-native classes use class {} (.bx files); CFML-compat classes use component {} (.cfc files).

Core Concepts

ColdBox REST APIs use:

• RestHandler — base handler with built-in error handling and response formatting
• event.renderData() — renders JSON/XML/text responses with status codes
• Route resources — maps CRUD verbs to handler actions
• Modules — ideal for versioned API isolation
• JWT/cbSecurity — provides API authentication

API Module Structure

modules_app/
  api/
    config/
      Router.cfc       # API-specific routes
    handlers/
      Users.cfc        # Users API handler
      Posts.cfc
    models/
      UserTransformer.cfc
    ModuleConfig.cfc

RestHandler Base Class

class Users extends coldbox.system.RestHandler {

    @inject
    property name="userService";

    // Runs before every action - great for input validation
    function preHandler( event, rc, prc, action ) {
        // Validate content type for mutation methods
        if( !listFindNoCase( "index,show", action ) ){
            if( !event.isPost() && !event.isPut() && !event.isPatch() ){
                return
            }
            validateContentType( event )
        }
    }

    /**
     * GET /api/v1/users
     */
    function index( event, rc, prc ) {
        var users = userService.list(
            page    = rc.page ?: 1,
            limit   = rc.limit ?: 25,
            filters = getFilters( rc )
        )

        event.renderData(
            data = {
                "data"       : users.getRecords(),
                "pagination" : users.getPagination()
            },
            statusCode = 200
        )
    }

    /**
     * GET /api/v1/users/:id
     */
    function show( event, rc, prc ) {
        var user = userService.getById( rc.id ?: 0 )

        if( isNull( user ) ){
            return apiNotFound( "User not found" )
        }

        event.renderData( data = user.getMemento(), statusCode = 200 )
    }

    /**
     * POST /api/v1/users
     */
    function create( event, rc, prc ) {
        var payload = event.getHTTPContent( json = true )
        var result  = userService.create( payload )

        if( result.hasErrors() ){
            return apiValidationFailed( result.getErrors() )
        }

        event.renderData( data = result.getMemento(), statusCode = 201 )
    }

    /**
     * PUT /api/v1/users/:id
     */
    function update( event, rc, prc ) {
        var payload = event.getHTTPContent( json = true )
        var result  = userService.update( rc.id ?: 0, payload )

        if( isNull( result ) ){
            return apiNotFound( "User not found" )
        }

        if( result.hasErrors() ){
            return apiValidationFailed( result.getErrors() )
        }

        event.renderData( data = result.getMemento(), statusCode = 200 )
    }

    /**
     * DELETE /api/v1/users/:id
     */
    function delete( event, rc, prc ) {
        var deleted = userService.delete( rc.id ?: 0 )

        if( !deleted ){
            return apiNotFound( "User not found" )
        }

        event.renderData( data = "", statusCode = 204 )
    }

    // Private helpers

    private function getFilters( rc ) {
        return {
            search : rc.search ?: "",
            role   : rc.role ?: "",
            active : rc.active ?: ""
        }
    }

    private function apiNotFound( message ) {
        event.renderData(
            data       = { "error": message, "statusCode": 404 },
            statusCode = 404
        )
    }

    private function apiValidationFailed( errors ) {
        event.renderData(
            data = {
                "error"      : "Validation failed",
                "errors"     : errors,
                "statusCode" : 422
            },
            statusCode = 422
        )
    }

    private function validateContentType( event ) {
        if( event.getHTTPHeader( "Content-Type", "" ) does not contain "application/json" ){
            event.renderData(
                data       = { "error": "Content-Type must be application/json" },
                statusCode = 415
            )
            event.noRender( false )
        }
    }
}

CFML (.cfc):

component extends="coldbox.system.RestHandler" {

    property name="userService" inject="userService";

    // Runs before every action - great for input validation
    function preHandler( event, rc, prc, action ) {
        // Validate content type for mutation methods
        if( !listFindNoCase( "index,show", action ) ){
            if( !event.isPost() && !event.isPut() && !event.isPatch() ){
                return
            }
            validateContentType( event )
        }
    }

    /**
     * GET /api/v1/users
     */
    function index( event, rc, prc ) {
        var users = userService.list(
            page    = rc.page ?: 1,
            limit   = rc.limit ?: 25,
            filters = getFilters( rc )
        )

        event.renderData(
            data = {
                "data"       : users.getRecords(),
                "pagination" : users.getPagination()
            },
            statusCode = 200
        )
    }

    /**
     * GET /api/v1/users/:id
     */
    function show( event, rc, prc ) {
        var user = userService.getById( rc.id ?: 0 )

        if( isNull( user ) ){
            return apiNotFound( "User not found" )
        }

        event.renderData( data = user.getMemento(), statusCode = 200 )
    }

    /**
     * POST /api/v1/users
     */
    function create( event, rc, prc ) {
        var payload = event.getHTTPContent( json = true )
        var result  = userService.create( payload )

        if( result.hasErrors() ){
            return apiValidationFailed( result.getErrors() )
        }

        event.renderData( data = result.getMemento(), statusCode = 201 )
    }

    /**
     * PUT /api/v1/users/:id
     */
    function update( event, rc, prc ) {
        var payload = event.getHTTPContent( json = true )
        var result  = userService.update( rc.id ?: 0, payload )

        if( isNull( result ) ){
            return apiNotFound( "User not found" )
        }

        if( result.hasErrors() ){
            return apiValidationFailed( result.getErrors() )
        }

        event.renderData( data = result.getMemento(), statusCode = 200 )
    }

    /**
     * DELETE /api/v1/users/:id
     */
    function delete( event, rc, prc ) {
        var deleted = userService.delete( rc.id ?: 0 )

        if( !deleted ){
            return apiNotFound( "User not found" )
        }

        event.renderData( data = "", statusCode = 204 )
    }

    // Private helpers

    private function getFilters( rc ) {
        return {
            search : rc.search ?: "",
            role   : rc.role ?: "",
            active : rc.active ?: ""
        }
    }

    private function apiNotFound( message ) {
        event.renderData(
            data       = { "error": message, "statusCode": 404 },
            statusCode = 404
        )
    }

    private function apiValidationFailed( errors ) {
        event.renderData(
            data = {
                "error"      : "Validation failed",
                "errors"     : errors,
                "statusCode" : 422
            },
            statusCode = 422
        )
    }

    private function validateContentType( event ) {
        if( event.getHTTPHeader( "Content-Type", "" ) does not contain "application/json" ){
            event.renderData(
                data       = { "error": "Content-Type must be application/json" },
                statusCode = 415
            )
            event.noRender( false )
        }
    }
}

API Module Configuration

// modules_app/api/ModuleConfig.cfc
class ModuleConfig {

    property name="title"       default="API Module";
    property name="description" default="REST API";
    property name="version"     default="1.0.0";
    property name="entryPoint"  default="api";
    property name="author"      default="Ortus Solutions";

    function configure() {
        // Module settings
        settings = {
            jwtSecret     : getSystemSetting( "JWT_SECRET", "" ),
            tokenExpiry   : 60, // minutes
            refreshExpiry : 10080 // 7 days
        }
    }
}

// modules_app/api/config/Router.cfc
class Router extends coldbox.system.web.routing.Router {

    function configure() {
        // V1 resource routes
        group( pattern = "/v1" ) {
            resources( "users" )
            resources( "posts" )
        }
    }
}

CFML (.cfc):

// modules_app/api/ModuleConfig.cfc
component {

    property name="title"       default="API Module";
    property name="description" default="REST API";
    property name="version"     default="1.0.0";
    property name="entryPoint"  default="api";
    property name="author"      default="Ortus Solutions";

    function configure() {
        // Module settings
        settings = {
            jwtSecret     : getSystemSetting( "JWT_SECRET", "" ),
            tokenExpiry   : 60, // minutes
            refreshExpiry : 10080 // 7 days
        }
    }
}

// modules_app/api/config/Router.cfc
component extends="coldbox.system.web.routing.Router" {

    function configure() {
        // V1 resource routes
        group( pattern = "/v1" ) {
            resources( "users" )
            resources( "posts" )
        }
    }
}

JWT Authentication

class Auth extends coldbox.system.RestHandler {

    @inject
    property name="authService";

    @inject
    property name="jwtService";

    /**
     * POST /api/v1/auth/login
     */
    function login( event, rc, prc ) {
        var credentials = event.getHTTPContent( json = true )

        if( !authService.authenticate( credentials.email, credentials.password ) ){
            event.renderData(
                data       = { "error": "Invalid credentials" },
                statusCode = 401
            )
            return
        }

        var user  = authService.getAuthenticatedUser()
        var token = jwtService.fromUser( user )

        event.renderData(
            data = {
                "access_token"  : token,
                "token_type"    : "Bearer",
                "expires_in"    : 3600,
                "user"          : user.getMemento()
            },
            statusCode = 200
        )
    }

    /**
     * POST /api/v1/auth/refresh
     */
    function refresh( event, rc, prc ) {
        var bearer = getBearerToken( event )
        var token  = jwtService.refreshToken( bearer )

        event.renderData(
            data = { "access_token": token, "token_type": "Bearer" },
            statusCode = 200
        )
    }

    /**
     * POST /api/v1/auth/logout
     */
    function logout( event, rc, prc ) {
        var bearer = getBearerToken( event )
        jwtService.invalidateToken( bearer )
        event.renderData( data = { "message": "Logged out" }, statusCode = 200 )
    }

    private function getBearerToken( event ) {
        var header = event.getHTTPHeader( "Authorization", "" )
        return replaceNoCase( header, "Bearer ", "", "one" )
    }
}

CFML (.cfc):

component extends="coldbox.system.RestHandler" {

    property name="authService" inject="authService";

    property name="jwtService" inject="jwtService";

    /**
     * POST /api/v1/auth/login
     */
    function login( event, rc, prc ) {
        var credentials = event.getHTTPContent( json = true )

        if( !authService.authenticate( credentials.email, credentials.password ) ){
            event.renderData(
                data       = { "error": "Invalid credentials" },
                statusCode = 401
            )
            return
        }

        var user  = authService.getAuthenticatedUser()
        var token = jwtService.fromUser( user )

        event.renderData(
            data = {
                "access_token"  : token,
                "token_type"    : "Bearer",
                "expires_in"    : 3600,
                "user"          : user.getMemento()
            },
            statusCode = 200
        )
    }

    /**
     * POST /api/v1/auth/refresh
     */
    function refresh( event, rc, prc ) {
        var bearer = getBearerToken( event )
        var token  = jwtService.refreshToken( bearer )

        event.renderData(
            data = { "access_token": token, "token_type": "Bearer" },
            statusCode = 200
        )
    }

    /**
     * POST /api/v1/auth/logout
     */
    function logout( event, rc, prc ) {
        var bearer = getBearerToken( event )
        jwtService.invalidateToken( bearer )
        event.renderData( data = { "message": "Logged out" }, statusCode = 200 )
    }

    private function getBearerToken( event ) {
        var header = event.getHTTPHeader( "Authorization", "" )
        return replaceNoCase( header, "Bearer ", "", "one" )
    }
}

API Versioning

// Using modules for versioning
// modules_app/apiV1/ModuleConfig.cfc
class ModuleConfig {
    property name="entryPoint" default="api/v1";
}

// modules_app/apiV2/ModuleConfig.cfc
class ModuleConfig {
    property name="entryPoint" default="api/v2";
}

// URL-based versioning
group( pattern = "/api/v1" ) {
    resources( "users" )
}
group( pattern = "/api/v2" ) {
    resources( "users" )
}

// Header-based versioning
function preHandler( event, rc, prc, action ) {
    var version = event.getHTTPHeader( "Accept-Version", "v1" )
    prc.apiVersion = version
}

CFML (.cfc):

// Using modules for versioning
// modules_app/apiV1/ModuleConfig.cfc
component {
    property name="entryPoint" default="api/v1";
}

// modules_app/apiV2/ModuleConfig.cfc
component {
    property name="entryPoint" default="api/v2";
}

// URL-based versioning
group( pattern = "/api/v1" ) {
    resources( "users" )
}
group( pattern = "/api/v2" ) {
    resources( "users" )
}

// Header-based versioning
function preHandler( event, rc, prc, action ) {
    var version = event.getHTTPHeader( "Accept-Version", "v1" )
    prc.apiVersion = version
}

Pagination Response Structure

function index( event, rc, prc ) {
    var page  = rc.page ?: 1
    var limit = min( rc.limit ?: 25, 100 )   // cap at 100

    var results = userService.paginate(
        offset = ( page - 1 ) * limit,
        limit  = limit
    )

    event.renderData(
        data = {
            "data"  : results.records,
            "meta"  : {
                "total"       : results.total,
                "page"        : page,
                "limit"       : limit,
                "total_pages" : ceiling( results.total / limit ),
                "has_more"    : ( page * limit ) < results.total
            },
            "links" : {
                "self"  : buildLink( event.getCurrentEvent(), { page: page, limit: limit } ),
                "next"  : ( page * limit ) < results.total ? buildLink( event.getCurrentEvent(), { page: page + 1, limit: limit } ) : "",
                "prev"  : page > 1 ? buildLink( event.getCurrentEvent(), { page: page - 1, limit: limit } ) : ""
            }
        },
        statusCode = 200
    )
}

REST API Best Practices

• Use RestHandler over EventHandler for APIs — it adds proper error handling
• Use HTTP status codes correctly (200, 201, 204, 400, 401, 403, 404, 422, 500)
• Read request body with event.getHTTPContent( json = true ) for POST/PUT
• Structure responses consistently — always return data + optional meta + optional links
• Use modules for API versioning to keep versions independent
• Validate inputs before processing — return 422 with errors structure
• Secure endpoints with JWT + cbSecurity @secured annotations
• Use CORS interceptors for cross-origin access