diff --git a/server/api/Login/LoginByID.ts b/server/api/Login/LoginByID.ts
index 0f4e35e..bbf1575 100644
--- a/server/api/Login/LoginByID.ts
+++ b/server/api/Login/LoginByID.ts
@@ -11,10 +11,14 @@ class Q implements QType {
     username!: string;
     password!: string;
 }
-export class LoginByID extends POST<RType, EType, QType>{
+
+const procDecorator = [] as const;
+
+export class LoginByID extends POST<RType, EType, QType, typeof procDecorator>{
     readonly argValidator = Q;
+    readonly procDecorator = procDecorator;
     protected LoginByID = Symbol("LoginByID");//TODO: remove this
-    protected override async api(query: QType): Promise<RType | EType | true> {
+    protected override async api(query: QType, ctx,): Promise<RType | EType | true> {
         throw new Error("Method not implemented.");
     }
 }
\ No newline at end of file
diff --git a/server/api/Login/ReqNonce.ts b/server/api/Login/ReqNonce.ts
index ed5c8bd..71417c2 100644
--- a/server/api/Login/ReqNonce.ts
+++ b/server/api/Login/ReqNonce.ts
@@ -9,6 +9,7 @@ type QType = ExtractQuery<BaseAPI>;
 
 export class ReqNonce extends GET<RType, EType, QType>{
     readonly argValidator = undefined;
+    readonly procDecorator = [] as const;
     protected ReqNonce = Symbol("ReqNonce");//TODO: remove this
     protected override async api(query: QType): Promise<RType | EType | true> {
         throw new Error("Method not implemented.");
diff --git a/server/api/ProcDecorator/base.ts b/server/api/ProcDecorator/base.ts
index 72444bb..ecb00a7 100644
--- a/server/api/ProcDecorator/base.ts
+++ b/server/api/ProcDecorator/base.ts
@@ -1,67 +1,28 @@
 import type { Request, Response } from "express";
+import type { InvalidResponse } from "../../apiStructure/defs";
 
 type MayBePromise<T> = T | Promise<T>;
 
-export type InvalidProc = {
+export type Empty = Record<string, never>;
+export type InvalidProc = InvalidResponse & {
     invalidProcSymbol: unknown;
-    reason?: string;
     alreadyProcessed?: boolean;
-}
+};
 
 export interface ProcDecorator<Out, In extends object = Record<string, never>> {
-    (inCtx: In, req: Request, res: Response): MayBePromise<Out | InvalidProc>;
-}
-
-export type Empty = Record<string, never>;
-
-type Login = {
-    userID: number;
-}
-type GameLogin = {
-    userID: number;
-    generalID: number;
-}
-type UserLevel = {
-    userID: number;
-    userLevel: number;
-}
-
-export function ParseUserLevel<Q extends Login = Login>(): ProcDecorator<Q & UserLevel, Q> {
-    return (inCtx) => {
-        return {
-            userLevel: 123,
-            ...inCtx,
-        };
-    }
-}
-
-export function ReqLogin<Q extends object = Empty>(): [ProcDecorator<Q & Login, Q>, ProcDecorator<Login & object, Login & object>] {
-    return [
-        (inCtx) => {
-            return {
-                userID: 999,
-                ...inCtx,
-            };
-        },
-        (inCtx) => {
-            //무언가
-            return inCtx;
-        }
-    ]
-}
-
-export function ReqGameLogin<Q extends Login = Login>(): ProcDecorator<Q & GameLogin, Q> {
-    return (inCtx) => {
-        return {
-            generalID: inCtx.userID * 4,
-            ...inCtx,
-        };
-    }
+    (inCtx: In, req: Request, res: Response, isValidRoute: boolean): MayBePromise<Out | InvalidProc>;
 }
 
 export type ProcDecoratorGenerator<B extends object, A extends object> = ProcDecorator<B & A, A>;
 export type ProcDecoratorPrePostGenerator<B extends object, A extends object> = [ProcDecorator<B & A, A>, ProcDecorator<B & object, B & object>];
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type ProcDecoratorChain = undefined | readonly ((() => ProcDecorator<any, any>) | (() => [ProcDecorator<any, any>, ProcDecorator<any, any>]))[];
+
+export type ResolveChain<T> = T extends undefined ? Empty : T extends ProcDecoratorChain ? Resolve<PackChain<T>> : never;
+
+
+
 type Compose2<B extends object, A extends object, D, C> = D & B extends A & C ? B extends C ? ProcDecorator<D & B, A> : never : never;
 
 type PD1<B extends object, A extends object> = () => ProcDecorator<B, A>;
@@ -79,74 +40,3 @@ type PackChain<T> =
     never;
 
 type Resolve<T> = T extends ProcDecorator<infer B, infer A> ? Empty extends A ? B : never : never;
-
-
-export type ResolveChain<T extends ProcDecoratorChain> = Resolve<PackChain<T>>;
-
-const q1 = [
-    ReqLogin,
-    ParseUserLevel,
-    ReqGameLogin,
-] as const;
-
-const q2 = [
-    ReqLogin,
-    ParseUserLevel,
-] as const;
-
-
-type R1 = Resolve<PackChain<typeof q1>>;
-type R2 = Resolve<PackChain<typeof q2>>;
-const r1: R1 = undefined as unknown as R1;
-const r2: R2 = undefined as unknown as R2;
-r1.userLevel;
-r2.userID;
-
-
-async function test(req: Request, res: Response) {
-    const a0 = await ReqLogin()[0]({}, req, res);
-    if ('invalidProcSymbol' in a0) {
-        return false;
-    }
-    const a1 = await ParseUserLevel()(a0, req, res);
-    if ('invalidProcSymbol' in a1) {
-        return false;
-    }
-    const a2 = await ReqGameLogin()(a1, req, res);
-    if ('invalidProcSymbol' in a2) {
-        return false;
-    }
-    const b0 = await ReqLogin()[1](a2, req, res);
-    return true;
-}
-
-
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
-export type ProcDecoratorChain = readonly ((() => ProcDecorator<any, any>) | (() => [ProcDecorator<any, any>, ProcDecorator<any, any>]))[];
-
-function unpack2<A extends ProcDecorator<any, any>, B>(v: A | [A, B]): A {
-    if (Array.isArray(v)) {
-        return v[0];
-    }
-    return v;
-}
-
-function test2<T extends ProcDecoratorChain>(req: Request, res: Response, chain: T): Resolve<PackChain<T>> | false {
-    const tmp = chain[0]();
-
-    const actors = chain.map((v) => unpack2(v()));
-
-    let result = {};
-    for (const actor of actors) {
-        result = actor(result, req, res);
-        if ('isInvalid' in result) {
-            return false;
-        }
-    }
-    return result as Resolve<PackChain<T>>;
-}
-
-const finalResult1 = test2({} as Request, {} as Response, q1);
-if (finalResult1 !== false) {
-    finalResult1.userLevel;
-}
\ No newline at end of file
diff --git a/server/api/defs.ts b/server/api/defs.ts
index 37595be..25288fc 100644
--- a/server/api/defs.ts
+++ b/server/api/defs.ts
@@ -6,46 +6,164 @@ import {
     type ValidatorOptions,
 } from "class-validator";
 import { type ClassTransformOptions, plainToInstance } from "class-transformer";
+import { InvalidProc, ProcDecorator, ProcDecoratorChain, ResolveChain } from './ProcDecorator/base';
+import { clamp } from 'lodash-es';
 
 export type APINamespace = {
     [key: string]: APINamespace
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    | ClassType<GET<any, any, any>>
+    | ClassType<GET<any, any, any, any>>
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    | ClassType<POST<any, any, any>>
+    | ClassType<POST<any, any, any, any>>
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    | ClassType<PUT<any, any, any>>
+    | ClassType<PUT<any, any, any, any>>
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    | ClassType<DELETE<any, any, any>>
+    | ClassType<DELETE<any, any, any, any>>
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    | ClassType<PATCH<any, any, any>>
+    | ClassType<PATCH<any, any, any, any>>
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    | ClassType<HEAD<any, any, any>>
+    | ClassType<HEAD<any, any, any, any>>
     ;
 }
 
 type ValidatorType<T> = T extends undefined ? undefined : ClassType<T>;
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-export type AnyAPIExecuter = APIExecuter<any, any, any>;
+export type AnyAPIExecuter = APIExecuter<any, any, any, any>;
 
-export abstract class APIExecuter<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType>{
+export abstract class APIExecuter<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType, PD extends ProcDecoratorChain = ProcDecoratorChain>{
     readonly abstract reqType: HttpMethod;
     readonly abstract argValidator?: ValidatorType<Q>;
-    protected abstract parseQuery(expressReq: Request): Promise<Q>;
-    protected abstract api(query: Q, expressReq: Request, expressRes: Response): Promise<R | E | true>;
-    public async run(expressReq: Request, expressRes: Response): Promise<void> {
-        const query = await this.parseQuery(expressReq);
-        //TODO: middleware (인증, 요구사항, 아마도 decorator)
-        const result = await this.api(query, expressReq, expressRes);
-        if (result === true) {
+    readonly abstract procDecorator: PD;
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    private preDecorator: ProcDecorator<any, any>[] = [];
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    private postDecorator: (ProcDecorator<any, any> | undefined)[] = [];
+    private decoratorParsed = false;
+
+    public parseDecorator(): void {
+        if (this.decoratorParsed) {
             return;
         }
-        expressRes.json(result);
+        this.decoratorParsed = true;
+        if (!this.procDecorator) {
+            return;
+        }
+        for (const procGen of this.procDecorator) {
+            const proc = procGen();
+            if (Array.isArray(proc)) {
+                this.preDecorator.push(proc[0]);
+                this.postDecorator.push(undefined);
+            }
+            else {
+                this.preDecorator.push(proc);
+                this.postDecorator.push(proc);
+            }
+        }
+    }
+
+    private async preCtx(expressReq: Request, expressRes: Response): Promise<ResolveChain<PD> | [InvalidProc, ResolveChain<PD>, number]> {
+        if (!this.procDecorator) {
+            return {} as ResolveChain<PD>;
+        }
+
+        let ctx = {} as ResolveChain<PD>;
+        for (const [idx, proc] of this.preDecorator.entries()) {
+            try {
+                const result = await proc(ctx, expressReq, expressRes, true);
+                if ('invalidProcSymbol' in result) {
+                    return [result, ctx, idx];
+                }
+                ctx = result;
+            }
+            catch (e) {
+                return [{
+                    result: false,
+                    reason: `internal error[${idx}]: ${e}`,
+                    invalidProcSymbol: ['preCtx', idx],
+                }, ctx, idx];
+            }
+        }
+        return ctx;
+    }
+
+    private async postCtx(ctx: ResolveChain<PD>, expressReq: Request, expressRes: Response, index = -1): Promise<[InvalidProc, number] | undefined> {
+        if (!this.procDecorator) {
+            return;
+        }
+
+        let isValidRoute = true;
+        if(index !== -1 && index !== this.postDecorator.length){
+            isValidRoute = false;
+            index = clamp(index, 0, this.postDecorator.length);
+        }
+
+        for (let i = index - 1; i >= 0; i--) {
+            const proc = this.postDecorator[i];
+            if(!proc){
+                continue;
+            }
+
+            try {
+                const result = await proc(ctx, expressReq, expressRes, isValidRoute);
+                if ('invalidProcSymbol' in result) {
+                    result.invalidProcSymbol = ['postCtx', i, result.invalidProcSymbol];
+                    return [result, i];
+                }
+                ctx = result;
+            }
+            catch (e) {
+                return [{
+                    result: false,
+                    reason: `internal error[${i}]: ${e}`,
+                    invalidProcSymbol: ['postCtx', i],
+                }, i];
+            }
+        }
+        return;
+    }
+
+    protected abstract parseQuery(expressReq: Request): Promise<Q>;
+    protected abstract api(query: Q, ctx: ResolveChain<PD>, expressReq: Request, expressRes: Response): Promise<R | E | true>;
+    public async run(expressReq: Request, expressRes: Response): Promise<void> {
+        const query = await this.parseQuery(expressReq);
+        const ctx = await this.preCtx(expressReq, expressRes);
+        if (Array.isArray(ctx)) {
+            const [invalidProc, errCtx, idx] = ctx;
+            if (idx == 0){
+                expressRes.json(invalidProc);
+                return;
+            }
+            const result = await this.postCtx(errCtx, expressReq, expressRes, idx);
+            if (result === undefined) {
+                expressRes.json(invalidProc);
+                return;
+            }
+            const [postInvalidProc,] = result;
+            expressRes.json(postInvalidProc);
+            return;
+        }
+        const result = await this.api(query, ctx, expressReq, expressRes);
+        const postResult = await this.postCtx(ctx, expressReq, expressRes);
+        if (postResult !== undefined) {
+            if(result === true){
+                //NOTE: 이미 api에서 response를 보낸 특이 케이스.
+                return;
+            }
+            const [invalidProc,] = postResult;
+            invalidProc.alreadyProcessed = true;
+            expressRes.json(invalidProc);
+            return;
+        }
+
+        if (result !== true) {
+            expressRes.json(result);
+        }
     }
 }
 
-export abstract class APIBodyParseExecuter<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType> extends APIExecuter<R, E, Q>{
+export abstract class APIBodyParseExecuter<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType, PD extends ProcDecoratorChain> extends APIExecuter<R, E, Q, PD>{
     protected async parseQuery(expressReq: Request): Promise<Q> {
 
         if (!this.argValidator) {
@@ -63,7 +181,7 @@ export abstract class APIBodyParseExecuter<R extends ValidResponse, E extends In
     }
 }
 
-export abstract class GET<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType> extends APIExecuter<R, E, Q>{
+export abstract class GET<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType, PD extends ProcDecoratorChain = []> extends APIExecuter<R, E, Q, PD>{
     override readonly reqType = 'get';
     protected async parseQuery(expressReq: Request): Promise<Q> {
         if (!this.argValidator) {
@@ -81,23 +199,23 @@ export abstract class GET<R extends ValidResponse, E extends InvalidResponse, Q
     }
 }
 
-export abstract class POST<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType> extends APIBodyParseExecuter<R, E, Q>{
+export abstract class POST<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType, PD extends ProcDecoratorChain> extends APIBodyParseExecuter<R, E, Q, PD>{
     readonly reqType = 'post';
 }
 
-export abstract class PUT<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType> extends APIBodyParseExecuter<R, E, Q>{
+export abstract class PUT<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType, PD extends ProcDecoratorChain> extends APIBodyParseExecuter<R, E, Q, PD>{
     readonly reqType = 'put';
 }
 
-export abstract class DELETE<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType> extends APIBodyParseExecuter<R, E, Q>{
+export abstract class DELETE<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType, PD extends ProcDecoratorChain> extends APIBodyParseExecuter<R, E, Q, PD>{
     readonly reqType = 'delete';
 }
 
-export abstract class PATCH<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType> extends APIBodyParseExecuter<R, E, Q>{
+export abstract class PATCH<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType, PD extends ProcDecoratorChain> extends APIBodyParseExecuter<R, E, Q, PD>{
     readonly reqType = 'patch';
 }
 
-export abstract class HEAD<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType> extends APIBodyParseExecuter<R, E, Q>{
+export abstract class HEAD<R extends ValidResponse, E extends InvalidResponse, Q extends RawArgType, PD extends ProcDecoratorChain> extends APIBodyParseExecuter<R, E, Q, PD>{
     readonly reqType = 'head';
 }
 
@@ -120,12 +238,18 @@ export function raiseError(reason: string, recovery?: recoveryMethod): InvalidRe
 export type ClassType<T> = new (...args: any[]) => T;
 
 export type APIServerType<T extends Callable> =
-    T extends GetAPICallT<infer Q, infer R, infer E> ? ClassType<GET<R, E, Q>> :
-    T extends PostAPICallT<infer Q, infer R, infer E> ? ClassType<POST<R, E, Q>> :
-    T extends PutAPICallT<infer Q, infer R, infer E> ? ClassType<PUT<R, E, Q>> :
-    T extends DeleteAPICallT<infer Q, infer R, infer E> ? ClassType<DELETE<R, E, Q>> :
-    T extends PatchAPICallT<infer Q, infer R, infer E> ? ClassType<PATCH<R, E, Q>> :
-    T extends HeadAPICallT<infer Q, infer R, infer E> ? ClassType<HEAD<R, E, Q>> :
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    T extends GetAPICallT<infer Q, infer R, infer E> ? ClassType<GET<R, E, Q, any>> :
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    T extends PostAPICallT<infer Q, infer R, infer E> ? ClassType<POST<R, E, Q, any>> :
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    T extends PutAPICallT<infer Q, infer R, infer E> ? ClassType<PUT<R, E, Q, any>> :
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    T extends DeleteAPICallT<infer Q, infer R, infer E> ? ClassType<DELETE<R, E, Q, any>> :
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    T extends PatchAPICallT<infer Q, infer R, infer E> ? ClassType<PATCH<R, E, Q, any>> :
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    T extends HeadAPICallT<infer Q, infer R, infer E> ? ClassType<HEAD<R, E, Q, any>> :
     never;
 export type APINamespaceType<T extends DefAPINamespace> = {
     [K in keyof T]: