diff --git a/bun.lockb b/bun.lockb
index 147b2ac..0f04df2 100755
Binary files a/bun.lockb and b/bun.lockb differ
diff --git a/src/calculations/calculator.ts b/src/calculations/calculator.ts
index c784a63..9eded77 100644
--- a/src/calculations/calculator.ts
+++ b/src/calculations/calculator.ts
@@ -4,10 +4,10 @@ import { ISpace } from './interfaces/space'
 import { IConfig } from './interfaces/config'
 import { ISpaceCalculation } from './interfaces/space_calculation'
 import { ISpaceResult } from './interfaces/space_result'
-import { ISpaceConstant } from './interfaces/space_constant'
 import { IVariable } from './interfaces/variable'
 import { IConstant } from './interfaces/constant'
 import { ICalculationResult } from './interfaces/calculationresult'
+import { TCustomSpaceConstants } from './types/custom_space_constant'
 import getSpace from './spaces'
 import Dummy from './spaces/dummy'
 
@@ -16,8 +16,8 @@ import Dummy from './spaces/dummy'
  */
 export default class Calculator {
   variables: IVariable
-  customSpaceConstants: ISpaceConstant
-  customConstants: IConstant
+  customSpaceConstants?: TCustomSpaceConstants
+  customConstants?: IConstant
   config: IConfig
   constants: IConstant
   totalWorkplaceArea: number = 0
@@ -34,7 +34,7 @@ export default class Calculator {
    * @param {IConstant} customConstants – Custom constants
    * @param {string} [configFile] – The config file to use
    */
-  constructor(variables: IVariable, customSpaceConstants: ISpaceConstant, customConstants: IConstant , configFile: string = 'default.json') {
+  constructor(variables: IVariable, customSpaceConstants: TCustomSpaceConstants|undefined, customConstants: IConstant|undefined , configFile: string = 'default.json') {
     this.variables = variables
     this.customSpaceConstants = customSpaceConstants
     this.customConstants = customConstants
diff --git a/src/calculations/interfaces/request.ts b/src/calculations/interfaces/request.ts
new file mode 100644
index 0000000..ff0dc44
--- /dev/null
+++ b/src/calculations/interfaces/request.ts
@@ -0,0 +1,9 @@
+import { IVariable } from './variable'
+import { IConstant } from './constant'
+import { TCustomSpaceConstants } from '../types/custom_space_constant'
+
+export interface IRequest {
+  variables: IVariable
+  customConstants?: IConstant
+  customSpaceConstants?: TCustomSpaceConstants
+}
diff --git a/src/calculations/spaces/main_space_class.ts b/src/calculations/spaces/main_space_class.ts
index ebcf3f4..ca58cab 100644
--- a/src/calculations/spaces/main_space_class.ts
+++ b/src/calculations/spaces/main_space_class.ts
@@ -5,8 +5,7 @@ import { ISpaceCalculation } from '../interfaces/space_calculation'
 import { IConstant } from '../interfaces/constant'
 import { IVariable } from '../interfaces/variable'
 import { findSpace } from '../helpers'
-
-type TCustomSpaceConstants = {[key:string]:ISpaceConstant}
+import { TCustomSpaceConstants } from '../types/custom_space_constant'
 
 /**
  * This is the main class for the spaces. It contains shared methods for all spaces.
diff --git a/src/calculations/types/custom_space_constant.ts b/src/calculations/types/custom_space_constant.ts
new file mode 100644
index 0000000..f8111e5
--- /dev/null
+++ b/src/calculations/types/custom_space_constant.ts
@@ -0,0 +1,3 @@
+import { ISpaceConstant } from '../interfaces/space_constant'
+
+export type TCustomSpaceConstants = {[key:string]:ISpaceConstant}
diff --git a/src/index.ts b/src/index.ts
index e6432ba..b3a7f0b 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,9 +1,10 @@
-import { ISpaceConstant } from './calculations/interfaces/space_constant'
 import { IConstant } from './calculations/interfaces/constant'
 import { IVariable } from './calculations/interfaces/variable'
+import { IRequest } from './calculations/interfaces/request'
 import Calculator from './calculations/calculator'
 import redis from 'redis'
 import { RedisClientType } from '@redis/client'
+import { TCustomSpaceConstants } from './calculations/types/custom_space_constant'
 
 let redisClient: RedisClientType
 if (process.env.USE_CACHE_REDIS === '1') {
@@ -32,22 +33,16 @@ Bun.serve({
     const url = new URL(req.url)
     if (url.pathname === "/") return new Response("Agiliate is running", { headers })
     if (url.pathname === "/calculate") {
-      const jsonReq = await req.json()
+      const jsonReq: IRequest = await req.json() as IRequest
       if (process.env.CACHE === '1') {
-        const cachedResult = await redisClient.get(jsonReq)
+        const cachedResult = await redisClient.get(JSON.stringify(jsonReq))
         if (cachedResult) {
           return Response.json(JSON.parse(cachedResult), { headers })
         }
       }
-      const variables: IVariable = {
-        ...jsonReq.variables
-      }
-      const customSpaceConstants: ISpaceConstant = {
-        ...jsonReq?.customSpaceConstants
-      }
-      const customConstants: IConstant = {
-        ...jsonReq?.customConstants
-      }
+      const variables: IVariable = jsonReq.variables
+      const customSpaceConstants: TCustomSpaceConstants|undefined = jsonReq?.customSpaceConstants
+      const customConstants: IConstant|undefined = jsonReq?.customConstants
       const calculator = new Calculator(variables, customSpaceConstants, customConstants)
       const result = calculator.result()
       if (process.env.CACHE === '1')