diff --git a/package-lock.json b/package-lock.json
index 3324bf6..adf8140 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1103,9 +1103,9 @@
           "dev": true
         },
         "supports-color": {
-          "version": "7.1.0",
-          "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-7.1.0.tgz",
-          "integrity": "sha512-oRSIpR8pxT1Wr2FquTNnGet79b3BWljqOuoW/h4oBhxJ/HUbX5nX6JSruTkvXDCFMwDPvsaTTbvMLKZWSy0R5g==",
+          "version": "7.2.0",
+          "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-7.2.0.tgz",
+          "integrity": "sha512-qpCAvRl9stuOHveKsn7HncJRvv501qIacKzQlO/+Lwxc9+0q2wLyv4Dfvt80/DPn2pqOBsJdDiogXGR9+OvwRw==",
           "dev": true,
           "requires": {
             "has-flag": "^4.0.0"
@@ -1648,9 +1648,9 @@
       }
     },
     "@types/jest": {
-      "version": "26.0.10",
-      "resolved": "https://registry.npmjs.org/@types/jest/-/jest-26.0.10.tgz",
-      "integrity": "sha512-i2m0oyh8w/Lum7wWK/YOZJakYF8Mx08UaKA1CtbmFeDquVhAEdA7znacsVSf2hJ1OQ/OfVMGN90pw/AtzF8s/Q==",
+      "version": "26.0.13",
+      "resolved": "https://registry.npmjs.org/@types/jest/-/jest-26.0.13.tgz",
+      "integrity": "sha512-sCzjKow4z9LILc6DhBvn5AkIfmQzDZkgtVVKmGwVrs5tuid38ws281D4l+7x1kP487+FlKDh5kfMZ8WSPAdmdA==",
       "dev": true,
       "requires": {
         "jest-diff": "^25.2.1",
@@ -5904,9 +5904,9 @@
           "dev": true
         },
         "supports-color": {
-          "version": "7.1.0",
-          "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-7.1.0.tgz",
-          "integrity": "sha512-oRSIpR8pxT1Wr2FquTNnGet79b3BWljqOuoW/h4oBhxJ/HUbX5nX6JSruTkvXDCFMwDPvsaTTbvMLKZWSy0R5g==",
+          "version": "7.2.0",
+          "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-7.2.0.tgz",
+          "integrity": "sha512-qpCAvRl9stuOHveKsn7HncJRvv501qIacKzQlO/+Lwxc9+0q2wLyv4Dfvt80/DPn2pqOBsJdDiogXGR9+OvwRw==",
           "dev": true,
           "requires": {
             "has-flag": "^4.0.0"
diff --git a/package.json b/package.json
index 3e38466..5e9edce 100644
--- a/package.json
+++ b/package.json
@@ -37,7 +37,7 @@
   "license": "ISC",
   "devDependencies": {
     "@types/isomorphic-fetch": "0.0.35",
-    "@types/jest": "^26.0.10",
+    "@types/jest": "^26.0.13",
     "cp": "^0.2.0",
     "jest": "^25.5.4",
     "path": "^0.12.7",
diff --git a/src/FileUploader.ts b/src/FileUploader.ts
index 8bd62be..c7be45a 100644
--- a/src/FileUploader.ts
+++ b/src/FileUploader.ts
@@ -1,4 +1,4 @@
-import { isLogInRequired, needsRetry } from './utils'
+import { isLogInRequired, needsRetry, isUrl } from './utils'
 import { CsrfToken } from './types/CsrfToken'
 import { UploadFile } from './types/UploadFile'
 
@@ -11,7 +11,10 @@ export class FileUploader {
     private jobsPath: string,
     private setCsrfTokenWeb: any,
     private csrfToken: CsrfToken | null = null
-  ) {}
+  ) {
+    if (serverUrl) isUrl(serverUrl)
+  }
+
   private retryCount = 0
 
   public uploadFile(sasJob: string, files: UploadFile[], params: any) {
diff --git a/src/SAS9ApiClient.ts b/src/SAS9ApiClient.ts
index 010d63a..40ffb09 100644
--- a/src/SAS9ApiClient.ts
+++ b/src/SAS9ApiClient.ts
@@ -1,9 +1,13 @@
+import { isUrl } from './utils'
+
 /**
  * A client for interfacing with the SAS9 REST API
  *
  */
 export class SAS9ApiClient {
-  constructor(private serverUrl: string) {}
+  constructor(private serverUrl: string) {
+    if (serverUrl) isUrl(serverUrl)
+  }
 
   /**
    * returns on object containing the server URL
diff --git a/src/SASViyaApiClient.ts b/src/SASViyaApiClient.ts
index e1a222a..b1084e3 100644
--- a/src/SASViyaApiClient.ts
+++ b/src/SASViyaApiClient.ts
@@ -2,7 +2,8 @@ import {
   isAuthorizeFormRequired,
   parseAndSubmitAuthorizeForm,
   convertToCSV,
-  makeRequest
+  makeRequest,
+  isUrl
 } from './utils'
 import * as NodeFormData from 'form-data'
 import * as path from 'path'
@@ -26,7 +27,10 @@ export class SASViyaApiClient {
     if (!rootFolderName) {
       throw new Error('Root folder must be provided.')
     }
+
+    if (serverUrl) isUrl(serverUrl)
   }
+
   private csrfToken: CsrfToken | null = null
   private rootFolder: Folder | null = null
   private sessionManager = new SessionManager(
diff --git a/src/SASjs.ts b/src/SASjs.ts
index b901917..2e0c812 100644
--- a/src/SASjs.ts
+++ b/src/SASjs.ts
@@ -883,7 +883,7 @@ export default class SASjs {
             ) {
               if (this.retryCountWeb < requestRetryLimit) {
                 this.retryCountWeb++
-                this.request(sasJob, data).then(
+                this.request(sasJob, data, config, loginRequiredCallback).then(
                   (res: any) => resolve(res),
                   (err: any) => reject(err)
                 )
diff --git a/src/SessionManager.ts b/src/SessionManager.ts
index 5a782c2..a0c6fb9 100644
--- a/src/SessionManager.ts
+++ b/src/SessionManager.ts
@@ -1,5 +1,5 @@
 import { Session, Context, CsrfToken } from './types'
-import { asyncForEach, makeRequest } from './utils'
+import { asyncForEach, makeRequest, isUrl } from './utils'
 
 const MAX_SESSION_COUNT = 1
 
@@ -8,7 +8,10 @@ export class SessionManager {
     private serverUrl: string,
     private contextName: string,
     private setCsrfToken: (csrfToken: CsrfToken) => void
-  ) {}
+  ) {
+    if (serverUrl) isUrl(serverUrl)
+  }
+
   private sessions: Session[] = []
   private currentContext: Context | null = null
   private csrfToken: CsrfToken | null = null
diff --git a/src/utils/index.ts b/src/utils/index.ts
index 6a15042..0eb205b 100644
--- a/src/utils/index.ts
+++ b/src/utils/index.ts
@@ -13,3 +13,4 @@ export * from './parseSasViyaLog'
 export * from './serialize'
 export * from './splitChunks'
 export * from './parseWeboutResponse'
+export * from './isUrl'
diff --git a/src/utils/isUrl.ts b/src/utils/isUrl.ts
new file mode 100644
index 0000000..1e64fa7
--- /dev/null
+++ b/src/utils/isUrl.ts
@@ -0,0 +1,12 @@
+export const isUrl = (url: string): boolean => {
+  const pattern = new RegExp(
+    '^(http://|https://)[a-z0-9]+([-.]{1}[a-z0-9]+)*.[a-z]{2,5}(:[0-9]{1,5})?(/.*)?$',
+    'gi'
+  )
+
+  if (pattern.test(url)) return true
+  else
+    throw new Error(
+      `'${url}' is not a valid url. An example of a valid url is 'http://valid-url.com'.`
+    )
+}