diff --git a/qortal-ui-core/src/apiKeyUtils.js b/qortal-ui-core/src/apiKeyUtils.js
new file mode 100644
index 00000000..9d2078f1
--- /dev/null
+++ b/qortal-ui-core/src/apiKeyUtils.js
@@ -0,0 +1,76 @@
+import * as api from 'qortal-ui-crypto'
+
+'use strict'
+
+export const checkApiKey = async (nodeConfig) => {
+
+    let selectedNode = nodeConfig.knownNodes[nodeConfig.node];
+    if (selectedNode.enableManagement === false) {
+        console.log("Skipping API key check because enableManagement is false");
+        return;
+    }
+
+    let apiKey = selectedNode.apiKey;
+
+    // Attempt to generate an API key
+    const generateUrl = "/admin/apikey/generate";
+    let generateRes = await api.request(generateUrl, {
+        method: "POST"
+    });
+
+    if (generateRes != null && generateRes.error == null && generateRes.length >= 8) {
+        console.log("Generated API key");
+        apiKey = generateRes;
+    }
+    else {
+        console.log("Unable to generate API key");
+    }
+
+    // Now test the API key
+    let testResult = await testApiKey(apiKey);
+    if (testResult === true) {
+        console.log("API key test passed");
+    }
+    else {
+        console.log("API key test failed");
+
+        let apiKeyValid = false;
+
+        while (apiKeyValid === false) {
+
+            let apiKeyPrompt = prompt("Please enter the API key for this node.\n\nIt can be found in a file called 'apikey.txt' in the directory where the core is installed.\n\nAlternatively, click Cancel to use the core with reduced functionality.", "");
+            if (apiKeyPrompt === null) {
+                // Cancel was pushed - so give up
+                return;
+            }
+
+            let testResult = await testApiKey(apiKeyPrompt);
+            if (testResult === true) {
+                console.log("API key prompt test passed");
+                apiKeyValid = true;
+                apiKey = apiKeyPrompt;
+                break;
+            }
+            else {
+                console.log("API key prompt test failed. Re-prompting...");
+            }
+
+        }
+    }
+
+    // Store API key
+    selectedNode.apiKey = apiKey;
+    nodeConfig.knownNodes[nodeConfig.node] = selectedNode;
+    localStorage.setItem('myQortalNodes', JSON.stringify(nodeConfig.knownNodes));
+}
+
+export const testApiKey = async (apiKey) => {
+    const testUrl = "/admin/apikey/test?apiKey=" + apiKey;
+    let testRes = await api.request(testUrl, {
+        method: "GET"
+    });
+    if (testRes === true) {
+        return true;
+    }
+    return false;
+}
diff --git a/qortal-ui-core/src/components/app-info.js b/qortal-ui-core/src/components/app-info.js
index 83981f94..a5905a0e 100644
--- a/qortal-ui-core/src/components/app-info.js
+++ b/qortal-ui-core/src/components/app-info.js
@@ -97,7 +97,7 @@ class AppInfo extends connect(store)(LitElement) {
         return html`
             <div id="profileInMenu">
                 <span class="info">Block Height: ${this.blockInfo.height ? this.blockInfo.height : ''}  <span class=${this.cssStatus}>${this._renderStatus()}</span></span>
-                <span class="info">UI Version: v${this.nodeConfig.version ? this.nodeConfig.version : ''} </span>
+                <span class="info">UI Version: ${this.nodeConfig.version ? this.nodeConfig.version : ''} </span>
                 <span class="info">Core Version: ${this.nodeInfo.buildVersion ? this.nodeInfo.buildVersion : ''} </span>
                 <a id="pageLink"></a>
             </div>
diff --git a/qortal-ui-core/src/components/login-view/create-account-section.js b/qortal-ui-core/src/components/login-view/create-account-section.js
index 546162c7..051bccc7 100644
--- a/qortal-ui-core/src/components/login-view/create-account-section.js
+++ b/qortal-ui-core/src/components/login-view/create-account-section.js
@@ -10,6 +10,7 @@ import FileSaver from 'file-saver'
 
 import { doLogin, doLogout, doSelectAddress } from '../../redux/app/app-actions.js'
 import { doStoreWallet } from '../../redux/user/user-actions.js'
+import { checkApiKey } from '../../apiKeyUtils.js'
 
 import snackbar from '../../functional-components/snackbar.js'
 
@@ -48,7 +49,8 @@ class CreateAccountSection extends connect(store)(LitElement) {
             _wallet: { type: Object },
             _pass: { type: String },
             _name: { type: String },
-            isDownloadedBackup: { type: Boolean }
+            isDownloadedBackup: { type: Boolean },
+            nodeConfig: { type: Object }
         }
     }
 
@@ -181,6 +183,7 @@ class CreateAccountSection extends connect(store)(LitElement) {
                                         .then(() => {
                                             store.dispatch(doLogin(this._wallet))
                                             store.dispatch(doSelectAddress(this._wallet.addresses[0]))
+                                            checkApiKey(this.nodeConfig);
                                             this.cleanup()
                                             return ripple.fade()
                                         })
@@ -191,6 +194,7 @@ class CreateAccountSection extends connect(store)(LitElement) {
                         } else {
                             store.dispatch(doLogin(this._wallet))
                             store.dispatch(doSelectAddress(this._wallet.addresses[0]))
+                            checkApiKey()
                             this.cleanup()
                         }
                     }
@@ -490,6 +494,7 @@ class CreateAccountSection extends connect(store)(LitElement) {
     }
 
     stateChanged(state) {
+        this.nodeConfig = state.app.nodeConfig
         // this.loggedIn = state.app.loggedIn
     }
 
diff --git a/qortal-ui-core/src/components/login-view/login-section.js b/qortal-ui-core/src/components/login-view/login-section.js
index b1cc3deb..d96e3785 100644
--- a/qortal-ui-core/src/components/login-view/login-section.js
+++ b/qortal-ui-core/src/components/login-view/login-section.js
@@ -1,6 +1,7 @@
 import { LitElement, html, css } from 'lit-element'
 import { connect } from 'pwa-helpers'
 import { store } from '../../store.js'
+import { checkApiKey } from '../../apiKeyUtils.js'
 
 import '@material/mwc-button'
 import '@material/mwc-checkbox'
@@ -45,7 +46,8 @@ class LoginSection extends connect(store)(LitElement) {
             hasStoredWallets: { type: Boolean },
             saveInBrowser: { type: Boolean },
             backedUpWalletJSON: { type: Object },
-            backedUpSeedLoading: { type: Boolean }
+            backedUpSeedLoading: { type: Boolean },
+            nodeConfig: { type: Object }
         }
     }
 
@@ -280,7 +282,7 @@ class LoginSection extends connect(store)(LitElement) {
                         <div page="seed" id="seedPage">
                             <div>
                                 <div style="display:flex;">
-                                    <mwc-textfield style="width:100%;" icon="clear_all" label="Qora address seed" id="v1SeedInput" type="password"></mwc-textfield>
+                                    <mwc-textfield style="width:100%;" icon="clear_all" label="Qortal address seed" id="v1SeedInput" type="password"></mwc-textfield>
                                 </div>
                             </div>
                         </div>
@@ -375,6 +377,7 @@ class LoginSection extends connect(store)(LitElement) {
         this.loggedIn = state.app.loggedIn
         this.wallets = state.user.storedWallets
         this.hasStoredWallets = this.wallets.length > 0
+        this.nodeConfig = state.app.nodeConfig
     }
 
     keyupEnter(e, action) {
@@ -535,6 +538,7 @@ class LoginSection extends connect(store)(LitElement) {
                                 })).catch(err => console.error(err))
                             }
                         }
+                        checkApiKey(this.nodeConfig)
                         this.cleanup()
                         return this.loadingRipple.fade()
                     })
diff --git a/qortal-ui-core/src/plugins/routes.js b/qortal-ui-core/src/plugins/routes.js
index f47f1da0..37e68f98 100644
--- a/qortal-ui-core/src/plugins/routes.js
+++ b/qortal-ui-core/src/plugins/routes.js
@@ -11,6 +11,7 @@ import framePasteMenu from '../functional-components/frame-paste-menu.js'
 const createTransaction = api.createTransaction
 const processTransaction = api.processTransaction
 const signChatTransaction = api.signChatTransaction
+const signArbitraryTransaction = api.signArbitraryTransaction
 const tradeBotCreateRequest = api.tradeBotCreateRequest
 const tradeBotRespondRequest = api.tradeBotRespondRequest
 const signTradeBotTxn = api.signTradeBotTxn
@@ -169,7 +170,7 @@ export const routes = {
 		}
 		return response
 	},
-	
+
 	username: async (req) => {
 		const state = store.getState()
 		const username = state.user.storedWallets[state.app.wallet.addresses[0].address].name
@@ -206,6 +207,21 @@ export const routes = {
 		return response
 	},
 
+	sign_arbitrary: async (req) => {
+		let response
+		try {
+			const signedArbitraryBytes = await signArbitraryTransaction(req.data.arbitraryBytesBase58, req.data.arbitraryBytesForSigningBase58, req.data.arbitraryNonce, store.getState().app.wallet._addresses[req.data.nonce].keyPair)
+
+			const res = await processTransaction(signedArbitraryBytes)
+			response = res
+		} catch (e) {
+			console.error(e)
+			console.error(e.message)
+			response = false
+		}
+		return response
+	},
+
 	showNotification: async (req) => {
 		doNewMessage(req.data)
 	},