diff --git a/keyserver/src/endpoints.js b/keyserver/src/endpoints.js
index 6c7111b8f..0d195e0e7 100644
--- a/keyserver/src/endpoints.js
+++ b/keyserver/src/endpoints.js
@@ -1,229 +1,234 @@
 // @flow
 
 import { policyTypes } from 'lib/facts/policies.js';
 import type { Endpoint } from 'lib/types/endpoints';
 
 import {
   updateActivityResponder,
   threadSetUnreadStatusResponder,
 } from './responders/activity-responders';
 import { deviceTokenUpdateResponder } from './responders/device-responders';
 import {
   entryFetchResponder,
   entryRevisionFetchResponder,
   entryCreationResponder,
   entryUpdateResponder,
   entryDeletionResponder,
   entryRestorationResponder,
   calendarQueryUpdateResponder,
 } from './responders/entry-responders';
 import type { JSONResponder } from './responders/handlers';
 import { getSessionPublicKeysResponder } from './responders/keys-responders';
 import { messageReportCreationResponder } from './responders/message-report-responder';
 import {
   textMessageCreationResponder,
   messageFetchResponder,
   multimediaMessageCreationResponder,
 } from './responders/message-responders';
 import { updateRelationshipsResponder } from './responders/relationship-responders';
 import {
   reportCreationResponder,
   reportMultiCreationResponder,
   errorReportFetchInfosResponder,
 } from './responders/report-responders';
 import { userSearchResponder } from './responders/search-responders';
+import { siweNonceResponder } from './responders/siwe-nonce-responders';
 import {
   threadDeletionResponder,
   roleUpdateResponder,
   memberRemovalResponder,
   threadLeaveResponder,
   threadUpdateResponder,
   threadCreationResponder,
   threadJoinResponder,
 } from './responders/thread-responders';
 import {
   userSubscriptionUpdateResponder,
   passwordUpdateResponder,
   sendVerificationEmailResponder,
   sendPasswordResetEmailResponder,
   logOutResponder,
   accountDeletionResponder,
   accountCreationResponder,
   logInResponder,
   oldPasswordUpdateResponder,
   updateUserSettingsResponder,
   policyAcknowledgmentResponder,
 } from './responders/user-responders';
 import { codeVerificationResponder } from './responders/verification-responders';
 import { uploadDeletionResponder } from './uploads/uploads';
 
 const baseLegalPolicies = [policyTypes.tosAndPrivacyPolicy];
 
 const jsonEndpoints: { [id: Endpoint]: JSONResponder } = {
   create_account: {
     responder: accountCreationResponder,
     requiredPolicies: [],
   },
   create_entry: {
     responder: entryCreationResponder,
     requiredPolicies: baseLegalPolicies,
   },
   create_error_report: {
     responder: reportCreationResponder,
     requiredPolicies: [],
   },
   create_message_report: {
     responder: messageReportCreationResponder,
     requiredPolicies: baseLegalPolicies,
   },
   create_multimedia_message: {
     responder: multimediaMessageCreationResponder,
     requiredPolicies: baseLegalPolicies,
   },
   create_report: {
     responder: reportCreationResponder,
     requiredPolicies: [],
   },
   create_reports: {
     responder: reportMultiCreationResponder,
     requiredPolicies: [],
   },
   create_text_message: {
     responder: textMessageCreationResponder,
     requiredPolicies: baseLegalPolicies,
   },
   create_thread: {
     responder: threadCreationResponder,
     requiredPolicies: baseLegalPolicies,
   },
   delete_account: {
     responder: accountDeletionResponder,
     requiredPolicies: [],
   },
   delete_entry: {
     responder: entryDeletionResponder,
     requiredPolicies: baseLegalPolicies,
   },
   delete_thread: {
     responder: threadDeletionResponder,
     requiredPolicies: baseLegalPolicies,
   },
   delete_upload: {
     responder: uploadDeletionResponder,
     requiredPolicies: baseLegalPolicies,
   },
   fetch_entries: {
     responder: entryFetchResponder,
     requiredPolicies: baseLegalPolicies,
   },
   fetch_entry_revisions: {
     responder: entryRevisionFetchResponder,
     requiredPolicies: baseLegalPolicies,
   },
   fetch_error_report_infos: {
     responder: errorReportFetchInfosResponder,
     requiredPolicies: baseLegalPolicies,
   },
   fetch_messages: {
     responder: messageFetchResponder,
     requiredPolicies: baseLegalPolicies,
   },
   get_session_public_keys: {
     responder: getSessionPublicKeysResponder,
     requiredPolicies: baseLegalPolicies,
   },
   join_thread: {
     responder: threadJoinResponder,
     requiredPolicies: baseLegalPolicies,
   },
   leave_thread: {
     responder: threadLeaveResponder,
     requiredPolicies: baseLegalPolicies,
   },
   log_in: {
     responder: logInResponder,
     requiredPolicies: [],
   },
   log_out: {
     responder: logOutResponder,
     requiredPolicies: [],
   },
   policy_acknowledgment: {
     responder: policyAcknowledgmentResponder,
     requiredPolicies: [],
   },
   remove_members: {
     responder: memberRemovalResponder,
     requiredPolicies: baseLegalPolicies,
   },
   restore_entry: {
     responder: entryRestorationResponder,
     requiredPolicies: baseLegalPolicies,
   },
   search_users: {
     responder: userSearchResponder,
     requiredPolicies: baseLegalPolicies,
   },
   send_password_reset_email: {
     responder: sendPasswordResetEmailResponder,
     requiredPolicies: [],
   },
   send_verification_email: {
     responder: sendVerificationEmailResponder,
     requiredPolicies: [],
   },
   set_thread_unread_status: {
     responder: threadSetUnreadStatusResponder,
     requiredPolicies: baseLegalPolicies,
   },
   update_account: {
     responder: passwordUpdateResponder,
     requiredPolicies: baseLegalPolicies,
   },
   update_activity: {
     responder: updateActivityResponder,
     requiredPolicies: baseLegalPolicies,
   },
   update_calendar_query: {
     responder: calendarQueryUpdateResponder,
     requiredPolicies: baseLegalPolicies,
   },
   update_user_settings: {
     responder: updateUserSettingsResponder,
     requiredPolicies: baseLegalPolicies,
   },
   update_device_token: {
     responder: deviceTokenUpdateResponder,
     requiredPolicies: baseLegalPolicies,
   },
   update_entry: {
     responder: entryUpdateResponder,
     requiredPolicies: baseLegalPolicies,
   },
   update_password: {
     responder: oldPasswordUpdateResponder,
     requiredPolicies: baseLegalPolicies,
   },
   update_relationships: {
     responder: updateRelationshipsResponder,
     requiredPolicies: baseLegalPolicies,
   },
   update_role: {
     responder: roleUpdateResponder,
     requiredPolicies: baseLegalPolicies,
   },
   update_thread: {
     responder: threadUpdateResponder,
     requiredPolicies: baseLegalPolicies,
   },
   update_user_subscription: {
     responder: userSubscriptionUpdateResponder,
     requiredPolicies: baseLegalPolicies,
   },
   verify_code: {
     responder: codeVerificationResponder,
     requiredPolicies: baseLegalPolicies,
   },
+  siwe_nonce: {
+    responder: siweNonceResponder,
+    requiredPolicies: [],
+  },
 };
 
 export { jsonEndpoints };
diff --git a/keyserver/src/responders/siwe-nonce-responders.js b/keyserver/src/responders/siwe-nonce-responders.js
new file mode 100644
index 000000000..ae3c3e8c3
--- /dev/null
+++ b/keyserver/src/responders/siwe-nonce-responders.js
@@ -0,0 +1,7 @@
+// @flow
+
+async function siweNonceResponder(): Promise<string> {
+  return 'UNIMPLEMENTED';
+}
+
+export { siweNonceResponder };
diff --git a/lib/actions/siwe-actions.js b/lib/actions/siwe-actions.js
new file mode 100644
index 000000000..0df49299b
--- /dev/null
+++ b/lib/actions/siwe-actions.js
@@ -0,0 +1,17 @@
+// @flow
+
+import type { CallServerEndpoint } from '../utils/call-server-endpoint';
+
+const getSIWENonceActionTypes = Object.freeze({
+  started: 'GET_SIWE_NONCE_STARTED',
+  success: 'GET_SIWE_NONCE_SUCCESS',
+  failed: 'GET_SIWE_NONCE_FAILED',
+});
+const getSIWENonce = (
+  callServerEndpoint: CallServerEndpoint,
+): (() => Promise<string>) => async () => {
+  const nonce = await callServerEndpoint('siwe_nonce');
+  return nonce;
+};
+
+export { getSIWENonceActionTypes, getSIWENonce };
diff --git a/lib/types/endpoints.js b/lib/types/endpoints.js
index cd4630e21..bbab351c8 100644
--- a/lib/types/endpoints.js
+++ b/lib/types/endpoints.js
@@ -1,111 +1,112 @@
 // @flow
 
 export type APIRequest = {
   endpoint: Endpoint,
   input: Object,
 };
 export type SocketAPIHandler = (request: APIRequest) => Promise<Object>;
 
 export type Endpoint =
   | HTTPOnlyEndpoint
   | SocketOnlyEndpoint
   | HTTPPreferredEndpoint
   | SocketPreferredEndpoint;
 
 // Endpoints that can cause session changes should occur over HTTP, since the
 // socket code does not currently support changing sessions. In the future they
 // could be made to work for native, but cookie changes on web require HTTP
 // since websockets aren't able to Set-Cookie. Note that technically any
 // endpoint can cause a sessionChange, and in that case the server will close
 // the socket with a specific error code, and the client will proceed via HTTP.
 const sessionChangingEndpoints = Object.freeze({
   LOG_OUT: 'log_out',
   DELETE_ACCOUNT: 'delete_account',
   CREATE_ACCOUNT: 'create_account',
   LOG_IN: 'log_in',
   UPDATE_PASSWORD: 'update_password',
   POLICY_ACKNOWLEDGMENT: 'policy_acknowledgment',
 });
 type SessionChangingEndpoint = $Values<typeof sessionChangingEndpoints>;
 
 // We do uploads over HTTP as well. This is because Websockets use TCP, which
 // guarantees ordering. That means that if we start an upload, any messages we
 // try to send the server after the upload starts will have to wait until the
 // upload ends. To avoid blocking other messages we upload using HTTP
 // multipart/form-data.
 const uploadEndpoints = Object.freeze({
   UPLOAD_MULTIMEDIA: 'upload_multimedia',
 });
 type UploadEndpoint = $Values<typeof uploadEndpoints>;
 
 type HTTPOnlyEndpoint = SessionChangingEndpoint | UploadEndpoint;
 
 const socketOnlyEndpoints = Object.freeze({
   UPDATE_ACTIVITY: 'update_activity',
   UPDATE_CALENDAR_QUERY: 'update_calendar_query',
 });
 type SocketOnlyEndpoint = $Values<typeof socketOnlyEndpoints>;
 
 const socketPreferredEndpoints = Object.freeze({
   CREATE_ENTRY: 'create_entry',
   CREATE_ERROR_REPORT: 'create_error_report',
   CREATE_MESSAGE_REPORT: 'create_message_report',
   CREATE_MULTIMEDIA_MESSAGE: 'create_multimedia_message',
   CREATE_TEXT_MESSAGE: 'create_text_message',
   CREATE_THREAD: 'create_thread',
   DELETE_ENTRY: 'delete_entry',
   DELETE_THREAD: 'delete_thread',
   DELETE_UPLOAD: 'delete_upload',
   FETCH_ENTRIES: 'fetch_entries',
   FETCH_ENTRY_REVISIONS: 'fetch_entry_revisions',
   FETCH_ERROR_REPORT_INFOS: 'fetch_error_report_infos',
   FETCH_MESSAGES: 'fetch_messages',
   GET_SESSION_PUBLIC_KEYS: 'get_session_public_keys',
   JOIN_THREAD: 'join_thread',
   LEAVE_THREAD: 'leave_thread',
   REMOVE_MEMBERS: 'remove_members',
   REQUEST_ACCESS: 'request_access',
   RESTORE_ENTRY: 'restore_entry',
   SEARCH_USERS: 'search_users',
   SEND_PASSWORD_RESET_EMAIL: 'send_password_reset_email',
   SEND_VERIFICATION_EMAIL: 'send_verification_email',
   SET_THREAD_UNREAD_STATUS: 'set_thread_unread_status',
   UPDATE_ACCOUNT: 'update_account',
   UPDATE_USER_SETTINGS: 'update_user_settings',
   UPDATE_DEVICE_TOKEN: 'update_device_token',
   UPDATE_ENTRY: 'update_entry',
   UPDATE_RELATIONSHIPS: 'update_relationships',
   UPDATE_ROLE: 'update_role',
   UPDATE_THREAD: 'update_thread',
   UPDATE_USER_SUBSCRIPTION: 'update_user_subscription',
   VERIFY_CODE: 'verify_code',
+  SIWE_NONCE: 'siwe_nonce',
 });
 type SocketPreferredEndpoint = $Values<typeof socketPreferredEndpoints>;
 
 const httpPreferredEndpoints = Object.freeze({
   CREATE_REPORT: 'create_report',
   CREATE_REPORTS: 'create_reports',
 });
 type HTTPPreferredEndpoint = $Values<typeof httpPreferredEndpoints>;
 
 const socketPreferredEndpointSet = new Set([
   ...Object.values(socketOnlyEndpoints),
   ...Object.values(socketPreferredEndpoints),
 ]);
 export function endpointIsSocketPreferred(endpoint: Endpoint): boolean {
   return socketPreferredEndpointSet.has(endpoint);
 }
 
 const socketSafeEndpointSet = new Set([
   ...Object.values(socketOnlyEndpoints),
   ...Object.values(socketPreferredEndpoints),
   ...Object.values(httpPreferredEndpoints),
 ]);
 export function endpointIsSocketSafe(endpoint: Endpoint): boolean {
   return socketSafeEndpointSet.has(endpoint);
 }
 
 const socketOnlyEndpointSet = new Set(Object.values(socketOnlyEndpoints));
 export function endpointIsSocketOnly(endpoint: Endpoint): boolean {
   return socketOnlyEndpointSet.has(endpoint);
 }