diff --git a/lib/utils/keyserver-call.js b/lib/utils/keyserver-call.js
--- a/lib/utils/keyserver-call.js
+++ b/lib/utils/keyserver-call.js
@@ -11,6 +11,7 @@
   CallServerEndpoint,
   CallServerEndpointOptions,
 } from './call-server-endpoint.js';
+import { promiseAll } from './promises.js';
 import { useSelector } from './redux-utils.js';
 import type { PlatformDetails } from '../types/device-types.js';
 import type { Endpoint } from '../types/endpoints.js';
@@ -19,28 +20,19 @@
 import type { ConnectionStatus } from '../types/socket-types.js';
 import type { CurrentUserInfo } from '../types/user-types.js';
 
-export type CallKeyserverEndpoint<Args: $ReadOnlyArray<mixed>> = (
+export type CallKeyserverEndpoint = (
   endpoint: Endpoint,
-  input: { +[string]: mixed },
-  args: Args,
+  requests: { +[string]: mixed },
   options?: ?CallServerEndpointOptions,
-) => Promise<any>;
+) => Promise<{ +[id: string]: any }>;
 
-export type ActionFunc<Args: $ReadOnlyArray<mixed>, Return> = (
-  callServerEndpoint: CallKeyserverEndpoint<Args>,
-) => (...Args) => Promise<Return>;
-
-export type KeyserverCallConfig<Args: $ReadOnlyArray<mixed>> =
-  | { +keyserverSelection: 'fanout' }
-  | {
-      +keyserverSelection: 'specific',
-      +keyserverIDExtractor: (...Args) => string,
-    };
-
-export type KeyserverCall<Args: $ReadOnlyArray<mixed>, Return> = {
-  +actionFunc: ActionFunc<Args, Return>,
-  +config: KeyserverCallConfig<Args>,
-};
+export type ActionFunc<Args: mixed, Return> = (
+  callServerEndpoint: CallKeyserverEndpoint,
+  // The second argument is only used in actions that call all keyservers,
+  // and the request to all keyservers are exactly the same.
+  // An example of such action is fetchEntries.
+  allKeyserverIDs: $ReadOnlyArray<string>,
+) => Args => Promise<Return>;
 
 // _memoize memoizes the function by caching the result.
 // The first argument of the memoized function is used as the map cache key.
@@ -87,11 +79,6 @@
   +keyserverInfos: { +[keyserverID: string]: KeyserverInfo },
 };
 
-export type GetCallKeyserverEndpointParams<Args: $ReadOnlyArray<mixed>> = {
-  ...BindKeyserverCallParams,
-  +keyserverCallConfig: KeyserverCallConfig<Args>,
-};
-
 const bindCallKeyserverEndpointSelector = createSelector(
   (state: BindKeyserverCallParams) => state.dispatch,
   (state: BindKeyserverCallParams) => state.currentUserInfo,
@@ -102,55 +89,59 @@
     keyserverInfos: { +[keyserverID: string]: KeyserverInfo },
   ) => {
     return _memoize(
-      <Args: $ReadOnlyArray<mixed>, Return>(
-        keyserverCall: KeyserverCall<Args, Return>,
-      ): ((...Args) => Promise<Return>) => {
+      <Args: mixed, Return>(
+        keyserverCall: ActionFunc<Args, Return>,
+      ): (Args => Promise<Return>) => {
         const callKeyserverEndpoint = (
           endpoint: Endpoint,
-          data: Object,
-          args: Args,
+          requests: { +[id: string]: Object },
           options?: ?CallServerEndpointOptions,
         ) => {
-          // TODO
-          if (keyserverCall.config.keyserverSelection === 'fanout') {
-            return Promise.resolve(undefined);
+          const bindCallKeyserverEndpoint = (keyserverID: string) => {
+            const {
+              cookie,
+              urlPrefix,
+              sessionID,
+              connection,
+              lastCommunicatedPlatformDetails,
+            } = keyserverInfos[keyserverID];
+
+            const boundCallServerEndpoint = createBoundServerCallsSelector(
+              keyserverID,
+            )({
+              dispatch,
+              currentUserInfo,
+              cookie,
+              urlPrefix,
+              sessionID,
+              connectionStatus: connection.status,
+              lastCommunicatedPlatformDetails,
+            });
+
+            return boundCallServerEndpoint(
+              endpoint,
+              requests[keyserverID],
+              options,
+            );
+          };
+
+          const promises = {};
+          for (const keyserverID in requests) {
+            promises[keyserverID] = bindCallKeyserverEndpoint(keyserverID);
           }
-          const keyserverID = keyserverCall.config.keyserverIDExtractor(
-            ...args,
-          );
-          const {
-            cookie,
-            urlPrefix,
-            sessionID,
-            connection,
-            lastCommunicatedPlatformDetails,
-          } = keyserverInfos[keyserverID];
-
-          const boundCallServerEndpoint = createBoundServerCallsSelector(
-            keyserverID,
-          )({
-            dispatch,
-            currentUserInfo,
-            cookie,
-            urlPrefix,
-            sessionID,
-            connectionStatus: connection.status,
-            lastCommunicatedPlatformDetails,
-          });
-
-          return boundCallServerEndpoint(endpoint, data, options);
+          return promiseAll(promises);
         };
-
-        return keyserverCall.actionFunc(callKeyserverEndpoint);
+        const keyserverIDs = Object.keys(keyserverInfos);
+        return keyserverCall(callKeyserverEndpoint, keyserverIDs);
       },
     );
   },
 );
 
-function useKeyserverCall<Args: $ReadOnlyArray<mixed>, Return>(
-  keyserverCall: KeyserverCall<Args, Return>,
+function useKeyserverCall<Args: mixed, Return>(
+  keyserverCall: ActionFunc<Args, Return>,
   paramOverride?: ?$Shape<BindKeyserverCallParams>,
-): (...Args) => Promise<Return> {
+): Args => Promise<Return> {
   const dispatch = useDispatch();
   const keyserverInfos = useSelector(
     state => state.keyserverStore.keyserverInfos,