diff --git a/keyserver/src/endpoints.js b/keyserver/src/endpoints.js
--- a/keyserver/src/endpoints.js
+++ b/keyserver/src/endpoints.js
@@ -19,6 +19,7 @@
 } from './responders/entry-responders.js';
 import type { JSONResponder } from './responders/handlers.js';
 import { getSessionPublicKeysResponder } from './responders/keys-responders.js';
+import { inviteLinkVerificationResponder } from './responders/link-responders.js';
 import { messageReportCreationResponder } from './responders/message-report-responder.js';
 import {
   textMessageCreationResponder,
@@ -250,6 +251,10 @@
     responder: codeVerificationResponder,
     requiredPolicies: baseLegalPolicies,
   },
+  verify_invite_link: {
+    responder: inviteLinkVerificationResponder,
+    requiredPolicies: baseLegalPolicies,
+  },
   siwe_nonce: {
     responder: siweNonceResponder,
     requiredPolicies: [],
diff --git a/keyserver/src/fetchers/link-fetchers.js b/keyserver/src/fetchers/link-fetchers.js
new file mode 100644
--- /dev/null
+++ b/keyserver/src/fetchers/link-fetchers.js
@@ -0,0 +1,42 @@
+// @flow
+
+import type {
+  InviteLinkVerificationRequest,
+  InviteLinkVerificationResponse,
+} from 'lib/types/link-types.js';
+
+import { dbQuery, SQL } from '../database/database.js';
+import { Viewer } from '../session/viewer.js';
+
+async function verifyInviteLink(
+  viewer: Viewer,
+  request: InviteLinkVerificationRequest,
+): Promise<InviteLinkVerificationResponse> {
+  const query = SQL`
+    SELECT c.name, i.community AS communityID, m.role
+    FROM invite_links i
+    INNER JOIN threads c ON c.id = i.community
+    LEFT JOIN memberships m 
+      ON m.thread = i.community AND m.user = ${viewer.userID}
+    WHERE i.name = ${request.secret}
+      AND c.community IS NULL
+  `;
+  const [result] = await dbQuery(query);
+  if (result.length === 0) {
+    return {
+      status: 'invalid',
+    };
+  }
+
+  const { name, communityID, role } = result[0];
+  const status = role > 0 ? 'already_joined' : 'valid';
+  return {
+    status,
+    community: {
+      name,
+      id: communityID.toString(),
+    },
+  };
+}
+
+export { verifyInviteLink };
diff --git a/keyserver/src/responders/link-responders.js b/keyserver/src/responders/link-responders.js
new file mode 100644
--- /dev/null
+++ b/keyserver/src/responders/link-responders.js
@@ -0,0 +1,32 @@
+// @flow
+
+import t from 'tcomb';
+
+import type {
+  InviteLinkVerificationRequest,
+  InviteLinkVerificationResponse,
+} from 'lib/types/link-types.js';
+import { tShape } from 'lib/utils/validation-utils.js';
+
+import { verifyInviteLink } from '../fetchers/link-fetchers.js';
+import { Viewer } from '../session/viewer.js';
+import { validateInput } from '../utils/validation-utils.js';
+
+const inviteLinkVerificationRequestInputValidator = tShape({
+  secret: t.String,
+});
+
+async function inviteLinkVerificationResponder(
+  viewer: Viewer,
+  input: any,
+): Promise<InviteLinkVerificationResponse> {
+  const request: InviteLinkVerificationRequest = input;
+  await validateInput(
+    viewer,
+    inviteLinkVerificationRequestInputValidator,
+    request,
+  );
+  return await verifyInviteLink(viewer, request);
+}
+
+export { inviteLinkVerificationResponder };
diff --git a/lib/types/endpoints.js b/lib/types/endpoints.js
--- a/lib/types/endpoints.js
+++ b/lib/types/endpoints.js
@@ -84,6 +84,7 @@
   UPDATE_THREAD: 'update_thread',
   UPDATE_USER_SUBSCRIPTION: 'update_user_subscription',
   VERIFY_CODE: 'verify_code',
+  VERIFY_INVITE_LINK: 'verify_invite_link',
   SIWE_NONCE: 'siwe_nonce',
   SIWE_AUTH: 'siwe_auth',
   UPDATE_USER_AVATAR: 'update_user_avatar',
diff --git a/lib/types/link-types.js b/lib/types/link-types.js
new file mode 100644
--- /dev/null
+++ b/lib/types/link-types.js
@@ -0,0 +1,17 @@
+// @flow
+
+export type InviteLinkVerificationRequest = {
+  +secret: string,
+};
+
+export type InviteLinkVerificationResponse =
+  | {
+      +status: 'valid' | 'already_joined',
+      +community: {
+        +name: string,
+        +id: string,
+      },
+    }
+  | {
+      +status: 'invalid' | 'expired',
+    };