diff --git a/fluxer_api/src/api/utils/featureUtils.ts b/fluxer_api/src/api/utils/featureUtils.ts
index 75f4d2923..2a64400f2 100644
--- a/fluxer_api/src/api/utils/featureUtils.ts
+++ b/fluxer_api/src/api/utils/featureUtils.ts
@@ -1,8 +1,9 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
 import {Permissions} from '@fluxer/constants/src/ChannelConstants';
+import {Headers} from '@fluxer/constants/src/Headers';
 
-export const CLIENT_FEATURES_HEADER = 'X-Fluxer-Features';
+export const CLIENT_FEATURES_HEADER = Headers.X_FLUXER_FEATURES;
 const PERMISSION_BIT_CLIENT_FEATURES: ReadonlyArray<{
 	bit: bigint;
 	feature: string;
diff --git a/packages/constants/src/Headers.ts b/packages/constants/src/Headers.ts
index 60269a52f..da489ee59 100644
--- a/packages/constants/src/Headers.ts
+++ b/packages/constants/src/Headers.ts
@@ -7,6 +7,10 @@ export const Headers = {
 	AUTHORIZATION: 'Authorization',
 	ACCEPT: 'Accept',
 	CACHE_CONTROL: 'Cache-Control',
+	ETAG: 'ETag',
+	LAST_MODIFIED: 'Last-Modified',
+	IF_NONE_MATCH: 'If-None-Match',
+	IF_MODIFIED_SINCE: 'If-Modified-Since',
 	USER_AGENT: 'User-Agent',
 	X_FORWARDED_FOR: 'X-Forwarded-For',
 	X_FORWARDED_PROTO: 'X-Forwarded-Proto',
@@ -18,8 +22,11 @@ export const Headers = {
 	X_CONTENT_TYPE_OPTIONS: 'X-Content-Type-Options',
 	X_FRAME_OPTIONS: 'X-Frame-Options',
 	X_XSS_PROTECTION: 'X-XSS-Protection',
+	X_FLUXER_FEATURES: 'X-Fluxer-Features',
 	X_FLUXER_SUDO_MODE_JWT: 'X-Fluxer-Sudo-Mode-JWT',
 	X_FLUXER_VERSION: 'X-Fluxer-Version',
+	X_CAPTCHA_TOKEN: 'X-Captcha-Token',
+	X_CAPTCHA_TYPE: 'X-Captcha-Type',
 	X_AUDIT_LOG_REASON: 'X-Audit-Log-Reason',
 	X_INTERNAL_API_KEY: 'X-Internal-API-Key',
 	X_AMZ_REQUEST_ID: 'x-amz-request-id',