diff --git a/install/centos-7.sh b/install/centos-7.sh
index 2b37581af..d2f5eae6b 100644
--- a/install/centos-7.sh
+++ b/install/centos-7.sh
@@ -65,7 +65,7 @@ pm2 start "./minio server /data/file" --name minio
 # TODO: install basic addons?
 echo "Installing Hydro"
 yarn global add hydrooj @hydrooj/ui-default @hydrooj/hydrojudge
-wget https://github.com/criyle/go-judge/releases/download/v1.0.5/executorserver-amd64 -O /usr/bin/sandbox
+wget https://github.com/criyle/go-judge/releases/download/v1.0.5/executorserver-amd64 -O /usr/bin/sandbox_
 chmod +x /usr/bin/sandbox_
 pm2 start "/usr/bin/sandbox_"
 mkdir ~/.hydro
diff --git a/packages/hydrooj/package.json b/packages/hydrooj/package.json
index eb01a9ce8..0ee2dae3c 100644
--- a/packages/hydrooj/package.json
+++ b/packages/hydrooj/package.json
@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "2.15.30",
+    "version": "2.15.31",
     "bin": "bin/hydrooj.js",
     "main": "dist/loader.js",
     "typings": "dist/loader.d.ts",
diff --git a/packages/hydrooj/src/interface.ts b/packages/hydrooj/src/interface.ts
index 2e641caab..aa203cf78 100644
--- a/packages/hydrooj/src/interface.ts
+++ b/packages/hydrooj/src/interface.ts
@@ -310,7 +310,7 @@ export interface DomainDoc extends Dictionary<any> {
     bulletin: string,
     pidCounter: number,
     join?: any,
-    hostname?: string,
+    host?: string,
 }
 
 // Message
diff --git a/packages/hydrooj/src/model/domain.ts b/packages/hydrooj/src/model/domain.ts
index f5b771369..d7df0b158 100644
--- a/packages/hydrooj/src/model/domain.ts
+++ b/packages/hydrooj/src/model/domain.ts
@@ -53,6 +53,16 @@ export async function get(domainId: string): Promise<DomainDoc | null> {
     return result;
 }
 
+export async function getByHost(host: string): Promise<DomainDoc | null> {
+    const query: FilterQuery<DomainDoc> = { host };
+    await bus.serial('domain/before-get', query);
+    console.log(query);
+    const result = await coll.findOne(query);
+    console.log(result);
+    await bus.serial('domain/get', result);
+    return result;
+}
+
 export function getMulti(query: FilterQuery<DomainDoc> = {}) {
     return coll.find(query);
 }
@@ -212,6 +222,7 @@ global.Hydro.model.domain = {
     add,
     inc,
     get,
+    getByHost,
     edit,
     getMulti,
     getList,
diff --git a/packages/hydrooj/src/model/setting.ts b/packages/hydrooj/src/model/setting.ts
index 4bac005aa..155c1f6ac 100644
--- a/packages/hydrooj/src/model/setting.ts
+++ b/packages/hydrooj/src/model/setting.ts
@@ -108,6 +108,7 @@ DomainSetting(
     Setting('setting_domain', 'gravatar', null, '', 'text', 'gravatar', 'Will be used as the domain icon.'),
     Setting('setting_domain', 'bulletin', null, '', 'markdown', 'Bulletin'),
     Setting('setting_storage', 'pidCounter', null, 0, 'number', 'Problem ID Counter', null, FLAG_HIDDEN | FLAG_DISABLED),
+    Setting('setting_storage', 'host', null, '', 'text', 'Custom host', null, FLAG_HIDDEN | FLAG_DISABLED),
 );
 
 DomainUserSetting(
diff --git a/packages/hydrooj/src/service/server.ts b/packages/hydrooj/src/service/server.ts
index ee039cf43..7dd044b25 100644
--- a/packages/hydrooj/src/service/server.ts
+++ b/packages/hydrooj/src/service/server.ts
@@ -302,12 +302,20 @@ export class HandlerCommon {
             else query[key] = kwargs.query[key].toString();
         }
         try {
-            if (this.domainId !== 'system' || args.domainId) {
-                name += '_with_domainId';
-                args.domainId = args.domainId || this.domainId;
-            }
             const { anchor } = args;
-            res = router.url(name, args, { query });
+            if (!this.domain.host) {
+                if (this.domainId !== 'system' || args.domainId) {
+                    name += '_with_domainId';
+                    args.domainId = args.domainId || this.domainId;
+                }
+                res = router.url(name, args, { query });
+            } else {
+                if ((this.request.path || '').startsWith('/d/')) {
+                    name += '_with_domainId';
+                    args.domainId = args.domainId || this.domainId;
+                }
+                res = `//${this.domain.host}${router.url(name, args, { query })}`;
+            }
             if (anchor) return `${res}#${anchor}`;
         } catch (e) {
             logger.warn(e.message);
@@ -431,13 +439,20 @@ export class Handler extends HandlerCommon {
     }
 
     async init({ domainId }) {
-        [this.domain] = await Promise.all([
+        const [absoluteDomain, inferDomain] = await Promise.all([
             domain.get(domainId),
+            domain.getByHost(this.request.host),
             this.limitRate('global', 10, 100),
             this.getSession(),
             this.getBdoc(),
         ]);
-        if (!this.domain) {
+        if (inferDomain) {
+            this.domainId = inferDomain._id;
+            this.args.domainId = inferDomain._id;
+            this.domain = inferDomain;
+            domainId = inferDomain._id;
+        } else if (absoluteDomain) this.domain = absoluteDomain;
+        else {
             this.args.domainId = 'system';
             this.user = await user.getById('system', this.session.uid);
             if (!this.user) this.user = await user.getById('system', 0);