diff --git a/packages/hydrooj/package.json b/packages/hydrooj/package.json
index a234c6245..d3e4f72c3 100644
--- a/packages/hydrooj/package.json
+++ b/packages/hydrooj/package.json
@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "3.2.27",
+    "version": "3.2.28",
     "bin": "bin/hydrooj.js",
     "main": "src/loader",
     "module": "src/loader",
diff --git a/packages/hydrooj/src/handler/blog.ts b/packages/hydrooj/src/handler/blog.ts
index 9c0068bd0..f4fb74155 100644
--- a/packages/hydrooj/src/handler/blog.ts
+++ b/packages/hydrooj/src/handler/blog.ts
@@ -100,10 +100,10 @@ class BlogEditHandler extends BlogHandler {
     @param('content', Types.Content)
     async postUpdate(domainId: string, did: ObjectID, title: string, content: string) {
         if (!this.user.own(this.ddoc)) this.checkPriv(PRIV.PRIV_EDIT_SYSTEM);
-        await blog.edit(did, title, content);
-        await oplog.add({
-            ...this.ddoc, operator: this.user._id, type: 'edit',
-        });
+        await Promise.all([
+            blog.edit(did, title, content),
+            oplog.log(this, 'blog.edit', this.ddoc),
+        ]);
         this.response.body = { did };
         this.response.redirect = this.url('blog_detail', { uid: this.user._id, did });
     }
@@ -111,10 +111,10 @@ class BlogEditHandler extends BlogHandler {
     @param('did', Types.ObjectID)
     async postDelete(domainId: string, did: ObjectID) {
         if (!this.user.own(this.ddoc)) this.checkPriv(PRIV.PRIV_EDIT_SYSTEM);
-        await blog.del(did);
-        await oplog.add({
-            ...this.ddoc, operator: this.user._id, operateIp: this.request.ip, type: 'delete',
-        });
+        await Promise.all([
+            blog.del(did),
+            oplog.log(this, 'blog.delete', this.ddoc),
+        ]);
         this.response.redirect = this.url('blog_main', { uid: this.ddoc.owner });
     }
 }
diff --git a/packages/hydrooj/src/handler/discussion.ts b/packages/hydrooj/src/handler/discussion.ts
index 12055b6cb..761a6c234 100644
--- a/packages/hydrooj/src/handler/discussion.ts
+++ b/packages/hydrooj/src/handler/discussion.ts
@@ -251,10 +251,10 @@ class DiscussionDetailHandler extends DiscussionHandler {
     async postEditReply(domainId: string, drid: ObjectID, content: string) {
         this.checkPerm(PERM.PERM_EDIT_DISCUSSION_REPLY_SELF);
         if (!this.user.own(this.drdoc)) throw new PermissionError(PERM.PERM_EDIT_DISCUSSION_REPLY_SELF);
-        await discussion.editReply(domainId, drid, content);
-        await oplog.add({
-            ...this.drdoc, operator: this.user._id, operateIp: this.request.ip, type: 'edit',
-        });
+        await Promise.all([
+            discussion.editReply(domainId, drid, content),
+            oplog.log(this, 'discussion.reply.edit', this.drdoc),
+        ]);
         this.back();
     }
 
@@ -266,10 +266,10 @@ class DiscussionDetailHandler extends DiscussionHandler {
                 this.checkPerm(PERM.PERM_DELETE_DISCUSSION_REPLY);
             } else this.checkPerm(PERM.PERM_DELETE_DISCUSSION_SELF);
         }
-        await discussion.delReply(domainId, drid);
-        await oplog.add({
-            ...this.drdoc, operator: this.user._id, operateIp: this.request.ip, type: 'delete',
-        });
+        await Promise.all([
+            discussion.delReply(domainId, drid),
+            oplog.log(this, 'discussion.reply.delete', this.drdoc),
+        ]);
         this.back();
     }
 
@@ -279,11 +279,10 @@ class DiscussionDetailHandler extends DiscussionHandler {
     async postEditTailReply(domainId: string, drid: ObjectID, drrid: ObjectID, content: string) {
         this.checkPerm(PERM.PERM_EDIT_DISCUSSION_REPLY_SELF);
         if (!this.user.own(this.drrdoc)) throw new PermissionError(PERM.PERM_EDIT_DISCUSSION_REPLY_SELF);
-        await discussion.editTailReply(domainId, drid, drrid, content);
-        // TODO: history?
-        await oplog.add({
-            ...this.drrdoc, operator: this.user._id, operateIp: this.request.ip, type: 'edit',
-        });
+        await Promise.all([
+            discussion.editTailReply(domainId, drid, drrid, content),
+            oplog.log(this, 'discussion.tailReply.edit', this.drrdoc),
+        ]);
         this.back();
     }
 
@@ -291,10 +290,10 @@ class DiscussionDetailHandler extends DiscussionHandler {
     @param('drrid', Types.ObjectID)
     async postDeleteTailReply(domainId: string, drid: ObjectID, drrid: ObjectID) {
         if (!this.user.own(this.drrdoc)) this.checkPerm(PERM.PERM_DELETE_DISCUSSION_REPLY);
-        await discussion.delTailReply(domainId, drid, drrid);
-        await oplog.add({
-            ...this.drrdoc, operator: this.user._id, operateIp: this.request.ip, type: 'delete',
-        });
+        await Promise.all([
+            discussion.delTailReply(domainId, drid, drrid),
+            oplog.log(this, 'discussion.tailReply.delete', this.drrdoc),
+        ]);
         this.back();
     }
 
@@ -346,10 +345,10 @@ class DiscussionEditHandler extends DiscussionHandler {
         else this.checkPerm(PERM.PERM_EDIT_DISCUSSION_SELF);
         if (!this.user.hasPerm(PERM.PERM_HIGHLIGHT_DISCUSSION)) highlight = this.ddoc.highlight;
         if (!this.user.hasPerm(PERM.PERM_PIN_DISCUSSION)) pin = this.ddoc.pin;
-        await discussion.edit(domainId, did, title, content, highlight, pin);
-        await oplog.add({
-            ...this.ddoc, operator: this.user._id, type: 'edit',
-        });
+        await Promise.all([
+            discussion.edit(domainId, did, title, content, highlight, pin),
+            oplog.log(this, 'discussion.edit', this.ddoc),
+        ]);
         this.response.body = { did };
         this.response.redirect = this.url('discussion_detail', { did });
     }
@@ -358,10 +357,10 @@ class DiscussionEditHandler extends DiscussionHandler {
     async postDelete(domainId: string, did: ObjectID) {
         if (!this.user.own(this.ddoc)) this.checkPerm(PERM.PERM_DELETE_DISCUSSION);
         else this.checkPerm(PERM.PERM_DELETE_DISCUSSION_SELF);
-        await discussion.del(domainId, did);
-        await oplog.add({
-            ...this.ddoc, operator: this.user._id, operateIp: this.request.ip, type: 'delete',
-        });
+        await Promise.all([
+            oplog.log(this, 'discussion.delete', this.ddoc),
+            discussion.del(domainId, did),
+        ]);
         this.response.body = { type: this.ddoc.parentType, parent: this.ddoc.parentId };
         this.response.redirect = this.url('discussion_node', {
             type: discussion.typeDisplay[this.ddoc.parentType],
diff --git a/packages/hydrooj/src/handler/domain.ts b/packages/hydrooj/src/handler/domain.ts
index 52d0e6ac4..a1286296c 100644
--- a/packages/hydrooj/src/handler/domain.ts
+++ b/packages/hydrooj/src/handler/domain.ts
@@ -11,6 +11,7 @@ import paginate from '../lib/paginate';
 import { PERM, PERMS_BY_FAMILY, PRIV } from '../model/builtin';
 import * as discussion from '../model/discussion';
 import domain from '../model/domain';
+import * as oplog from '../model/oplog';
 import { DOMAIN_SETTINGS, DOMAIN_SETTINGS_BY_KEY } from '../model/setting';
 import * as system from '../model/system';
 import user from '../model/user';
@@ -114,14 +115,20 @@ class DomainUserHandler extends ManageHandler {
     @post('uid', Types.Int)
     @post('role', Types.Name)
     async postSetUser(domainId: string, uid: number, role: string) {
-        await domain.setUserRole(domainId, uid, role);
+        await Promise.all([
+            domain.setUserRole(domainId, uid, role),
+            oplog.log(this, 'domain.setRole', { uid, role }),
+        ]);
         this.back();
     }
 
     @param('uid', Types.NumericArray)
     @param('role', Types.Name)
     async postSetUsers(domainId: string, uid: number[], role: string) {
-        await domain.setUserRole(domainId, uid, role);
+        await Promise.all([
+            domain.setUserRole(domainId, uid, role),
+            oplog.log(this, 'domain.setRole', { uid, role }),
+        ]);
         this.back();
     }
 }
@@ -242,7 +249,10 @@ class DomainJoinHandler extends Handler {
                 throw new InvalidJoinInvitationCodeError(this.domain._id);
             }
         }
-        await domain.setUserRole(this.domain._id, this.user._id, this.joinSettings.role);
+        await Promise.all([
+            domain.setUserRole(this.domain._id, this.user._id, this.joinSettings.role),
+            oplog.log(this, 'domain.join', {}),
+        ]);
         this.response.redirect = this.url('homepage', { query: { notification: 'Successfully joined domain.' } });
     }
 }
diff --git a/packages/hydrooj/src/handler/misc.ts b/packages/hydrooj/src/handler/misc.ts
index f24a03c47..d7ae26485 100644
--- a/packages/hydrooj/src/handler/misc.ts
+++ b/packages/hydrooj/src/handler/misc.ts
@@ -91,14 +91,8 @@ export class FSDownloadHandler extends Handler {
         this.response.addHeader('Cache-Control', 'public');
         const target = `user/${uid}/${filename}`;
         const file = await storage.getMeta(target);
-        await oplog.add({
-            type: 'download',
-            time: new Date(),
-            uid: this.user._id,
-            ip: this.request.ip,
-            fileType: 'user',
+        await oplog.log(this, 'download.file.user', {
             target,
-            referer: this.request.referer,
             size: file?.size || 0,
         });
         if (!file) {
diff --git a/packages/hydrooj/src/handler/problem.ts b/packages/hydrooj/src/handler/problem.ts
index 36a3c6cc8..37f33b86e 100644
--- a/packages/hydrooj/src/handler/problem.ts
+++ b/packages/hydrooj/src/handler/problem.ts
@@ -514,14 +514,8 @@ export class ProblemFilesHandler extends ProblemDetailHandler {
                 ?.filter((i) => files.has(i.name))
                 ?.map((i) => i.size),
         ) || 0;
-        await oplog.add({
-            type: 'bulkDownload',
-            time: new Date(),
-            uid: this.user._id,
-            ip: this.request.ip,
-            fileType: 'problem',
+        await oplog.log(this, 'download.problem.bulk', {
             target: Array.from(files).map((file) => `problem/${this.pdoc.domainId}/${this.pdoc.docId}/${type}/${file}`),
-            referer: this.request.referer,
             size,
         });
         for (const file of files) {
@@ -618,14 +612,8 @@ export class ProblemFileDownloadHandler extends ProblemDetailHandler {
         }
         const target = `problem/${this.pdoc.domainId}/${this.pdoc.docId}/${type}/${filename}`;
         const file = await storage.getMeta(target);
-        await oplog.add({
-            type: 'download',
-            time: new Date(),
-            uid: this.user._id,
-            ip: this.request.ip,
-            fileType: 'problem',
+        await oplog.log(this, 'download.problem.single', {
             target,
-            referer: this.request.referer,
             size: file?.size || 0,
         });
         if (!file) {
diff --git a/packages/hydrooj/src/handler/user.ts b/packages/hydrooj/src/handler/user.ts
index 8cd29b05b..e8d5203a9 100644
--- a/packages/hydrooj/src/handler/user.ts
+++ b/packages/hydrooj/src/handler/user.ts
@@ -14,6 +14,7 @@ import BlackListModel from '../model/blacklist';
 import { PERM, PRIV, STATUS } from '../model/builtin';
 import domain from '../model/domain';
 import oauth from '../model/oauth';
+import * as oplog from '../model/oplog';
 import problem, { ProblemDoc } from '../model/problem';
 import * as system from '../model/system';
 import task from '../model/task';
@@ -118,7 +119,10 @@ class UserLoginHandler extends Handler {
         let udoc = await user.getByEmail(domainId, uname);
         if (!udoc) udoc = await user.getByUname(domainId, uname);
         if (!udoc) throw new UserNotFoundError(uname);
-        await this.limitRate('user_login', 60, 5);
+        await Promise.all([
+            this.limitRate('user_login', 60, 5),
+            oplog.log(this, 'user.login', { redirect }),
+        ]);
         if (udoc._tfa && !verifyToken(udoc._tfa, tfa)) throw new InvalidTokenError('2FA token invalid.');
         udoc.checkPassword(password);
         await user.setById(udoc._id, { loginat: new Date(), loginip: this.request.ip });
diff --git a/packages/hydrooj/src/model/oplog.ts b/packages/hydrooj/src/model/oplog.ts
index 337c7204e..79d2e0360 100644
--- a/packages/hydrooj/src/model/oplog.ts
+++ b/packages/hydrooj/src/model/oplog.ts
@@ -1,6 +1,7 @@
 import { ObjectID } from 'mongodb';
 import { OplogDoc } from '../interface';
 import db from '../service/db';
+import type { Handler } from '../service/server';
 
 export const coll = db.collection('oplog');
 
@@ -14,8 +15,26 @@ export async function add(data: Partial<OplogDoc> & { type: string }): Promise<O
     return res.insertedId;
 }
 
+export async function log<T extends Handler>(handler: T, type: string, data: any) {
+    const res = await coll.insertOne({
+        ...data,
+        _id: new ObjectID(),
+        type,
+        time: new Date(),
+        domainId: handler.domainId,
+        ua: handler.request.headers?.['user-agent'],
+        referer: handler.request.headers?.referer,
+        args: handler.args,
+        operator: handler.user?.id,
+        operateIp: handler.request.ip,
+    });
+    return res.insertedId;
+}
+
 export async function get(id: ObjectID): Promise<OplogDoc | null> {
     return await coll.findOne({ _id: id });
 }
 
-global.Hydro.model.oplog = { coll, add, get };
+global.Hydro.model.oplog = {
+    coll, add, get, log,
+};