diff --git a/build/gen-patch.ts b/build/gen-patch.ts
new file mode 100644
index 00000000..6c81164b
--- /dev/null
+++ b/build/gen-patch.ts
@@ -0,0 +1,21 @@
+import child from 'child_process';
+import fs from 'fs';
+import path from 'path';
+import superagent from 'superagent';
+
+if (!process.argv[2]) throw new Error('No target specified');
+
+// TODO support module other than packages
+const target = process.argv[2].startsWith('packages/') ? process.argv[2] : `packages/${process.argv[2]}`;
+
+const result = child.execSync(`git diff ${target}`);
+const patch = result.toString().replace(new RegExp(`${target}/`, 'g'), '');
+const filename = `${path.basename(target)}.patch`;
+fs.writeFileSync(filename, patch);
+superagent.post('https://hydro.ac/paste')
+    .set('accept', 'application/json')
+    .send({ body: patch, filename })
+    .end((err, res) => {
+        if (err) throw err;
+        console.log('Paste created on ', res.text);
+    });
diff --git a/package.json b/package.json
index c129539f..226ae6eb 100644
--- a/package.json
+++ b/package.json
@@ -25,7 +25,8 @@
         "lint:ui:ci": "yarn workspace @hydrooj/ui-default lint --ext .js,.ts,.jsx,.tsx .",
         "debug": "node --trace-warnings --async-stack-traces --trace-deprecation packages/hydrooj/bin/hydrooj --debug --template",
         "start": "packages/hydrooj/bin/hydrooj",
-        "postinstall": "node build/prepare.js"
+        "postinstall": "node build/prepare.js",
+        "gen-patch": "node -r @hydrooj/utils/lib/register build/gen-patch.ts"
     },
     "version": "1.0.0",
     "license": "AGPL-3.0-only",
diff --git a/packages/hydrooj/bin/commands.ts b/packages/hydrooj/bin/commands.ts
index 123763ad..7ce2fe44 100644
--- a/packages/hydrooj/bin/commands.ts
+++ b/packages/hydrooj/bin/commands.ts
@@ -204,6 +204,7 @@ if (!argv.args[0] || argv.args[0] === 'cli') {
         fs.removeSync(newAddonPath);
         console.log(`Successfully uninstalled ${name}.`);
     });
+    require('../src/commands/patch').register(cli);
     cli.help();
     cli.parse();
     if (!cli.matchedCommand) {
diff --git a/packages/hydrooj/src/commands/patch.ts b/packages/hydrooj/src/commands/patch.ts
new file mode 100644
index 00000000..21f637e1
--- /dev/null
+++ b/packages/hydrooj/src/commands/patch.ts
@@ -0,0 +1,31 @@
+import child from 'child_process';
+import { CAC } from 'cac';
+import fs from 'fs-extra';
+import superagent from 'superagent';
+import { Logger } from '@hydrooj/utils';
+
+const logger = new Logger('patch');
+
+export function register(cli: CAC) {
+    cli.command('patch <module> <patch>').action(async (filename, patch) => {
+        const mod = require.resolve(filename);
+        if (!mod) {
+            logger.error('Module %s not found', filename);
+            return;
+        }
+        logger.info('Patching %s', mod);
+        const res = await superagent.get(patch);
+        logger.info('Downloaded patch');
+        for (let i = 0; i <= 100; i++) {
+            const fp = `${mod}.${i}.patch`;
+            if (fs.existsSync(fp)) continue;
+            patch = fp;
+            break;
+        }
+        await fs.writeFile(patch, res.text);
+        child.execSync(`patch ${mod} -o ${mod} < ${patch}`);
+        logger.info('Patched %s', mod);
+    });
+
+    // TODO: support revert patch
+}