diff --git a/backend/open_webui/migrations/versions/a1b2c3d4e5f6_add_missing_tables.py b/backend/open_webui/migrations/versions/a1b2c3d4e5f6_add_missing_tables.py
new file mode 100644
index 0000000000..793cf9e120
--- /dev/null
+++ b/backend/open_webui/migrations/versions/a1b2c3d4e5f6_add_missing_tables.py
@@ -0,0 +1,148 @@
+"""Add missing tables (announcement, user_model_credential, message)
+
+Revision ID: a1b2c3d4e5f6
+Revises: 240e45fa2f01
+Create Date: 2025-12-07 14:00:00.000000
+
+补充以下表的迁移（这些表之前通过手动建表方式创建）：
+- announcement: 公告主表
+- announcement_read: 公告阅读记录表
+- user_model_credential: 用户私有模型凭据表
+- message: 消息表
+- message_reaction: 消息反应表
+
+注意：此迁移会检查表是否已存在，仅创建不存在的表，兼容手动建表的环境。
+"""
+
+from alembic import op
+import sqlalchemy as sa
+from open_webui.internal.db import JSONField
+from open_webui.migrations.util import get_existing_tables
+
+
+revision = "a1b2c3d4e5f6"
+down_revision = "240e45fa2f01"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    """升级数据库：创建缺失的表"""
+    connection = op.get_bind()
+    is_sqlite = connection.dialect.name == "sqlite"
+    existing_tables = set(get_existing_tables())
+
+    # 1. 创建 announcement 表
+    if "announcement" not in existing_tables:
+        op.create_table(
+            "announcement",
+            sa.Column("id", sa.Text(), nullable=False),
+            sa.Column("title", sa.Text(), nullable=False),
+            sa.Column("content", sa.Text(), nullable=False),
+            sa.Column("status", sa.String(32), nullable=False, server_default="active"),
+            sa.Column("created_by", sa.Text(), nullable=False),
+            sa.Column("created_at", sa.BigInteger(), nullable=False),
+            sa.Column("updated_at", sa.BigInteger(), nullable=False),
+            sa.Column("meta", JSONField(), nullable=True),
+            sa.PrimaryKeyConstraint("id"),
+        )
+        # 创建索引
+        op.create_index("idx_announcement_status", "announcement", ["status"])
+        op.create_index("idx_announcement_created_at", "announcement", ["created_at"])
+
+    # 2. 创建 announcement_read 表
+    if "announcement_read" not in existing_tables:
+        op.create_table(
+            "announcement_read",
+            sa.Column("id", sa.Text(), nullable=False),
+            sa.Column("user_id", sa.Text(), nullable=False),
+            sa.Column("announcement_id", sa.Text(), nullable=False),
+            sa.Column("read_at", sa.BigInteger(), nullable=False),
+            sa.PrimaryKeyConstraint("id"),
+        )
+        # 创建索引
+        op.create_index("idx_announcement_read_user", "announcement_read", ["user_id"])
+        op.create_index(
+            "idx_announcement_read_announcement", "announcement_read", ["announcement_id"]
+        )
+        op.create_index(
+            "idx_announcement_read_unique",
+            "announcement_read",
+            ["user_id", "announcement_id"],
+            unique=True,
+        )
+
+    # 3. 创建 user_model_credential 表
+    if "user_model_credential" not in existing_tables:
+        op.create_table(
+            "user_model_credential",
+            sa.Column("id", sa.String(), nullable=False),
+            sa.Column("user_id", sa.String(), nullable=True),
+            sa.Column("name", sa.String(), nullable=True),
+            sa.Column("model_id", sa.String(), nullable=False),
+            sa.Column("base_url", sa.Text(), nullable=True),
+            sa.Column("api_key", sa.Text(), nullable=False),
+            sa.Column("config", JSONField(), nullable=True),
+            sa.Column("created_at", sa.BigInteger(), nullable=True),
+            sa.Column("updated_at", sa.BigInteger(), nullable=True),
+            sa.PrimaryKeyConstraint("id"),
+        )
+        # 创建索引
+        op.create_index(
+            "ix_user_model_credential_user_id", "user_model_credential", ["user_id"]
+        )
+
+    # 4. 创建 message 表
+    if "message" not in existing_tables:
+        op.create_table(
+            "message",
+            sa.Column("id", sa.Text(), nullable=False),
+            sa.Column("user_id", sa.Text(), nullable=True),
+            sa.Column("channel_id", sa.Text(), nullable=True),
+            sa.Column("reply_to_id", sa.Text(), nullable=True),
+            sa.Column("parent_id", sa.Text(), nullable=True),
+            sa.Column("content", sa.Text(), nullable=True),
+            sa.Column("data", JSONField(), nullable=True),
+            sa.Column("meta", JSONField(), nullable=True),
+            sa.Column("created_at", sa.BigInteger(), nullable=True),
+            sa.Column("updated_at", sa.BigInteger(), nullable=True),
+            sa.PrimaryKeyConstraint("id"),
+        )
+
+    # 5. 创建 message_reaction 表
+    if "message_reaction" not in existing_tables:
+        op.create_table(
+            "message_reaction",
+            sa.Column("id", sa.Text(), nullable=False),
+            sa.Column("user_id", sa.Text(), nullable=True),
+            sa.Column("message_id", sa.Text(), nullable=True),
+            sa.Column("name", sa.Text(), nullable=True),
+            sa.Column("created_at", sa.BigInteger(), nullable=True),
+            sa.PrimaryKeyConstraint("id"),
+        )
+
+
+def downgrade():
+    """降级数据库：删除表"""
+    # 按照依赖关系逆序删除
+
+    # 1. 删除 message_reaction 表
+    op.drop_table("message_reaction")
+
+    # 2. 删除 message 表
+    op.drop_table("message")
+
+    # 3. 删除 user_model_credential 表（先删除索引）
+    op.drop_index("ix_user_model_credential_user_id", "user_model_credential")
+    op.drop_table("user_model_credential")
+
+    # 4. 删除 announcement_read 表（先删除索引）
+    op.drop_index("idx_announcement_read_unique", "announcement_read")
+    op.drop_index("idx_announcement_read_announcement", "announcement_read")
+    op.drop_index("idx_announcement_read_user", "announcement_read")
+    op.drop_table("announcement_read")
+
+    # 5. 删除 announcement 表（先删除索引）
+    op.drop_index("idx_announcement_created_at", "announcement")
+    op.drop_index("idx_announcement_status", "announcement")
+    op.drop_table("announcement")