diff --git a/api/openapi.yaml b/api/openapi.yaml
index 6439c86..b20f677 100644
--- a/api/openapi.yaml
+++ b/api/openapi.yaml
@@ -196,7 +196,7 @@ paths:
     #               error:
     #                 type: string
 
-  /users:
+  # /users:
   #   get:
   #     summary: Search user
   #     parameters:
@@ -218,28 +218,28 @@ paths:
   #               items:
   #                 $ref: '#/components/schemas/User'
 
-    post:
-      summary: Add new user
-      requestBody:
-        required: true
-        content:
-          application/json:
-            schema:
-              $ref: '#/components/schemas/User'
-      responses:
-        '200':
-          description: Add result
-          content:
-            application/json:
-              schema:
-                type: object
-                properties:
-                  success:
-                    type: boolean
-                  error:
-                    type: string
-                  user_json:
-                    $ref: '#/components/schemas/User'
+  #   post:
+  #     summary: Add new user
+  #     requestBody:
+  #       required: true
+  #       content:
+  #         application/json:
+  #           schema:
+  #             $ref: '#/components/schemas/User'
+  #     responses:
+  #       '200':
+  #         description: Add result
+  #         content:
+  #           application/json:
+  #             schema:
+  #               type: object
+  #               properties:
+  #                 success:
+  #                   type: boolean
+  #                 error:
+  #                   type: string
+  #                 user_json:
+  #                   $ref: '#/components/schemas/User'
 
 #   /users/{user_id}/titles:
 #     get:
@@ -580,7 +580,7 @@ components:
       required:
         - user_id
         - nickname
-        # - creation_date
+        - creation_date
     UserTitle:
       type: object
       additionalProperties: true
diff --git a/sql/migrations/000001_init.up.sql b/sql/migrations/000001_init.up.sql
index abecd32..0b7fa33 100644
--- a/sql/migrations/000001_init.up.sql
+++ b/sql/migrations/000001_init.up.sql
@@ -27,8 +27,8 @@ CREATE TABLE users (
     id                  bigint              GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
     avatar_id           bigint              REFERENCES images (id),
     passhash            text                NOT NULL,
-    mail                text                CHECK (mail ~ '^[a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\.[a-zA-Z0-9_-]+$'),
-    nickname            text                UNIQUE NOT NULL CHECK (nickname ~ '^[a-zA-Z0-9_-]{3,}$'),
+    mail                text                CHECK (mail ~ '[a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\.[a-zA-Z0-9_-]+'),
+    nickname            text                NOT NULL CHECK (nickname ~ '^[a-zA-Z0-9_-]+$'),
     disp_name           text,
     user_desc           text,
     creation_date       timestamptz         NOT NULL,
@@ -85,12 +85,6 @@ CREATE TABLE signals (
     pending             boolean             NOT NULL
 );
 
-CREATE TABLE external_ids (
-    user_id                                 NOT NULL REFERENCES users (id),
-    service_id          text                NOT NULL,
-    external_ids        text                NOT NULL
-);
-
 -- Functions
 CREATE OR REPLACE FUNCTION update_title_rating()
 RETURNS TRIGGER AS $$