diff --git a/openapi.json b/openapi.json
index 5de2cf1..60368de 100644
--- a/openapi.json
+++ b/openapi.json
@@ -164,6 +164,52 @@
         }
       }
     },
+    "/token/balance": {
+      "get": {
+        "tags": [
+          "Tokens"
+        ],
+        "summary": "Get Balance",
+        "description": "Get token's balance by the given user address",
+        "operationId": "GetBalance",
+        "parameters": [
+          {
+            "in": "query",
+            "name": "address",
+            "required": true,
+            "schema": {
+              "type": "string",
+              "format": "common.Address"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "type": "object",
+                  "required": [
+                    "data"
+                  ],
+                  "properties": {
+                    "data": {
+                      "$ref": "#/components/schemas/Balance"
+                    }
+                  }
+                }
+              }
+            }
+          },
+          "400": {
+            "$ref": "#/components/responses/invalidParameter"
+          },
+          "500": {
+            "$ref": "#/components/responses/internalError"
+          }
+        }
+      }
+    },
     "/transfer": {
       "post": {
         "tags": [
@@ -504,6 +550,35 @@
           }
         ]
       },
+      "Balance": {
+        "allOf": [
+          {
+            "$ref": "#/components/schemas/TokenKey"
+          },
+          {
+            "type": "object",
+            "required": [
+              "attributes"
+            ],
+            "properties": {
+              "attributes": {
+                "type": "object",
+                "required": [
+                  "amount"
+                ],
+                "properties": {
+                  "amount": {
+                    "type": "integer",
+                    "format": "*big.Int",
+                    "description": "Amount of the tokens on the user address",
+                    "example": "123"
+                  }
+                }
+              }
+            }
+          }
+        ]
+      },
       "BuildPermitHash": {
         "allOf": [
           {
@@ -707,6 +782,24 @@
           }
         ]
       },
+      "TokenKey": {
+        "type": "object",
+        "required": [
+          "id",
+          "type"
+        ],
+        "properties": {
+          "id": {
+            "type": "string"
+          },
+          "type": {
+            "type": "string",
+            "enum": [
+              "token"
+            ]
+          }
+        }
+      },
       "TransferERC20Token": {
         "allOf": [
           {
diff --git a/openapi.yaml b/openapi.yaml
index e919aa5..48584bf 100644
--- a/openapi.yaml
+++ b/openapi.yaml
@@ -102,6 +102,35 @@ paths:
                 properties:
                   data:
                     $ref: '#/components/schemas/AirdropParams'
+  /token/balance:
+    get:
+      tags:
+        - Tokens
+      summary: Get Balance
+      description: Get token's balance by the given user address
+      operationId: GetBalance
+      parameters:
+        - in: query
+          name: address
+          required: true
+          schema:
+            type: string
+            format: common.Address
+      responses:
+        '200':
+          content:
+            application/vnd.api+json:
+              schema:
+                type: object
+                required:
+                  - data
+                properties:
+                  data:
+                    $ref: '#/components/schemas/Balance'
+        '400':
+          $ref: '#/components/responses/invalidParameter'
+        '500':
+          $ref: '#/components/responses/internalError'
   /transfer:
     post:
       tags:
@@ -328,6 +357,23 @@ components:
                   type: string
                   description: Query selector that is used for proof generation
                   example: 123
+    Balance:
+      allOf:
+        - $ref: '#/components/schemas/TokenKey'
+        - type: object
+          required:
+            - attributes
+          properties:
+            attributes:
+              type: object
+              required:
+                - amount
+              properties:
+                amount:
+                  type: integer
+                  format: '*big.Int'
+                  description: Amount of the tokens on the user address
+                  example: '123'
     BuildPermitHash:
       allOf:
         - $ref: '#/components/schemas/TransferKey'
@@ -463,6 +509,18 @@ components:
                   type: string
                   description: Permit message hash built by ERC-2612 standard that has to be signed by token owner.
                   example: '0x3f77218a74501051ac9f069e73523519e6a6cf34783811515da5a178e86634ca'
+    TokenKey:
+      type: object
+      required:
+        - id
+        - type
+      properties:
+        id:
+          type: string
+        type:
+          type: string
+          enum:
+            - token
     TransferERC20Token:
       allOf:
         - $ref: '#/components/schemas/TransferKey'