diff --git a/pom.xml b/pom.xml
index d716a75..7431833 100644
--- a/pom.xml
+++ b/pom.xml
@@ -28,6 +28,7 @@
 
         <!-- dependencies -->
         <wiremock.version>3.5.4</wiremock.version>
+        <openapi.version>2.5.0</openapi.version>
 
         <!-- plugins -->
         <jsonschema2pojo.version>1.2.1</jsonschema2pojo.version>
@@ -62,6 +63,11 @@
             <artifactId>lombok</artifactId>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>org.springdoc</groupId>
+            <artifactId>springdoc-openapi-starter-webmvc-ui</artifactId>
+            <version>${openapi.version}</version>
+        </dependency>
 
         <!-- Database -->
         <dependency>
diff --git a/src/main/java/eu/ztsh/wymiana/web/model/CurrencyExchangeRequest.java b/src/main/java/eu/ztsh/wymiana/web/model/CurrencyExchangeRequest.java
index c804720..5264636 100644
--- a/src/main/java/eu/ztsh/wymiana/web/model/CurrencyExchangeRequest.java
+++ b/src/main/java/eu/ztsh/wymiana/web/model/CurrencyExchangeRequest.java
@@ -1,6 +1,7 @@
 package eu.ztsh.wymiana.web.model;
 
 import eu.ztsh.wymiana.validation.ValidExchangeRequest;
+import jakarta.validation.constraints.Min;
 import jakarta.validation.constraints.NotNull;
 import lombok.Builder;
 import org.hibernate.validator.constraints.pl.PESEL;
@@ -10,11 +11,11 @@ import java.math.BigDecimal;
 @Builder
 @ValidExchangeRequest
 public record CurrencyExchangeRequest(
-    @PESEL String pesel,
+    @NotNull @PESEL String pesel,
     @NotNull String from,
     @NotNull String to,
-    BigDecimal toBuy,
-    BigDecimal toSell
+    @Min(0) BigDecimal toBuy,
+    @Min(0) BigDecimal toSell
 ) {
 
 }
diff --git a/src/main/java/eu/ztsh/wymiana/web/model/UserCreateRequest.java b/src/main/java/eu/ztsh/wymiana/web/model/UserCreateRequest.java
index cb5de05..0614f6b 100644
--- a/src/main/java/eu/ztsh/wymiana/web/model/UserCreateRequest.java
+++ b/src/main/java/eu/ztsh/wymiana/web/model/UserCreateRequest.java
@@ -12,7 +12,7 @@ import java.math.BigDecimal;
 public record UserCreateRequest(
     @NotNull String name,
     @NotNull String surname,
-    @PESEL @Adult String pesel,
-    @Min(0) BigDecimal initial) {
+    @PESEL @Adult @NotNull String pesel,
+    @NotNull @Min(0) BigDecimal initial) {
 
 }