diff --git a/README.md b/README.md
index 54f0fcf..2a6d8f4 100644
--- a/README.md
+++ b/README.md
@@ -22,9 +22,31 @@ This library is distributed via [jitpack.io](https://jitpack.io/#ArtemGet/entrys
 
 1) Properties passed via -D
 2) Environment variables
-3) Json strings
+3) Json strings 
+
+Note that using json entries requires additional dependencies:
+
+```xml
+
+<dependency>
+  <groupId>org.glassfish</groupId>
+  <artifactId>jakarta.json</artifactId>
+  <version>1.1.6</version>
+</dependency>
+```
+
 4) Yaml files
 
+Note that using yaml entries requires additional dependencies:
+
+```xml
+<dependency>
+   <groupId>com.amihaiemil.web</groupId>
+   <artifactId>eo-yaml</artifactId>
+   <version>8.0.6</version>
+</dependency>
+```
+
 # Examples
 
 ## Properties:
diff --git a/pom.xml b/pom.xml
index 12158d5..f0e9fcd 100644
--- a/pom.xml
+++ b/pom.xml
@@ -21,6 +21,7 @@
       <groupId>com.amihaiemil.web</groupId>
       <artifactId>eo-yaml</artifactId>
       <version>8.0.6</version>
+      <scope>provided</scope>
       <exclusions>
         <exclusion>
           <groupId>javax.json</groupId>
diff --git a/src/main/java/io/github/artemget/entrys/func/EBiFunc.java b/src/main/java/io/github/artemget/entrys/func/EBiFunc.java
new file mode 100644
index 0000000..6a97b2c
--- /dev/null
+++ b/src/main/java/io/github/artemget/entrys/func/EBiFunc.java
@@ -0,0 +1,41 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2024-2025. Artem Getmanskii
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package io.github.artemget.entrys.func;
+
+import io.github.artemget.entrys.EntryException;
+import org.cactoos.BiFunc;
+
+/**
+ * Binary function with concrete entry exception.
+ *
+ * @param <X> Type of input
+ * @param <Y> Type of input
+ * @param <Z> Type of output
+ * @since 0.4.2
+ */
+public interface EBiFunc<X, Y, Z> extends BiFunc<X, Y, Z> {
+    @Override
+    Z apply(X first, Y second) throws EntryException;
+}
diff --git a/src/main/java/io/github/artemget/entrys/func/EFunc.java b/src/main/java/io/github/artemget/entrys/func/EFunc.java
new file mode 100644
index 0000000..7a66e4b
--- /dev/null
+++ b/src/main/java/io/github/artemget/entrys/func/EFunc.java
@@ -0,0 +1,40 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2024-2025. Artem Getmanskii
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package io.github.artemget.entrys.func;
+
+import io.github.artemget.entrys.EntryException;
+import org.cactoos.Func;
+
+/**
+ * Function with concrete entry exception.
+ *
+ * @param <X> Type of input
+ * @param <Y> Type of output
+ * @since 0.4.2
+ */
+public interface EFunc<X, Y> extends Func<X, Y> {
+    @Override
+    Y apply(X input) throws EntryException;
+}
diff --git a/src/main/java/io/github/artemget/entrys/func/package-info.java b/src/main/java/io/github/artemget/entrys/func/package-info.java
new file mode 100644
index 0000000..3e6f3a7
--- /dev/null
+++ b/src/main/java/io/github/artemget/entrys/func/package-info.java
@@ -0,0 +1,28 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2024-2025. Artem Getmanskii
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/**
+ * Entry functions.
+ */
+package io.github.artemget.entrys.func;