2897 Add evaluator function DSL, definitions, and GraphQL endpoint

- Add EvaluatorFunctionDefinition record and EvaluatorFunctionDsl builder in evaluator-api
- Add EvaluatorFunctionDefinitionFactory interface for pluggable definition providers
- Add EvaluatorFunctionDefinitions with definitions for all 40+ built-in functions
  grouped by category (Collection, String, DateTime, Map, Type, Utility)
- Add GraphQL schema and controller for querying function definitions
  with list (filterable by name) and individual lookup queries
- Add spring-context dependency to evaluator-impl for @component support
- Add evaluator-api dependency to platform-configuration-graphql

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ivicac

server/libs/core/evaluator/evaluator-api/src/main/java/com/bytechef/evaluator/EvaluatorFunctionCategory.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2025 ByteChef
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.bytechef.evaluator;
+
+/**
+ * Enumerates the categories of evaluator functions.
+ *
+ * @author Ivica Cardic
+ */
+public enum EvaluatorFunctionCategory {
+
+    COLLECTION,
+    DATE_TIME,
+    MAP,
+    STRING,
+    TYPE,
+    UTILITY
+}

server/libs/core/evaluator/evaluator-api/src/main/java/com/bytechef/evaluator/EvaluatorFunctionDefinition.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2025 ByteChef
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.bytechef.evaluator;
+
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+import java.util.List;
+
+/**
+ * Describes an evaluator function available in the workflow expression language.
+ *
+ * @author Ivica Cardic
+ */
+@SuppressFBWarnings("EI")
+public record EvaluatorFunctionDefinition(
+    String name,
+    String title,
+    String description,
+    EvaluatorFunctionCategory category,
+    List<EvaluatorFunctionParameter> parameters,
+    EvaluatorFunctionType returnType,
+    String example) {
+
+    /**
+     * Describes a parameter of an evaluator function.
+     *
+     * @author Ivica Cardic
+     */
+    public record EvaluatorFunctionParameter(
+        String name, String description, EvaluatorFunctionType type, boolean required) {
+    }
+}

server/libs/core/evaluator/evaluator-api/src/main/java/com/bytechef/evaluator/EvaluatorFunctionDefinitionFactory.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2025 ByteChef
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.bytechef.evaluator;
+
+import java.util.List;
+
+/**
+ * Factory interface for providing evaluator function definitions.
+ *
+ * @author Ivica Cardic
+ */
+public interface EvaluatorFunctionDefinitionFactory {
+
+    /**
+     * Returns all evaluator function definitions provided by this factory.
+     *
+     * @return a list of {@link EvaluatorFunctionDefinition} instances
+     */
+    List<EvaluatorFunctionDefinition> getDefinitions();
+}

server/libs/core/evaluator/evaluator-api/src/main/java/com/bytechef/evaluator/EvaluatorFunctionDsl.java

@@ -0,0 +1,161 @@
+/*
+ * Copyright 2025 ByteChef
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.bytechef.evaluator;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Fluent DSL for building {@link EvaluatorFunctionDefinition} instances.
+ *
+ * @author Ivica Cardic
+ */
+public final class EvaluatorFunctionDsl {
+
+    private EvaluatorFunctionDsl() {
+    }
+
+    /**
+     * Creates a new modifiable function definition with the given name.
+     *
+     * @param name the function name as it appears in expressions
+     * @return a new {@link ModifiableEvaluatorFunctionDefinition}
+     */
+    public static ModifiableEvaluatorFunctionDefinition function(String name) {
+        return new ModifiableEvaluatorFunctionDefinition(name);
+    }
+
+    /**
+     * Creates a new modifiable parameter definition with the given name.
+     *
+     * @param name the parameter name
+     * @return a new {@link ModifiableEvaluatorFunctionParameter}
+     */
+    public static ModifiableEvaluatorFunctionParameter parameter(String name) {
+        return new ModifiableEvaluatorFunctionParameter(name);
+    }
+
+    /**
+     * Mutable builder for {@link EvaluatorFunctionDefinition}.
+     *
+     * @author Ivica Cardic
+     */
+    public static final class ModifiableEvaluatorFunctionDefinition {
+
+        private EvaluatorFunctionCategory category;
+        private String description;
+        private String example;
+        private final String name;
+        private List<ModifiableEvaluatorFunctionParameter> parameters = new ArrayList<>();
+        private EvaluatorFunctionType returnType;
+        private String title;
+
+        private ModifiableEvaluatorFunctionDefinition(String name) {
+            this.name = name;
+        }
+
+        public ModifiableEvaluatorFunctionDefinition title(String title) {
+            this.title = title;
+
+            return this;
+        }
+
+        public ModifiableEvaluatorFunctionDefinition description(String description) {
+            this.description = description;
+
+            return this;
+        }
+
+        public ModifiableEvaluatorFunctionDefinition category(EvaluatorFunctionCategory category) {
+            this.category = category;
+
+            return this;
+        }
+
+        public ModifiableEvaluatorFunctionDefinition parameters(ModifiableEvaluatorFunctionParameter... parameters) {
+            this.parameters = List.of(parameters);
+
+            return this;
+        }
+
+        public ModifiableEvaluatorFunctionDefinition returnType(EvaluatorFunctionType returnType) {
+            this.returnType = returnType;
+
+            return this;
+        }
+
+        public ModifiableEvaluatorFunctionDefinition example(String example) {
+            this.example = example;
+
+            return this;
+        }
+
+        /**
+         * Builds an immutable {@link EvaluatorFunctionDefinition} from this builder's current state.
+         *
+         * @return a new {@link EvaluatorFunctionDefinition}
+         */
+        public EvaluatorFunctionDefinition toDefinition() {
+            List<EvaluatorFunctionDefinition.EvaluatorFunctionParameter> builtParameters = parameters.stream()
+                .map(ModifiableEvaluatorFunctionParameter::toParameter)
+                .toList();
+
+            return new EvaluatorFunctionDefinition(
+                name, title, description, category, Collections.unmodifiableList(builtParameters), returnType, example);
+        }
+    }
+
+    /**
+     * Mutable builder for {@link EvaluatorFunctionDefinition.EvaluatorFunctionParameter}.
+     *
+     * @author Ivica Cardic
+     */
+    public static final class ModifiableEvaluatorFunctionParameter {
+
+        private String description;
+        private final String name;
+        private boolean required = true;
+        private EvaluatorFunctionType type;
+
+        private ModifiableEvaluatorFunctionParameter(String name) {
+            this.name = name;
+        }
+
+        public ModifiableEvaluatorFunctionParameter description(String description) {
+            this.description = description;
+
+            return this;
+        }
+
+        public ModifiableEvaluatorFunctionParameter type(EvaluatorFunctionType type) {
+            this.type = type;
+
+            return this;
+        }
+
+        public ModifiableEvaluatorFunctionParameter required(boolean required) {
+            this.required = required;
+
+            return this;
+        }
+
+        EvaluatorFunctionDefinition.EvaluatorFunctionParameter toParameter() {
+            return new EvaluatorFunctionDefinition.EvaluatorFunctionParameter(name, description, type, required);
+        }
+    }
+}

server/libs/core/evaluator/evaluator-api/src/main/java/com/bytechef/evaluator/EvaluatorFunctionType.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2025 ByteChef
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.bytechef.evaluator;
+
+/**
+ * Enumerates the data types available for evaluator function parameters and return values.
+ *
+ * @author Ivica Cardic
+ */
+public enum EvaluatorFunctionType {
+
+    BOOLEAN,
+    BYTE,
+    CHARACTER,
+    DATETIME,
+    DOUBLE,
+    FLOAT,
+    INTEGER,
+    LIST,
+    LONG,
+    MAP,
+    NUMBER,
+    SHORT,
+    STRING
+}

server/libs/core/evaluator/evaluator-impl/build.gradle.kts

@@ -2,6 +2,7 @@ dependencies {
     api(project(":server:libs:core:evaluator:evaluator-api"))
 
     implementation("org.slf4j:slf4j-api")
+    implementation("org.springframework:spring-context")
     implementation("org.springframework:spring-expression")
 
     testImplementation(project(":server:libs:config:jackson-config"))