diff --git a/app/core/src/main/java/stirling/software/SPDF/model/ApiEndpoint.java b/app/core/src/main/java/stirling/software/SPDF/model/ApiEndpoint.java
index 79a910300..04d2bb1fa 100644
--- a/app/core/src/main/java/stirling/software/SPDF/model/ApiEndpoint.java
+++ b/app/core/src/main/java/stirling/software/SPDF/model/ApiEndpoint.java
@@ -25,8 +25,9 @@ public class ApiEndpoint {
     }
 
     public boolean areParametersValid(Map<String, Object> providedParams) {
-        for (String requiredParam : parameters.keySet()) {
-            if (!providedParams.containsKey(requiredParam)) {
+        for (Map.Entry<String, JsonNode> entry : parameters.entrySet()) {
+            boolean isRequired = entry.getValue().path("required").asBoolean(false);
+            if (isRequired && !providedParams.containsKey(entry.getKey())) {
                 return false;
             }
         }
diff --git a/app/core/src/test/java/stirling/software/SPDF/model/ApiEndpointTest.java b/app/core/src/test/java/stirling/software/SPDF/model/ApiEndpointTest.java
index 85e1587a5..a9293f116 100644
--- a/app/core/src/test/java/stirling/software/SPDF/model/ApiEndpointTest.java
+++ b/app/core/src/test/java/stirling/software/SPDF/model/ApiEndpointTest.java
@@ -18,6 +18,11 @@ class ApiEndpointTest {
     private final ObjectMapper mapper = JsonMapper.builder().build();
 
     private JsonNode postNodeWithParams(String description, String... names) {
+        return postNodeWithParams(description, true, names);
+    }
+
+    private JsonNode postNodeWithParams(
+            String description, boolean required, String... names) {
         ObjectNode post = mapper.createObjectNode();
         post.put("description", description);
         ArrayNode params = mapper.createArrayNode();
@@ -26,6 +31,7 @@ class ApiEndpointTest {
             if (n != null) {
                 p.put("name", n);
             }
+            p.put("required", required);
             params.add(p);
         }
         post.set("parameters", params);
@@ -92,6 +98,75 @@ class ApiEndpointTest {
         assertTrue(endpoint.areParametersValid(Map.of("", 42)));
     }
 
+    @Test
+    void optional_parameters_can_be_omitted() {
+        JsonNode post = postNodeWithParams("desc", false, "fileOrder");
+        ApiEndpoint endpoint = new ApiEndpoint("merge", post);
+
+        assertTrue(
+                endpoint.areParametersValid(Map.of()),
+                "Should be valid when optional param is omitted");
+    }
+
+    @Test
+    void mixed_required_and_optional_validates_only_required() {
+        ObjectNode post = mapper.createObjectNode();
+        post.put("description", "merge pdfs");
+        ArrayNode params = mapper.createArrayNode();
+
+        ObjectNode required = mapper.createObjectNode();
+        required.put("name", "sortType");
+        required.put("required", true);
+        params.add(required);
+
+        ObjectNode optional = mapper.createObjectNode();
+        optional.put("name", "fileOrder");
+        optional.put("required", false);
+        params.add(optional);
+
+        post.set("parameters", params);
+        ApiEndpoint endpoint = new ApiEndpoint("/api/v1/general/merge-pdfs", post);
+
+        Map<String, Object> provided = new HashMap<>();
+        provided.put("sortType", "byFileName");
+
+        assertTrue(
+                endpoint.areParametersValid(provided),
+                "Should pass when required params present and optional omitted");
+
+        provided.put("fileOrder", "0,1,2");
+        assertTrue(
+                endpoint.areParametersValid(provided),
+                "Should also pass when optional param is provided");
+    }
+
+    @Test
+    void missing_required_param_with_optional_present_still_fails() {
+        ObjectNode post = mapper.createObjectNode();
+        post.put("description", "desc");
+        ArrayNode params = mapper.createArrayNode();
+
+        ObjectNode required = mapper.createObjectNode();
+        required.put("name", "file");
+        required.put("required", true);
+        params.add(required);
+
+        ObjectNode optional = mapper.createObjectNode();
+        optional.put("name", "fileOrder");
+        optional.put("required", false);
+        params.add(optional);
+
+        post.set("parameters", params);
+        ApiEndpoint endpoint = new ApiEndpoint("x", post);
+
+        Map<String, Object> provided = new HashMap<>();
+        provided.put("fileOrder", "0,1");
+
+        assertFalse(
+                endpoint.areParametersValid(provided),
+                "Should fail when required param is missing even if optional is present");
+    }
+
     @Test
     void toString_contains_name_and_parameter_names() {
         JsonNode post = postNodeWithParams("desc", "file", "mode");
diff --git a/app/core/src/test/java/stirling/software/SPDF/service/ApiDocServiceTest.java b/app/core/src/test/java/stirling/software/SPDF/service/ApiDocServiceTest.java
index baa6d3f2f..cf176c042 100644
--- a/app/core/src/test/java/stirling/software/SPDF/service/ApiDocServiceTest.java
+++ b/app/core/src/test/java/stirling/software/SPDF/service/ApiDocServiceTest.java
@@ -74,15 +74,37 @@ class ApiDocServiceTest {
     @Test
     void isValidOperationChecksRequiredParameters() throws Exception {
         String json =
-                "{\"description\": \"desc\", \"parameters\": [{\"name\":\"param1\"}, {\"name\":\"param2\"}]}";
+                "{\"description\": \"desc\", \"parameters\": [{\"name\":\"param1\", \"required\": true}, {\"name\":\"param2\", \"required\": true}]}";
         JsonNode postNode = mapper.readTree(json);
         ApiEndpoint endpoint = new ApiEndpoint("/op", postNode);
 
         setApiDocumentation(Map.of("/op", endpoint));
         setApiDocsJsonRootNode();
 
+        // All required params provided - valid
         assertTrue(apiDocService.isValidOperation("/op", Map.of("param1", "a", "param2", "b")));
+        // Missing required param2 - invalid
         assertFalse(apiDocService.isValidOperation("/op", Map.of("param1", "a")));
+        // Missing required param1 - invalid
+        assertFalse(apiDocService.isValidOperation("/op", Map.of("param2", "b")));
+    }
+
+    @Test
+    void isValidOperationAllowsOptionalParameters() throws Exception {
+        String json =
+                "{\"description\": \"desc\", \"parameters\": [{\"name\":\"param1\", \"required\": false}, {\"name\":\"param2\", \"required\": false}]}";
+        JsonNode postNode = mapper.readTree(json);
+        ApiEndpoint endpoint = new ApiEndpoint("/op", postNode);
+
+        setApiDocumentation(Map.of("/op", endpoint));
+        setApiDocsJsonRootNode();
+
+        // All optional params provided - valid
+        assertTrue(apiDocService.isValidOperation("/op", Map.of("param1", "a", "param2", "b")));
+        // Only one optional param provided - valid
+        assertTrue(apiDocService.isValidOperation("/op", Map.of("param1", "a")));
+        // No optional params provided - valid
+        assertTrue(apiDocService.isValidOperation("/op", Map.of()));
     }
 
     @Test