fix: add rerank_hybrid_matches to SearchParameters

buildSrc/src/main/groovy/DownloadSpecsPlugin.groovy

@@ -68,11 +68,46 @@ class DownloadSpecsPlugin implements Plugin<Project> {
 
                 if (content.contains(allOfBlock)) {
                     content = content.replace(allOfBlock, replacement)
-                    file.text = content
                     println('Successfully patched SynonymItemSchema')
                 } else {
                     println('Warning: SynonymItemSchema allOf block not found, skipping patch')
                 }
+
+                // Patch: Add rerank_hybrid_matches to SearchParameters
+                // The server accepts this parameter for all search endpoints (single and multi),
+                // but the spec only defines it on MultiSearchCollectionParameters.
+                println('Patching OpenAPI spec: adding rerank_hybrid_matches to SearchParameters')
+                String searchParamsAnchor = '''\
+        conversation_id:
+          description: >
+            The Id of a previous conversation to continue, this tells Typesense to include prior context when communicating with the LLM.
+          type: string
+
+    MultiSearchParameters:'''
+
+                String searchParamsReplacement = '''\
+        conversation_id:
+          description: >
+            The Id of a previous conversation to continue, this tells Typesense to include prior context when communicating with the LLM.
+          type: string
+        rerank_hybrid_matches:
+          type: boolean
+          description: >
+            When true, computes both text match and vector distance scores for all matches in hybrid search.
+            Documents found only through keyword search will get a vector distance score, and
+            documents found only through vector search will get a text match score.
+          default: false
+
+    MultiSearchParameters:'''
+
+                if (content.contains(searchParamsAnchor)) {
+                    content = content.replace(searchParamsAnchor, searchParamsReplacement)
+                    println('Successfully added rerank_hybrid_matches to SearchParameters')
+                } else {
+                    println('Warning: SearchParameters anchor not found, skipping rerank_hybrid_matches patch')
+                }
+
+                file.text = content
             }
         }
     }

src/test/java/org/typesense/api/SearchParametersRerankHybridTest.java

@@ -0,0 +1,55 @@
+package org.typesense.api;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.jupiter.api.Test;
+import org.typesense.model.SearchParameters;
+
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Bug: rerank_hybrid_matches was only available on MultiSearchCollectionParameters,
+ * forcing users to use multi_search even for single collection hybrid search.
+ * The Typesense server accepts this parameter for all search endpoints.
+ */
+class SearchParametersRerankHybridTest {
+
+    private final ObjectMapper mapper = new ObjectMapper();
+
+    @Test
+    void testRerankHybridMatchesDefaultsToFalseAndSerializes() {
+        SearchParameters params = new SearchParameters();
+        assertFalse(params.isRerankHybridMatches());
+
+        Map<String, Object> map = mapper.convertValue(params, Map.class);
+        assertEquals(false, map.get("rerank_hybrid_matches"));
+    }
+
+    @Test
+    void testRerankHybridMatchesTrueSerializesToCorrectJsonKey() {
+        SearchParameters params = new SearchParameters()
+                .q("search term")
+                .queryBy("title")
+                .rerankHybridMatches(true);
+
+        assertTrue(params.isRerankHybridMatches());
+
+        Map<String, Object> map = mapper.convertValue(params, Map.class);
+        assertTrue(map.containsKey("rerank_hybrid_matches"),
+                "Serialized map must contain 'rerank_hybrid_matches' key for Typesense server compatibility");
+        assertTrue((Boolean) map.get("rerank_hybrid_matches"));
+    }
+
+    @Test
+    void testRerankHybridMatchesFalseIsIncludedInSerialization() {
+        SearchParameters params = new SearchParameters()
+                .q("*")
+                .rerankHybridMatches(false);
+
+        Map<String, Object> map = mapper.convertValue(params, Map.class);
+        assertFalse((Boolean) map.get("rerank_hybrid_matches"));
+    }
+}