fix(dify): accept a bare string for the retrieval response query field

agentscope-extensions/agentscope-extensions-rag/agentscope-extensions-rag-dify/src/main/java/io/agentscope/core/rag/integration/dify/DifyDocumentConverter.java

@@ -51,6 +51,10 @@
  * }
  * }</pre>
  *
+ * <p>The top-level {@code query} field is a bare string on Dify Cloud
+ * ({@code "query": "..."}) and an object on self-hosted Dify; see
+ * {@link io.agentscope.core.rag.integration.dify.model.DifyQueryDeserializer}.
+ *
  * <p>Example usage:
  * <pre>{@code
  * DifyResponse response = difyClient.retrieve(...).block();

agentscope-extensions/agentscope-extensions-rag/agentscope-extensions-rag-dify/src/main/java/io/agentscope/core/rag/integration/dify/model/DifyQueryDeserializer.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2024-2026 the original author or authors.
+ *
+ * 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
+ *
+ *      http://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 io.agentscope.core.rag.integration.dify.model;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonNode;
+import java.io.IOException;
+
+/**
+ * Custom deserializer for {@link DifyResponse.Query}.
+ *
+ * <p>Dify serializes the top-level {@code query} field of a retrieval response in two different
+ * ways depending on the deployment:
+ *
+ * <pre>{@code
+ * // Dify Cloud (api.dify.ai)
+ * {"query": "ping", "records": [...]}
+ *
+ * // Self-hosted Dify
+ * {"query": {"content": "ping"}, "records": [...]}
+ * }</pre>
+ *
+ * <p>The field is informational only, so an unexpected shape must not fail the whole response.
+ * Modelling it as an object alone discarded every retrieved record when talking to Dify Cloud.
+ */
+public class DifyQueryDeserializer extends JsonDeserializer<DifyResponse.Query> {
+
+    @Override
+    public DifyResponse.Query deserialize(JsonParser p, DeserializationContext ctxt)
+            throws IOException {
+
+        JsonNode node = p.getCodec().readTree(p);
+
+        if (node == null || node.isNull()) {
+            return null;
+        }
+
+        DifyResponse.Query query = new DifyResponse.Query();
+
+        if (node.isTextual()) {
+            query.setContent(node.asText());
+            return query;
+        }
+
+        if (node.isObject()) {
+            JsonNode content = node.get("content");
+            if (content != null && content.isTextual()) {
+                query.setContent(content.asText());
+            }
+            return query;
+        }
+
+        // Unknown shape: the query text is informational, keep the records.
+        return null;
+    }
+}

agentscope-extensions/agentscope-extensions-rag/agentscope-extensions-rag-dify/src/main/java/io/agentscope/core/rag/integration/dify/model/DifyResponse.java

@@ -17,11 +17,15 @@
 
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
 import java.util.List;
 
 /**
  * Response model for Dify knowledge base retrieval API.
  *
+ * <p>Depending on the deployment, the top-level {@code query} field is either a bare string
+ * (Dify Cloud) or an object (self-hosted Dify); see {@link DifyQueryDeserializer}.
+ *
  * <p>This class maps the JSON response from Dify's retrieve endpoint:
  * <pre>{@code
  * {
@@ -65,8 +69,12 @@ public void setRecords(List<Record> records) {
 
     /**
      * Query information from the response.
+     *
+     * <p>Dify Cloud returns {@code "query": "..."} while self-hosted Dify returns
+     * {@code "query": {"content": "..."}}; both shapes are handled by {@link DifyQueryDeserializer}.
      */
     @JsonIgnoreProperties(ignoreUnknown = true)
+    @JsonDeserialize(using = DifyQueryDeserializer.class)
     public static class Query {
         private String content;
 

agentscope-extensions/agentscope-extensions-rag/agentscope-extensions-rag-dify/src/test/java/io/agentscope/core/rag/integration/dify/DifyRAGClientTest.java

@@ -408,6 +408,70 @@ void testParseSuccessfulResponse() throws Exception {
         assertEquals(0.95, response.getRecords().get(0).getScore(), 0.001);
     }
 
+    @Test
+    void testParseResponseWithBareStringQuery() throws Exception {
+        // Dify Cloud returns "query" as a bare string, while the documented self-hosted
+        // shape is {"content": "..."}. Both shapes must be accepted, otherwise the whole
+        // retrieval fails and every record is dropped.
+        String responseBody =
+                """
+                {
+                    "query": "What is RAG?",
+                    "records": [
+                        {
+                            "segment": {
+                                "id": "seg-1",
+                                "content": "Test content",
+                                "document_id": "doc-1"
+                            },
+                            "score": 0.95
+                        }
+                    ]
+                }
+                """;
+        mockWebServer.enqueue(
+                new MockResponse()
+                        .setResponseCode(200)
+                        .setHeader("Content-Type", "application/json")
+                        .setBody(responseBody));
+
+        DifyRAGClient client = new DifyRAGClient(createConfig());
+        DifyResponse response = client.retrieve("test query", 5).block();
+
+        assertNotNull(response);
+        assertNotNull(response.getQuery());
+        assertEquals("What is RAG?", response.getQuery().getContent());
+        assertNotNull(response.getRecords());
+        assertEquals(1, response.getRecords().size());
+        assertEquals("seg-1", response.getRecords().get(0).getSegment().getId());
+    }
+
+    @Test
+    void testParseResponseWithObjectQuery() throws Exception {
+        // Self-hosted Dify serializes query as {"content": "..."}; keep that shape working.
+        String responseBody =
+                """
+                {
+                    "query": { "content": "What is RAG?" },
+                    "records": []
+                }
+                """;
+        mockWebServer.enqueue(
+                new MockResponse()
+                        .setResponseCode(200)
+                        .setHeader("Content-Type", "application/json")
+                        .setBody(responseBody));
+
+        DifyRAGClient client = new DifyRAGClient(createConfig());
+        DifyResponse response = client.retrieve("test query", 5).block();
+
+        assertNotNull(response);
+        assertNotNull(response.getQuery());
+        assertEquals("What is RAG?", response.getQuery().getContent());
+        assertNotNull(response.getRecords());
+        assertTrue(response.getRecords().isEmpty());
+    }
+
     @Test
     void testHandleEmptyResponse() throws Exception {
         mockWebServer.enqueue(createEmptyResponse());