From a05946a80b23330749548ddf7f811fe45bc77686 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 00:36:49 +0530
Subject: [PATCH 01/21] rebased with main

---
 .../solr/client/api/endpoint/ConfigApi.java   | 20 ++++-
 .../solr/handler/SolrConfigHandler.java       | 89 +++----------------
 .../solr/handler/admin/api/GetConfig.java     | 68 +++++++++-----
 .../solr/handler/admin/api/GetConfigAPI.java  |  1 -
 .../handler/admin/V2ConfigAPIMappingTest.java |  1 -
 5 files changed, 76 insertions(+), 103 deletions(-)

diff --git a/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java b/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
index 49a4b018cc99..896142f24aad 100644
--- a/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
+++ b/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
@@ -70,7 +70,25 @@ ConfigZnodeVersionResponse getZnodeVersion(
             @Parameter(description = "Expected request-params znode version")
             int expectedParamsVersion);
 
-    // TODO: Keep this regex in sync with GetConfig.MIGRATED_CONFIG_COMPONENTS ("searchComponents"
+    @GET
+    @Path("/requestHandlers")
+    @StoreApiParameters
+    @Operation(
+        summary = "Fetch request handlers (including implicit handler)",
+        tags = {"config"})
+    ConfigInfoResponse getRequestHandler(
+        @PathParam("componentName") @Parameter(description = "Name of the specific request handler")
+            String component,
+        @QueryParam("expandParams")
+            @DefaultValue("false")
+            @Parameter(description = "Expand request handler useParams and effective parameters")
+            boolean expandParams,
+        @QueryParam("meta")
+            @DefaultValue("false")
+            @Parameter(description = "Include package metadata (_packageinfo_)")
+            boolean meta);
+
+    // TODO: Keep this regex in sync with GetConfig.MIGRATED_CONFIG_COMPONENTS
     // and "queryResponseWriters" here are the external, pluralized names for the internal
     // "searchComponent"/"queryResponseWriter" sections; see GetConfig#toExternalComponentName)
     @GET
diff --git a/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java b/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
index 08614a0a4bc6..5d7432ca34c9 100644
--- a/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
+++ b/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
@@ -21,10 +21,7 @@
 import static org.apache.solr.core.ConfigOverlay.NOT_EDITABLE;
 import static org.apache.solr.core.ConfigOverlay.ZNODEVER;
 import static org.apache.solr.core.ConfigSetProperties.IMMUTABLE_CONFIGSET_ARG;
-import static org.apache.solr.core.PluginInfo.APPENDS;
 import static org.apache.solr.core.PluginInfo.DEFAULTS;
-import static org.apache.solr.core.PluginInfo.INVARIANTS;
-import static org.apache.solr.core.RequestParams.USEPARAM;
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_CLASS;
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_NAME;
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_NAME_IN_OVERLAY;
@@ -69,7 +66,6 @@
 import org.apache.solr.common.cloud.Replica;
 import org.apache.solr.common.cloud.Slice;
 import org.apache.solr.common.params.CommonParams;
-import org.apache.solr.common.params.MapSolrParams;
 import org.apache.solr.common.params.ModifiableSolrParams;
 import org.apache.solr.common.params.SolrParams;
 import org.apache.solr.common.util.CommandOperation;
@@ -97,7 +93,6 @@
 import org.apache.solr.security.AuthorizationContext;
 import org.apache.solr.security.PermissionNameProvider;
 import org.apache.solr.util.RTimer;
-import org.apache.solr.util.SolrPluginUtils;
 import org.apache.solr.util.plugin.SolrCoreAware;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -221,6 +216,14 @@ private void handleGET() {
                     .getZnodeVersion(
                         req.getParams().getInt(ConfigOverlay.NAME, -1),
                         req.getParams().getInt(RequestParams.NAME, -1)));
+          } else if (SolrRequestHandler.TYPE.equals(parts.get(1))) {
+            V2ApiUtils.squashIntoSolrResponseWithoutHeader(
+                resp,
+                new GetConfig(req)
+                    .getRequestHandler(
+                        req.getParams().get("componentName"),
+                        req.getParams().getBool("expandParams", false),
+                        req.getParams().getBool("meta", false)));
           } else if (GetConfig.MIGRATED_CONFIG_COMPONENTS.contains(parts.get(1))) {
             String componentName = req.getParams().get("componentName");
             GetConfig getConfig = new GetConfig(req);
@@ -231,7 +234,8 @@ private void handleGET() {
                     : getConfig.getConfigComponentByName(
                         parts.get(1), componentName, req.getParams().getBool("meta", false)));
           } else {
-            Map<String, Object> m = getConfigDetails(parts.get(1), req);
+            Map<String, Object> m =
+                Utils.convertToMap(req.getCore().getSolrConfig(), new LinkedHashMap<>());
             Map<String, Object> val = new LinkedHashMap<>();
             val.put(parts.get(1), m.get(parts.get(1)));
             String componentName = req.getParams().get("componentName");
@@ -245,79 +249,6 @@ private void handleGET() {
       }
     }
 
-    private Map<String, Object> getConfigDetails(String componentType, SolrQueryRequest req) {
-      String componentName = componentType == null ? null : req.getParams().get("componentName");
-      boolean showParams = req.getParams().getBool("expandParams", false);
-      Map<String, Object> map =
-          Utils.convertToMap(this.req.getCore().getSolrConfig(), new LinkedHashMap<>());
-      if (componentType != null && !SolrRequestHandler.TYPE.equals(componentType)) return map;
-
-      @SuppressWarnings({"unchecked"})
-      Map<String, Object> reqHandlers =
-          (Map<String, Object>)
-              map.computeIfAbsent(SolrRequestHandler.TYPE, k -> new LinkedHashMap<>());
-      List<PluginInfo> plugins = this.req.getCore().getImplicitHandlers();
-      for (PluginInfo plugin : plugins) {
-        if (SolrRequestHandler.TYPE.equals(plugin.type)) {
-          if (!reqHandlers.containsKey(plugin.name)) {
-            reqHandlers.put(plugin.name, plugin);
-          }
-        }
-      }
-      if (!showParams) return map;
-      for (Map.Entry<String, Object> e : reqHandlers.entrySet()) {
-        if (componentName == null || e.getKey().equals(componentName)) {
-          Map<String, Object> m = expandUseParams(req, e.getValue());
-          e.setValue(m);
-        }
-      }
-
-      return map;
-    }
-
-    @SuppressWarnings({"unchecked"})
-    private Map<String, Object> expandUseParams(SolrQueryRequest req, Object plugin) {
-
-      Map<String, Object> pluginInfo = null;
-      if (plugin instanceof Map) {
-        pluginInfo = (Map) plugin;
-      } else if (plugin instanceof PluginInfo) {
-        pluginInfo = Utils.convertToMap((PluginInfo) plugin, new LinkedHashMap<>());
-      }
-      String useParams = (String) pluginInfo.get(USEPARAM);
-      String useParamsInReq = req.getOriginalParams().get(USEPARAM);
-      if (useParams != null || useParamsInReq != null) {
-        Map<String, Object> m = new LinkedHashMap<>();
-        pluginInfo.put("_useParamsExpanded_", m);
-        List<String> params = new ArrayList<>();
-        if (useParams != null) params.addAll(StrUtils.splitSmart(useParams, ','));
-        if (useParamsInReq != null) params.addAll(StrUtils.splitSmart(useParamsInReq, ','));
-        for (String param : params) {
-          RequestParams.ParamSet p =
-              this.req.getCore().getSolrConfig().getRequestParams().getParams(param);
-          if (p != null) {
-            m.put(param, p);
-          } else {
-            m.put(param, "[NOT AVAILABLE]");
-          }
-        }
-
-        SolrQueryRequest r = req.subRequest(req.getOriginalParams());
-        r.getContext().put(USEPARAM, useParams);
-        NamedList<?> nl = new PluginInfo(SolrRequestHandler.TYPE, pluginInfo).initArgs;
-        SolrPluginUtils.setDefaults(
-            r,
-            getSolrParamsFromNamedList(nl, DEFAULTS),
-            getSolrParamsFromNamedList(nl, APPENDS),
-            getSolrParamsFromNamedList(nl, INVARIANTS));
-        // SolrParams.wrapDefaults(maskUseParams, req.getParams())
-
-        MapSolrParams mask = new MapSolrParams(Map.of("componentName", "", "expandParams", ""));
-        pluginInfo.put("_effectiveParams_", SolrParams.wrapDefaults(mask, r.getParams()));
-      }
-      return pluginInfo;
-    }
-
     private void handlePOST() throws IOException {
       List<CommandOperation> ops = ApiBag.readCommands(req.getContentStreams(), resp.getValues());
       if (ops == null) return;
diff --git a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
index 1bc7db362bd9..9bff454fbe12 100644
--- a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
+++ b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
@@ -99,7 +99,7 @@ public GetConfig(SolrQueryRequest solrQueryRequest) {
   @PermissionName(CONFIG_READ_PERM)
   public ConfigInfoResponse getConfig(boolean expandParams) {
     final var response = instantiateJerseyResponse(ConfigInfoResponse.class);
-    response.config = buildConfigMap(solrQueryRequest, expandParams);
+    response.config = buildConfigMap(expandParams);
     return response;
   }
 
@@ -129,13 +129,32 @@ public ConfigZnodeVersionResponse getZnodeVersion(
     return response;
   }
 
+  @Override
+  @PermissionName(CONFIG_READ_PERM)
+  public ConfigInfoResponse getRequestHandler(
+      String componentName, boolean expandParams, boolean meta) {
+    final var response = instantiateJerseyResponse(ConfigInfoResponse.class);
+
+    Map<String, Object> configMap = solrConfigAsMap();
+    configMap.put(
+        SolrRequestHandler.TYPE,
+        requestHandlersWithImplicits(configMap, expandParams, componentName));
+    filterByComponentName(
+        configMap, SolrRequestHandler.TYPE, componentName, meta, solrQueryRequest);
+
+    response.config = jsonSafeCopy(configMap);
+    return response;
+  }
+
   @Override
   @PermissionName(CONFIG_READ_PERM)
   public ConfigInfoResponse getConfigComponent(String component) {
     final var response = instantiateJerseyResponse(ConfigInfoResponse.class);
-    Map<String, Object> section = new LinkedHashMap<>();
-    section.put(component, solrConfigAsMap().get(toInternalComponentName(component)));
-    response.config = jsonSafeCopy(section);
+
+    Map<String, Object> configMap = new LinkedHashMap<>();
+    configMap.put(component, solrConfigAsMap().get(toInternalComponentName(component)));
+
+    response.config = jsonSafeCopy(configMap);
     return response;
   }
 
@@ -144,10 +163,11 @@ public ConfigInfoResponse getConfigComponent(String component) {
   public ConfigInfoResponse getConfigComponentByName(
       String component, String componentName, boolean meta) {
     final var response = instantiateJerseyResponse(ConfigInfoResponse.class);
-    Map<String, Object> section = new LinkedHashMap<>();
-    section.put(component, solrConfigAsMap().get(toInternalComponentName(component)));
-    filterByComponentName(section, component, componentName, meta, solrQueryRequest);
-    response.config = jsonSafeCopy(section);
+
+    Map<String, Object> configMap = new LinkedHashMap<>();
+    configMap.put(component, solrConfigAsMap().get(toInternalComponentName(component)));
+    filterByComponentName(configMap, component, componentName, meta, solrQueryRequest);
+    response.config = jsonSafeCopy(configMap);
     return response;
   }
 
@@ -161,12 +181,12 @@ public ConfigInfoResponse getConfigComponentByName(
    */
   @SuppressWarnings({"unchecked", "rawtypes"})
   public static void filterByComponentName(
-      Map<String, Object> section,
+      Map<String, Object> configMap,
       String component,
       String componentName,
       boolean meta,
       SolrQueryRequest req) {
-    Map pluginNameVsPluginInfo = (Map) section.get(component);
+    Map pluginNameVsPluginInfo = (Map) configMap.get(component);
     if (pluginNameVsPluginInfo == null) {
       return;
     }
@@ -183,7 +203,7 @@ public static void filterByComponentName(
 
     Map<String, Object> pluginInfo =
         o instanceof MapWriter ? new SimpleOrderedMap<>((MapWriter) o) : (Map<String, Object>) o;
-    section.put(
+    configMap.put(
         component,
         pluginNameVsPluginInfo instanceof MapWriter
             ? pluginInfo
@@ -227,29 +247,35 @@ private NullKeyTolerantMap jsonSafeCopy(Map<String, Object> map) {
     return jsonSafeCopy;
   }
 
-  @SuppressWarnings({"unchecked"})
-  private Map<String, Object> buildConfigMap(
-      SolrQueryRequest solrQueryRequest, boolean expandParams) {
-
+  private Map<String, Object> buildConfigMap(boolean expandParams) {
     Map<String, Object> configMap = solrConfigAsMap();
+    requestHandlersWithImplicits(configMap, expandParams, null);
+    return jsonSafeCopy(configMap);
+  }
 
-    Map<String, Object> reqHandlers =
+  @SuppressWarnings({"unchecked"})
+  private Map<String, Object> requestHandlersWithImplicits(
+      Map<String, Object> configMap, boolean expandParams, String expandOnlyComponentName) {
+    Map<String, Object> reqHandlersMap =
         (Map<String, Object>)
             configMap.computeIfAbsent(SolrRequestHandler.TYPE, k -> new LinkedHashMap<>());
+
     List<PluginInfo> plugins = solrQueryRequest.getCore().getImplicitHandlers();
     for (PluginInfo plugin : plugins) {
-      if (SolrRequestHandler.TYPE.equals(plugin.type) && !reqHandlers.containsKey(plugin.name)) {
-        reqHandlers.put(plugin.name, plugin);
+      if (SolrRequestHandler.TYPE.equals(plugin.type) && !reqHandlersMap.containsKey(plugin.name)) {
+        reqHandlersMap.put(plugin.name, plugin);
       }
     }
 
     if (expandParams) {
-      for (Map.Entry<String, Object> entry : reqHandlers.entrySet()) {
-        entry.setValue(expandUseParams(solrQueryRequest, entry.getValue()));
+      for (Map.Entry<String, Object> entry : reqHandlersMap.entrySet()) {
+        if (expandOnlyComponentName == null || !expandOnlyComponentName.equals(entry.getKey())) {
+          entry.setValue(expandUseParams(solrQueryRequest, entry.getValue()));
+        }
       }
     }
 
-    return jsonSafeCopy(configMap);
+    return reqHandlersMap;
   }
 
   @SuppressWarnings({"unchecked", "rawtypes"})
diff --git a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfigAPI.java b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfigAPI.java
index 808bdf545f42..6cd437911006 100644
--- a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfigAPI.java
+++ b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfigAPI.java
@@ -61,7 +61,6 @@ public void getSingleParamSet(SolrQueryRequest req, SolrQueryResponse rsp) {
   @EndPoint(
       path = {
         "/config/luceneMatchVersion",
-        "/config/requestHandler",
         "/config/initParams",
         "/config/listener",
         "/config/requestDispatcher",
diff --git a/solr/core/src/test/org/apache/solr/handler/admin/V2ConfigAPIMappingTest.java b/solr/core/src/test/org/apache/solr/handler/admin/V2ConfigAPIMappingTest.java
index 6e0a2aa6e27a..e7912afa8faa 100644
--- a/solr/core/src/test/org/apache/solr/handler/admin/V2ConfigAPIMappingTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/admin/V2ConfigAPIMappingTest.java
@@ -49,7 +49,6 @@ public void populateApiBag() {
   // the API lookup works for a handful of the valid config "components".
   @Test
   public void testGetSingleComponentConfig() {
-    assertAnnotatedApiExistsFor("GET", "/config/requestHandler");
     assertAnnotatedApiExistsFor("GET", "/config/jmx");
     assertAnnotatedApiExistsFor("GET", "/config/requestDispatcher");
     assertAnnotatedApiExistsFor("GET", "/config/luceneMatchVersion");

From 1efb6026f4e237217a1d27f2b20b8461f341732e Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 01:34:37 +0530
Subject: [PATCH 02/21] queryparam

---
 .../java/org/apache/solr/client/api/endpoint/ConfigApi.java    | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java b/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
index 896142f24aad..e134fa25b5ea 100644
--- a/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
+++ b/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
@@ -77,7 +77,8 @@ ConfigZnodeVersionResponse getZnodeVersion(
         summary = "Fetch request handlers (including implicit handler)",
         tags = {"config"})
     ConfigInfoResponse getRequestHandler(
-        @PathParam("componentName") @Parameter(description = "Name of the specific request handler")
+        @QueryParam("componentName")
+            @Parameter(description = "Name of the specific request handler")
             String component,
         @QueryParam("expandParams")
             @DefaultValue("false")

From 5baa8ab3b81d8028402f25926ab7e1bcfc3bc2c0 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 01:37:09 +0530
Subject: [PATCH 03/21] minor

---
 .../src/java/org/apache/solr/client/api/endpoint/ConfigApi.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java b/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
index e134fa25b5ea..76787c45cca8 100644
--- a/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
+++ b/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
@@ -71,7 +71,7 @@ ConfigZnodeVersionResponse getZnodeVersion(
             int expectedParamsVersion);
 
     @GET
-    @Path("/requestHandlers")
+    @Path("/requestHandler")
     @StoreApiParameters
     @Operation(
         summary = "Fetch request handlers (including implicit handler)",

From 6c10a1450e5066a09bcccfdb140b9b7cad167684 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 01:43:38 +0530
Subject: [PATCH 04/21] corrections

---
 .../org/apache/solr/handler/admin/api/GetConfig.java   | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
index 9bff454fbe12..560137eaaec9 100644
--- a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
+++ b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
@@ -135,12 +135,14 @@ public ConfigInfoResponse getRequestHandler(
       String componentName, boolean expandParams, boolean meta) {
     final var response = instantiateJerseyResponse(ConfigInfoResponse.class);
 
-    Map<String, Object> configMap = solrConfigAsMap();
+    Map<String, Object> configMap = new LinkedHashMap<>();
     configMap.put(
         SolrRequestHandler.TYPE,
-        requestHandlersWithImplicits(configMap, expandParams, componentName));
-    filterByComponentName(
-        configMap, SolrRequestHandler.TYPE, componentName, meta, solrQueryRequest);
+        requestHandlersWithImplicits(solrConfigAsMap(), expandParams, componentName));
+    if (componentName != null) {
+      filterByComponentName(
+          configMap, SolrRequestHandler.TYPE, componentName, meta, solrQueryRequest);
+    }
 
     response.config = jsonSafeCopy(configMap);
     return response;

From b02cf83dfeb48da83aed98fa82c7f9671e543af0 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 01:52:23 +0530
Subject: [PATCH 05/21] minor fix

---
 .../src/java/org/apache/solr/handler/admin/api/GetConfig.java   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
index 560137eaaec9..cddbec5cdc59 100644
--- a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
+++ b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
@@ -271,7 +271,7 @@ private Map<String, Object> requestHandlersWithImplicits(
 
     if (expandParams) {
       for (Map.Entry<String, Object> entry : reqHandlersMap.entrySet()) {
-        if (expandOnlyComponentName == null || !expandOnlyComponentName.equals(entry.getKey())) {
+        if (expandOnlyComponentName == null || expandOnlyComponentName.equals(entry.getKey())) {
           entry.setValue(expandUseParams(solrQueryRequest, entry.getValue()));
         }
       }

From 4e159cda07f8ad7e3895e483a64c10a8196ecb74 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 01:56:14 +0530
Subject: [PATCH 06/21] added cl

---
 .../unreleased/SOLR-16396-config-requestHandler.yml      | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 changelog/unreleased/SOLR-16396-config-requestHandler.yml

diff --git a/changelog/unreleased/SOLR-16396-config-requestHandler.yml b/changelog/unreleased/SOLR-16396-config-requestHandler.yml
new file mode 100644
index 000000000000..53f2b8f1b792
--- /dev/null
+++ b/changelog/unreleased/SOLR-16396-config-requestHandler.yml
@@ -0,0 +1,9 @@
+title: >
+  Migrate GET /config/requestHandler to JAX-RS
+type: changed
+authors:
+  - name: Jalaz Kumar
+    nick: jaykay12
+links:
+  - name: SOLR-16396
+    url: https://issues.apache.org/jira/browse/SOLR-16396

From 05d0a9bb646f52f1b2b53063670bcdfa28e7d99c Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 02:32:54 +0530
Subject: [PATCH 07/21] added tests

---
 .../solr/client/api/endpoint/ConfigApi.java   |  2 +-
 .../solr/handler/admin/api/GetConfigTest.java | 85 +++++++++++++++++++
 2 files changed, 86 insertions(+), 1 deletion(-)

diff --git a/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java b/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
index 76787c45cca8..bb4b6a1cbc7a 100644
--- a/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
+++ b/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
@@ -89,7 +89,7 @@ ConfigInfoResponse getRequestHandler(
             @Parameter(description = "Include package metadata (_packageinfo_)")
             boolean meta);
 
-    // TODO: Keep this regex in sync with GetConfig.MIGRATED_CONFIG_COMPONENTS
+    // TODO: Keep this regex in sync with GetConfig.MIGRATED_CONFIG_COMPONENTS ("searchComponents"
     // and "queryResponseWriters" here are the external, pluralized names for the internal
     // "searchComponent"/"queryResponseWriter" sections; see GetConfig#toExternalComponentName)
     @GET
diff --git a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java
index 504fe7ecb5e7..d0415fc21cf4 100644
--- a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java
@@ -23,6 +23,7 @@
 import org.apache.solr.client.api.model.IndexType;
 import org.apache.solr.client.solrj.RemoteSolrException;
 import org.apache.solr.client.solrj.request.ConfigApi;
+import org.apache.solr.request.SolrRequestHandler;
 import org.apache.solr.util.ExternalPaths;
 import org.apache.solr.util.SolrJettyTestRule;
 import org.junit.BeforeClass;
@@ -83,6 +84,90 @@ public void testGetZnodeVersionFromCore() throws Exception {
     assertTrue(response.znodeVersion.params >= -1);
   }
 
+  @Test
+  @SuppressWarnings("unchecked")
+  public void testGetRequestHandlersFromCore() throws Exception {
+    var request = new ConfigApi.GetRequestHandler(IndexType.CORE, CORE_NAME);
+    var response = request.process(solrTestRule.getSolrClient(CORE_NAME));
+
+    assertNotNull(response);
+    assertNull(response.error);
+    assertNotNull(response.config);
+    assertEquals(1, response.config.size());
+
+    Map<String, Object> configSection =
+        (Map<String, Object>) response.config.get(SolrRequestHandler.TYPE);
+    assertNotNull(configSection);
+    assertTrue(configSection.containsKey("/select"));
+    assertTrue(configSection.containsKey("/admin/ping"));
+  }
+
+  @Test
+  @SuppressWarnings("unchecked")
+  public void testGetRequestHandlersFilteredByNameFromCore() throws Exception {
+    var request = new ConfigApi.GetRequestHandler(IndexType.CORE, CORE_NAME);
+    request.setComponentName("/select");
+    var response = request.process(solrTestRule.getSolrClient(CORE_NAME));
+
+    assertNotNull(response);
+    assertNull(response.error);
+    assertEquals(1, response.config.size());
+
+    Map<String, Object> configSection =
+        (Map<String, Object>) response.config.get(SolrRequestHandler.TYPE);
+    assertNotNull(configSection);
+    assertTrue(configSection.containsKey("/select"));
+
+    Map<String, Object> select = (Map<String, Object>) configSection.get("/select");
+    assertEquals("solr.SearchHandler", select.get("class"));
+  }
+
+  @Test
+  @SuppressWarnings("unchecked")
+  public void testGetRequestHandlersExpandParamsExpandsNamedHandler() throws Exception {
+    var request = new ConfigApi.GetRequestHandler(IndexType.CORE, CORE_NAME);
+    request.setComponentName("/admin/ping");
+    request.setExpandParams(true);
+    var response = request.process(solrTestRule.getSolrClient(CORE_NAME));
+
+    assertNotNull(response);
+    assertNull(response.error);
+    assertEquals(1, response.config.size());
+
+    Map<String, Object> configSection =
+        (Map<String, Object>) response.config.get(SolrRequestHandler.TYPE);
+
+    Map<String, Object> ping = (Map<String, Object>) configSection.get("/admin/ping");
+    assertNotNull(ping.get("_useParamsExpanded_"));
+    Map<String, Object> expanded = (Map<String, Object>) ping.get("_useParamsExpanded_");
+    assertEquals("[NOT AVAILABLE]", expanded.get("_ADMIN_PING"));
+  }
+
+  @Test
+  @SuppressWarnings("unchecked")
+  public void testGetRequestHandlersOmitsExpandedParamsByDefault() throws Exception {
+    var request = new ConfigApi.GetRequestHandler(IndexType.CORE, CORE_NAME);
+    request.setComponentName("/admin/ping");
+    var response = request.process(solrTestRule.getSolrClient(CORE_NAME));
+
+    Map<String, Object> configSection =
+        (Map<String, Object>) response.config.get(SolrRequestHandler.TYPE);
+
+    Map<String, Object> ping = (Map<String, Object>) configSection.get("/admin/ping");
+    assertFalse(ping.containsKey("_useParamsExpanded_"));
+  }
+
+  @Test
+  public void testGetRequestHandlersByUnknownNameReturnsNotFound() throws Exception {
+    var request = new ConfigApi.GetRequestHandler(IndexType.CORE, CORE_NAME);
+    request.setComponentName("/randomHandler");
+    final RemoteSolrException exception =
+        assertThrows(
+            RemoteSolrException.class,
+            () -> request.process(solrTestRule.getSolrClient(CORE_NAME)));
+    assertEquals(404, exception.code());
+  }
+
   @Test
   public void testGetConfigComponentFromCore() throws Exception {
     for (String component : GetConfig.MIGRATED_CONFIG_COMPONENTS) {

From a7618b82549544a4793512c85257c3eff48eb908 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 12:26:09 +0530
Subject: [PATCH 08/21] cl minor

---
 changelog/unreleased/SOLR-16396-config-requestHandler.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/changelog/unreleased/SOLR-16396-config-requestHandler.yml b/changelog/unreleased/SOLR-16396-config-requestHandler.yml
index 53f2b8f1b792..988571917264 100644
--- a/changelog/unreleased/SOLR-16396-config-requestHandler.yml
+++ b/changelog/unreleased/SOLR-16396-config-requestHandler.yml
@@ -1,4 +1,4 @@
-title: >
+title:
   Migrate GET /config/requestHandler to JAX-RS
 type: changed
 authors:

From e6b2f0734e0bc9dc441d907c10cc876bf9058ac3 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 18:17:08 +0530
Subject: [PATCH 09/21] changes

---
 .../apache/solr/client/api/endpoint/ConfigApi.java |  2 +-
 .../org/apache/solr/handler/SolrConfigHandler.java |  3 ++-
 .../apache/solr/handler/admin/api/GetConfig.java   |  7 ++++---
 .../test/org/apache/solr/cli/PackageToolTest.java  |  4 ++--
 .../solr/handler/admin/api/GetConfigTest.java      | 14 +++++---------
 5 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java b/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
index bb4b6a1cbc7a..0f3f64868b8c 100644
--- a/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
+++ b/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
@@ -71,7 +71,7 @@ ConfigZnodeVersionResponse getZnodeVersion(
             int expectedParamsVersion);
 
     @GET
-    @Path("/requestHandler")
+    @Path("/requestHandlers")
     @StoreApiParameters
     @Operation(
         summary = "Fetch request handlers (including implicit handler)",
diff --git a/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java b/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
index 5d7432ca34c9..1aeed97cd59d 100644
--- a/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
+++ b/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
@@ -25,6 +25,7 @@
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_CLASS;
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_NAME;
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_NAME_IN_OVERLAY;
+import static org.apache.solr.handler.admin.api.GetConfig.REQUEST_HANDLERS;
 import static org.apache.solr.schema.FieldType.CLASS_NAME;
 
 import java.io.IOException;
@@ -216,7 +217,7 @@ private void handleGET() {
                     .getZnodeVersion(
                         req.getParams().getInt(ConfigOverlay.NAME, -1),
                         req.getParams().getInt(RequestParams.NAME, -1)));
-          } else if (SolrRequestHandler.TYPE.equals(parts.get(1))) {
+          } else if (REQUEST_HANDLERS.equals(parts.get(1))) {
             V2ApiUtils.squashIntoSolrResponseWithoutHeader(
                 resp,
                 new GetConfig(req)
diff --git a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
index cddbec5cdc59..c444563c4f67 100644
--- a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
+++ b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
@@ -68,6 +68,8 @@ public class GetConfig extends JerseyResource implements ConfigApi.Get {
           "searchComponent",
           "queryResponseWriter");
 
+  public static final String REQUEST_HANDLERS = "requestHandlers";
+
   // v2-only renames: external (URL/response-key) component name -> internal SolrConfig section
   // name. v1's GET /config/{component} keeps using the internal names unchanged.
   private static final Map<String, String> EXTERNAL_TO_INTERNAL_COMPONENT_NAME =
@@ -137,11 +139,10 @@ public ConfigInfoResponse getRequestHandler(
 
     Map<String, Object> configMap = new LinkedHashMap<>();
     configMap.put(
-        SolrRequestHandler.TYPE,
+        REQUEST_HANDLERS,
         requestHandlersWithImplicits(solrConfigAsMap(), expandParams, componentName));
     if (componentName != null) {
-      filterByComponentName(
-          configMap, SolrRequestHandler.TYPE, componentName, meta, solrQueryRequest);
+      filterByComponentName(configMap, REQUEST_HANDLERS, componentName, meta, solrQueryRequest);
     }
 
     response.config = jsonSafeCopy(configMap);
diff --git a/solr/core/src/test/org/apache/solr/cli/PackageToolTest.java b/solr/core/src/test/org/apache/solr/cli/PackageToolTest.java
index a919b30555b7..312509746916 100644
--- a/solr/core/src/test/org/apache/solr/cli/PackageToolTest.java
+++ b/solr/core/src/test/org/apache/solr/cli/PackageToolTest.java
@@ -320,9 +320,9 @@ void assertPackageVersion(
 
     testForResponseElement(
         cluster.getJettySolrRunner(0).getBaseUrl().toString() + "/" + collection,
-        "/config/requestHandler?componentName=" + component + "&meta=true",
+        "/config/requestHandlers?componentName=" + component + "&meta=true",
         credentials,
-        Arrays.asList("config", "requestHandler", component, "_packageinfo_", "version"),
+        Arrays.asList("config", "requestHandlers", component, "_packageinfo_", "version"),
         componentVersion);
   }
 
diff --git a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java
index d0415fc21cf4..ed11ee4c2177 100644
--- a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java
@@ -17,13 +17,13 @@
 package org.apache.solr.handler.admin.api;
 
 import static org.apache.solr.core.CoreContainer.ALLOW_PATHS_SYSPROP;
+import static org.apache.solr.handler.admin.api.GetConfig.REQUEST_HANDLERS;
 
 import java.util.Map;
 import org.apache.solr.SolrTestCase;
 import org.apache.solr.client.api.model.IndexType;
 import org.apache.solr.client.solrj.RemoteSolrException;
 import org.apache.solr.client.solrj.request.ConfigApi;
-import org.apache.solr.request.SolrRequestHandler;
 import org.apache.solr.util.ExternalPaths;
 import org.apache.solr.util.SolrJettyTestRule;
 import org.junit.BeforeClass;
@@ -95,8 +95,7 @@ public void testGetRequestHandlersFromCore() throws Exception {
     assertNotNull(response.config);
     assertEquals(1, response.config.size());
 
-    Map<String, Object> configSection =
-        (Map<String, Object>) response.config.get(SolrRequestHandler.TYPE);
+    Map<String, Object> configSection = (Map<String, Object>) response.config.get(REQUEST_HANDLERS);
     assertNotNull(configSection);
     assertTrue(configSection.containsKey("/select"));
     assertTrue(configSection.containsKey("/admin/ping"));
@@ -113,8 +112,7 @@ public void testGetRequestHandlersFilteredByNameFromCore() throws Exception {
     assertNull(response.error);
     assertEquals(1, response.config.size());
 
-    Map<String, Object> configSection =
-        (Map<String, Object>) response.config.get(SolrRequestHandler.TYPE);
+    Map<String, Object> configSection = (Map<String, Object>) response.config.get(REQUEST_HANDLERS);
     assertNotNull(configSection);
     assertTrue(configSection.containsKey("/select"));
 
@@ -134,8 +132,7 @@ public void testGetRequestHandlersExpandParamsExpandsNamedHandler() throws Excep
     assertNull(response.error);
     assertEquals(1, response.config.size());
 
-    Map<String, Object> configSection =
-        (Map<String, Object>) response.config.get(SolrRequestHandler.TYPE);
+    Map<String, Object> configSection = (Map<String, Object>) response.config.get(REQUEST_HANDLERS);
 
     Map<String, Object> ping = (Map<String, Object>) configSection.get("/admin/ping");
     assertNotNull(ping.get("_useParamsExpanded_"));
@@ -150,8 +147,7 @@ public void testGetRequestHandlersOmitsExpandedParamsByDefault() throws Exceptio
     request.setComponentName("/admin/ping");
     var response = request.process(solrTestRule.getSolrClient(CORE_NAME));
 
-    Map<String, Object> configSection =
-        (Map<String, Object>) response.config.get(SolrRequestHandler.TYPE);
+    Map<String, Object> configSection = (Map<String, Object>) response.config.get(REQUEST_HANDLERS);
 
     Map<String, Object> ping = (Map<String, Object>) configSection.get("/admin/ping");
     assertFalse(ping.containsKey("_useParamsExpanded_"));

From 061c96605767d56771fc30003a0e487f32285450 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 18:30:18 +0530
Subject: [PATCH 10/21] fix

---
 .../src/java/org/apache/solr/handler/SolrConfigHandler.java   | 4 ++--
 .../src/java/org/apache/solr/handler/admin/api/GetConfig.java | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java b/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
index 1aeed97cd59d..2309f409a9c6 100644
--- a/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
+++ b/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
@@ -25,7 +25,7 @@
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_CLASS;
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_NAME;
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_NAME_IN_OVERLAY;
-import static org.apache.solr.handler.admin.api.GetConfig.REQUEST_HANDLERS;
+import static org.apache.solr.handler.admin.api.GetConfig.REQUEST_HANDLER_APIs;
 import static org.apache.solr.schema.FieldType.CLASS_NAME;
 
 import java.io.IOException;
@@ -217,7 +217,7 @@ private void handleGET() {
                     .getZnodeVersion(
                         req.getParams().getInt(ConfigOverlay.NAME, -1),
                         req.getParams().getInt(RequestParams.NAME, -1)));
-          } else if (REQUEST_HANDLERS.equals(parts.get(1))) {
+          } else if (REQUEST_HANDLER_APIs.contains(parts.get(1))) {
             V2ApiUtils.squashIntoSolrResponseWithoutHeader(
                 resp,
                 new GetConfig(req)
diff --git a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
index c444563c4f67..13a2be1cf685 100644
--- a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
+++ b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
@@ -69,6 +69,7 @@ public class GetConfig extends JerseyResource implements ConfigApi.Get {
           "queryResponseWriter");
 
   public static final String REQUEST_HANDLERS = "requestHandlers";
+  public static final Set<String> REQUEST_HANDLER_APIs = Set.of(SolrRequestHandler.TYPE, REQUEST_HANDLERS);
 
   // v2-only renames: external (URL/response-key) component name -> internal SolrConfig section
   // name. v1's GET /config/{component} keeps using the internal names unchanged.

From 13dd067db62862fc8e2289cf91837785a8d8aeb6 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 18:45:37 +0530
Subject: [PATCH 11/21] fix for v1 consistency

---
 .../org/apache/solr/handler/SolrConfigHandler.java  |  1 +
 .../apache/solr/handler/admin/api/GetConfig.java    | 13 +++++++++----
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java b/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
index 2309f409a9c6..83f76e771df1 100644
--- a/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
+++ b/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
@@ -222,6 +222,7 @@ private void handleGET() {
                 resp,
                 new GetConfig(req)
                     .getRequestHandler(
+                        parts.get(1),
                         req.getParams().get("componentName"),
                         req.getParams().getBool("expandParams", false),
                         req.getParams().getBool("meta", false)));
diff --git a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
index 13a2be1cf685..5b10765e4c06 100644
--- a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
+++ b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
@@ -69,7 +69,8 @@ public class GetConfig extends JerseyResource implements ConfigApi.Get {
           "queryResponseWriter");
 
   public static final String REQUEST_HANDLERS = "requestHandlers";
-  public static final Set<String> REQUEST_HANDLER_APIs = Set.of(SolrRequestHandler.TYPE, REQUEST_HANDLERS);
+  public static final Set<String> REQUEST_HANDLER_APIs =
+      Set.of(SolrRequestHandler.TYPE, REQUEST_HANDLERS);
 
   // v2-only renames: external (URL/response-key) component name -> internal SolrConfig section
   // name. v1's GET /config/{component} keeps using the internal names unchanged.
@@ -136,14 +137,18 @@ public ConfigZnodeVersionResponse getZnodeVersion(
   @PermissionName(CONFIG_READ_PERM)
   public ConfigInfoResponse getRequestHandler(
       String componentName, boolean expandParams, boolean meta) {
+    return getRequestHandler(REQUEST_HANDLERS, componentName, expandParams, meta);
+  }
+
+  public ConfigInfoResponse getRequestHandler(
+      String sectionName, String componentName, boolean expandParams, boolean meta) {
     final var response = instantiateJerseyResponse(ConfigInfoResponse.class);
 
     Map<String, Object> configMap = new LinkedHashMap<>();
     configMap.put(
-        REQUEST_HANDLERS,
-        requestHandlersWithImplicits(solrConfigAsMap(), expandParams, componentName));
+        sectionName, requestHandlersWithImplicits(solrConfigAsMap(), expandParams, componentName));
     if (componentName != null) {
-      filterByComponentName(configMap, REQUEST_HANDLERS, componentName, meta, solrQueryRequest);
+      filterByComponentName(configMap, sectionName, componentName, meta, solrQueryRequest);
     }
 
     response.config = jsonSafeCopy(configMap);

From 1291fff8c574cc7ec4d33576024d450be0225bda Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 21:12:28 +0530
Subject: [PATCH 12/21] test fixes

---
 changelog/unreleased/SOLR-16396-config-requestHandler.yml | 5 +++--
 .../solr/question-answer-repository/repository.json       | 4 ++--
 .../solr/cli/packagemanager/TestPackageManager.java       | 2 +-
 .../modules/configuration-guide/pages/config-api.adoc     | 8 ++++----
 .../pages/implicit-requesthandlers.adoc                   | 4 ++--
 5 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/changelog/unreleased/SOLR-16396-config-requestHandler.yml b/changelog/unreleased/SOLR-16396-config-requestHandler.yml
index 988571917264..a860843da618 100644
--- a/changelog/unreleased/SOLR-16396-config-requestHandler.yml
+++ b/changelog/unreleased/SOLR-16396-config-requestHandler.yml
@@ -1,5 +1,6 @@
-title:
-  Migrate GET /config/requestHandler to JAX-RS
+title: >
+  Migrate GET /config/requestHandler to JAX-RS; V2 path and response key
+  are now plural requestHandlers (V1 unchanged)
 type: changed
 authors:
   - name: Jalaz Kumar
diff --git a/solr/core/src/test-files/solr/question-answer-repository/repository.json b/solr/core/src/test-files/solr/question-answer-repository/repository.json
index 05fad9059784..bcfe7779ca3f 100644
--- a/solr/core/src/test-files/solr/question-answer-repository/repository.json
+++ b/solr/core/src/test-files/solr/question-answer-repository/repository.json
@@ -28,9 +28,9 @@
                 "method": "POST"
               },
               "verify-command": {
-                "path": "/api/collections/${collection}/config/requestHandler?componentName=${RH-HANDLER-PATH}&meta=true",
+                "path": "/api/collections/${collection}/config/requestHandlers?componentName=${RH-HANDLER-PATH}&meta=true",
                 "method": "GET",
-                "condition": "$['config'].['requestHandler'].['${RH-HANDLER-PATH}'].['_packageinfo_'].['version']",
+                "condition": "$['config'].['requestHandlers'].['${RH-HANDLER-PATH}'].['_packageinfo_'].['version']",
                 "expected": "${package-version}"
               }
             }
diff --git a/solr/core/src/test/org/apache/solr/cli/packagemanager/TestPackageManager.java b/solr/core/src/test/org/apache/solr/cli/packagemanager/TestPackageManager.java
index 2793af1641d7..825bd3b5a3c5 100644
--- a/solr/core/src/test/org/apache/solr/cli/packagemanager/TestPackageManager.java
+++ b/solr/core/src/test/org/apache/solr/cli/packagemanager/TestPackageManager.java
@@ -60,7 +60,7 @@ public void testWrongVerificationJPathIsThrown() throws IOException {
         plugin.verifyCommand = new SolrPackage.Command();
         plugin.verifyCommand.method = "GET";
         plugin.verifyCommand.path = /*"/api*/
-            "/collections/" + COLLECTION_NAME + "/config/requestHandler";
+            "/collections/" + COLLECTION_NAME + "/config/requestHandlers";
         plugin.verifyCommand.condition = "&[no_quotes_error_jpath]";
         manager.verify(
             new SolrPackageInstance(
diff --git a/solr/solr-ref-guide/modules/configuration-guide/pages/config-api.adoc b/solr/solr-ref-guide/modules/configuration-guide/pages/config-api.adoc
index 38981e7caf69..01c043ae6a63 100644
--- a/solr/solr-ref-guide/modules/configuration-guide/pages/config-api.adoc
+++ b/solr/solr-ref-guide/modules/configuration-guide/pages/config-api.adoc
@@ -109,7 +109,7 @@ V2 API::
 ====
 [source,bash]
 ----
-http://localhost:8983/api/collections/techproducts/config/requestHandler
+http://localhost:8983/api/collections/techproducts/config/requestHandlers
 ----
 ====
 ======
@@ -119,7 +119,7 @@ To see the configuration for implicit request handlers, add `expandParams=true`
 See the documentation for implicit request handlers linked above for examples using this command.
 
 The available top-level sections that can be added as path parameters are: `query`, `requestHandler`, `searchComponent`, `updateHandler`, `queryResponseWriter`, `initParams`, `znodeVersion`, `listener`, `directoryFactory`, `indexConfig`, and `codecFactory`.
-In the V2 API, `searchComponent` and `queryResponseWriter` are exposed under the pluralized names `searchComponents` and `queryResponseWriters` instead.
+In the V2 API, `requestHandler`, `searchComponent` and `queryResponseWriter` are exposed under the pluralized names `requestHandlers`, `searchComponents` and `queryResponseWriters` instead (including the response JSON key).
 
 To further restrict the request to a single component within a top-level section, use the `componentName` request parameter.
 
@@ -140,12 +140,12 @@ V2 API::
 ====
 [source,bash]
 ----
-http://localhost:8983/api/collections/techproducts/config/requestHandler?componentName=/select
+http://localhost:8983/api/collections/techproducts/config/requestHandlers?componentName=/select
 ----
 ====
 ======
 
-The output of this command will look similar to:
+The output of this command will look similar to(V1 nests under `requestHandler`; V2 under `requestHandlers`):
 
 [source,json]
 ----
diff --git a/solr/solr-ref-guide/modules/configuration-guide/pages/implicit-requesthandlers.adoc b/solr/solr-ref-guide/modules/configuration-guide/pages/implicit-requesthandlers.adoc
index 0aad010ddc92..67948d8f1446 100644
--- a/solr/solr-ref-guide/modules/configuration-guide/pages/implicit-requesthandlers.adoc
+++ b/solr/solr-ref-guide/modules/configuration-guide/pages/implicit-requesthandlers.adoc
@@ -693,12 +693,12 @@ V2 API::
 ====
 [source,bash]
 ----
-http://localhost:8983/api/collections/gettingstarted/config/requestHandler?componentName=/export&expandParams=true
+http://localhost:8983/api/collections/gettingstarted/config/requestHandlers?componentName=/export&expandParams=true
 ----
 ====
 ======
 
-The response will look similar to:
+The response will look similar to (V1 nests under `requestHandler`; V2 nests under `requestHandlers`):
 
 [source,json]
 ----

From 3372ab79ed3556660b50d24790d3e24fa45c6e0d Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 22:06:31 +0530
Subject: [PATCH 13/21] minor cleanup

---
 .../src/java/org/apache/solr/handler/SolrConfigHandler.java    | 3 +--
 .../src/java/org/apache/solr/handler/admin/api/GetConfig.java  | 2 --
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java b/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
index 83f76e771df1..2b2080a06737 100644
--- a/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
+++ b/solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java
@@ -25,7 +25,6 @@
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_CLASS;
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_NAME;
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_NAME_IN_OVERLAY;
-import static org.apache.solr.handler.admin.api.GetConfig.REQUEST_HANDLER_APIs;
 import static org.apache.solr.schema.FieldType.CLASS_NAME;
 
 import java.io.IOException;
@@ -217,7 +216,7 @@ private void handleGET() {
                     .getZnodeVersion(
                         req.getParams().getInt(ConfigOverlay.NAME, -1),
                         req.getParams().getInt(RequestParams.NAME, -1)));
-          } else if (REQUEST_HANDLER_APIs.contains(parts.get(1))) {
+          } else if (SolrRequestHandler.TYPE.equals(parts.get(1))) {
             V2ApiUtils.squashIntoSolrResponseWithoutHeader(
                 resp,
                 new GetConfig(req)
diff --git a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
index 5b10765e4c06..3f0466d86af6 100644
--- a/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
+++ b/solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java
@@ -69,8 +69,6 @@ public class GetConfig extends JerseyResource implements ConfigApi.Get {
           "queryResponseWriter");
 
   public static final String REQUEST_HANDLERS = "requestHandlers";
-  public static final Set<String> REQUEST_HANDLER_APIs =
-      Set.of(SolrRequestHandler.TYPE, REQUEST_HANDLERS);
 
   // v2-only renames: external (URL/response-key) component name -> internal SolrConfig section
   // name. v1's GET /config/{component} keeps using the internal names unchanged.

From ba2c8a956396db56d55b11274c86cd015168ee45 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 22:49:38 +0530
Subject: [PATCH 14/21] todo

---
 .../src/java/org/apache/solr/client/api/endpoint/ConfigApi.java | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java b/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
index 0f3f64868b8c..f10026be9249 100644
--- a/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
+++ b/solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java
@@ -70,6 +70,8 @@ ConfigZnodeVersionResponse getZnodeVersion(
             @Parameter(description = "Expected request-params znode version")
             int expectedParamsVersion);
 
+    // TODO: RH names contain '/' (e.g. /select, /update/json), so they cannot be a @PathParam in
+    // the current design; Keeping filtering via @QueryParam for now.
     @GET
     @Path("/requestHandlers")
     @StoreApiParameters

From e84d371856f2f5eed231f58f0a61e71f9f544f48 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 23:10:40 +0530
Subject: [PATCH 15/21] more tests coverage & strictness

---
 .../admin/api/GetConfigSolrCloudTest.java     | 89 +++++++++++++++++++
 .../solr/handler/admin/api/GetConfigTest.java | 25 ++++--
 2 files changed, 105 insertions(+), 9 deletions(-)

diff --git a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
index 19b29380afd8..e480e660c2c3 100644
--- a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
@@ -17,14 +17,17 @@
 package org.apache.solr.handler.admin.api;
 
 import static org.apache.solr.core.CoreContainer.ALLOW_PATHS_SYSPROP;
+import static org.apache.solr.handler.admin.api.GetConfig.REQUEST_HANDLERS;
 
 import org.apache.solr.client.api.model.IndexType;
+import org.apache.solr.client.solrj.RemoteSolrException;
 import org.apache.solr.client.solrj.request.CollectionAdminRequest;
 import org.apache.solr.client.solrj.request.ConfigApi;
 import org.apache.solr.cloud.SolrCloudTestCase;
 import org.apache.solr.util.ExternalPaths;
 import org.junit.BeforeClass;
 import org.junit.Test;
+import java.util.Map;
 
 /** HTTP tests for fetching the full config via the collection-scoped v2 path. */
 public class GetConfigSolrCloudTest extends SolrCloudTestCase {
@@ -77,6 +80,92 @@ public void testGetZnodeVersionFromCollection() throws Exception {
     assertTrue(response.znodeVersion.params >= -1);
   }
 
+  @Test
+  @SuppressWarnings("unchecked")
+  public void testGetRequestHandlersFromCollection() throws Exception {
+    var request = new ConfigApi.GetRequestHandler(IndexType.COLLECTION, COLLECTION_NAME);
+    var response = request.process(cluster.getSolrClient());
+
+    assertNotNull(response);
+    assertNull(response.error);
+    assertNotNull(response.config);
+    assertEquals(1, response.config.size());
+    assertTrue(response.config.containsKey(REQUEST_HANDLERS));
+
+    Map<String, Object> configSection = (Map<String, Object>) response.config.get(REQUEST_HANDLERS);
+    assertNotNull(configSection);
+    assertTrue(configSection.containsKey("/select"));
+    assertTrue(configSection.containsKey("/admin/ping"));
+  }
+
+  @Test
+  @SuppressWarnings("unchecked")
+  public void testGetRequestHandlersFilteredByNameFromCollection() throws Exception {
+    var request = new ConfigApi.GetRequestHandler(IndexType.COLLECTION, COLLECTION_NAME);
+    request.setComponentName("/select");
+    var response = request.process(cluster.getSolrClient());
+
+    assertNotNull(response);
+    assertNull(response.error);
+    assertEquals(1, response.config.size());
+    assertTrue(response.config.containsKey(REQUEST_HANDLERS));
+
+    Map<String, Object> configSection = (Map<String, Object>) response.config.get(REQUEST_HANDLERS);
+    assertNotNull(configSection);
+    assertEquals(1, configSection.size());
+    assertTrue(configSection.containsKey("/select"));
+
+    Map<String, Object> selectRHSection = (Map<String, Object>) configSection.get("/select");
+    assertEquals("/select", selectRHSection.get("name"));
+    assertEquals("solr.SearchHandler", selectRHSection.get("class"));
+  }
+
+  @Test
+  @SuppressWarnings("unchecked")
+  public void testGetRequestHandlersExpandParamsTrue() throws Exception {
+    var request = new ConfigApi.GetRequestHandler(IndexType.COLLECTION, COLLECTION_NAME);
+    request.setComponentName("/admin/ping");
+    request.setExpandParams(true);
+    var response = request.process(cluster.getSolrClient());
+
+    assertNotNull(response);
+    assertNull(response.error);
+    assertEquals(1, response.config.size());
+    assertTrue(response.config.containsKey(REQUEST_HANDLERS));
+
+    Map<String, Object> configSection = (Map<String, Object>) response.config.get(REQUEST_HANDLERS);
+
+    Map<String, Object> pingRHSection = (Map<String, Object>) configSection.get("/admin/ping");
+    assertTrue(pingRHSection.containsKey("_useParamsExpanded_"));
+    assertNotNull(pingRHSection.get("_useParamsExpanded_"));
+    Map<String, Object> expandedPingRHSection = (Map<String, Object>) pingRHSection.get("_useParamsExpanded_");
+    assertEquals("[NOT AVAILABLE]", expandedPingRHSection.get("_ADMIN_PING"));
+  }
+
+  @Test
+  @SuppressWarnings("unchecked")
+  public void testGetRequestHandlersOmitsExpandedParamsByDefault() throws Exception {
+    var request = new ConfigApi.GetRequestHandler(IndexType.COLLECTION, COLLECTION_NAME);
+    request.setComponentName("/admin/ping");
+    var response = request.process(cluster.getSolrClient());
+
+    Map<String, Object> configSection = (Map<String, Object>) response.config.get(REQUEST_HANDLERS);
+
+    Map<String, Object> pingRHSection = (Map<String, Object>) configSection.get("/admin/ping");
+    assertFalse(pingRHSection.containsKey("_useParamsExpanded_"));
+  }
+
+  @Test
+  public void testGetRequestHandlersByUnknownNameReturnsNotFound() throws Exception {
+    var request = new ConfigApi.GetRequestHandler(IndexType.COLLECTION, COLLECTION_NAME);
+    request.setComponentName("/randomHandler");
+    final RemoteSolrException exception =
+        assertThrows(
+            RemoteSolrException.class,
+            () -> request.process(cluster.getSolrClient()));
+    assertEquals(404, exception.code());
+  }
+
   @Test
   public void testGetConfigComponentFromCollection() throws Exception {
     for (String component : GetConfig.MIGRATED_CONFIG_COMPONENTS) {
diff --git a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java
index ed11ee4c2177..5c0563cc7133 100644
--- a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java
@@ -94,11 +94,13 @@ public void testGetRequestHandlersFromCore() throws Exception {
     assertNull(response.error);
     assertNotNull(response.config);
     assertEquals(1, response.config.size());
+    assertTrue(response.config.containsKey(REQUEST_HANDLERS));
 
     Map<String, Object> configSection = (Map<String, Object>) response.config.get(REQUEST_HANDLERS);
     assertNotNull(configSection);
     assertTrue(configSection.containsKey("/select"));
     assertTrue(configSection.containsKey("/admin/ping"));
+    assertTrue(configSection.containsKey("/spell"));
   }
 
   @Test
@@ -111,18 +113,21 @@ public void testGetRequestHandlersFilteredByNameFromCore() throws Exception {
     assertNotNull(response);
     assertNull(response.error);
     assertEquals(1, response.config.size());
+    assertTrue(response.config.containsKey(REQUEST_HANDLERS));
 
     Map<String, Object> configSection = (Map<String, Object>) response.config.get(REQUEST_HANDLERS);
     assertNotNull(configSection);
+    assertEquals(1, configSection.size());
     assertTrue(configSection.containsKey("/select"));
 
-    Map<String, Object> select = (Map<String, Object>) configSection.get("/select");
-    assertEquals("solr.SearchHandler", select.get("class"));
+    Map<String, Object> selectRHSection = (Map<String, Object>) configSection.get("/select");
+    assertEquals("/select", selectRHSection.get("name"));
+    assertEquals("solr.SearchHandler", selectRHSection.get("class"));
   }
 
   @Test
   @SuppressWarnings("unchecked")
-  public void testGetRequestHandlersExpandParamsExpandsNamedHandler() throws Exception {
+  public void testGetRequestHandlersExpandParamsTrue() throws Exception {
     var request = new ConfigApi.GetRequestHandler(IndexType.CORE, CORE_NAME);
     request.setComponentName("/admin/ping");
     request.setExpandParams(true);
@@ -131,13 +136,15 @@ public void testGetRequestHandlersExpandParamsExpandsNamedHandler() throws Excep
     assertNotNull(response);
     assertNull(response.error);
     assertEquals(1, response.config.size());
+    assertTrue(response.config.containsKey(REQUEST_HANDLERS));
 
     Map<String, Object> configSection = (Map<String, Object>) response.config.get(REQUEST_HANDLERS);
 
-    Map<String, Object> ping = (Map<String, Object>) configSection.get("/admin/ping");
-    assertNotNull(ping.get("_useParamsExpanded_"));
-    Map<String, Object> expanded = (Map<String, Object>) ping.get("_useParamsExpanded_");
-    assertEquals("[NOT AVAILABLE]", expanded.get("_ADMIN_PING"));
+    Map<String, Object> pingRHSection = (Map<String, Object>) configSection.get("/admin/ping");
+    assertTrue(pingRHSection.containsKey("_useParamsExpanded_"));
+    assertNotNull(pingRHSection.get("_useParamsExpanded_"));
+    Map<String, Object> expandedPingRHSection = (Map<String, Object>) pingRHSection.get("_useParamsExpanded_");
+    assertEquals("[NOT AVAILABLE]", expandedPingRHSection.get("_ADMIN_PING"));
   }
 
   @Test
@@ -149,8 +156,8 @@ public void testGetRequestHandlersOmitsExpandedParamsByDefault() throws Exceptio
 
     Map<String, Object> configSection = (Map<String, Object>) response.config.get(REQUEST_HANDLERS);
 
-    Map<String, Object> ping = (Map<String, Object>) configSection.get("/admin/ping");
-    assertFalse(ping.containsKey("_useParamsExpanded_"));
+    Map<String, Object> pingRHSection = (Map<String, Object>) configSection.get("/admin/ping");
+    assertFalse(pingRHSection.containsKey("_useParamsExpanded_"));
   }
 
   @Test

From 6fede4cf402781576f36443d977b2e3e1edfa260 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Fri, 16 Oct 2026 23:15:04 +0530
Subject: [PATCH 16/21] minor

---
 .../apache/solr/handler/admin/api/GetConfigSolrCloudTest.java    | 1 +
 1 file changed, 1 insertion(+)

diff --git a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
index e480e660c2c3..a706f4088f82 100644
--- a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
@@ -96,6 +96,7 @@ public void testGetRequestHandlersFromCollection() throws Exception {
     assertNotNull(configSection);
     assertTrue(configSection.containsKey("/select"));
     assertTrue(configSection.containsKey("/admin/ping"));
+    assertTrue(configSection.containsKey("/graph"));
   }
 
   @Test

From c045334e9d43934f07a695af7cbad6b6be504f01 Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Sat, 17 Oct 2026 19:14:04 +0530
Subject: [PATCH 17/21] tidying

---
 .../solr/handler/admin/api/GetConfigSolrCloudTest.java   | 9 ++++-----
 .../org/apache/solr/handler/admin/api/GetConfigTest.java | 3 ++-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
index a706f4088f82..29c10ec2a96b 100644
--- a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
@@ -19,6 +19,7 @@
 import static org.apache.solr.core.CoreContainer.ALLOW_PATHS_SYSPROP;
 import static org.apache.solr.handler.admin.api.GetConfig.REQUEST_HANDLERS;
 
+import java.util.Map;
 import org.apache.solr.client.api.model.IndexType;
 import org.apache.solr.client.solrj.RemoteSolrException;
 import org.apache.solr.client.solrj.request.CollectionAdminRequest;
@@ -27,7 +28,6 @@
 import org.apache.solr.util.ExternalPaths;
 import org.junit.BeforeClass;
 import org.junit.Test;
-import java.util.Map;
 
 /** HTTP tests for fetching the full config via the collection-scoped v2 path. */
 public class GetConfigSolrCloudTest extends SolrCloudTestCase {
@@ -139,7 +139,8 @@ public void testGetRequestHandlersExpandParamsTrue() throws Exception {
     Map<String, Object> pingRHSection = (Map<String, Object>) configSection.get("/admin/ping");
     assertTrue(pingRHSection.containsKey("_useParamsExpanded_"));
     assertNotNull(pingRHSection.get("_useParamsExpanded_"));
-    Map<String, Object> expandedPingRHSection = (Map<String, Object>) pingRHSection.get("_useParamsExpanded_");
+    Map<String, Object> expandedPingRHSection =
+        (Map<String, Object>) pingRHSection.get("_useParamsExpanded_");
     assertEquals("[NOT AVAILABLE]", expandedPingRHSection.get("_ADMIN_PING"));
   }
 
@@ -161,9 +162,7 @@ public void testGetRequestHandlersByUnknownNameReturnsNotFound() throws Exceptio
     var request = new ConfigApi.GetRequestHandler(IndexType.COLLECTION, COLLECTION_NAME);
     request.setComponentName("/randomHandler");
     final RemoteSolrException exception =
-        assertThrows(
-            RemoteSolrException.class,
-            () -> request.process(cluster.getSolrClient()));
+        assertThrows(RemoteSolrException.class, () -> request.process(cluster.getSolrClient()));
     assertEquals(404, exception.code());
   }
 
diff --git a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java
index 5c0563cc7133..4407845d1554 100644
--- a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigTest.java
@@ -143,7 +143,8 @@ public void testGetRequestHandlersExpandParamsTrue() throws Exception {
     Map<String, Object> pingRHSection = (Map<String, Object>) configSection.get("/admin/ping");
     assertTrue(pingRHSection.containsKey("_useParamsExpanded_"));
     assertNotNull(pingRHSection.get("_useParamsExpanded_"));
-    Map<String, Object> expandedPingRHSection = (Map<String, Object>) pingRHSection.get("_useParamsExpanded_");
+    Map<String, Object> expandedPingRHSection =
+        (Map<String, Object>) pingRHSection.get("_useParamsExpanded_");
     assertEquals("[NOT AVAILABLE]", expandedPingRHSection.get("_ADMIN_PING"));
   }
 

From bc37b68e292c1434e032b69fa9dea97b662ce4c0 Mon Sep 17 00:00:00 2001
From: Eric Pugh <epugh@opensourceconnections.com>
Date: Sat, 17 Oct 2026 10:01:01 -0400
Subject: [PATCH 18/21] Fix v2 API 404 when a /config request is proxied to
 another node

Solr forwards a v2 request to the node that actually hosts the target
collection using the short "/c/{collection}/..." path alias (see
HttpSolrCall#sendRemoteProxy), but Constants.INDEX_PATH_PREFIX's JAX-RS
@Path regex only recognized "cores" or "collections", not "c". Any
JAX-RS resource built on that prefix therefore 404'd with "Cannot find
API for the path" whenever a request needed to be proxied cross-node.

Reproduced with a new 2-node test in GetConfigSolrCloudTest that
deliberately sends a GET /config/overlay request to the node that does
NOT host the collection's only replica, then fixed by accepting "c" as
an alias for "collections" in the path regex.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RzzUgiebQ8ZhhgE2E7ZZU5
---
 .../solr/client/api/util/Constants.java       | 12 ++++++-
 .../admin/api/GetConfigSolrCloudTest.java     | 34 ++++++++++++++++++-
 2 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/solr/api/src/java/org/apache/solr/client/api/util/Constants.java b/solr/api/src/java/org/apache/solr/client/api/util/Constants.java
index 3e3c7443c18f..13f8009fbb41 100644
--- a/solr/api/src/java/org/apache/solr/client/api/util/Constants.java
+++ b/solr/api/src/java/org/apache/solr/client/api/util/Constants.java
@@ -24,8 +24,18 @@ private Constants() {
 
   public static final String INDEX_TYPE_PATH_PARAMETER = "indexType";
   public static final String INDEX_NAME_PATH_PARAMETER = "indexName";
+
+  // "c" is accepted alongside "collections" because Solr internally forwards a v2 request to the
+  // node actually hosting a collection using the short "/c/{collection}/..." alias (see
+  // HttpSolrCall#sendRemoteProxy and V2HttpCall's "c"/"collections" handling); without it, any
+  // JAX-RS resource built on this prefix 404s with "Cannot find API for the path" whenever the
+  // request has to be proxied to another node.
   public static final String INDEX_PATH_PREFIX =
-      "/{" + INDEX_TYPE_PATH_PARAMETER + ":cores|collections}/{" + INDEX_NAME_PATH_PARAMETER + "}";
+      "/{"
+          + INDEX_TYPE_PATH_PARAMETER
+          + ":cores|collections|c}/{"
+          + INDEX_NAME_PATH_PARAMETER
+          + "}";
 
   public static final String CORE_NAME_PATH_PARAMETER = "coreName";
 
diff --git a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
index 19b29380afd8..8a23c749e1db 100644
--- a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
@@ -19,9 +19,12 @@
 import static org.apache.solr.core.CoreContainer.ALLOW_PATHS_SYSPROP;
 
 import org.apache.solr.client.api.model.IndexType;
+import org.apache.solr.client.solrj.jetty.HttpJettySolrClient;
 import org.apache.solr.client.solrj.request.CollectionAdminRequest;
 import org.apache.solr.client.solrj.request.ConfigApi;
 import org.apache.solr.cloud.SolrCloudTestCase;
+import org.apache.solr.common.cloud.Replica;
+import org.apache.solr.embedded.JettySolrRunner;
 import org.apache.solr.util.ExternalPaths;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -34,7 +37,9 @@ public class GetConfigSolrCloudTest extends SolrCloudTestCase {
   @BeforeClass
   public static void setupCluster() throws Exception {
     System.setProperty(ALLOW_PATHS_SYSPROP, ExternalPaths.SERVER_HOME.toAbsolutePath().toString());
-    configureCluster(1).addConfig("conf", configset("cloud-minimal")).configure();
+    // 2 nodes so that a request can land on a node that does *not* host the collection's only
+    // replica, forcing Solr to internally proxy the request to the node that does.
+    configureCluster(2).addConfig("conf", configset("cloud-minimal")).configure();
     CollectionAdminRequest.createCollection(COLLECTION_NAME, "conf", 1, 1)
         .process(cluster.getSolrClient());
   }
@@ -77,6 +82,33 @@ public void testGetZnodeVersionFromCollection() throws Exception {
     assertTrue(response.znodeVersion.params >= -1);
   }
 
+  /**
+   * Reproduces a bug where a v2 "/config" request proxied internally to the node actually hosting
+   * the collection fails with "Cannot find API for the path", because Solr forwards such requests
+   * using the short "/c/{collection}/..." alias, but {@code Constants.INDEX_PATH_PREFIX}'s JAX-RS
+   * {@code @Path} regex only recognizes "cores" or "collections", not "c".
+   */
+  @Test
+  public void testGetOverlayFromCollectionViaNonHostingNode() throws Exception {
+    Replica replica = getCollectionState(COLLECTION_NAME).replicaStream().findFirst().orElseThrow();
+    JettySolrRunner hostingJetty = cluster.getReplicaJetty(replica);
+    JettySolrRunner otherJetty =
+        cluster.getJettySolrRunners().stream()
+            .filter(jetty -> jetty != hostingJetty)
+            .findFirst()
+            .orElseThrow();
+
+    try (var client = new HttpJettySolrClient.Builder(otherJetty.getBaseUrl().toString()).build()) {
+      var request = new ConfigApi.GetOverlay(IndexType.COLLECTION, COLLECTION_NAME);
+      var response = request.process(client);
+
+      assertNotNull(response);
+      assertNull(response.error);
+      assertNotNull(response.overlay);
+      assertTrue(response.overlay.containsKey("znodeVersion"));
+    }
+  }
+
   @Test
   public void testGetConfigComponentFromCollection() throws Exception {
     for (String component : GetConfig.MIGRATED_CONFIG_COMPONENTS) {

From 5b168595944fb182ecd2a67716e53ce4fce23c86 Mon Sep 17 00:00:00 2001
From: Eric Pugh <epugh@opensourceconnections.com>
Date: Sat, 17 Oct 2026 11:13:33 -0400
Subject: [PATCH 19/21] Fix ErrorProne ReferenceEquality failure in the new
 regression test

CI builds with -Werror, and errorprone flags comparing JettySolrRunner
instances with != instead of .equals().

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RzzUgiebQ8ZhhgE2E7ZZU5
---
 .../apache/solr/handler/admin/api/GetConfigSolrCloudTest.java   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
index 8a23c749e1db..51ff1504293d 100644
--- a/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/admin/api/GetConfigSolrCloudTest.java
@@ -94,7 +94,7 @@ public void testGetOverlayFromCollectionViaNonHostingNode() throws Exception {
     JettySolrRunner hostingJetty = cluster.getReplicaJetty(replica);
     JettySolrRunner otherJetty =
         cluster.getJettySolrRunners().stream()
-            .filter(jetty -> jetty != hostingJetty)
+            .filter(jetty -> !jetty.equals(hostingJetty))
             .findFirst()
             .orElseThrow();
 

From 54d11e2c9015464ee7ef62f8b5b561e3087ce19b Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Mon, 19 Oct 2026 22:18:43 +0530
Subject: [PATCH 20/21] fixed packagetooltest

---
 .../repository.json                           | 29 ++++++++++++++++++-
 .../org/apache/solr/cli/PackageToolTest.java  |  4 +--
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/solr/core/src/test-files/solr/question-answer-repository/repository.json b/solr/core/src/test-files/solr/question-answer-repository/repository.json
index bcfe7779ca3f..626361d25d5b 100644
--- a/solr/core/src/test-files/solr/question-answer-repository/repository.json
+++ b/solr/core/src/test-files/solr/question-answer-repository/repository.json
@@ -48,7 +48,34 @@
             "url": "question-answer-request-handler-1.1.jar.tmp",
             "sig": "2PBHV2xBqd+teFpSY322lviCrr6EXB7g1Q7UAZcNsr2qzR+w+sPSyfV4YYeHKHYbMkyw1YBz11Gw/Fdgd1VIOQ=="
           }
-        ]
+        ],
+        "manifest": {
+          "version-constraint": ">8",
+          "plugins": [
+            {
+              "name": "request-handler",
+              "setup-command": {
+                "path": "/api/collections/${collection}/config",
+                "payload": {"add-requesthandler": {"name": "${RH-HANDLER-PATH}", "class": "question-answer:fullstory.QARequestHandler"}},
+                "method": "POST"
+              },
+              "uninstall-command": {
+                "path": "/api/collections/${collection}/config",
+                "payload": {"delete-requesthandler": "${RH-HANDLER-PATH}"},
+                "method": "POST"
+              },
+              "verify-command": {
+                "path": "/api/collections/${collection}/config/requestHandlers?componentName=${RH-HANDLER-PATH}&meta=true",
+                "method": "GET",
+                "condition": "$['config'].['requestHandlers'].['${RH-HANDLER-PATH}'].['_packageinfo_'].['version']",
+                "expected": "${package-version}"
+              }
+            }
+          ],
+          "parameter-defaults": {
+            "RH-HANDLER-PATH": "/mypath"
+          }
+        }
       }
     ]
   }
diff --git a/solr/core/src/test/org/apache/solr/cli/PackageToolTest.java b/solr/core/src/test/org/apache/solr/cli/PackageToolTest.java
index 312509746916..a919b30555b7 100644
--- a/solr/core/src/test/org/apache/solr/cli/PackageToolTest.java
+++ b/solr/core/src/test/org/apache/solr/cli/PackageToolTest.java
@@ -320,9 +320,9 @@ void assertPackageVersion(
 
     testForResponseElement(
         cluster.getJettySolrRunner(0).getBaseUrl().toString() + "/" + collection,
-        "/config/requestHandlers?componentName=" + component + "&meta=true",
+        "/config/requestHandler?componentName=" + component + "&meta=true",
         credentials,
-        Arrays.asList("config", "requestHandlers", component, "_packageinfo_", "version"),
+        Arrays.asList("config", "requestHandler", component, "_packageinfo_", "version"),
         componentVersion);
   }
 

From dc409474c575e274bdef2ed7cd677c719c58f6ef Mon Sep 17 00:00:00 2001
From: jaykay12 <jalazkumar1208@gmail.com>
Date: Mon, 19 Oct 2026 22:28:09 +0530
Subject: [PATCH 21/21] cl

---
 changelog/unreleased/SOLR-16396-config-requestHandler.yml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/changelog/unreleased/SOLR-16396-config-requestHandler.yml b/changelog/unreleased/SOLR-16396-config-requestHandler.yml
index a860843da618..44164b792c51 100644
--- a/changelog/unreleased/SOLR-16396-config-requestHandler.yml
+++ b/changelog/unreleased/SOLR-16396-config-requestHandler.yml
@@ -5,6 +5,8 @@ type: changed
 authors:
   - name: Jalaz Kumar
     nick: jaykay12
+  - name: Eric Pugh
+    nick: epugh
 links:
   - name: SOLR-16396
     url: https://issues.apache.org/jira/browse/SOLR-16396