diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/pull/api/PullReplicationFilter.java b/src/main/java/com/googlesource/gerrit/plugins/replication/pull/api/PullReplicationFilter.java
index 5a4393c..d0e5c10 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/pull/api/PullReplicationFilter.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/pull/api/PullReplicationFilter.java
@@ -18,10 +18,8 @@
 import static com.googlesource.gerrit.plugins.replication.pull.api.HttpServletOps.checkAcceptHeader;
 import static javax.servlet.http.HttpServletResponse.SC_BAD_REQUEST;
 import static javax.servlet.http.HttpServletResponse.SC_CONFLICT;
-import static javax.servlet.http.HttpServletResponse.SC_CREATED;
 import static javax.servlet.http.HttpServletResponse.SC_FORBIDDEN;
 import static javax.servlet.http.HttpServletResponse.SC_INTERNAL_SERVER_ERROR;
-import static javax.servlet.http.HttpServletResponse.SC_OK;
 import static javax.servlet.http.HttpServletResponse.SC_UNAUTHORIZED;
 
 import com.google.common.flogger.FluentLogger;
@@ -38,28 +36,22 @@
 import com.google.gerrit.extensions.restapi.UnprocessableEntityException;
 import com.google.gerrit.httpd.AllRequestFilter;
 import com.google.gerrit.httpd.restapi.RestApiServlet;
-import com.google.gerrit.json.OutputFormat;
 import com.google.gerrit.server.AnonymousUser;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.permissions.PermissionBackendException;
 import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.project.ProjectResource;
 import com.google.gerrit.server.project.ProjectState;
-import com.google.gson.Gson;
 import com.google.gson.JsonParseException;
-import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.MalformedJsonException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
-import com.google.inject.TypeLiteral;
 import com.googlesource.gerrit.plugins.replication.pull.api.FetchAction.Input;
 import com.googlesource.gerrit.plugins.replication.pull.api.data.RevisionInput;
 import com.googlesource.gerrit.plugins.replication.pull.api.data.RevisionsInput;
 import com.googlesource.gerrit.plugins.replication.pull.api.exception.UnauthorizedAuthException;
-import java.io.BufferedReader;
-import java.io.EOFException;
+import com.googlesource.gerrit.plugins.replication.pull.api.util.PayloadSerDes;
 import java.io.IOException;
-import java.io.PrintWriter;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Optional;
@@ -86,7 +78,6 @@
   private UpdateHeadAction updateHEADAction;
   private ProjectDeletionAction projectDeletionAction;
   private ProjectCache projectCache;
-  private Gson gson;
   private String pluginName;
   private final Provider<CurrentUser> currentUserProvider;
 
@@ -109,7 +100,6 @@
     this.projectDeletionAction = projectDeletionAction;
     this.projectCache = projectCache;
     this.pluginName = pluginName;
-    this.gson = OutputFormat.JSON.newGsonBuilder().create();
     this.currentUserProvider = currentUserProvider;
   }
 
@@ -126,13 +116,13 @@
     try {
       if (isFetchAction(httpRequest)) {
         failIfcurrentUserIsAnonymous();
-        writeResponse(httpResponse, doFetch(httpRequest));
+        PayloadSerDes.writeResponse(httpResponse, doFetch(httpRequest));
       } else if (isApplyObjectAction(httpRequest)) {
         failIfcurrentUserIsAnonymous();
-        writeResponse(httpResponse, doApplyObject(httpRequest));
+        PayloadSerDes.writeResponse(httpResponse, doApplyObject(httpRequest));
       } else if (isApplyObjectsAction(httpRequest)) {
         failIfcurrentUserIsAnonymous();
-        writeResponse(httpResponse, doApplyObjects(httpRequest));
+        PayloadSerDes.writeResponse(httpResponse, doApplyObjects(httpRequest));
       } else if (isInitProjectAction(httpRequest)) {
         failIfcurrentUserIsAnonymous();
         if (!checkAcceptHeader(httpRequest, httpResponse)) {
@@ -141,10 +131,10 @@
         doInitProject(httpRequest, httpResponse);
       } else if (isUpdateHEADAction(httpRequest)) {
         failIfcurrentUserIsAnonymous();
-        writeResponse(httpResponse, doUpdateHEAD(httpRequest));
+        PayloadSerDes.writeResponse(httpResponse, doUpdateHEAD(httpRequest));
       } else if (isDeleteProjectAction(httpRequest)) {
         failIfcurrentUserIsAnonymous();
-        writeResponse(httpResponse, doDeleteProject(httpRequest));
+        PayloadSerDes.writeResponse(httpResponse, doDeleteProject(httpRequest));
       } else {
         chain.doFilter(request, response);
       }
@@ -199,7 +189,7 @@
   @SuppressWarnings("unchecked")
   private Response<String> doApplyObject(HttpServletRequest httpRequest)
       throws RestApiException, IOException, PermissionBackendException {
-    RevisionInput input = readJson(httpRequest, TypeLiteral.get(RevisionInput.class));
+    RevisionInput input = PayloadSerDes.parseRevisionInput(httpRequest);
     IdString id = getProjectName(httpRequest).get();
 
     return (Response<String>) applyObjectAction.apply(parseProjectResource(id), input);
@@ -208,7 +198,7 @@
   @SuppressWarnings("unchecked")
   private Response<String> doApplyObjects(HttpServletRequest httpRequest)
       throws RestApiException, IOException, PermissionBackendException {
-    RevisionsInput input = readJson(httpRequest, TypeLiteral.get(RevisionsInput.class));
+    RevisionsInput input = PayloadSerDes.parseRevisionsInput(httpRequest);
     IdString id = getProjectName(httpRequest).get();
 
     return (Response<String>) applyObjectsAction.apply(parseProjectResource(id), input);
@@ -216,7 +206,7 @@
 
   @SuppressWarnings("unchecked")
   private Response<String> doUpdateHEAD(HttpServletRequest httpRequest) throws Exception {
-    HeadInput input = readJson(httpRequest, TypeLiteral.get(HeadInput.class));
+    HeadInput input = PayloadSerDes.parseHeadInput(httpRequest);
     IdString id = getProjectName(httpRequest).get();
 
     return (Response<String>) updateHEADAction.apply(parseProjectResource(id), input);
@@ -233,7 +223,7 @@
   @SuppressWarnings("unchecked")
   private Response<Map<String, Object>> doFetch(HttpServletRequest httpRequest)
       throws IOException, RestApiException, PermissionBackendException {
-    Input input = readJson(httpRequest, TypeLiteral.get(Input.class));
+    Input input = PayloadSerDes.parseInput(httpRequest);
     IdString id = getProjectName(httpRequest).get();
 
     return (Response<Map<String, Object>>) fetchAction.apply(parseProjectResource(id), input);
@@ -247,50 +237,6 @@
     return new ProjectResource(project.get(), currentUserProvider.get());
   }
 
-  private <T> void writeResponse(HttpServletResponse httpResponse, Response<T> response)
-      throws IOException {
-    String responseJson = gson.toJson(response);
-    if (response.statusCode() == SC_OK || response.statusCode() == SC_CREATED) {
-
-      httpResponse.setContentType("application/json");
-      httpResponse.setStatus(response.statusCode());
-      PrintWriter writer = httpResponse.getWriter();
-      writer.print(new String(RestApiServlet.JSON_MAGIC));
-      writer.print(responseJson);
-    } else {
-      httpResponse.sendError(response.statusCode(), responseJson);
-    }
-  }
-
-  private <T> T readJson(HttpServletRequest httpRequest, TypeLiteral<T> typeLiteral)
-      throws IOException, BadRequestException {
-
-    try (BufferedReader br = httpRequest.getReader();
-        JsonReader json = new JsonReader(br)) {
-      try {
-        json.setLenient(true);
-
-        try {
-          json.peek();
-        } catch (EOFException e) {
-          throw new BadRequestException("Expected JSON object", e);
-        }
-
-        return gson.fromJson(json, typeLiteral.getType());
-      } finally {
-        try {
-          // Reader.close won't consume the rest of the input. Explicitly consume the request
-          // body.
-          br.skip(Long.MAX_VALUE);
-        } catch (Exception e) {
-          // ignore, e.g. trying to consume the rest of the input may fail if the request was
-          // cancelled
-          logger.atFine().withCause(e).log("Exception during the parsing of the request json");
-        }
-      }
-    }
-  }
-
   /**
    * Return project name from request URI. Request URI format:
    * /a/projects/<project_name>/pull-replication~apply-object
diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/pull/api/util/PayloadSerDes.java b/src/main/java/com/googlesource/gerrit/plugins/replication/pull/api/util/PayloadSerDes.java
new file mode 100644
index 0000000..414af37
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/pull/api/util/PayloadSerDes.java
@@ -0,0 +1,106 @@
+// Copyright (C) 2023 The Android Open Source Project
+//
+// 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 com.googlesource.gerrit.plugins.replication.pull.api.util;
+
+import static javax.servlet.http.HttpServletResponse.SC_CREATED;
+import static javax.servlet.http.HttpServletResponse.SC_OK;
+
+import com.google.common.flogger.FluentLogger;
+import com.google.gerrit.extensions.api.projects.HeadInput;
+import com.google.gerrit.extensions.restapi.BadRequestException;
+import com.google.gerrit.extensions.restapi.Response;
+import com.google.gerrit.httpd.restapi.RestApiServlet;
+import com.google.gerrit.json.OutputFormat;
+import com.google.gson.Gson;
+import com.google.gson.stream.JsonReader;
+import com.google.inject.TypeLiteral;
+import com.googlesource.gerrit.plugins.replication.pull.api.FetchAction;
+import com.googlesource.gerrit.plugins.replication.pull.api.data.RevisionInput;
+import com.googlesource.gerrit.plugins.replication.pull.api.data.RevisionsInput;
+import java.io.BufferedReader;
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.PrintWriter;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+public class PayloadSerDes {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+  private static final Gson gson = OutputFormat.JSON.newGsonBuilder().create();
+
+  public static RevisionInput parseRevisionInput(HttpServletRequest httpRequest)
+      throws BadRequestException, IOException {
+    return parse(httpRequest, TypeLiteral.get(RevisionInput.class));
+  }
+
+  public static RevisionsInput parseRevisionsInput(HttpServletRequest httpRequest)
+      throws BadRequestException, IOException {
+    return parse(httpRequest, TypeLiteral.get(RevisionsInput.class));
+  }
+
+  public static HeadInput parseHeadInput(HttpServletRequest httpRequest)
+      throws BadRequestException, IOException {
+    return parse(httpRequest, TypeLiteral.get(HeadInput.class));
+  }
+
+  public static FetchAction.Input parseInput(HttpServletRequest httpRequest)
+      throws BadRequestException, IOException {
+    return parse(httpRequest, TypeLiteral.get(FetchAction.Input.class));
+  }
+
+  public static <T> void writeResponse(HttpServletResponse httpResponse, Response<T> response)
+      throws IOException {
+    String responseJson = gson.toJson(response);
+    if (response.statusCode() == SC_OK || response.statusCode() == SC_CREATED) {
+
+      httpResponse.setContentType("application/json");
+      httpResponse.setStatus(response.statusCode());
+      PrintWriter writer = httpResponse.getWriter();
+      writer.print(new String(RestApiServlet.JSON_MAGIC));
+      writer.print(responseJson);
+    } else {
+      httpResponse.sendError(response.statusCode(), responseJson);
+    }
+  }
+
+  private static <T> T parse(HttpServletRequest httpRequest, TypeLiteral<T> typeLiteral)
+      throws IOException, BadRequestException {
+
+    try (BufferedReader br = httpRequest.getReader();
+        JsonReader json = new JsonReader(br)) {
+      try {
+        json.setLenient(true);
+
+        try {
+          json.peek();
+        } catch (EOFException e) {
+          throw new BadRequestException("Expected JSON object", e);
+        }
+
+        return gson.fromJson(json, typeLiteral.getType());
+      } finally {
+        try {
+          // Reader.close won't consume the rest of the input. Explicitly consume the request
+          // body.
+          br.skip(Long.MAX_VALUE);
+        } catch (Exception e) {
+          // ignore, e.g. trying to consume the rest of the input may fail if the request was
+          // cancelled
+          logger.atFine().withCause(e).log("Exception during the parsing of the request json");
+        }
+      }
+    }
+  }
+}