diff --git a/examples/forge-functionality/api_examples.js b/examples/forge-functionality/api_examples.js
index 955c0205b..0b598824f 100644
--- a/examples/forge-functionality/api_examples.js
+++ b/examples/forge-functionality/api_examples.js
@@ -11,7 +11,7 @@ const STANDARD_FONT_DATA_URL =
 
 // Loading file from file system into typed array.
 const pdfPath =
-  process.argv[2] || "../../web/compressed.tracemonkey-pldi-09.pdf";
+  process.argv[2] || "C:\\Users\\kj131\\pdf-forge\\test_pdfs\\ISO_32000-2_2020(en).pdf";
 const data = new Uint8Array(fs.readFileSync(pdfPath));
 
 // Load the PDF file.
@@ -21,12 +21,46 @@ const loadingTask = getDocument({
   cMapPacked: CMAP_PACKED,
   standardFontDataUrl: STANDARD_FONT_DATA_URL,
 });
-try {
-  const pdfDocument = await loadingTask.promise;
-  console.log("# PDF document loaded.");
-  const page = await pdfDocument.getPage(1);
-  const opList = await page.getOperatorList();
-  console.log(opList);
-} catch (e) {
-  console.error(e);
+test(loadingTask);
+async function test(loading) {
+  try {
+    const pdfDocument = await loading.promise;
+    console.log("# PDF document loaded.");
+    const page = await pdfDocument.getPage(4);
+    printOpList(page);
+    console.time("contents");
+    const contents = await page.getContents();
+    console.timeEnd("contents");
+    console.time("oplist");
+    const opList = await page.getOperatorList();
+    console.timeEnd("oplist");
+    // console.log(opList);
+    let newContents = "";
+    for (let i = 0; i < 5; i++) {
+      const range = opList.rangeArray[i];
+      if (range) {
+        newContents += contents.slice(range[0], range[1]);
+        newContents += "\n";
+      }
+    }
+    console.log(newContents);
+    await page.updateContents(newContents);
+    await printOpList(page);
+  } catch (e) {
+    console.error(e);
+  }
+}
+
+async function printOpList(page) {
+  const contents = await page.getContents();
+  const opList = await page.getOperatorList();
+  // console.log(opList);
+  const ops = [];
+  for (let i = 0; i < opList.rangeArray.length; i++) {
+    const range = opList.rangeArray[i];
+    if (range) {
+      ops.push(contents.slice(range[0], range[1]));
+    }
+  }
+  console.log(ops.slice(0, 100));
 }
diff --git a/examples/forge-functionality/fetch_primitives.js b/examples/forge-functionality/fetch_primitives.js
index 78e751894..9fb94d31c 100644
--- a/examples/forge-functionality/fetch_primitives.js
+++ b/examples/forge-functionality/fetch_primitives.js
@@ -45,7 +45,7 @@ function bytesToString(bytes) {
 }
 
 async function parse(doc) {
-  const path = "/Page2/Contents/2";
+  const path = "/Page2/Contents/1";
   let [stream] = await getPrimitive(path, doc);
   const lexer = new Lexer(stream);
   const parser = new Parser({ lexer, xref: doc.xref, trackRanges: true });
@@ -63,12 +63,12 @@ async function parse(doc) {
   const bytes = stream.getBytes();
   const classes = new Set();
   for (const o of objs) {
-    console.log(o[0].constructor.name);
+    // console.log(o[0].constructor.name);
     classes.add(o[0].constructor.name);
     const lexemmeBytes = bytes.slice(o[1], o[2]);
-    console.log(bytesToString(lexemmeBytes));
+    // console.log(bytesToString(lexemmeBytes));
   }
-  console.log("unique classes", classes);
+  // console.log("unique classes", classes);
   [stream] = await getPrimitive(path, doc);
   const preprocessor = new EvaluatorPreprocessor(stream, doc.xref);
   const operation = {};
@@ -78,10 +78,10 @@ async function parse(doc) {
     const fn = operation.fn;
     const range = operation.range;
     const op = bytesToString(bytes.slice(range[0], range[1]));
-    console.log(args, fn);
-    console.log(`${range[0]}------------------------------------`);
-    console.log(op);
-    console.log(`${range[1]}------------------------------------`);
+    // console.log(args, fn);
+    // console.log(`----------------- ${range} -------------------`);
+    console.log(`${fn}: ${op}`);
+    // console.log(`---------------------------------------------`);
   }
   // console.time("xref");
   // let table = await retrieveXref(doc);
diff --git a/src/core/document.js b/src/core/document.js
index b3a550c4e..1deffb7ca 100644
--- a/src/core/document.js
+++ b/src/core/document.js
@@ -65,7 +65,7 @@ import { Catalog } from "./catalog.js";
 import { clearGlobalCaches } from "./cleanup_helper.js";
 import { DatasetReader } from "./dataset_reader.js";
 import { Linearization } from "./parser.js";
-import { NullStream } from "./stream.js";
+import { NullStream, StringStream } from "./stream.js";
 import { ObjectLoader } from "./object_loader.js";
 import { OperatorList } from "./operator_list.js";
 import { PartialEvaluator } from "./evaluator.js";
@@ -107,6 +107,8 @@ class Page {
     this.resourcesPromise = null;
     this.xfaFactory = xfaFactory;
 
+    this.updatedContents = null;
+
     const idCounters = {
       obj: 0,
     };
@@ -246,10 +248,19 @@ class Page {
     throw reason;
   }
 
+  setContents(newContents) {
+    this.updatedContents = newContents;
+  }
+
   /**
    * @returns {Promise<BaseStream>}
    */
   getContentStream() {
+    if (this.updatedContents !== null) {
+      return new Promise(resolve => {
+        resolve(new StringStream(this.updatedContents));
+      });
+    }
     return this.pdfManager.ensure(this, "content").then(content => {
       if (content instanceof BaseStream) {
         return content;
@@ -426,8 +437,11 @@ class Page {
     cacheKey,
     annotationStorage = null,
     modifiedIds = null,
+    contentOverride = null,
   }) {
-    const contentStreamPromise = this.getContentStream();
+    const contentStreamPromise = contentOverride
+      ? new StringStream(contentOverride)
+      : this.getContentStream();
     const resourcesPromise = this.loadResources([
       "ColorSpace",
       "ExtGState",
diff --git a/src/core/evaluator.js b/src/core/evaluator.js
index 08737beb5..0ac5cd3bf 100644
--- a/src/core/evaluator.js
+++ b/src/core/evaluator.js
@@ -802,6 +802,7 @@ class PartialEvaluator {
     operatorList.addImageOps(
       OPS.paintImageXObject,
       args,
+      range,
       optionalContent,
       hasMask
     );
@@ -1445,15 +1446,20 @@ class PartialEvaluator {
           minMax = [Infinity, Infinity, -Infinity, -Infinity];
           break;
       }
-      operatorList.addOp(OPS.constructPath, [[fn], args, minMax], range);
+      operatorList.addOp(
+        OPS.constructPath,
+        [[fn], args, minMax, [range[0], range[1]]],
+        range
+      );
 
       if (parsingText) {
-        operatorList.addOp(OPS.restore, null, range);
+        operatorList.addOp(OPS.restore, null);
       }
     } else {
       const opArgs = operatorList.argsArray[lastIndex];
       opArgs[0].push(fn);
       opArgs[1].push(...args);
+      opArgs[3].push(...range);
       const minMax = opArgs[2];
 
       const opRange = operatorList.rangeArray[lastIndex];
@@ -5215,7 +5221,7 @@ class EvaluatorPreprocessor {
 
         operation.fn = fn;
         operation.args = args;
-        const end = this.parser.getPosition();
+        const end = this.parser.getEnd();
         operation.range = [start, end];
         return true;
       }
diff --git a/src/core/parser.js b/src/core/parser.js
index 3a7ea1de4..b107a9606 100644
--- a/src/core/parser.js
+++ b/src/core/parser.js
@@ -59,12 +59,7 @@ function getInlineImageCacheKey(bytes) {
 }
 
 class Parser {
-  constructor({
-    lexer,
-    xref,
-    allowStreams = false,
-    recoveryMode = false,
-  }) {
+  constructor({ lexer, xref, allowStreams = false, recoveryMode = false }) {
     this.lexer = lexer;
     this.xref = xref;
     this.allowStreams = allowStreams;
@@ -75,8 +70,8 @@ class Parser {
   }
 
   refill() {
-    const [buf1, start1, end1] = this.lexer.getObj(true);
-    const [buf2, start2, end2] = this.lexer.getObj(true);
+    const [buf1, start1, end1] = this.lexer.getObjWithRange();
+    const [buf2, start2, end2] = this.lexer.getObjWithRange();
     this.buf1 = buf1;
     this.range1 = [start1, end1];
     this.buf2 = buf2;
@@ -87,12 +82,14 @@ class Parser {
     if (this.buf2 instanceof Cmd && this.buf2.cmd === "ID") {
       this.buf1 = this.buf2;
       this.buf2 = null;
+      this.lastEnd = this.range1[1];
       this.range1 = this.range2;
       this.range2 = null;
     } else {
       this.buf1 = this.buf2;
+      this.lastEnd = this.range1[1];
       this.range1 = this.range2;
-      const [buf2, start2, end2] = this.lexer.getObj(true);
+      const [buf2, start2, end2] = this.lexer.getObjWithRange();
       this.buf2 = buf2;
       this.range2 = [start2, end2];
     }
@@ -116,6 +113,10 @@ class Parser {
     return this.range1 ? this.range1[0] : 0;
   }
 
+  getEnd() {
+    return this.lastEnd ?? 0;
+  }
+
   getObjWithRange(cipherTransform = null) {
     const start = this.range1[0];
     const obj = this.getObj(cipherTransform);
@@ -1229,14 +1230,18 @@ class Lexer {
   }
 
   getObjWithRange() {
-    // at the start of getObj() the stream has stepped beyond currentChar by one
-    const start = this.stream.pos - 1;
+    const ch = this._skipWhitespaceAndComments();
+    if (ch === EOF) {
+      return [ch, -1, -1];
+    }
+    // currentChar is always at pos - 1
+    const start = Math.max(this.stream.pos - 1, 0);
     const obj = this.getObj();
-    const end = this.stream.pos;
+    const end = this.stream.pos - 1;
     return [obj, start, end];
   }
 
-  getObj(withRange = false) {
+  _skipWhitespaceAndComments() {
     // Skip whitespace and comments.
     let comment = false;
     let ch = this.currentChar;
@@ -1255,16 +1260,14 @@ class Lexer {
       }
       ch = this.nextChar();
     }
-    const start = this.stream.pos - 1;
-    const obj = this.extracted(ch);
-    const end = this.stream.pos - 1;
-    if (withRange) {
-      return [start, obj, end];
-    }
-    return obj;
+    return ch;
   }
 
-  extracted(ch) {
+  getObj() {
+    let ch = this._skipWhitespaceAndComments();
+    if (ch === EOF) {
+      return ch;
+    }
     // Start reading a token.
     switch (ch | 0) {
       case 0x30: // '0'
diff --git a/src/core/worker.js b/src/core/worker.js
index 925f648cc..5d433ebc3 100644
--- a/src/core/worker.js
+++ b/src/core/worker.js
@@ -123,7 +123,7 @@ class WorkerMessageHandler {
     if (apiVersion !== workerVersion) {
       throw new Error(
         `The API version "${apiVersion}" does not match ` +
-          `the Worker version "${workerVersion}".`
+        `the Worker version "${workerVersion}".`
       );
     }
 
@@ -141,8 +141,8 @@ class WorkerMessageHandler {
       if (enumerableProperties.length) {
         throw new Error(
           "The `Array.prototype` contains unexpected enumerable properties: " +
-            enumerableProperties.join(", ") +
-            "; thus breaking e.g. `for...in` iteration of `Array`s."
+          enumerableProperties.join(", ") +
+          "; thus breaking e.g. `for...in` iteration of `Array`s."
         );
       }
     }
@@ -206,15 +206,15 @@ class WorkerMessageHandler {
     }
 
     async function getPdfManager({
-      data,
-      password,
-      disableAutoFetch,
-      rangeChunkSize,
-      length,
-      docBaseUrl,
-      enableXfa,
-      evaluatorOptions,
-    }) {
+                                   data,
+                                   password,
+                                   disableAutoFetch,
+                                   rangeChunkSize,
+                                   length,
+                                   docBaseUrl,
+                                   enableXfa,
+                                   evaluatorOptions,
+                                 }) {
       const pdfManagerArgs = {
         source: null,
         disableAutoFetch,
@@ -242,7 +242,7 @@ class WorkerMessageHandler {
         loaded = 0;
 
       fullRequest.headersReady
-        .then(function () {
+        .then(function() {
           if (!fullRequest.isRangeSupported) {
             return;
           }
@@ -263,13 +263,13 @@ class WorkerMessageHandler {
           pdfManagerCapability.resolve(newPdfManager);
           cancelXHRs = null;
         })
-        .catch(function (reason) {
+        .catch(function(reason) {
           pdfManagerCapability.reject(reason);
           cancelXHRs = null;
         });
 
-      new Promise(function (resolve, reject) {
-        const readChunk = function ({ value, done }) {
+      new Promise(function(resolve, reject) {
+        const readChunk = function({ value, done }) {
           try {
             ensureNotTerminated();
             if (done) {
@@ -314,7 +314,7 @@ class WorkerMessageHandler {
           }
         };
         fullRequest.read().then(readChunk, reject);
-      }).catch(function (e) {
+      }).catch(function(e) {
         pdfManagerCapability.reject(e);
         cancelXHRs = null;
       });
@@ -341,12 +341,12 @@ class WorkerMessageHandler {
 
           handler
             .sendWithPromise("PasswordRequest", ex)
-            .then(function ({ password }) {
+            .then(function({ password }) {
               finishWorkerTask(task);
               pdfManager.updatePassword(password);
               pdfManagerReady();
             })
-            .catch(function () {
+            .catch(function() {
               finishWorkerTask(task);
               handler.send("DocException", ex);
             });
@@ -359,7 +359,7 @@ class WorkerMessageHandler {
       function pdfManagerReady() {
         ensureNotTerminated();
 
-        loadDocument(false).then(onSuccess, function (reason) {
+        loadDocument(false).then(onSuccess, function(reason) {
           ensureNotTerminated();
 
           // Try again with recoveryMode == true
@@ -367,7 +367,7 @@ class WorkerMessageHandler {
             onFailure(reason);
             return;
           }
-          pdfManager.requestLoadedStream().then(function () {
+          pdfManager.requestLoadedStream().then(function() {
             ensureNotTerminated();
 
             loadDocument(true).then(onSuccess, onFailure);
@@ -378,7 +378,7 @@ class WorkerMessageHandler {
       ensureNotTerminated();
 
       getPdfManager(data)
-        .then(function (newPdfManager) {
+        .then(function(newPdfManager) {
           if (terminated) {
             // We were in a process of setting up the manager, but it got
             // terminated in the middle.
@@ -396,14 +396,14 @@ class WorkerMessageHandler {
         .then(pdfManagerReady, onFailure);
     }
 
-    handler.on("GetPage", function (data) {
-      return pdfManager.getPage(data.pageIndex).then(function (page) {
+    handler.on("GetPage", function(data) {
+      return pdfManager.getPage(data.pageIndex).then(function(page) {
         return Promise.all([
           pdfManager.ensure(page, "rotate"),
           pdfManager.ensure(page, "ref"),
           pdfManager.ensure(page, "userUnit"),
           pdfManager.ensure(page, "view"),
-        ]).then(function ([rotate, ref, userUnit, view]) {
+        ]).then(function([rotate, ref, userUnit, view]) {
           return {
             rotate,
             ref,
@@ -415,104 +415,104 @@ class WorkerMessageHandler {
       });
     });
 
-    handler.on("GetPageIndex", function (data) {
+    handler.on("GetPageIndex", function(data) {
       const pageRef = Ref.get(data.num, data.gen);
       return pdfManager.ensureCatalog("getPageIndex", [pageRef]);
     });
 
-    handler.on("GetDestinations", function (data) {
+    handler.on("GetDestinations", function(data) {
       return pdfManager.ensureCatalog("destinations");
     });
 
-    handler.on("GetDestination", function (data) {
+    handler.on("GetDestination", function(data) {
       return pdfManager.ensureCatalog("getDestination", [data.id]);
     });
 
-    handler.on("GetPageLabels", function (data) {
+    handler.on("GetPageLabels", function(data) {
       return pdfManager.ensureCatalog("pageLabels");
     });
 
-    handler.on("GetPageLayout", function (data) {
+    handler.on("GetPageLayout", function(data) {
       return pdfManager.ensureCatalog("pageLayout");
     });
 
-    handler.on("GetPageMode", function (data) {
+    handler.on("GetPageMode", function(data) {
       return pdfManager.ensureCatalog("pageMode");
     });
 
-    handler.on("GetViewerPreferences", function (data) {
+    handler.on("GetViewerPreferences", function(data) {
       return pdfManager.ensureCatalog("viewerPreferences");
     });
 
-    handler.on("GetOpenAction", function (data) {
+    handler.on("GetOpenAction", function(data) {
       return pdfManager.ensureCatalog("openAction");
     });
 
-    handler.on("GetAttachments", function (data) {
+    handler.on("GetAttachments", function(data) {
       return pdfManager.ensureCatalog("attachments");
     });
 
-    handler.on("GetDocJSActions", function (data) {
+    handler.on("GetDocJSActions", function(data) {
       return pdfManager.ensureCatalog("jsActions");
     });
 
-    handler.on("GetPageJSActions", function ({ pageIndex }) {
-      return pdfManager.getPage(pageIndex).then(function (page) {
+    handler.on("GetPageJSActions", function({ pageIndex }) {
+      return pdfManager.getPage(pageIndex).then(function(page) {
         return pdfManager.ensure(page, "jsActions");
       });
     });
 
-    handler.on("GetOutline", function (data) {
+    handler.on("GetOutline", function(data) {
       return pdfManager.ensureCatalog("documentOutline");
     });
 
-    handler.on("GetOptionalContentConfig", function (data) {
+    handler.on("GetOptionalContentConfig", function(data) {
       return pdfManager.ensureCatalog("optionalContentConfig");
     });
 
-    handler.on("GetPermissions", function (data) {
+    handler.on("GetPermissions", function(data) {
       return pdfManager.ensureCatalog("permissions");
     });
 
-    handler.on("GetMetadata", function (data) {
+    handler.on("GetMetadata", function(data) {
       return Promise.all([
         pdfManager.ensureDoc("documentInfo"),
         pdfManager.ensureCatalog("metadata"),
       ]);
     });
 
-    handler.on("GetMarkInfo", function (data) {
+    handler.on("GetMarkInfo", function(data) {
       return pdfManager.ensureCatalog("markInfo");
     });
 
-    handler.on("GetData", function (data) {
-      return pdfManager.requestLoadedStream().then(function (stream) {
+    handler.on("GetData", function(data) {
+      return pdfManager.requestLoadedStream().then(function(stream) {
         return stream.bytes;
       });
     });
 
-    handler.on("GetPrimitiveByPath", function (path_str) {
+    handler.on("GetPrimitiveByPath", function(path_str) {
       return getPrim(path_str, pdfManager.pdfDocument);
     });
 
-    handler.on("GetXRefEntries", function (data) {
+    handler.on("GetXRefEntries", function(data) {
       return retrieveXref(pdfManager.pdfDocument);
     });
 
-    handler.on("GetPrimTree", function (request) {
+    handler.on("GetPrimTree", function(request) {
       return getPrimTree(request, pdfManager.pdfDocument);
     });
 
-    handler.on("GetImageData", function (path) {
+    handler.on("GetImageData", function(path) {
       return getImageAsBlob(path, pdfManager.pdfDocument);
     });
 
-    handler.on("GetStreamAsString", function (path) {
+    handler.on("GetStreamAsString", function(path) {
       return getStreamAsString(path, pdfManager.pdfDocument);
     });
 
-    handler.on("GetAnnotations", function ({ pageIndex, intent }) {
-      return pdfManager.getPage(pageIndex).then(function (page) {
+    handler.on("GetAnnotations", function({ pageIndex, intent }) {
+      return pdfManager.getPage(pageIndex).then(function(page) {
         const task = new WorkerTask(`GetAnnotations: page ${pageIndex}`);
         startWorkerTask(task);
 
@@ -529,23 +529,23 @@ class WorkerMessageHandler {
       });
     });
 
-    handler.on("GetFieldObjects", function (data) {
+    handler.on("GetFieldObjects", function(data) {
       return pdfManager
         .ensureDoc("fieldObjects")
         .then(fieldObjects => fieldObjects?.allFields || null);
     });
 
-    handler.on("HasJSActions", function (data) {
+    handler.on("HasJSActions", function(data) {
       return pdfManager.ensureDoc("hasJSActions");
     });
 
-    handler.on("GetCalculationOrderIds", function (data) {
+    handler.on("GetCalculationOrderIds", function(data) {
       return pdfManager.ensureDoc("calculationOrderIds");
     });
 
     handler.on(
       "SaveDocument",
-      async function ({ isPureXfa, numPages, annotationStorage, filename }) {
+      async function({ isPureXfa, numPages, annotationStorage, filename }) {
         const globalPromises = [
           pdfManager.requestLoadedStream(),
           pdfManager.ensureCatalog("acroForm"),
@@ -615,7 +615,7 @@ class WorkerMessageHandler {
                     imagePromises,
                     changes
                   )
-                  .finally(function () {
+                  .finally(function() {
                     finishWorkerTask(task);
                   });
               })
@@ -652,13 +652,13 @@ class WorkerMessageHandler {
         } else {
           for (let pageIndex = 0; pageIndex < numPages; pageIndex++) {
             promises.push(
-              pdfManager.getPage(pageIndex).then(function (page) {
+              pdfManager.getPage(pageIndex).then(function(page) {
                 const task = new WorkerTask(`Save: page ${pageIndex}`);
                 startWorkerTask(task);
 
                 return page
                   .save(handler, task, annotationStorage, changes)
-                  .finally(function () {
+                  .finally(function() {
                     finishWorkerTask(task);
                   });
               })
@@ -748,6 +748,31 @@ class WorkerMessageHandler {
       }
     );
 
+    handler.on("StreamContents", function(data, sink) {
+      const pageIndex = data.pageIndex;
+      pdfManager.getPage(pageIndex).then(function(page) {
+        page.getContentStream().then(stream => {
+          let byte;
+          let string = "";
+          while ((byte = stream.getByte()) !== -1) {
+            string += String.fromCharCode(byte);
+          }
+          sink.enqueue(string, string.length);
+          sink.close();
+        });
+      });
+    });
+
+    handler.on("UpdateContents", function (data) {
+      return new Promise(resolve => {
+        const pageIndex = data.pageIndex;
+        pdfManager.getPage(pageIndex).then(function (page) {
+          page.setContents(data.value);
+          resolve();
+        });
+      });
+    });
+
     handler.on("GetOperatorList", function (data, sink) {
       const pageIndex = data.pageIndex;
       pdfManager.getPage(pageIndex).then(function (page) {
@@ -767,6 +792,7 @@ class WorkerMessageHandler {
             cacheKey: data.cacheKey,
             annotationStorage: data.annotationStorage,
             modifiedIds: data.modifiedIds,
+            contentOverride: data.contentOverride,
           })
           .then(
             function (operatorListInfo) {
diff --git a/src/display/api.js b/src/display/api.js
index b84a02434..d85fa6dfe 100644
--- a/src/display/api.js
+++ b/src/display/api.js
@@ -35,6 +35,7 @@ import {
   AbortException,
   AnnotationMode,
   assert,
+  djb2Hash,
   FeatureTest,
   getVerbosityLevel,
   info,
@@ -1660,6 +1661,37 @@ class PDFPageProxy {
     return renderTask;
   }
 
+  updateContents(newContents) {
+    if (!newContents) {
+      throw new Error("Contents may not be null or undefined");
+    }
+    this._intentStates.clear();
+    return this._transport.updateContents(newContents, this._pageIndex);
+  }
+
+  getContents() {
+    const readableStream = this._transport.streamContents(this._pageIndex);
+
+    return new Promise(function (resolve, reject) {
+      function pump() {
+        reader.read().then(function ({ value, done }) {
+          if (done) {
+            resolve(textContent.text);
+            return;
+          }
+          textContent.text += value;
+          pump();
+        }, reject);
+      }
+
+      const reader = readableStream.getReader();
+      const textContent = {
+        text: "",
+      };
+      pump();
+    });
+  }
+
   /**
    * @param {GetOperatorListParameters} params - Page getOperatorList
    *   parameters.
@@ -1671,6 +1703,7 @@ class PDFPageProxy {
     annotationMode = AnnotationMode.ENABLE,
     printAnnotationStorage = null,
     isEditing = false,
+    contentOverride = null,
   } = {}) {
     if (typeof PDFJSDev !== "undefined" && !PDFJSDev.test("GENERIC")) {
       throw new Error("Not implemented: getOperatorList");
@@ -1688,7 +1721,8 @@ class PDFPageProxy {
       annotationMode,
       printAnnotationStorage,
       isEditing,
-      /* isOpList = */ true
+      /* isOpList = */ true,
+      contentOverride
     );
     let intentState = this._intentStates.get(intentArgs.cacheKey);
     if (!intentState) {
@@ -1910,6 +1944,7 @@ class PDFPageProxy {
     cacheKey,
     annotationStorageSerializable,
     modifiedIds,
+    contentOverride,
   }) {
     if (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) {
       assert(
@@ -1927,6 +1962,7 @@ class PDFPageProxy {
         cacheKey,
         annotationStorage: map,
         modifiedIds,
+        contentOverride,
       },
       transfer
     );
@@ -2528,7 +2564,8 @@ class WorkerTransport {
     annotationMode = AnnotationMode.ENABLE,
     printAnnotationStorage = null,
     isEditing = false,
-    isOpList = false
+    isOpList = false,
+    contentOverride = null
   ) {
     let renderingIntent = RenderingIntentFlag.DISPLAY; // Default value.
     let annotationStorageSerializable = SerializableEmpty;
@@ -2586,11 +2623,16 @@ class WorkerTransport {
       modifiedIdsHash,
     ];
 
+    if (contentOverride) {
+      cacheKeyBuf.push(djb2Hash(contentOverride));
+    }
+
     return {
       renderingIntent,
       cacheKey: cacheKeyBuf.join("_"),
       annotationStorageSerializable,
       modifiedIds,
+      contentOverride,
     };
   }
 
@@ -2974,6 +3016,23 @@ class WorkerTransport {
     return this.messageHandler.sendWithPromise("GetXRefEntries", null);
   }
 
+  streamContents(pageIndex) {
+    return this.messageHandler.sendWithStream("StreamContents", {
+      pageIndex,
+    });
+  }
+
+  /**
+   * @returns {Promise<void>} A promise that is resolved once the contents
+   * are updated.
+   */
+  updateContents(newContents, pageIndex) {
+    return this.messageHandler.sendWithPromise("UpdateContents", {
+      value: newContents,
+      pageIndex,
+    });
+  }
+
   saveDocument() {
     if (this.annotationStorage.size <= 0) {
       warn(
diff --git a/src/shared/util.js b/src/shared/util.js
index baf53a1b0..76b899596 100644
--- a/src/shared/util.js
+++ b/src/shared/util.js
@@ -578,6 +578,16 @@ function objectFromMap(map) {
   return obj;
 }
 
+// fast and easy hash
+function djb2Hash(str) {
+  let hash = 5381;
+  for (let i = 0; i < str.length; i++) {
+    hash = (hash << 5) + hash + str.charCodeAt(i);
+    hash &= hash; // Convert to 32-bit integer
+  }
+  return hash >>> 0; // Convert to unsigned
+}
+
 // Checks the endianness of the platform.
 function isLittleEndian() {
   const buffer8 = new Uint8Array(4);
@@ -1136,6 +1146,7 @@ export {
   BASELINE_FACTOR,
   bytesToString,
   createValidAbsoluteUrl,
+  djb2Hash,
   DocumentActionEventType,
   FeatureTest,
   FONT_IDENTITY_MATRIX,