diff --git a/README.md b/README.md
index e101a39..3ebd4f6 100644
--- a/README.md
+++ b/README.md
@@ -20,12 +20,15 @@ No **development knowledge** required :x:
 
 Just [log in](https://sfdc-happy-soup.herokuapp.com/) and start sipping the soup! :stew: :clap: :white_check_mark:
 
+[Watch full demo](https://www.youtube.com/watch?v=2asljhebqlY&t=6s) 
 
 <p align="center">
   <img src="./github-images/happysoupmini.gif" >
 </p>
 
-[Watch full demo](https://www.youtube.com/watch?v=NH4LGbdYaaE) 
+
+
+
 
 ## Contents
 
@@ -191,6 +194,8 @@ Salesforce Happy Soup is built on top of the `MetadataComponentDependency` tooli
 
 * Lookup filters are returned with cryptic names depending on whether they belong to a custom object or a standard one. 
 
+* The app will tell you if a field is used in an apex class in read or write mode. For example, if a field is used in an assignment expression, then you know the class is assigning values to that field. The app will show you this with a visual indicator; something that the raw API cannot do.  
+
 As said above, Salesforce Happy Soup has **fixed all** this issues so that you can focus on learning about your dependencies rather than fighting the API! :facepunch:
 
 [Back to top](#salesforce-happy-soup)
diff --git a/public/css/main.css b/public/css/main.css
index c80caaa..e80b8e7 100644
--- a/public/css/main.css
+++ b/public/css/main.css
@@ -455,4 +455,24 @@ select {
 
 .metadata-info .prop{
     font-weight: bold;
+}
+
+
+.class-info{
+    border: 1px solid white;
+    border-radius: 50px;
+    padding-left: 5px;
+    padding-right: 5px;
+    margin-left: 5px;
+    padding-top: 0px;
+    padding-bottom: 1px;
+    font-size: 11px;
+}
+
+.write{
+    background-color: #d63031;
+}
+
+.read{
+    background-color: #49b677;
 }
\ No newline at end of file
diff --git a/public/index.html b/public/index.html
index 28269c2..95fb863 100644
--- a/public/index.html
+++ b/public/index.html
@@ -60,7 +60,7 @@ <h1>Happy Soup</h1>
         </div>
         
         <div class="video">
-          <iframe width="160" height="115" src="https://www.youtube.com/embed/NH4LGbdYaaE" 
+          <iframe width="160" height="115" src="https://www.youtube.com/embed/2asljhebqlY" 
           frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" 
           allowfullscreen></iframe>
       </div>
diff --git a/public/js/tree.js b/public/js/tree.js
index cafc3ca..9743f73 100644
--- a/public/js/tree.js
+++ b/public/js/tree.js
@@ -80,6 +80,10 @@ function createTreeNodes(refs,parentNode){
     if(member.namespace){
       memberNodeName.appendChild(createWarningIcon());
     }
+
+    if(member.fieldMode){
+      memberNodeName.appendChild(createPill(member.fieldMode));
+    }
   
     memberNames.appendChild(memberNodeName);
     metadataTypeNode.appendChild(memberNames);
@@ -102,6 +106,13 @@ function createTreeNodes(refs,parentNode){
     return warningIcon;
   }
 
+  function createPill(text){
+    let pill = document.createElement('span');
+    pill.classList.add(...['class-info',text]);
+    pill.innerText = text;
+    return pill;
+  }
+
   export const treeApi = {
     createDependencyTree,createUsageTree
   };
\ No newline at end of file
diff --git a/sfdc_apis/usage.js b/sfdc_apis/usage.js
index 52d1a69..49803d8 100644
--- a/sfdc_apis/usage.js
+++ b/sfdc_apis/usage.js
@@ -64,6 +64,7 @@ function usageApi(connection,entryPoint,cache){
         let customFields = [];
         let layouts = [];
         let lookupFilters = [];
+        let apexClasses = [];
         let otherMetadata = [];
 
         metadataArray.forEach(metadata => {
@@ -84,6 +85,9 @@ function usageApi(connection,entryPoint,cache){
             else if(type == 'LOOKUPFILTER'){ 
                 lookupFilters.push(metadata);
             }
+            else if(type == 'APEXCLASS' && entryPoint.type == 'CustomField'){ 
+                apexClasses.push(metadata);
+            }
             else{
                 otherMetadata.push(metadata);
             }
@@ -101,16 +105,72 @@ function usageApi(connection,entryPoint,cache){
         if(lookupFilters.length){
             lookupFilters = await getLookupFilterDetails(lookupFilters);
         }
+        if(apexClasses.length){
+            apexClasses = await getFieldUsageMode(apexClasses);
+        }
 
         otherMetadata.push(...customFields);
         otherMetadata.push(...validationRules);
         otherMetadata.push(...layouts);
         otherMetadata.push(...lookupFilters);
+        otherMetadata.push(...apexClasses);
 
         return otherMetadata;
 
     }
 
+    /**
+     * We know that the field is referenced in this class, but is it
+     * used for reading or assignment? We determine that here by checking
+     * if the field is used in an assignment expression in the body of the class
+     */
+    async function getFieldUsageMode(apexClasses){
+
+        //i.e field_name__c without the object prefix
+        let refCustomField = entryPoint.name.split('.')[1];
+
+        /**
+         * This matches on custom_field__c = but it does NOT match
+         * on custom_field__c == because the latter is a boolean exp
+         * and we are searching for assignment expressions
+         * gi means global and case insensitive search
+         */
+        let assignmentExp = new RegExp(`${refCustomField}=(?!=)`,'gi');
+
+        let ids = apexClasses.map(ac => ac.id);
+        ids = utils.filterableId(ids);
+
+        let query = `SELECT Id,Name,Body FROM ApexClass WHERE Id IN ('${ids}')`;
+        let soqlQuery = {query,filterById:true};
+    
+        let results = await toolingApi.query(soqlQuery);
+
+        let classBodyById = new Map();
+    
+        results.records.forEach(rec => {
+            classBodyById.set(rec.Id,rec.Body);
+        });
+
+        
+        apexClasses.forEach(ac => {
+
+            //by default we assume that the mode is read only
+            ac.fieldMode = 'read';
+
+            let body = classBodyById.get(ac.id);
+            if(body){
+                //remove all white space/new lines
+                body = body.replace(/\s/g,'');
+
+                if(body.match(assignmentExp)){
+                    ac.fieldMode = 'write';
+                }
+            }
+        });
+
+        return apexClasses;
+    }
+
     async function getLookupFilterDetails(lookupFilters){
 
         let metadataRecordToEntityMap = new Map();