diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2ddf79b9f3..8e1d873776 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,8 @@ This is the log of notable changes to EAS CLI and related packages.
 
 ### 🎉 New features
 
+- Allow undefined update message for EAS Update publishing when no VCS. ([#2148](https://github.com/expo/eas-cli/pull/2148) by [@wschurman](https://github.com/wschurman))
+
 ### 🐛 Bug fixes
 
 ### 🧹 Chores
diff --git a/packages/eas-cli/src/commands/update/index.ts b/packages/eas-cli/src/commands/update/index.ts
index 222085e6b8..14b570783b 100644
--- a/packages/eas-cli/src/commands/update/index.ts
+++ b/packages/eas-cli/src/commands/update/index.ts
@@ -515,7 +515,7 @@ export default class UpdatePublish extends EasCommand {
               ? [{ label: 'Android update ID', value: newAndroidUpdate.id }]
               : []),
             ...(newIosUpdate ? [{ label: 'iOS update ID', value: newIosUpdate.id }] : []),
-            { label: 'Message', value: updateMessage },
+            { label: 'Message', value: updateMessage ?? '' },
             ...(gitCommitHash
               ? [
                   {
diff --git a/packages/eas-cli/src/commands/update/roll-back-to-embedded.ts b/packages/eas-cli/src/commands/update/roll-back-to-embedded.ts
index da721e5c21..1d03b06257 100644
--- a/packages/eas-cli/src/commands/update/roll-back-to-embedded.ts
+++ b/packages/eas-cli/src/commands/update/roll-back-to-embedded.ts
@@ -270,7 +270,7 @@ export default class UpdateRollBackToEmbedded extends EasCommand {
               ? [{ label: 'Android update ID', value: newAndroidUpdate.id }]
               : []),
             ...(newIosUpdate ? [{ label: 'iOS update ID', value: newIosUpdate.id }] : []),
-            { label: 'Message', value: updateMessage },
+            { label: 'Message', value: updateMessage ?? '' },
             ...(gitCommitHash
               ? [
                   {
@@ -300,7 +300,7 @@ export default class UpdateRollBackToEmbedded extends EasCommand {
     graphqlClient: ExpoGraphqlClient;
     isGitWorkingTreeDirty: boolean | undefined;
     gitCommitHash: string | undefined;
-    updateMessage: string;
+    updateMessage: string | undefined;
     branchId: string;
     codeSigningInfo: CodeSigningInfo | undefined;
     runtimeVersions: { platform: string; runtimeVersion: string }[];
diff --git a/packages/eas-cli/src/project/publish.ts b/packages/eas-cli/src/project/publish.ts
index ad53ea0598..a0d3d31533 100644
--- a/packages/eas-cli/src/project/publish.ts
+++ b/packages/eas-cli/src/project/publish.ts
@@ -631,32 +631,38 @@ export async function getUpdateMessageForCommandAsync(
     nonInteractive: boolean;
     jsonFlag: boolean;
   }
-): Promise<string> {
+): Promise<string | undefined> {
   let updateMessage = updateMessageArg;
   if (!updateMessageArg && autoFlag) {
     updateMessage = (await vcsClient.getLastCommitMessageAsync())?.trim();
   }
 
   if (!updateMessage) {
-    if (nonInteractive) {
-      throw new Error('Must supply --message or use --auto when in non-interactive mode');
+    if (nonInteractive || jsonFlag) {
+      if (vcsClient.canGetLastCommitMessage()) {
+        throw new Error(
+          'Must supply --message or use --auto when in non-interactive mode and VCS is available'
+        );
+      }
+      return undefined;
     }
 
-    const validationMessage = 'publish message may not be empty.';
-    if (jsonFlag) {
-      throw new Error(validationMessage);
-    }
     const { updateMessageLocal } = await promptAsync({
       type: 'text',
       name: 'updateMessageLocal',
       message: `Provide an update message:`,
       initial: (await vcsClient.getLastCommitMessageAsync())?.trim(),
-      validate: (value: any) => (value ? true : validationMessage),
     });
+    if (!updateMessageLocal) {
+      return undefined;
+    }
+
     updateMessage = updateMessageLocal;
   }
 
-  assert(updateMessage, 'Update message must be specified.');
+  if (!updateMessage) {
+    return undefined;
+  }
 
   const truncatedMessage = truncateUpdateMessage(updateMessage, 1024);
   if (truncatedMessage !== updateMessage) {
diff --git a/packages/eas-cli/src/vcs/clients/git.ts b/packages/eas-cli/src/vcs/clients/git.ts
index 46c5f4d567..1b67a28b2d 100644
--- a/packages/eas-cli/src/vcs/clients/git.ts
+++ b/packages/eas-cli/src/vcs/clients/git.ts
@@ -217,6 +217,10 @@ export default class GitClient extends Client {
       return false;
     }
   }
+
+  public override canGetLastCommitMessage(): boolean {
+    return true;
+  }
 }
 
 async function ensureGitConfiguredAsync({
diff --git a/packages/eas-cli/src/vcs/clients/noVcs.ts b/packages/eas-cli/src/vcs/clients/noVcs.ts
index e1adb9b95e..b8ebee7593 100644
--- a/packages/eas-cli/src/vcs/clients/noVcs.ts
+++ b/packages/eas-cli/src/vcs/clients/noVcs.ts
@@ -16,4 +16,8 @@ export default class NoVcsClient extends Client {
     await ignore.initIgnoreAsync();
     return ignore.ignores(filePath);
   }
+
+  public override canGetLastCommitMessage(): boolean {
+    return true;
+  }
 }
diff --git a/packages/eas-cli/src/vcs/vcs.ts b/packages/eas-cli/src/vcs/vcs.ts
index 2720c4101b..72101c8050 100644
--- a/packages/eas-cli/src/vcs/vcs.ts
+++ b/packages/eas-cli/src/vcs/vcs.ts
@@ -78,4 +78,10 @@ export abstract class Client {
   public async isFileIgnoredAsync(_filePath: string): Promise<boolean> {
     return false;
   }
+
+  /**
+   * Whether this VCS client can get the last commit message.
+   * Used for EAS Update - implementation can be false for noVcs client.
+   */
+  public abstract canGetLastCommitMessage(): boolean;
 }