diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/ArchiveController.java b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/ArchiveController.java
index 99e1a7e5c..711393d53 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/ArchiveController.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/ArchiveController.java
@@ -32,7 +32,6 @@
 import javax.validation.Valid;
 import javax.validation.constraints.Max;
 import javax.validation.constraints.Min;
-import javax.validation.constraints.NotBlank;
 import javax.validation.constraints.NotNull;
 import javax.validation.constraints.PositiveOrZero;
 import javax.validation.constraints.Size;
@@ -60,13 +59,13 @@
 import org.whispersystems.textsecuregcm.backup.CopyParameters;
 import org.whispersystems.textsecuregcm.backup.CopyResult;
 import org.whispersystems.textsecuregcm.backup.MediaEncryptionParameters;
+import org.whispersystems.textsecuregcm.entities.RemoteAttachment;
 import org.whispersystems.textsecuregcm.util.BackupAuthCredentialAdapter;
 import org.whispersystems.textsecuregcm.util.ByteArrayAdapter;
 import org.whispersystems.textsecuregcm.util.ByteArrayBase64UrlAdapter;
 import org.whispersystems.textsecuregcm.util.ECPublicKeyAdapter;
 import org.whispersystems.textsecuregcm.util.ExactlySize;
 import org.whispersystems.textsecuregcm.util.Util;
-import org.whispersystems.textsecuregcm.util.ValidBase64URLString;
 import org.whispersystems.websocket.auth.Mutable;
 import org.whispersystems.websocket.auth.ReadOnly;
 import reactor.core.publisher.Mono;
@@ -462,16 +461,6 @@ public CompletionStage<UploadDescriptorResponse> uploadTemporaryAttachment(
             result.signedUploadLocation()));
   }
 
-  public record RemoteAttachment(
-      @Schema(description = "The attachment cdn")
-      @NotNull
-      Integer cdn,
-
-      @NotBlank
-      @ValidBase64URLString
-      @Schema(description = "The attachment key")
-      String key) {}
-
   public record CopyMediaRequest(
       @Schema(description = "The object on the attachment CDN to copy")
       @NotNull
@@ -510,7 +499,7 @@ public record CopyMediaRequest(
 
     CopyParameters toCopyParameters() {
       return new CopyParameters(
-          sourceAttachment.cdn, sourceAttachment.key,
+          sourceAttachment.cdn(), sourceAttachment.key(),
           objectLength,
           new MediaEncryptionParameters(encryptionKey, hmacKey, iv),
           mediaId);
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/entities/RemoteAttachment.java b/service/src/main/java/org/whispersystems/textsecuregcm/entities/RemoteAttachment.java
new file mode 100644
index 000000000..9b95e0554
--- /dev/null
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/entities/RemoteAttachment.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright 2024 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.entities;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotNull;
+import org.whispersystems.textsecuregcm.util.ValidBase64URLString;
+
+public record RemoteAttachment(
+    @Schema(description = "The attachment cdn")
+    @NotNull
+    Integer cdn,
+
+    @NotBlank
+    @ValidBase64URLString
+    @Schema(description = "The attachment key")
+    String key) {
+}
diff --git a/service/src/test/java/org/whispersystems/textsecuregcm/controllers/ArchiveControllerTest.java b/service/src/test/java/org/whispersystems/textsecuregcm/controllers/ArchiveControllerTest.java
index 21de15c31..a26955c90 100644
--- a/service/src/test/java/org/whispersystems/textsecuregcm/controllers/ArchiveControllerTest.java
+++ b/service/src/test/java/org/whispersystems/textsecuregcm/controllers/ArchiveControllerTest.java
@@ -66,6 +66,7 @@
 import org.whispersystems.textsecuregcm.backup.BackupManager;
 import org.whispersystems.textsecuregcm.backup.BackupUploadDescriptor;
 import org.whispersystems.textsecuregcm.backup.CopyResult;
+import org.whispersystems.textsecuregcm.entities.RemoteAttachment;
 import org.whispersystems.textsecuregcm.mappers.CompletionExceptionMapper;
 import org.whispersystems.textsecuregcm.mappers.GrpcStatusRuntimeExceptionMapper;
 import org.whispersystems.textsecuregcm.mappers.RateLimitExceededExceptionMapper;
@@ -357,7 +358,7 @@ public void putMediaBatchSuccess() throws VerificationFailedException {
         .header("X-Signal-ZK-Auth-Signature", "aaa")
         .put(Entity.json(new ArchiveController.CopyMediaBatchRequest(List.of(
             new ArchiveController.CopyMediaRequest(
-                new ArchiveController.RemoteAttachment(3, "abc"),
+                new RemoteAttachment(3, "abc"),
                 100,
                 mediaIds[0],
                 TestRandomUtil.nextBytes(32),
@@ -365,7 +366,7 @@ public void putMediaBatchSuccess() throws VerificationFailedException {
                 TestRandomUtil.nextBytes(16)),
 
             new ArchiveController.CopyMediaRequest(
-                new ArchiveController.RemoteAttachment(3, "def"),
+                new RemoteAttachment(3, "def"),
                 200,
                 mediaIds[1],
                 TestRandomUtil.nextBytes(32),
@@ -402,7 +403,7 @@ public void putMediaBatchPartialFailure() throws VerificationFailedException {
 
     final List<ArchiveController.CopyMediaRequest> copyRequests = Arrays.stream(mediaIds)
         .map(mediaId -> new ArchiveController.CopyMediaRequest(
-            new ArchiveController.RemoteAttachment(3, "abc"),
+            new RemoteAttachment(3, "abc"),
             100,
             mediaId,
             TestRandomUtil.nextBytes(32),
@@ -458,7 +459,7 @@ public void copyMediaWithNegativeLength() throws VerificationFailedException {
         .header("X-Signal-ZK-Auth-Signature", "aaa")
         .put(Entity.json(new ArchiveController.CopyMediaBatchRequest(List.of(
             new ArchiveController.CopyMediaRequest(
-                new ArchiveController.RemoteAttachment(3, "abc"),
+                new RemoteAttachment(3, "abc"),
                 1,
                 mediaIds[0],
                 TestRandomUtil.nextBytes(32),
@@ -466,7 +467,7 @@ public void copyMediaWithNegativeLength() throws VerificationFailedException {
                 TestRandomUtil.nextBytes(16)),
 
             new ArchiveController.CopyMediaRequest(
-                new ArchiveController.RemoteAttachment(3, "def"),
+                new RemoteAttachment(3, "def"),
                 -1,
                 mediaIds[1],
                 TestRandomUtil.nextBytes(32),
@@ -639,7 +640,7 @@ public void invalidSourceAttachmentKey() throws VerificationFailedException {
         .header("X-Signal-ZK-Auth", Base64.getEncoder().encodeToString(presentation.serialize()))
         .header("X-Signal-ZK-Auth-Signature", "aaa")
         .put(Entity.json(new ArchiveController.CopyMediaRequest(
-                new ArchiveController.RemoteAttachment(3, "invalid/urlBase64"),
+                new RemoteAttachment(3, "invalid/urlBase64"),
                 100,
                 TestRandomUtil.nextBytes(15),
                 TestRandomUtil.nextBytes(32),