diff --git a/packages/opencode/src/session/index.ts b/packages/opencode/src/session/index.ts
index 524eceac..86e3e15b 100644
--- a/packages/opencode/src/session/index.ts
+++ b/packages/opencode/src/session/index.ts
@@ -407,6 +407,12 @@ export namespace Session {
                     synthetic: true,
                     text: Buffer.from(part.url, "base64url").toString(),
                   },
+                  {
+                    ...part,
+                    id: part.id ?? Identifier.ascending("part"),
+                    messageID: userMsg.id,
+                    sessionID: input.sessionID,
+                  },
                 ]
               }
               break