From 25f43adaa0c5168927e8d7358cbaee878bc28721 Mon Sep 17 00:00:00 2001
From: Aiden Cline <63023139+rekram1-node@users.noreply.github.com>
Date: Tue, 19 Aug 2025 15:32:31 -0500
Subject: [PATCH] tweak: notify agent it is in build mode when switching from
 plan mode (#2065)

---
 packages/opencode/src/session/index.ts | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/packages/opencode/src/session/index.ts b/packages/opencode/src/session/index.ts
index 2455962d..796294ec 100644
--- a/packages/opencode/src/session/index.ts
+++ b/packages/opencode/src/session/index.ts
@@ -726,6 +726,18 @@ export namespace Session {
         synthetic: true,
       })
     }
+
+    const lastAssistantMsg = msgs.filter((x) => x.info.role === "assistant").at(-1)?.info as MessageV2.Assistant
+    if (lastAssistantMsg?.mode === "plan" && agent.name === "build") {
+      msgs.at(-1)?.parts.push({
+        id: Identifier.ascending("part"),
+        messageID: userMsg.id,
+        sessionID: input.sessionID,
+        type: "text",
+        text: "You are now in build mode and are permitted to make edits",
+        synthetic: true,
+      })
+    }
     let system = SystemPrompt.header(input.providerID)
     system.push(
       ...(() => {