From a8ae58df199c28ba3337237a47118d04cc6077a7 Mon Sep 17 00:00:00 2001
From: Josh Holmer <jholmer.in@gmail.com>
Date: Tue, 7 Apr 2026 05:02:06 -0400
Subject: [PATCH] fix(core): make follow-up execution aware of the saved plan
 file

Users launching a follow-up implementation session now get an explicit plan-file path and instruction to read it first, so execution stays aligned with the canonical plan even when copied plan text drifts.
---
 .../opencode/src/kilocode/plan-followup.ts    | 26 +++++++++--------
 .../test/kilocode/plan-followup.test.ts       | 28 ++++++++++++++++---
 2 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/packages/opencode/src/kilocode/plan-followup.ts b/packages/opencode/src/kilocode/plan-followup.ts
index 70cdab89fd6..869fcc3377e 100644
--- a/packages/opencode/src/kilocode/plan-followup.ts
+++ b/packages/opencode/src/kilocode/plan-followup.ts
@@ -273,20 +273,24 @@ export namespace PlanFollowup {
       Todo.get(input.sessionID),
     ])
 
-    const sections = [`Implement the following plan:\n\n${input.plan}`]
-
-    if (handover) {
-      sections.push(`## Handover from Planning Session\n\n${handover}`)
-    }
-
-    const todoList = formatTodos(todos)
-    if (todoList) {
-      sections.push(`## Todo List\n\n${todoList}`)
-    }
-
     await Instance.provide({
       directory: session.directory,
       fn: async () => {
+        const file = Session.plan(session)
+        const sections = [
+          `Plan file: ${file}\nRead this file first and treat it as the source of truth for implementation.`,
+          `Implement the following plan:\n\n${input.plan}`,
+        ]
+
+        if (handover) {
+          sections.push(`## Handover from Planning Session\n\n${handover}`)
+        }
+
+        const todoList = formatTodos(todos)
+        if (todoList) {
+          sections.push(`## Todo List\n\n${todoList}`)
+        }
+
         const next = await Session.create({})
         await inject({
           sessionID: next.id,
diff --git a/packages/opencode/test/kilocode/plan-followup.test.ts b/packages/opencode/test/kilocode/plan-followup.test.ts
index 5cb75675bc8..70b4bc73748 100644
--- a/packages/opencode/test/kilocode/plan-followup.test.ts
+++ b/packages/opencode/test/kilocode/plan-followup.test.ts
@@ -449,6 +449,7 @@ describe("plan follow-up", () => {
       if (!newSessionID || !next) throw new Error("expected follow-up session")
       expect(next.id).toBe(newSessionID)
       expect(next.parentID).toBeUndefined()
+      const planPath = Session.plan(await Session.get(seeded.sessionID))
       const messages = await Session.messages({ sessionID: newSessionID })
       const user = messages.find((item) => item.info.role === "user")
       expect(user?.info.role).toBe("user")
@@ -461,6 +462,7 @@ describe("plan follow-up", () => {
       expect(part?.type).toBe("text")
       if (!part || part.type !== "text") throw new Error("expected text part")
       expect(part.text).toContain("Implement the following plan:")
+      expect(part.text).toContain(`Plan file: ${planPath}`)
       expect(part.text).toContain("1. Add API\n2. Add tests")
       expect(part.text).toContain("## Handover from Planning Session")
       expect(part.text).toContain("Found REST endpoints in src/api.ts")
@@ -479,6 +481,7 @@ describe("plan follow-up", () => {
 
   test("ask - creates a new session in the planning session directory when the current instance differs", () =>
     withInstance(async () => {
+      await using other = await tmpdir({ git: true })
       const get = spyOn(Agent, "get").mockImplementation(async () => undefined as any)
       const modelSpy = spyOn(Provider, "getModel").mockResolvedValue(fakeModel)
       const llmSpy = spyOn(LLM, "stream").mockResolvedValue({
@@ -492,15 +495,17 @@ describe("plan follow-up", () => {
         },
       }
 
-      const dir = path.join(Instance.directory, "worktrees", "feature")
-      await fs.mkdir(dir, { recursive: true })
+      const dir = other.path
 
       const seeded = await Instance.provide({
         directory: dir,
         fn: async () => seed({ text: "1. Add API\n2. Add tests" }),
       })
 
-      const before = await sessions()
+      const before = await Instance.provide({
+        directory: dir,
+        fn: async () => sessions(),
+      })
       const pending = PlanFollowup.ask({
         sessionID: seeded.sessionID,
         messages: seeded.messages,
@@ -517,16 +522,31 @@ describe("plan follow-up", () => {
       })
 
       await expect(pending).resolves.toBe("break")
+      const after = await Instance.provide({
+        directory: dir,
+        fn: async () => sessions(),
+      })
 
-      const after = await sessions()
       const prev = new Set(before.map((item) => item.id))
       const added = after.filter((item) => !prev.has(item.id))
       expect(added).toHaveLength(1)
       const next = added[0]
+      if (!next) throw new Error("expected follow-up session")
       expect(next?.directory).toBe(dir)
       expect(next?.parentID).toBeUndefined()
 
       if (next) {
+        const planPath = await Instance.provide({
+          directory: dir,
+          fn: async () => Session.plan(await Session.get(seeded.sessionID)),
+        })
+        const messages = await Session.messages({ sessionID: next.id })
+        const user = messages.find((item) => item.info.role === "user")
+        if (!user || user.info.role !== "user") throw new Error("expected user message")
+        const part = user.parts.find((item) => item.type === "text")
+        if (!part || part.type !== "text") throw new Error("expected text part")
+        expect(part.text).toContain(`Plan file: ${planPath}`)
+
         SessionPrompt.cancel(next.id)
       }
     }))