feat: support personal local instruction overrides via .local.md

CLAUDE.local.md

@@ -0,0 +1,10 @@
+# CLAUDE.local.md
+
+---
+
+## [最高行为准则 - 严禁污染上游]
+
+- 严禁以任何形式修改、暂存（stage）或提交项目全局的 `AGENTS.md` 或 `CLAUDE.md`，它们对你而言是绝对只读的。
+- 所有个人偏好、本地工作流或提示词调整，只能写入当前本地文件（`AGENTS.local.md` 或 `CLAUDE.local.md`）。
+
+---

packages/opencode/src/session/instruction.ts

@@ -149,6 +149,19 @@ export const layer: Layer.Layer<Service, never, AppFileSystem.Service | Config.S
               }
             }
           }
+
+          // .local.md files are project-local personal overrides (typically gitignored),
+          // stacked on top of the main AGENTS.md/CLAUDE.md. Like the main files, local
+          // overrides are first-match-wins across candidates: AGENTS.local.md beats CLAUDE.local.md.
+          if (!Flag.MIMOCODE_DISABLE_CLAUDE_CODE_PROMPT) {
+            for (const name of ["AGENTS.local.md", "CLAUDE.local.md"]) {
+              const local = yield* fs.findUp(name, ctx.directory, ctx.worktree)
+              if (local.length > 0) {
+                local.forEach((item) => paths.add(path.resolve(item)))
+                break // first-match-wins
+              }
+            }
+          }
         }
 
         for (const file of globalFiles()) {

packages/opencode/test/session/instruction.test.ts

@@ -270,6 +270,86 @@ describe("Instruction.system", () => {
       }
     }
   })
+
+  test("loads CLAUDE.local.md alongside AGENTS.md (stacking)", async () => {
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "AGENTS.md"), "# Project Instructions")
+        await Bun.write(path.join(dir, "CLAUDE.local.md"), "# Personal Local")
+      },
+    })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: () =>
+        run(
+          Instruction.Service.use((svc) =>
+            Effect.gen(function* () {
+              const paths = yield* svc.systemPaths()
+              expect(paths.has(path.join(tmp.path, "AGENTS.md"))).toBe(true)
+              expect(paths.has(path.join(tmp.path, "CLAUDE.local.md"))).toBe(true)
+
+              const rules = (yield* svc.system()).content
+              expect(rules).toContain(
+                `Instructions from: ${path.join(tmp.path, "CLAUDE.local.md")}\n# Personal Local`,
+              )
+            }),
+          ),
+        ),
+    })
+  })
+
+  test("loads CLAUDE.local.md alongside CLAUDE.md fallback (no AGENTS.md)", async () => {
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "CLAUDE.md"), "# Claude Instructions")
+        await Bun.write(path.join(dir, "CLAUDE.local.md"), "# Personal Local")
+      },
+    })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: () =>
+        run(
+          Instruction.Service.use((svc) =>
+            Effect.gen(function* () {
+              const paths = yield* svc.systemPaths()
+              expect(paths.has(path.join(tmp.path, "CLAUDE.md"))).toBe(true)
+              expect(paths.has(path.join(tmp.path, "CLAUDE.local.md"))).toBe(true)
+            }),
+          ),
+        ),
+    })
+  })
+
+  test("prefers AGENTS.local.md over CLAUDE.local.md (first-match-wins)", async () => {
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "AGENTS.md"), "# Project Instructions")
+        await Bun.write(path.join(dir, "AGENTS.local.md"), "# Agents Local")
+        await Bun.write(path.join(dir, "CLAUDE.local.md"), "# Claude Local")
+      },
+    })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: () =>
+        run(
+          Instruction.Service.use((svc) =>
+            Effect.gen(function* () {
+              const paths = yield* svc.systemPaths()
+              expect(paths.has(path.join(tmp.path, "AGENTS.local.md"))).toBe(true)
+              expect(paths.has(path.join(tmp.path, "CLAUDE.local.md"))).toBe(false)
+
+              const rules = (yield* svc.system()).content
+              expect(rules).toContain(
+                `Instructions from: ${path.join(tmp.path, "AGENTS.local.md")}\n# Agents Local`,
+              )
+              expect(rules).not.toContain(
+                `Instructions from: ${path.join(tmp.path, "CLAUDE.local.md")}\n# Claude Local`,
+              )
+            }),
+          ),
+        ),
+    })
+  })
 })
 
 describe("Instruction.systemPaths MIMOCODE_CONFIG_DIR", () => {