diff --git a/apps/api/src/judge/ast.ts b/apps/api/src/judge/ast.ts
index 7fc5a4f..2f55fff 100644
--- a/apps/api/src/judge/ast.ts
+++ b/apps/api/src/judge/ast.ts
@@ -1,3 +1,4 @@
+import type { AstRule } from "@oj2/contract"
 import { Language, Parser, type Node } from "web-tree-sitter"
 // 语法 wasm 内嵌成资源。原来是 `Bun.resolveSync(pkg + "/" + name, import.meta.dir)`，
 // 编译成单二进制后 import.meta.dir 是 /$bunfs/root，解析不到 node_modules。见 vendor/jieba.ts
@@ -6,17 +7,9 @@ import pythonWasmPath from "tree-sitter-python/tree-sitter-python.wasm" with { t
 // web-tree-sitter 自己的运行时 wasm，Parser.init() 要用
 import treeSitterWasmPath from "web-tree-sitter/web-tree-sitter.wasm" with { type: "file" }
 
-export interface AstRule {
-  engine?: string
-  target?: string
-  outer?: string
-  inner?: string
-  label?: string
-  message?: string
-  exact?: number
-  min?: number
-  max?: number
-}
+// AstRule 的形状在契约里（astRuleSchema）—— 原来这份和前端两份各写各的。
+// 这里 re-export，判题机的调用方不用再去 import 契约。
+export type { AstRule } from "@oj2/contract"
 
 export interface AstResult {
   description: string
diff --git a/apps/api/src/judge/run.ts b/apps/api/src/judge/run.ts
index d2d82f3..b8f7128 100644
--- a/apps/api/src/judge/run.ts
+++ b/apps/api/src/judge/run.ts
@@ -1,5 +1,6 @@
 import { createHash } from "node:crypto"
 
+import { astRuleSchema } from "@oj2/contract"
 import { and, eq, inArray } from "drizzle-orm"
 
 import { config } from "../config"
@@ -54,9 +55,19 @@ function templateForLanguage(value: unknown, language: string) {
   return typeof template === "string" ? template : null
 }
 
+/**
+ * 取某个语言的 AST 规则。逐条过 astRuleSchema 而不是整片 `as AstRule[]` 硬转 ——
+ * 这是从库里读出来的 JSONB，形状不对（比如 engine 是个 evaluateRule 不认识的值）
+ * 时丢掉那一条，行为和 evaluateRule 的 `default: return null` 一致，只是提前到了
+ * 这里、并且不再骗类型系统。
+ */
 function astRulesForLanguage(value: unknown, language: string): AstRule[] {
   const rules = objectValue(value)[language]
-  return Array.isArray(rules) ? (rules as AstRule[]) : []
+  if (!Array.isArray(rules)) return []
+  return rules.flatMap((rule) => {
+    const parsed = astRuleSchema.safeParse(rule)
+    return parsed.success ? [parsed.data] : []
+  })
 }
 
 async function requestJudge(
diff --git a/apps/web/src/admin/problem/components/AstRulesEditor.vue b/apps/web/src/admin/problem/components/AstRulesEditor.vue
index 3c5aedf..caf906b 100644
--- a/apps/web/src/admin/problem/components/AstRulesEditor.vue
+++ b/apps/web/src/admin/problem/components/AstRulesEditor.vue
@@ -1,24 +1,14 @@
 <script setup lang="ts">
-import type { LANGUAGE } from "utils/types"
-
-interface AstRule {
-  engine: string
-  target?: string
-  label?: string
-  exact?: number
-  min?: number
-  max?: number
-  message: string
-}
+import type { AstRule, AstRules, LANGUAGE } from "utils/types"
 
 interface Props {
-  modelValue: { [key: string]: AstRule[] } | null
+  modelValue: AstRules | null
   languages: LANGUAGE[]
 }
 
 const props = defineProps<Props>()
 const emit = defineEmits<{
-  (e: "update:modelValue", value: { [key: string]: AstRule[] } | null): void
+  (e: "update:modelValue", value: AstRules | null): void
 }>()
 
 const activeTab = ref(props.languages[0] || "Python3")
diff --git a/apps/web/src/oj/problem/components/ProblemContent.vue b/apps/web/src/oj/problem/components/ProblemContent.vue
index fb45677..f34e14f 100644
--- a/apps/web/src/oj/problem/components/ProblemContent.vue
+++ b/apps/web/src/oj/problem/components/ProblemContent.vue
@@ -6,7 +6,7 @@ import { useCodeStore } from "oj/store/code"
 import { useProblemStore } from "oj/store/problem"
 import { createTestSubmission } from "utils/judge"
 import { DIFFICULTY } from "utils/constants"
-import type { Problem, ProblemStatus } from "utils/types"
+import type { AstRule, Problem, ProblemStatus } from "utils/types"
 import Copy from "shared/components/Copy.vue"
 import { useDark } from "@vueuse/core"
 import { MdPreview } from "md-editor-v3"
@@ -115,16 +115,6 @@ const NODE_TARGET_LABELS: Record<string, string> = {
   class_definition: "类定义",
 }
 
-type AstRule = {
-  engine: string
-  target?: string
-  label?: string
-  exact?: number
-  min?: number
-  max?: number
-  message: string
-}
-
 function ruleDescription(rule: AstRule): string {
   if (rule.message) return rule.message
   const target = rule.target || ""
diff --git a/apps/web/src/utils/types.ts b/apps/web/src/utils/types.ts
index 6dc46f8..be8fd41 100644
--- a/apps/web/src/utils/types.ts
+++ b/apps/web/src/utils/types.ts
@@ -13,6 +13,7 @@ import type {
   ProblemDetail,
   ProblemDifficulty,
   JudgeStatus,
+  AstRules,
   CreateAnnouncementRequest,
 } from "@oj2/contract"
 
@@ -111,7 +112,6 @@ export type { ProblemTestCaseScore as Testcase } from "@oj2/contract"
 /**
  * 题目详情。以契约的 ProblemDetail 为准，只在这里补两处前端自己的窄化：
  * - `languages` / `template` 的键窄化成 LANGUAGE，组件按语言查模板要靠它
- * - `astRules` 契约里是 unknown，这里给出组件实际读的形状
  */
 export type Problem = Omit<ProblemDetail, "languages" | "template"> & {
   languages: LANGUAGE[]
@@ -122,15 +122,11 @@ export type Problem = Omit<ProblemDetail, "languages" | "template"> & {
   answers?: { language: LANGUAGE; code: string }[]
 }
 
-export type AstRules = {
-  [key: string]: {
-    engine: string
-    target?: string
-    min?: number
-    max?: number
-    message: string
-  }[]
-}
+/**
+ * AST 代码要求。原来这里手抄的那份少了 label / exact / outer / inner ——
+ * 编辑器写得出 label 和 exact，判题机也认，只有这个类型不认。形状在契约里。
+ */
+export type { AstRule, AstRules, AstRuleEngine } from "@oj2/contract"
 
 export type {
   ProblemDetail,
diff --git a/packages/contract/src/admin.ts b/packages/contract/src/admin.ts
index bb1a0d7..fdac6f3 100644
--- a/packages/contract/src/admin.ts
+++ b/packages/contract/src/admin.ts
@@ -43,6 +43,9 @@ export const createAnnouncementRequestSchema = z.object({
 
 export const updateAnnouncementRequestSchema = createAnnouncementRequestSchema
 
+export type AstRuleEngine = z.infer<typeof astRuleEngineSchema>
+export type AstRule = z.infer<typeof astRuleSchema>
+export type AstRules = z.infer<typeof astRulesSchema>
 export type ProblemSample = z.infer<typeof problemSampleSchema>
 export type ProblemAnswer = z.infer<typeof problemAnswerSchema>
 export type ProblemTestCaseScore = z.infer<typeof problemTestCaseScoreSchema>
@@ -566,6 +569,50 @@ export const problemTestCaseScoreSchema = z.object({
   score: z.coerce.number().int().min(0),
 })
 
+/**
+ * AST 代码要求。同一个形状原来在**三个地方**各写了一份，三份都不一样：
+ * apps/api/src/judge/ast.ts 的 AstRule（判题机真读的那份，九个字段）、
+ * apps/web/src/utils/types.ts 的 AstRules（少了 label / exact / outer / inner）、
+ * AstRulesEditor.vue 里的本地 AstRule（少了 outer / inner）。
+ * 编辑器写得出 label / exact，题目类型却描述不了它们。现在以这里为准。
+ *
+ * 除 engine 外全部可选：判题机每条规则只读自己那几个字段
+ * （见 ast.ts 的 evaluateRule），缺了就走默认文案。
+ */
+export const astRuleEngineSchema = z.enum([
+  "must_exist_node",
+  "must_not_exist_node",
+  "count_node",
+  "must_call_function",
+  "must_not_call_function",
+  "count_function_call",
+  "must_call_method",
+  "must_not_call_method",
+  "must_use_operator",
+  // 判题机实现了，但后台编辑器还没有对应的选项，目前只能手工造数据用上
+  "must_have_nesting",
+])
+
+export const astRuleSchema = z.object({
+  engine: astRuleEngineSchema,
+  /** 检查目标：节点类型 / 函数名 / 方法名 / 运算符，按 engine 而定 */
+  target: z.string().optional(),
+  /** must_have_nesting 专用：外层、内层节点 */
+  outer: z.string().optional(),
+  inner: z.string().optional(),
+  /** 展示用的中文名，缺省回落到 target */
+  label: z.string().optional(),
+  /** 自定义提示。生产库里存的是空串而不是缺键，判题机按 `||` 回落到默认文案 */
+  message: z.string().optional(),
+  /** count_* 引擎的次数约束 */
+  exact: z.number().int().optional(),
+  min: z.number().int().optional(),
+  max: z.number().int().optional(),
+})
+
+/** 按语言分组：`{ Python3: [...], C: [...] }`，键是 languages 里的语言名 */
+export const astRulesSchema = z.record(z.string(), z.array(astRuleSchema))
+
 /** 后台题目详情：包含 oj 侧永不下发的 answers / testCase* / astRules */
 export const adminProblemSchema = z.object({
   id: z.number().int(),
@@ -599,7 +646,7 @@ export const adminProblemSchema = z.object({
   showFlowchart: z.boolean(),
   mermaidCode: z.string().nullable(),
   flowchartHint: z.string().nullable(),
-  astRules: z.unknown(),
+  astRules: astRulesSchema.nullable(),
   answers: z.array(problemAnswerSchema),
   prompt: z.string().nullable(),
   sqlConfig: sqlConfigSchema.nullable(),
@@ -631,7 +678,7 @@ export const createProblemRequestSchema = z.object({
   showFlowchart: z.boolean().default(false),
   mermaidCode: z.string().nullable().default(null),
   flowchartHint: z.string().nullable().default(null),
-  astRules: z.unknown().default(null),
+  astRules: astRulesSchema.nullable().default(null),
   // order_sensitive 缺省补 false —— 与旧后端 SQLConfigSerializer 的
   // `BooleanField(default=False)` 一致
   sqlConfig: sqlConfigSchema