diff --git a/ci/flow-test-schema.sql b/ci/flow-test-schema.sql
index 7b1c308..0f16c4c 100644
--- a/ci/flow-test-schema.sql
+++ b/ci/flow-test-schema.sql
@@ -339,7 +339,7 @@ CREATE TABLE `flw_instance` (
   `submitter_name` varchar(128) COLLATE utf8mb4_general_ci NOT NULL,
   `version` int NOT NULL,
   PRIMARY KEY (`id`),
-  UNIQUE KEY `uk_flw_instance_legacy` (`sch_id`,`biz_type`,`biz_id`,`legacy_slot`),
+  UNIQUE KEY `uk_flw_instance_legacy` (`sch_id`,`source_principal_id`,`biz_type`,`biz_id`,`legacy_slot`),
   UNIQUE KEY `uk_flw_instance_round` (`sch_id`,`source_principal_id`,`biz_type`,`biz_id`,`apply_round`),
   KEY `idx_flw_inst_submitter` (`sch_id`,`submitter_id`,`status`),
   KEY `idx_flw_inst_status_time` (`sch_id`,`status`,`submit_time`)
diff --git a/src/main/java/com/yunhai/flowcenter/entity/FlwInstance.java b/src/main/java/com/yunhai/flowcenter/entity/FlwInstance.java
index b8e8143..67e9426 100644
--- a/src/main/java/com/yunhai/flowcenter/entity/FlwInstance.java
+++ b/src/main/java/com/yunhai/flowcenter/entity/FlwInstance.java
@@ -16,7 +16,7 @@ import java.time.LocalDateTime;
  * 办件实例（概览 §4.3 + V2.0 Part D）：托管模式下业务对象留在业务方，本表只存
  * biz_title/biz_url/biz_snapshot 快照与关联键。正式命令每轮独立实例，唯一域为
  * (school, sourcePrincipalId, bizType, bizId, applyRound)，单在途由坐标表事务指针保护。
- * sourcePrincipalId=NULL / legacySlot=1 仅保留迁移前旧入口的一业务一行语义；正式模式关闭旧写入口。
+ * 旧入口以 sourcePrincipalId + legacySlot=1 实现每来源一业务一行；正式命令 legacySlot=NULL。
  *
  * <p>version 是乐观锁（推进串行化）兼回调 payload 的 instanceVersion（业务方按它丢弃乱序旧事件），
  * 由 JPA @Version 在 flush 时自增。
@@ -26,7 +26,7 @@ import java.time.LocalDateTime;
 @Entity
 @Table(name = "flw_instance",
         uniqueConstraints = {
-                @UniqueConstraint(name = "uk_flw_instance_legacy", columnNames = {"sch_id", "biz_type", "biz_id", "legacy_slot"}),
+                @UniqueConstraint(name = "uk_flw_instance_legacy", columnNames = {"sch_id", "source_principal_id", "biz_type", "biz_id", "legacy_slot"}),
                 @UniqueConstraint(name = "uk_flw_instance_round", columnNames = {"sch_id", "source_principal_id", "biz_type", "biz_id", "apply_round"})},
         indexes = {
                 @Index(name = "idx_flw_inst_submitter", columnList = "sch_id, submitter_id, status"),
@@ -34,7 +34,7 @@ import java.time.LocalDateTime;
 public class FlwInstance extends BaseEntity {
     @Column(name="source_principal_id",length=36,updatable=false)
     private String sourcePrincipalId;
-    /** 1 for legacy writers, NULL for formal commands. Migration must drop the old three-column UK. */
+    /** 1 for source-scoped legacy API writers, NULL for formal commands. */
     @Column(name="legacy_slot")
     private Integer legacySlot = 1;
 
diff --git a/src/main/java/com/yunhai/flowcenter/repository/FlwInstanceRepository.java b/src/main/java/com/yunhai/flowcenter/repository/FlwInstanceRepository.java
index 05e6cd0..0bdcb45 100644
--- a/src/main/java/com/yunhai/flowcenter/repository/FlwInstanceRepository.java
+++ b/src/main/java/com/yunhai/flowcenter/repository/FlwInstanceRepository.java
@@ -39,7 +39,10 @@ public interface FlwInstanceRepository extends JpaRepository<FlwInstance, Long>
     @Query("select i from FlwInstance i where i.schId=:school and i.sourcePrincipalId=:source and (:bizType is null or i.bizType=:bizType) and (:status is null or i.status=:status) order by i.id desc")
     Page<FlwInstance> pageSelf(@Param("school") Long school,@Param("source") String source,@Param("bizType") String bizType,@Param("status") Integer status, Pageable pageable);
 
-    /** biz uk 幂等主键 */
+    Optional<FlwInstance> findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(
+            Long school, String source, String bizType, String bizId, Integer slot);
+
+    /** Unknown-source rows are never used to recover a caller's instance. */
     @Query("select i from FlwInstance i where i.schId=?1 and i.bizType=?2 and i.bizId=?3 and i.sourcePrincipalId is null")
     Optional<FlwInstance> findBySchIdAndBizTypeAndBizId(Long schId, String bizType, String bizId);
 
diff --git a/src/main/java/com/yunhai/flowcenter/service/FlowInstanceService.java b/src/main/java/com/yunhai/flowcenter/service/FlowInstanceService.java
index 0f54436..5f843d1 100644
--- a/src/main/java/com/yunhai/flowcenter/service/FlowInstanceService.java
+++ b/src/main/java/com/yunhai/flowcenter/service/FlowInstanceService.java
@@ -71,51 +71,44 @@ public class FlowInstanceService {
      * null=存量调用方，指纹核对缺省关）。
      */
     public String payloadHash;
+    /** Assigned only by authenticated server-side source resolution; not a request DTO field. */
+    public String sourcePrincipalId;
     }
 
     /** 代发起结果：instanceId + duplicated（命中既有办件=true，含重启重提） */
     @Transactional
     public ApplyOutcome apply(ApplyCommand cmd) {
-        FlwInstance existing = instanceRepository
-                .findBySchIdAndBizTypeAndBizId(cmd.schId, cmd.bizType, cmd.bizId).orElse(null);
+        FlwInstance existing = findOwned(cmd);
         if (existing != null) {
+            requireSameOwner(existing, cmd);
             int status = existing.getStatus();
             if (status == FlwEnums.InstanceStatus.APPROVING.getCode()
                     || status == FlwEnums.InstanceStatus.COMPLETED.getCode()) {
                 return new ApplyOutcome(existing.getId(), true);
             }
-            // 30/40：R4 重启推进（复用办件行，定义/快照/时间刷新，重新走 START）
             restart(existing, cmd);
             return new ApplyOutcome(existing.getId(), true);
         }
-        FlwInstance instance = new FlwInstance();
-        instance.setSchId(cmd.schId);
-        instance.setDefId(cmd.def.getId());
-        instance.setDefCode(cmd.def.getCode());
-        instance.setDefVersion(cmd.def.getVersion());
-        instance.setBizType(cmd.bizType);
-        instance.setBizId(cmd.bizId);
-        instance.setBizTitle(cmd.bizTitle);
-        instance.setBizUrl(cmd.bizUrl);
-        instance.setBizSnapshot(cmd.bizSnapshot);
-        instance.setFormDataJson(cmd.formDataJson);
-        instance.setAssignJson(cmd.assignJson);
-        instance.setApplyAppKey(cmd.applyAppKey);
-        instance.setApplyAppCode(cmd.applyAppCode);
-        instance.setSubmitterId(cmd.submitterId);
-        instance.setSubmitterName(cmd.submitterName);
-        instance.setStatus(FlwEnums.InstanceStatus.APPROVING.getCode());
-        instance.setSubmitTime(LocalDateTime.now());
-        instanceRepository.saveAndFlush(instance);
-        appendTraceEvent(instance, FlwEnums.TaskStatus.NODE_SUBMIT, "发起申请",
-                FlwEnums.TaskStatus.SUBMITTED, cmd.submitterId, cmd.submitterName);
-        flowEngine.startAdvance(instance, cmd.def);
-        publishSubmitted(instance);
-        return new ApplyOutcome(instance.getId(), false);
+        FlwInstance created = createInstance(cmd, java.util.UUID.randomUUID().toString(), 1, cmd.sourcePrincipalId, 1, true);
+        return new ApplyOutcome(created.getId(), false);
+    }
+
+    private FlwInstance findOwned(ApplyCommand cmd) {
+        if (cmd.schId == null || cmd.schId <= 0 || cmd.sourcePrincipalId == null
+                || !cmd.sourcePrincipalId.matches("[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}")) {
+            throw new BizException(ErrorCode.FORBIDDEN, "缺少可信来源或有效申报学校");
+        }
+        FlwInstance existing = instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(
+                cmd.schId, cmd.sourcePrincipalId, cmd.bizType, cmd.bizId, 1).orElse(null);
+        if (existing == null && instanceRepository.findFirstBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdOrderByApplyRoundDesc(
+                cmd.schId, cmd.sourcePrincipalId, cmd.bizType, cmd.bizId).isPresent()) {
+            throw new BizException(ErrorCode.FORBIDDEN, "该业务对象已有正式命令实例，请使用原命令通道");
+        }
+        return existing;
     }
 
     private void restart(FlwInstance instance, ApplyCommand cmd) {
-        restart(instance, cmd, null, null);
+        restart(instance, cmd, java.util.UUID.randomUUID().toString(), instance.getApplyRound());
     }
 
     /**
@@ -349,15 +342,14 @@ public class FlowInstanceService {
      */
     @Transactional
     public GuardedOutcome applyGuarded(ApplyCommand cmd, ApplyRetryPolicy policy) {
-        FlwInstance existing = instanceRepository
-                .findBySchIdAndBizTypeAndBizId(cmd.schId, cmd.bizType, cmd.bizId).orElse(null);
+        FlwInstance existing = findOwned(cmd);
         if (existing != null) {
             return settleExisting(existing, cmd, policy);
         }
         String token = policy == null ? null : trimToNull(policy.requestToken);
         Integer round = policy == null || policy.attempt == null ? Integer.valueOf(1) : policy.attempt;
-        createInstance(cmd, token, round);
-        return new GuardedOutcome(instanceOf(cmd), false, FlowApplyRetryModels.Branch.CREATED, round);
+        FlwInstance created = createInstance(cmd, token, round, cmd.sourcePrincipalId, 1, true);
+        return new GuardedOutcome(created.getId(), false, FlowApplyRetryModels.Branch.CREATED, round);
     }
 
     private GuardedOutcome settleExisting(FlwInstance existing, ApplyCommand cmd, ApplyRetryPolicy policy) {
@@ -441,14 +433,15 @@ public class FlowInstanceService {
         publishSubmitted(instance);
     }
 
-    private void createInstance(ApplyCommand cmd, String token, Integer round) {
-        createInstance(cmd, token, round, null);
+    private FlwInstance createInstance(ApplyCommand cmd, String token, Integer round, String source) {
+        return createInstance(cmd, token, round, source, null, false);
     }
 
-    private FlwInstance createInstance(ApplyCommand cmd, String token, Integer round, String source) {
+    private FlwInstance createInstance(ApplyCommand cmd, String token, Integer round, String source,
+                                      Integer legacySlot, boolean start) {
         FlwInstance instance = new FlwInstance();
         instance.setSourcePrincipalId(source);
-        instance.setLegacySlot(source == null ? 1 : null);
+        instance.setLegacySlot(legacySlot);
         instance.setSchId(cmd.schId);
         instance.setDefId(cmd.def.getId());
         instance.setDefCode(cmd.def.getCode());
@@ -472,31 +465,19 @@ public class FlowInstanceService {
         instanceRepository.saveAndFlush(instance);
         appendTraceEvent(instance, FlwEnums.TaskStatus.NODE_SUBMIT, "发起申请",
                 FlwEnums.TaskStatus.SUBMITTED, cmd.submitterId, cmd.submitterName);
-        if (source == null) {
+        if (start) {
             flowEngine.startAdvance(instance, cmd.def);
             publishSubmitted(instance);
         }
         return instance;
     }
 
-    /**
-     * 旧 {@link #apply(ApplyCommand)} 的建件段复用（行为逐字不变，只是把 new 出来的那段抽出来）。
-     * 这里不复用 createInstance 是因为旧路径不写 token/round（保持存量行 NULL，不伪装"有守卫"）。
-     */
-    private Long instanceOf(ApplyCommand cmd) {
-        FlwInstance created = instanceRepository
-                .findBySchIdAndBizTypeAndBizId(cmd.schId, cmd.bizType, cmd.bizId).orElse(null);
-        return created == null ? null : created.getId();
-    }
-
     /**
      * 归属复核：调用应用 / 提交者 / 流程线三者任一明确不符都拒（C.3"不能把别的应用
-     * 相同 bizType 键当自己的结果"）。两侧都非空才判——历史行没有 token/appKey 快照，
-     * 不能因为"当年没记"就把存量件判成别人的。
+     * 相同 bizType 键当自己的结果"）。来源必须存在且匹配，不用 appKey 快照替代来源 UUID。
      */
     private void requireSameOwner(FlwInstance existing, ApplyCommand cmd) {
-        if (existing.getApplyAppKey() != null && cmd.applyAppKey != null
-                && !existing.getApplyAppKey().equals(cmd.applyAppKey)) {
+        if (cmd.sourcePrincipalId == null || !cmd.sourcePrincipalId.equals(existing.getSourcePrincipalId())) {
             throw new BizException(ErrorCode.FORBIDDEN,
                     "该业务键的办件属于另一调用应用（bizType=" + cmd.bizType + " bizId=" + cmd.bizId + "）");
         }
diff --git a/src/main/java/com/yunhai/flowcenter/service/FlowOapiSourceScope.java b/src/main/java/com/yunhai/flowcenter/service/FlowOapiSourceScope.java
index f70ed42..79a22dc 100644
--- a/src/main/java/com/yunhai/flowcenter/service/FlowOapiSourceScope.java
+++ b/src/main/java/com/yunhai/flowcenter/service/FlowOapiSourceScope.java
@@ -6,7 +6,6 @@ import com.yunhai.flowcenter.repository.FlwTaskRepository;
 import com.yunhai.platform.apistd.BizException;
 import com.yunhai.platform.utils.exception.ErrorCode;
 import lombok.RequiredArgsConstructor;
-import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Component;
 import org.springframework.web.context.request.RequestContextHolder;
 import org.springframework.web.context.request.ServletRequestAttributes;
@@ -22,11 +21,9 @@ public class FlowOapiSourceScope implements HandlerInterceptor {
     private final FlowSourcePrincipalResolver resolver;
     private final FlwInstanceRepository instances;
     private final FlwTaskRepository tasks;
-    @Value("${flow-center.formal-command.enabled:false}") private boolean enabled;
 
     @Override
     public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
-        if (!enabled) return true;
         String source = resolver.resolve((String) request.getAttribute("yh.app.auth")).id;
         request.setAttribute(ATTRIBUTE, source);
         String id = request.getParameter("instanceId");
diff --git a/src/main/java/com/yunhai/flowcenter/service/FlowSourcePrincipalResolver.java b/src/main/java/com/yunhai/flowcenter/service/FlowSourcePrincipalResolver.java
index 56da8dc..a2bc4c5 100644
--- a/src/main/java/com/yunhai/flowcenter/service/FlowSourcePrincipalResolver.java
+++ b/src/main/java/com/yunhai/flowcenter/service/FlowSourcePrincipalResolver.java
@@ -18,8 +18,12 @@ public class FlowSourcePrincipalResolver {
         if (authenticatedAppKey == null || authenticatedAppKey.trim().isEmpty()) {
             throw new BizException(ErrorCode.UNAUTHORIZED, "缺少已认证的调用应用");
         }
-        JsonNode app = appClient.getAppByKey(authenticatedAppKey);
-        if (app == null || !app.path("id").isIntegralNumber()) {
+        JsonNode app;
+        try { app = appClient.getAppByKey(authenticatedAppKey.trim()); }
+        catch (RuntimeException unavailable) {
+            throw new BizException(ErrorCode.UNAUTHORIZED, "调用应用主体查询不可用");
+        }
+        if (app == null || !app.path("id").isIntegralNumber() || app.path("id").intValue() <= 0) {
             throw new BizException(ErrorCode.UNAUTHORIZED, "调用应用主体不可解析");
         }
         String source = app.path("sourcePrincipalId").asText("");
diff --git a/src/main/java/com/yunhai/flowcenter/service/FlowUsageGrantAdminService.java b/src/main/java/com/yunhai/flowcenter/service/FlowUsageGrantAdminService.java
index 3e0e9ea..a39df24 100644
--- a/src/main/java/com/yunhai/flowcenter/service/FlowUsageGrantAdminService.java
+++ b/src/main/java/com/yunhai/flowcenter/service/FlowUsageGrantAdminService.java
@@ -32,9 +32,6 @@ public class FlowUsageGrantAdminService {
     @Autowired(required = false)
     private OpenApiAppClient appClient;
 
-    @org.springframework.beans.factory.annotation.Value("${flow-center.formal-command.enabled:false}")
-    private boolean formalEnabled;
-
     public List<FlwUsageGrant> listByFlow(Long schId, String flowGuid) {
         return grantRepository.findBySchIdAndFlowGuidOrderByUpdateTimeDescIdDesc(schId, flowGuid);
     }
@@ -62,8 +59,7 @@ public class FlowUsageGrantAdminService {
             throw new BizException(ErrorCode.PARAM_ERROR,
                     "appKey 未能在 UserBase 解析出稳定应用主体，拒绝授权：" + cleanKey);
         }
-        if (activationClient.isEnforce()
-                && !activationClient.isAppActivatedAtSchool(appId, schId)) {
+        if (!activationClient.isAppActivatedStrict(appId, schId)) {
             throw new BizException(ErrorCode.FORBIDDEN,
                     "该应用未在学校 " + schId + " 开通，不能授予流程使用许可");
         }
@@ -76,14 +72,13 @@ public class FlowUsageGrantAdminService {
             grant.setFlowGuid(flowGuid.trim());
             grant.setAppId(appId);
         }
-        if (formalEnabled) {
+        {
             String source = registered.path("sourcePrincipalId").asText("");
             try {
                 if (!java.util.UUID.fromString(source).toString().equals(source)) throw new IllegalArgumentException();
             } catch (IllegalArgumentException invalid) {
                 throw new BizException(ErrorCode.FORBIDDEN, "UserBase 稳定来源未迁移，不能发放正式许可");
             }
-            if (!activationClient.isAppActivatedStrict(appId, schId)) throw new BizException(ErrorCode.FORBIDDEN, "学校未开通");
             grant.setSourcePrincipalId(source);
         }
         grant.setAppKeySnapshot(cleanKey);
diff --git a/src/main/java/com/yunhai/flowcenter/service/FlowUsageGrantGuard.java b/src/main/java/com/yunhai/flowcenter/service/FlowUsageGrantGuard.java
index f8c8512..f4d26c9 100644
--- a/src/main/java/com/yunhai/flowcenter/service/FlowUsageGrantGuard.java
+++ b/src/main/java/com/yunhai/flowcenter/service/FlowUsageGrantGuard.java
@@ -14,7 +14,7 @@ import org.springframework.stereotype.Service;
 /**
  * 应用使用许可闸门（2026-10-25 T01）：新发起必须持有生效的 (school, flowGuid, appId) 许可。
  *
- * <p>三层独立事实，缺一不可（enforce 开启时）：</p>
+ * <p>三层独立事实，缺一不可（所有环境）：</p>
  * <ol>
  *   <li><b>稳定主体</b>：appKey 验签凭据 → UserBase 注册行主键 appId（appKey 可重置/复用，
  *       不是主体；主体解析不可达=fail-closed 拒绝）；</li>
@@ -37,38 +37,44 @@ public class FlowUsageGrantGuard {
     @Autowired(required = false)
     private OpenApiAppClient appClient;
 
-    /** enforce 关闭时直通（灰度开关，与 FC 同款迁移策略）；开启后任何一关不过即拒 */
+    /** Mandatory in every profile; the historical enforce flag cannot disable authorization. */
     public boolean isEnforce() {
-        return activationClient.isEnforce();
+        return true;
     }
 
     /**
      * 新发起资格核验：返回稳定主体 appId（供命令快照/审计使用）。
      *
-     * @throws BizException enforce 开启时：主体解析不可用、无生效许可、未在该校开通、
+     * @throws BizException 所有环境：主体解析不可用、无生效许可、未在该校开通、
      *                      UB 资格核验不可用——四类都拒绝，不猜不降级
      */
     public Integer requireNewApplyGrant(Long schId, String flowGuid, String appKey) {
-        if (!isEnforce()) {
-            return null;
-        }
         if (schId == null || flowGuid == null || flowGuid.trim().isEmpty()
                 || appKey == null || appKey.trim().isEmpty()) {
             throw new BizException(ErrorCode.FORBIDDEN, "缺少使用许可判定所需的学校/流程线/调用主体");
         }
-        Integer appId = resolveAppId(appKey.trim());
-        if (appId == null) {
+        return requireNewApplyGrant(schId, flowGuid, new FlowSourcePrincipalResolver(appClient).resolve(appKey));
+    }
+
+    /** UserBase app-school and FL app-flow are independent mandatory gates. */
+    public Integer requireNewApplyGrant(Long schId, String flowGuid, FlowSourcePrincipalResolver.Principal source) {
+        if (schId == null || schId <= 0 || flowGuid == null || flowGuid.trim().isEmpty() || source == null) {
+            throw new BizException(ErrorCode.FORBIDDEN, "缺少有效申报学校/流程线/来源主体");
+        }
+        Integer appId = source.appId;
+        if (appId == null || appId <= 0 || source.id == null) {
             throw new BizException(ErrorCode.FORBIDDEN, "调用应用主体解析不可用，已按未授权拒绝");
         }
         FlwUsageGrant grant = grantRepository.findBySchIdAndFlowGuidAndAppId(schId, flowGuid.trim(), appId)
                 .orElse(null);
-        if (grant == null || !Integer.valueOf(1).equals(grant.getEnabled())) {
+        if (grant == null || !Integer.valueOf(1).equals(grant.getEnabled())
+                || !source.id.equals(grant.getSourcePrincipalId())) {
             log.warn("[usage-grant] 拒绝新发起（无生效使用许可）：schId={} flowGuid={} appId={} appKey={}",
-                    schId, flowGuid, appId, appKey);
+                    schId, flowGuid, appId, source.appKey);
             throw new BizException(ErrorCode.FORBIDDEN,
                     "该应用未获此流程线的使用许可（school=" + schId + " flow=" + flowGuid + "）");
         }
-        if (!activationClient.isAppActivatedAtSchool(appId, schId)) {
+        if (!activationClient.isAppActivatedStrict(appId, schId)) {
             log.warn("[usage-grant] 拒绝新发起（应用未在该校开通）：schId={} appId={}", schId, appId);
             throw new BizException(ErrorCode.FORBIDDEN,
                     "该应用未在学校 " + schId + " 开通，不能发起新申报");
@@ -76,21 +82,4 @@ public class FlowUsageGrantGuard {
         return appId;
     }
 
-    /** appKey → UserBase 稳定主体主键；注册表不可达/查无/缺 id 一律 null（调用方拒绝） */
-    private Integer resolveAppId(String appKey) {
-        if (appClient == null) {
-            return null;
-        }
-        try {
-            JsonNode registered = appClient.getAppByKey(appKey);
-            if (registered == null || registered.isNull()) {
-                return null;
-            }
-            JsonNode idNode = registered.path("id");
-            return idNode.isNumber() ? idNode.intValue() : null;
-        } catch (RuntimeException e) {
-            log.warn("[usage-grant] UserBase 主体解析不可用 appKey={}：{}", appKey, e.toString());
-            return null;
-        }
-    }
 }
diff --git a/src/main/java/com/yunhai/flowcenter/service/FormalApplyCommandService.java b/src/main/java/com/yunhai/flowcenter/service/FormalApplyCommandService.java
index edd91ea..e95fa4f 100644
--- a/src/main/java/com/yunhai/flowcenter/service/FormalApplyCommandService.java
+++ b/src/main/java/com/yunhai/flowcenter/service/FormalApplyCommandService.java
@@ -93,7 +93,9 @@ public class FormalApplyCommandService {
             coordinate.setBizType(request.getBizType()); coordinate.setBizId(request.getBizId());
             coordinates.saveAndFlush(coordinate);
         }
-        if (instances.findBySchIdAndBizTypeAndBizId(school, request.getBizType(), request.getBizId()).isPresent()) {
+        if (instances.findBySchIdAndBizTypeAndBizId(school, request.getBizType(), request.getBizId()).isPresent()
+                || instances.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(
+                        school, source.id, request.getBizType(), request.getBizId(), 1).isPresent()) {
             return reject(command, "LEGACY_COORDINATE_NOT_MIGRATED", "旧业务坐标尚未审核迁移");
         }
         if (coordinate.getActiveInstanceId() != null) return reject(command, "IN_FLIGHT", "同一业务坐标已有在途实例");
diff --git a/src/main/java/com/yunhai/flowcenter/service/OapiFlowService.java b/src/main/java/com/yunhai/flowcenter/service/OapiFlowService.java
index 2f1d870..6e84806 100644
--- a/src/main/java/com/yunhai/flowcenter/service/OapiFlowService.java
+++ b/src/main/java/com/yunhai/flowcenter/service/OapiFlowService.java
@@ -145,8 +145,8 @@ public class OapiFlowService {
                 FlowDefModel.parse(objectMapper, def.getContentJson()), formDataJson);
     }
 
-    private FlowInstanceService.GuardedOutcome inTransaction(
-            org.springframework.transaction.support.TransactionCallback<FlowInstanceService.GuardedOutcome> action) {
+    private <T> T inTransaction(
+            org.springframework.transaction.support.TransactionCallback<T> action) {
         return transactionTemplate == null ? action.doInTransaction(null) : transactionTemplate.execute(action);
     }
 
@@ -229,7 +229,6 @@ public class OapiFlowService {
 
     /** 代发起（biz uk 幂等 + R4 重启重提，见 FlowInstanceService）：appKey=验签上下文调用方身份，
      *  与 app_code 一起快照进办件（消息 jump_app 的权威来源，2026-10-12 起替代 bizType 冒充） */
-    @Transactional
     public OapiModels.ApplyResultVo apply(Long schId, String appKey, OapiModels.ApplyBody body) {
         requireLegacyWriter();
         if (schId == null || body.getFlowGuid() == null || body.getBizType() == null
@@ -241,7 +240,8 @@ public class OapiFlowService {
         String cleanAppKey = appKey == null || appKey.trim().isEmpty() ? null : appKey.trim();
         // T01 使用许可（v1 路径）：回执幂等（既有在途/通过件）不拦；无实例或终态件 R4 重启=新申报，
         // 必须持有效使用许可。恢复感知的分支判定与 FlowInstanceService.apply 保持同键同序。
-        requireUsageGrantLegacyApply(schId, body.getFlowGuid(), cleanAppKey, body.getBizType(), body.getBizId());
+        FlowSourcePrincipalResolver.Principal source = requireApplySource(schId, cleanAppKey);
+        requireUsageGrant(schId, body.getFlowGuid(), source);
         FlwDef def = requirePublishedDefForApply(schId, body.getFlowGuid());
         // T06 变量终审：EXPRESSION 引用的业务变量缺失/空=null 即拒（零实例），不等运行期 nil 放行
         requireExpressionVariablesPresent(def, asFormDataString(body.getFormData()));
@@ -260,8 +260,15 @@ public class OapiFlowService {
                 body.getBizUrl(), asSnapshotString(body.getBizSnapshot()),
                 body.getSubmitterId(), body.getSubmitterName(),
                 asFormDataString(body.getFormData()),
-                cleanAppKey, resolveApplyAppCode(cleanAppKey), assignJson);
-        FlowInstanceService.ApplyOutcome outcome = instanceService.apply(cmd);
+                cleanAppKey, source.appCode, assignJson);
+        cmd.sourcePrincipalId = source.id;
+        cmd.payloadHash = payloadHash(cmd);
+        FlowInstanceService.ApplyOutcome outcome;
+        try { outcome = inTransaction(tx -> instanceService.apply(cmd)); }
+        catch (DataIntegrityViolationException concurrent) {
+            // Outside the failed transaction: retry the SAME source-scoped lookup, never a broad business-key read.
+            outcome = inTransaction(tx -> instanceService.apply(cmd));
+        }
         OapiModels.ApplyResultVo vo = new OapiModels.ApplyResultVo();
         vo.setInstanceId(outcome.getInstanceId());
         vo.setDuplicated(outcome.isDuplicated());
@@ -295,15 +302,9 @@ public class OapiFlowService {
         }
         requireSchoolMember(schId, body.getSubmitterId());
         String cleanAppKey = appKey == null || appKey.trim().isEmpty() ? null : appKey.trim();
-        // T01 使用许可（v2 路径）：恢复感知——SAME_REQUEST/REPLAY_ONLY/IDEMPOTENT/STALE_ROUND
-        // 四类回执分支不拦（已受理命令的回执不因许可撤销丢失）；CREATED/RESTARTED（新申报/新轮）
-        // 必须持有效使用许可。分支判定与 FlowInstanceService.applyGuarded 同键同序；
-        // 完整命令协议（requestId/指纹/服务端轮次）统一归 T04 重排，此处不重构。
-        requireUsageGrantGuardedApply(schId, body.getFlowGuid(), cleanAppKey, body.getBizType(),
-                body.getBizId(), body.getRequestToken(), body.getAttempt(),
-                Boolean.TRUE.equals(body.getRetryOnly()));
-        FlwInstance existing = instanceRepository.findBySchIdAndBizTypeAndBizId(
-                schId, body.getBizType(), body.getBizId()).orElse(null);
+        FlowSourcePrincipalResolver.Principal source = requireApplySource(schId, cleanAppKey);
+        FlwInstance existing = instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(
+                schId, source.id, body.getBizType(), body.getBizId(), 1).orElse(null);
         boolean replay = existing != null && body.getRequestToken() != null
                 && !body.getRequestToken().trim().isEmpty()
                 && body.getRequestToken().trim().equals(existing.getApplyRequestToken());
@@ -327,9 +328,15 @@ public class OapiFlowService {
                 body.getBizUrl(), asSnapshotString(body.getBizSnapshot()),
                 body.getSubmitterId(), body.getSubmitterName(),
                 asFormDataString(body.getFormData()),
-                cleanAppKey, resolveApplyAppCode(cleanAppKey), assignJson);
+                cleanAppKey, source.appCode, assignJson);
+        cmd.sourcePrincipalId = source.id;
         // T04：受理载荷指纹（服务端计算，不信任客户端自报）——同 token 异载荷按冲突拒绝
         cmd.payloadHash = payloadHash(cmd);
+        // Only an exact, source-owned, already accepted command can recover after revocation.
+        boolean provenReceipt = replay && source.id.equals(existing.getSourcePrincipalId())
+                && existing.getApplyPayloadHash() != null && existing.getApplyPayloadHash().equals(cmd.payloadHash)
+                && java.util.Objects.equals(existing.getSubmitterId(), cmd.submitterId);
+        if (!provenReceipt) requireUsageGrant(schId, body.getFlowGuid(), source);
         FlowInstanceService.ApplyRetryPolicy policy = new FlowInstanceService.ApplyRetryPolicy(
                 body.getRequestToken(), body.getAttempt(), Boolean.TRUE.equals(body.getRetryOnly()),
                 body.getExpectedPrevRound());
@@ -379,37 +386,18 @@ public class OapiFlowService {
     /**
      * T01 使用许可闸·v1 路径（恢复感知最小形态）：v1 无 token/轮次，回执与新申报的区分只能靠
      * 既有实例状态——在途（10）/通过（20）命中=幂等回读放行；无实例=CREATED；终态（30/40）=R4
-     * 重启即新一轮申报。guard 未装配或未 enforce 时零行为（灰度开关，见 {@link FlowUsageGrantGuard}）。
+     * 重启即新一轮申报。每次均强制通过独立的学校开通与流程使用授权校验。
      */
-    private void requireUsageGrantLegacyApply(Long schId, String flowGuid, String appKey,
-                                              String bizType, String bizId) {
-        if (usageGrantGuard == null || !usageGrantGuard.isEnforce() || appKey == null) {
-            return;
-        }
-        FlwInstance existing = instanceRepository
-                .findBySchIdAndBizTypeAndBizId(schId, bizType, bizId).orElse(null);
-        if (!legacyApplyIsReceiptOnly(existing)) {
-            usageGrantGuard.requireNewApplyGrant(schId, flowGuid, appKey);
+    private FlowSourcePrincipalResolver.Principal requireApplySource(Long school, String appKey) {
+        if (school == null || school <= 0 || sourcePrincipalResolver == null) {
+            throw new BizException(ErrorCode.FORBIDDEN, "缺少有效申报学校或来源解析服务");
         }
+        return sourcePrincipalResolver.resolve(appKey);
     }
 
-    /**
-     * T01 使用许可闸·v2 路径：与 {@code FlowInstanceService.applyGuarded/settleExisting}
-     * 同键同序的分支预判（判定逻辑见 {@link #guardedApplyIsReceiptOnly}）；
-     * 新申报（CREATED/RESTARTED）必须过 {@link FlowUsageGrantGuard#requireNewApplyGrant}。
-     * 完整命令协议统一归 T04。
-     */
-    private void requireUsageGrantGuardedApply(Long schId, String flowGuid, String appKey,
-                                               String bizType, String bizId,
-                                               String requestToken, Integer attempt, boolean retryOnly) {
-        if (usageGrantGuard == null || !usageGrantGuard.isEnforce() || appKey == null) {
-            return;
-        }
-        FlwInstance existing = instanceRepository
-                .findBySchIdAndBizTypeAndBizId(schId, bizType, bizId).orElse(null);
-        if (!guardedApplyIsReceiptOnly(existing, requestToken, attempt, retryOnly)) {
-            usageGrantGuard.requireNewApplyGrant(schId, flowGuid, appKey);
-        }
+    private void requireUsageGrant(Long school, String flow, FlowSourcePrincipalResolver.Principal source) {
+        if (usageGrantGuard == null) throw new BizException(ErrorCode.FORBIDDEN, "流程使用授权服务未装配");
+        usageGrantGuard.requireNewApplyGrant(school, flow, source);
     }
 
     /**
@@ -497,39 +485,18 @@ public class OapiFlowService {
     private FlowApplyRetryModels.ApplyResultV2 fromConcurrent(Long schId,
                                                               FlowInstanceService.ApplyCommand cmd,
                                                               FlowInstanceService.ApplyRetryPolicy policy) {
-        FlwInstance existing = instanceRepository.findBySchIdAndBizTypeAndBizId(
-                schId, cmd.bizType, cmd.bizId).orElse(null);
-        if (existing == null) {
-            throw new BizException(ErrorCode.CUSTOM, "办件创建冲突且读不到既有实例，请稍后重试");
-        }
-        if (existing.getApplyAppKey() != null && cmd.applyAppKey != null
-                && !existing.getApplyAppKey().equals(cmd.applyAppKey)) {
-            throw new BizException(ErrorCode.FORBIDDEN,
-                    "该业务键的办件属于另一调用应用（bizType=" + cmd.bizType + " bizId=" + cmd.bizId + "）");
-        }
-        if (existing.getSubmitterId() != null && cmd.submitterId != null
-                && !existing.getSubmitterId().equals(cmd.submitterId)) {
-            throw new BizException(ErrorCode.FORBIDDEN, "该业务键的办件提交者与本次请求不符");
-        }
-        String token = policy.requestToken == null ? null : policy.requestToken.trim();
+        FlowInstanceService.GuardedOutcome outcome = inTransaction(tx -> instanceService.applyGuarded(cmd, policy));
+        requireNotConflict(outcome);
         FlowApplyRetryModels.ApplyResultV2 vo = new FlowApplyRetryModels.ApplyResultV2();
-        vo.setInstanceId(existing.getId());
-        vo.setDuplicated(true);
-        vo.setApplyRound(existing.getApplyRound());
-        vo.setStatus(existing.getStatus());
-        vo.setVersion(existing.getVersion());
-        if (token != null && !token.equals(existing.getApplyRequestToken())) {
-            // T04：并发撞键且 token 不符=两份不同命令抢同一业务键——后到者冲突，不伪装幂等成功
-            //（旧 CONCURRENT_CREATED 分支只保留给无 token 的存量调用方）。
-            log.warn("[flow-center] 并发建件 token 不符（冲突拒绝）：instance={} biz={}/{}",
-                    existing.getId(), cmd.bizType, cmd.bizId);
-            throw new BizException(ErrorCode.CUSTOM,
-                    "该业务键已被另一并发命令创建（请求标识不符），请按实例查询恢复，不要换 ID 重发");
-        }
-        vo.setBranch(token != null ? FlowApplyRetryModels.Branch.SAME_REQUEST
-                : FlowApplyRetryModels.Branch.CONCURRENT_CREATED);
-        log.warn("[flow-center] 并发建件命中既有实例：instance={} biz={}/{} branch={}",
-                existing.getId(), cmd.bizType, cmd.bizId, vo.getBranch());
+        vo.setInstanceId(outcome.instanceId); vo.setDuplicated(outcome.duplicated);
+        vo.setBranch(outcome.branch); vo.setApplyRound(outcome.applyRound);
+        instanceRepository.findById(outcome.instanceId).ifPresent(current -> {
+            int currentRound = current.getApplyRound() == null ? 1 : current.getApplyRound();
+            int outcomeRound = outcome.applyRound == null ? 1 : outcome.applyRound;
+            if (currentRound == outcomeRound && cmd.sourcePrincipalId.equals(current.getSourcePrincipalId())) {
+                vo.setStatus(current.getStatus()); vo.setVersion(current.getVersion());
+            }
+        });
         return vo;
     }
 
@@ -1087,9 +1054,8 @@ public class OapiFlowService {
 
     /** 进度/换图共用的办件定位（schId 收敛在次） */
     private java.util.Optional<FlwInstance> findByBizForOapi(Long school, String type, String biz) {
-        return formalCommandEnabled
-                ? instanceRepository.findFirstBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdOrderByApplyRoundDesc(school, FlowOapiSourceScope.current(), type, biz)
-                : instanceRepository.findBySchIdAndBizTypeAndBizId(school, type, biz);
+        return instanceRepository.findFirstBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdOrderByApplyRoundDesc(
+                school, FlowOapiSourceScope.current(), type, biz);
     }
 
     private FlwInstance requireInstance(Long schId, Long instanceId) {
@@ -1356,12 +1322,16 @@ public class OapiFlowService {
             reg.setAppKey(appKey);
             reg.setFlowGuid(body.getFlowGuid());
         }
-        if (formalCommandEnabled) {
+        {
             FlowSourcePrincipalResolver.Principal source = sourcePrincipalResolver.resolve(appKey);
-            com.yunhai.flowcenter.entity.FlwUsageGrant grant = formalGrants.findBySchIdAndFlowGuidAndAppId(schId, body.getFlowGuid(), source.appId).orElse(null);
-            boolean permitted = grant != null && Integer.valueOf(1).equals(grant.getEnabled()) && source.id.equals(grant.getSourcePrincipalId());
-            if (!permitted && !formalCommands.existsBySchIdAndSourcePrincipalIdAndFlowGuidAndState(schId, source.id, body.getFlowGuid(), "ACCEPTED")) {
-                throw new BizException(ErrorCode.FORBIDDEN, "没有 SELF 订阅权限");
+            if (formalCommandEnabled) {
+                com.yunhai.flowcenter.entity.FlwUsageGrant grant = formalGrants.findBySchIdAndFlowGuidAndAppId(schId, body.getFlowGuid(), source.appId).orElse(null);
+                boolean permitted = grant != null && Integer.valueOf(1).equals(grant.getEnabled()) && source.id.equals(grant.getSourcePrincipalId());
+                if (!permitted && !formalCommands.existsBySchIdAndSourcePrincipalIdAndFlowGuidAndState(schId, source.id, body.getFlowGuid(), "ACCEPTED")) {
+                    throw new BizException(ErrorCode.FORBIDDEN, "没有 SELF 订阅权限");
+                }
+            } else {
+                requireUsageGrant(schId, body.getFlowGuid(), source);
             }
             reg.setSourcePrincipalId(source.id);
         }
diff --git a/src/main/java/com/yunhai/flowcenter/service/UserBaseActivationClient.java b/src/main/java/com/yunhai/flowcenter/service/UserBaseActivationClient.java
index a958b08..f33664f 100644
--- a/src/main/java/com/yunhai/flowcenter/service/UserBaseActivationClient.java
+++ b/src/main/java/com/yunhai/flowcenter/service/UserBaseActivationClient.java
@@ -29,7 +29,7 @@ public class UserBaseActivationClient {
     private final YschOpenCall openCall;
 
     /**
-     * 资格核验总开关（T01 灰度）：false=不核（存量环境兼容）；true=强制核验。
+     * 历史配置保留绑定；任何值均不能关闭学校开通校验。
      * 生产开启前须确认 UserBase 已部署 {@code /oapi/app/activated} 且开通数据齐备。
      */
     @Value("${yh.flow.school-activation-enforce:false}")
@@ -40,7 +40,7 @@ public class UserBaseActivationClient {
     }
 
     public boolean isEnforce() {
-        return enforce;
+        return true;
     }
 
     /**
@@ -48,15 +48,12 @@ public class UserBaseActivationClient {
      * @throws BizException enforce 开启且 UserBase 不可达/返回异常——fail-closed
      */
     public boolean isAppActivatedAtSchool(Integer appId, Long schoolId) {
-        if (!enforce) {
-            return true;
-        }
         return isAppActivatedStrict(appId, schoolId);
     }
 
     /** Formal commands never inherit the legacy bypass switch. */
     public boolean isAppActivatedStrict(Integer appId, Long schoolId) {
-        if (appId == null || schoolId == null || schoolId <= 0) {
+        if (appId == null || appId <= 0 || schoolId == null || schoolId <= 0) {
             throw new BizException(ErrorCode.UNAUTHORIZED, "应用学校开通资格核验缺少主体或校域");
         }
         if (openCall == null) {
@@ -76,6 +73,11 @@ public class UserBaseActivationClient {
             log.warn("[usage-grant] UserBase 开通资格核验返回异常 appId={} schoolId={}", appId, schoolId);
             throw new BizException(ErrorCode.UNAUTHORIZED, "应用学校开通资格核验不可用，请稍后重试");
         }
-        return data.path("activated").asBoolean(false);
+        if (!data.path("activated").isBoolean()
+                || !data.path("appId").isIntegralNumber() || data.path("appId").intValue() != appId
+                || !data.path("schoolId").isIntegralNumber() || data.path("schoolId").longValue() != schoolId) {
+            throw new BizException(ErrorCode.UNAUTHORIZED, "应用学校开通资格响应不匹配");
+        }
+        return data.path("activated").booleanValue();
     }
 }
diff --git a/src/main/resources/sql/20261028_f01_f02_source_unique.sql b/src/main/resources/sql/20261028_f01_f02_source_unique.sql
new file mode 100644
index 0000000..0ae186e
--- /dev/null
+++ b/src/main/resources/sql/20261028_f01_f02_source_unique.sql
@@ -0,0 +1,15 @@
+-- F01/F02. Apply only to the verified FL schema after reviewing SHOW INDEX.
+-- No grant INSERT, source backfill, instance deletion or other database changes.
+-- Preconditions: source_principal_id and legacy_slot already exist (302216a schema).
+-- If the older 3-column uk_flw_instance_biz also exists, it MUST be dropped separately
+-- after SHOW INDEX confirms its exact name; otherwise it still blocks distinct sources.
+ALTER TABLE flw_instance
+    DROP INDEX uk_flw_instance_legacy,
+    ADD UNIQUE KEY uk_flw_instance_legacy
+        (sch_id, source_principal_id, biz_type, biz_id, legacy_slot);
+-- Keep uk_flw_instance_round for the formal command path.
+-- Existing NULL-source rows are not reassigned or used as callers' receipts.
+-- Rollback: first stop new writers and check cross-source duplicate coordinates.
+-- Restoring the old index can FAIL once two sources have created identical coordinates.
+-- Never delete those rows to force rollback; restore a verified pre-change backup
+-- only under an explicitly approved FL-only recovery plan.
diff --git a/src/test/java/com/yunhai/flowcenter/service/FlApplyRecoveryTest.java b/src/test/java/com/yunhai/flowcenter/service/FlApplyRecoveryTest.java
index f08b6b2..f3ee1f4 100644
--- a/src/test/java/com/yunhai/flowcenter/service/FlApplyRecoveryTest.java
+++ b/src/test/java/com/yunhai/flowcenter/service/FlApplyRecoveryTest.java
@@ -51,6 +51,7 @@ import static org.mockito.Mockito.when;
 class FlApplyRecoveryTest {
 
     private static final long SCH = 1L;
+    private static final String SOURCE = "11111111-1111-1111-1111-111111111111";
     private static final String BIZ_TYPE = "svc-hall";
     private static final String BIZ_ID = "42";
     private static final String FLOW_GUID = "fg-1";
@@ -95,7 +96,7 @@ class FlApplyRecoveryTest {
     @DisplayName("同 requestToken 命中被拒(30)的办件：只回读现状，绝不重启推进")
     void sameTokenOnRejectedInstanceDoesNotRestart() {
         FlwInstance existing = instance(900L, FlwEnums.InstanceStatus.REJECTED.getCode(), TOKEN_A, 1, "100018");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(existing));
 
         FlowInstanceService.GuardedOutcome outcome =
@@ -112,7 +113,7 @@ class FlApplyRecoveryTest {
     @DisplayName("同 requestToken 命中在途(10)：同一条判定优先于幂等分支，回 SAME_REQUEST")
     void sameTokenOnApprovingInstanceIsSameRequest() {
         FlwInstance existing = instance(900L, FlwEnums.InstanceStatus.APPROVING.getCode(), TOKEN_A, 1, "100018");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(existing));
 
         assertThat(service.applyGuarded(cmd(TOKEN_A), policy(TOKEN_A, 1, false)).branch)
@@ -124,7 +125,7 @@ class FlApplyRecoveryTest {
     @DisplayName("retryOnly 命中终态(40)：恢复链补发也不重启（C.2 点名不把 30/40 当网络重试）")
     void retryOnlyNeverRestartsTerminal() {
         FlwInstance existing = instance(900L, FlwEnums.InstanceStatus.WITHDRAWN.getCode(), TOKEN_A, 1, "100018");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(existing));
 
         FlowInstanceService.GuardedOutcome outcome =
@@ -141,7 +142,7 @@ class FlApplyRecoveryTest {
         // T04（2026-10-25）改判：带 token 的请求撞在途/通过件且 token 不符 = 另一份命令 →
         // CONFLICT（不把他人命令的成功当自己的，审计 P0-2）；无 token 的存量调用方保持 IDEMPOTENT。
         FlwInstance approving = instance(900L, FlwEnums.InstanceStatus.APPROVING.getCode(), TOKEN_A, 1, "100018");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(approving));
         assertThat(service.applyGuarded(cmd(TOKEN_B), policy(TOKEN_B, 2, false)).branch)
                 .isEqualTo(FlowApplyRetryModels.Branch.CONFLICT);
@@ -161,7 +162,7 @@ class FlApplyRecoveryTest {
     void sameTokenDifferentPayloadIsConflict() {
         FlwInstance existing = instance(900L, FlwEnums.InstanceStatus.REJECTED.getCode(), TOKEN_A, 1, "100018");
         existing.setApplyPayloadHash("hash-a");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(existing));
 
         FlowInstanceService.ApplyCommand replay = cmd(TOKEN_A);
@@ -179,7 +180,7 @@ class FlApplyRecoveryTest {
     @DisplayName("expectedPrevRound 命中行轮次：服务端只分配 N+1，不信客户端 attempt（T04）")
     void serverAllocatesNextRoundFromExpectedPrev() {
         FlwInstance existing = instance(900L, FlwEnums.InstanceStatus.REJECTED.getCode(), TOKEN_A, 2, "100018");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(existing));
 
         // 客户端谎报 attempt=99：服务端按 expectedPrev=2 分配第 3 轮
@@ -189,7 +190,7 @@ class FlApplyRecoveryTest {
         assertThat(outcome.applyRound).isEqualTo(3);
 
         // expectedPrev 与行轮次不符：STALE_ROUND 不重启（restart 会原地改 token，这里换新实例）
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(
                         instance(901L, FlwEnums.InstanceStatus.REJECTED.getCode(), TOKEN_A, 2, "100018")));
         assertThat(service.applyGuarded(cmd(TOKEN_B),
@@ -204,7 +205,7 @@ class FlApplyRecoveryTest {
     @DisplayName("更高轮次 + 新 token 命中 30：才是新一轮授权重提，走既有 R4 重启并推进")
     void higherRoundRestartsPerExistingR4Semantics() {
         FlwInstance existing = instance(900L, FlwEnums.InstanceStatus.REJECTED.getCode(), TOKEN_A, 1, "100018");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(existing));
 
         FlowInstanceService.GuardedOutcome outcome =
@@ -224,7 +225,7 @@ class FlApplyRecoveryTest {
     @DisplayName("轮次不高于行上轮次：陈旧轮次迟到重投只回读，不重启")
     void staleRoundIsRejectedForRestart() {
         FlwInstance existing = instance(900L, FlwEnums.InstanceStatus.REJECTED.getCode(), TOKEN_A, 2, "100018");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(existing));
 
         assertThat(service.applyGuarded(cmd(TOKEN_B), policy(TOKEN_B, 2, false)).branch)
@@ -237,7 +238,7 @@ class FlApplyRecoveryTest {
     @DisplayName("存量行（apply_round 为 NULL）按第 1 轮处理：attempt=1 重投重启不了它")
     void legacyRowWithoutRoundDefaultsToGuarded() {
         FlwInstance legacy = instance(900L, FlwEnums.InstanceStatus.REJECTED.getCode(), null, null, "100018");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(legacy));
 
         assertThat(service.applyGuarded(cmd(TOKEN_B), policy(TOKEN_B, 1, false)).branch)
@@ -254,7 +255,7 @@ class FlApplyRecoveryTest {
     @DisplayName("别的应用同 bizType+bizId：拒绝，不把别人的办件 id 当自己的结果")
     void otherApplicationSameBizKeyIsRefused() {
         FlwInstance foreign = instance(900L, FlwEnums.InstanceStatus.APPROVING.getCode(), TOKEN_A, 1, "100020");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(foreign));
 
         assertThatThrownBy(() -> service.applyGuarded(cmd(TOKEN_B), policy(TOKEN_B, 1, false)))
@@ -267,14 +268,14 @@ class FlApplyRecoveryTest {
         FlwInstance otherSubmitter = instance(900L, FlwEnums.InstanceStatus.APPROVING.getCode(),
                 TOKEN_A, 1, "100018");
         otherSubmitter.setSubmitterId(2002);
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(otherSubmitter));
         assertThatThrownBy(() -> service.applyGuarded(cmd(TOKEN_B), policy(TOKEN_B, 1, false)))
                 .isInstanceOf(BizException.class).hasMessageContaining("提交者");
 
         FlwInstance otherFlow = instance(900L, FlwEnums.InstanceStatus.APPROVING.getCode(),
                 TOKEN_A, 1, "100018");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(otherFlow));
         when(defRepository.findById(anyLong())).thenReturn(Optional.of(def(2L, "fg-other", 1)));
         assertThatThrownBy(() -> service.applyGuarded(cmd(TOKEN_B), policy(TOKEN_B, 1, false)))
@@ -286,7 +287,7 @@ class FlApplyRecoveryTest {
     @Test
     @DisplayName("无既有实例：新建并落 token/轮次，走 START 推进（守卫不影响首发路径）")
     void createsWhenAbsentAndStampsIdentity() {
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.<FlwInstance>empty());
 
         FlowInstanceService.GuardedOutcome outcome =
@@ -307,7 +308,7 @@ class FlApplyRecoveryTest {
     void concurrentUkCollisionIsResolvedOutsideTransaction() {
         // 撞键路径由 OapiFlowService 在事务边界外收口；这里证服务层两步读到的结果自洽
         FlwInstance existing = instance(900L, FlwEnums.InstanceStatus.APPROVING.getCode(), TOKEN_A, 1, "100018");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.<FlwInstance>empty())
                 .thenReturn(Optional.of(existing));
         assertThat(service.applyGuarded(cmd(TOKEN_A), policy(TOKEN_A, 1, false)).branch)
@@ -321,23 +322,24 @@ class FlApplyRecoveryTest {
     }
 
     @Test
-    @DisplayName("旧 apply(cmd) 路径逐字不变：不写 token/轮次，30/40 仍按 R4 重启（存量兼容）")
-    void legacyApplyPathIsUnchanged() {
+    @DisplayName("旧 apply 同来源终态仍按 R4 重启，并记录服务端请求身份")
+    void legacyApplyRetainsRestartButStampsTrustedIdentity() {
         FlwInstance existing = instance(900L, FlwEnums.InstanceStatus.REJECTED.getCode(), null, null, "100018");
-        when(instanceRepository.findBySchIdAndBizTypeAndBizId(SCH, BIZ_TYPE, BIZ_ID))
+        when(instanceRepository.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(SCH, SOURCE, BIZ_TYPE, BIZ_ID, 1))
                 .thenReturn(Optional.of(existing));
 
         FlowInstanceService.ApplyOutcome outcome = service.apply(cmd(null));
 
         assertThat(outcome.isDuplicated()).isTrue();
         assertThat(existing.getStatus()).isEqualTo(FlwEnums.InstanceStatus.APPROVING.getCode());
-        assertThat(existing.getApplyRequestToken()).isNull();
+        assertThat(existing.getApplyRequestToken()).isNotBlank();
         assertThat(existing.getApplyRound()).isNull();
     }
 
     @Test
     void callbackIdentityIsFrozenBeforeCommitAndNeverRelabelsOldEvent() throws Exception {
         FlwInstance row = instance(900L, 30, TOKEN_A, 1, "100018");
+        row.setSourcePrincipalId(null); // This existing test exercises the legacy callback fixture, not source admission.
         row.setVersion(3);
         when(instanceRepository.findById(900L)).thenReturn(Optional.of(row));
         com.yunhai.flowcenter.engine.FlowEvent event = com.yunhai.flowcenter.engine.FlowEvent.of(
@@ -370,9 +372,11 @@ class FlApplyRecoveryTest {
 
     /** 提交者恒 1001、调用应用恒 100018；不符的一侧都在被测行上构造 */
     private FlowInstanceService.ApplyCommand cmd(String token) {
-        return new FlowInstanceService.ApplyCommand(SCH, def(1L, FLOW_GUID, 3), BIZ_TYPE, BIZ_ID,
+        FlowInstanceService.ApplyCommand command = new FlowInstanceService.ApplyCommand(SCH, def(1L, FLOW_GUID, 3), BIZ_TYPE, BIZ_ID,
                 "张三的测试事项", "/svc-hall/apply-detail?id=42", "{}", 1001,
                 "张三", "{}", "100018", "svc-hall", null);
+        command.sourcePrincipalId = SOURCE;
+        return command;
     }
 
     private FlowInstanceService.ApplyRetryPolicy policy(String token, Integer attempt, boolean retryOnly) {
@@ -403,6 +407,7 @@ class FlApplyRecoveryTest {
         instance.setBizId(BIZ_ID);
         instance.setStatus(status);
         instance.setApplyAppKey(appKey);
+        instance.setSourcePrincipalId("100020".equals(appKey) ? "22222222-2222-2222-2222-222222222222" : SOURCE);
         instance.setApplyRequestToken(token);
         instance.setApplyRound(round);
         instance.setSubmitterId(1001);
diff --git a/src/test/java/com/yunhai/flowcenter/service/FlDefLineOfflineTest.java b/src/test/java/com/yunhai/flowcenter/service/FlDefLineOfflineTest.java
index 3cff9e9..fb97fd8 100644
--- a/src/test/java/com/yunhai/flowcenter/service/FlDefLineOfflineTest.java
+++ b/src/test/java/com/yunhai/flowcenter/service/FlDefLineOfflineTest.java
@@ -76,6 +76,11 @@ class FlDefLineOfflineTest {
                 mock(FlowEngine.class), mock(AssigneeResolver.class), new ObjectMapper(),
                 mock(OpenApiUserClient.class), mock(OpenApiAppClient.class),
                 mock(DiagramTokenService.class), mock(ObjectProvider.class));
+        FlowSourcePrincipalResolver resolver = mock(FlowSourcePrincipalResolver.class);
+        when(resolver.resolve(anyString())).thenReturn(new FlowSourcePrincipalResolver.Principal(
+                "11111111-1111-1111-1111-111111111111", 1, "100018", "test"));
+        ReflectionTestUtils.setField(oapiService, "sourcePrincipalResolver", resolver);
+        oapiService.setUsageGrantGuard(mock(FlowUsageGrantGuard.class));
         when(defRepository.findFirstBySchIdAndFlowGuidOrderByVersionDesc(eq(SCH), eq(GUID)))
                 .thenReturn(Optional.of(def(9, 3, 0)));
     }
diff --git a/src/test/java/com/yunhai/flowcenter/service/FlNewInstancePathTest.java b/src/test/java/com/yunhai/flowcenter/service/FlNewInstancePathTest.java
index 0c35bb7..1ebf951 100644
--- a/src/test/java/com/yunhai/flowcenter/service/FlNewInstancePathTest.java
+++ b/src/test/java/com/yunhai/flowcenter/service/FlNewInstancePathTest.java
@@ -81,6 +81,7 @@ class FlNewInstancePathTest {
         FlowInstanceService.ApplyCommand command = new FlowInstanceService.ApplyCommand(
                 1L, def, "test", "fresh-20261027", "Fresh", "/test", "{}", 101, "Applicant",
                 null, "100001", "notice", null);
+        command.sourcePrincipalId = "11111111-1111-1111-1111-111111111111";
         FlowInstanceService.GuardedOutcome outcome = apply.applyGuarded(command,
                 new FlowInstanceService.ApplyRetryPolicy("fresh-token", 1, false));
         assertThat(outcome.duplicated).isFalse();
diff --git a/src/test/java/com/yunhai/flowcenter/service/FlSourceAuthorizationTest.java b/src/test/java/com/yunhai/flowcenter/service/FlSourceAuthorizationTest.java
new file mode 100644
index 0000000..a3a6687
--- /dev/null
+++ b/src/test/java/com/yunhai/flowcenter/service/FlSourceAuthorizationTest.java
@@ -0,0 +1,183 @@
+package com.yunhai.flowcenter.service;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.yunhai.flowcenter.engine.*;
+import com.yunhai.flowcenter.entity.*;
+import com.yunhai.flowcenter.model.*;
+import com.yunhai.flowcenter.repository.*;
+import com.yunhai.platform.apistd.BizException;
+import com.yunhai.platform.openapi.base.*;
+import com.yunhai.platform.openapi.core.YschOpenCall;
+import org.junit.jupiter.api.*;
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.dao.DataIntegrityViolationException;
+import org.springframework.test.util.ReflectionTestUtils;
+import java.util.*;
+import java.util.concurrent.atomic.AtomicLong;
+import static org.assertj.core.api.Assertions.*;
+import static org.mockito.Mockito.*;
+import static org.mockito.ArgumentMatchers.*;
+
+/** Real OAPI, source resolver, authorization, activation client and instance service.
+ * Only repositories, outbound UserBase transport, people resolver and engine are mocks.
+ * No real DB/transaction/unique-index claim. */
+class FlSourceAuthorizationTest {
+    static final String A="11111111-1111-1111-1111-111111111111";
+    static final String B="22222222-2222-2222-2222-222222222222";
+    final ObjectMapper mapper=new ObjectMapper();
+    FlwInstanceRepository instances; FlwDefRepository defs; FlwUsageGrantRepository grants;
+    FlwTaskRepository tasks; FlwBranchRepository branches;
+    OpenApiAppClient apps; YschOpenCall outbound; UserBaseActivationClient activation;
+    ApplicationEventPublisher publisher; FlowEngine engine; FlowUsageGrantGuard guard;
+    FlowInstanceService lifecycle; OapiFlowService api; FlwDef def;
+    Map<String,FlwInstance> rows;
+    @BeforeEach void setup() throws Exception {
+        instances=mock(FlwInstanceRepository.class);defs=mock(FlwDefRepository.class);
+        grants=mock(FlwUsageGrantRepository.class);tasks=mock(FlwTaskRepository.class);branches=mock(FlwBranchRepository.class);
+        apps=mock(OpenApiAppClient.class);outbound=mock(YschOpenCall.class);
+        activation=new UserBaseActivationClient(outbound);
+        // Even an explicitly false legacy value cannot disable either gate.
+        ReflectionTestUtils.setField(activation,"enforce",false);
+        guard=new FlowUsageGrantGuard(grants,activation);ReflectionTestUtils.setField(guard,"appClient",apps);
+        when(apps.getAppByKey(anyString())).thenAnswer(c -> mapper.readTree("{\"id\":"+("app-b".equals(c.getArgument(0))?2:1)+",\"sourcePrincipalId\":\""+("app-b".equals(c.getArgument(0))?B:A)+"\",\"appCode\":\"test\"}"));
+        when(outbound.get(anyString(),anyString(),anyMap(),any())).thenAnswer(c -> {
+            Map<String,String> q=c.getArgument(2);
+            return mapper.readTree("{\"appId\":"+q.get("appId")+",\"schoolId\":"+q.get("schoolId")+",\"activated\":true}");
+        });
+        when(grants.findBySchIdAndFlowGuidAndAppId(eq(27L),eq("flow"),anyInt())).thenAnswer(c -> {
+            int id=c.getArgument(2);FlwUsageGrant g=new FlwUsageGrant();g.setAppId(id);g.setSchId(27L);g.setFlowGuid("flow");g.setEnabled(1);g.setSourcePrincipalId(id==1?A:B);return Optional.of(g);
+        });
+        def=new FlwDef();def.setId(7L);def.setSchId(27L);def.setFlowGuid("flow");def.setCode("test");def.setVersion(1);def.setStatus(1);def.setContentJson("{\"nodes\":[],\"edges\":[]}");
+        when(defs.findById(7L)).thenReturn(Optional.of(def));
+        when(defs.findFirstBySchIdAndFlowGuidAndStatusOrderByVersionDesc(27L,"flow",1)).thenReturn(Optional.of(def));
+        engine=mock(FlowEngine.class);publisher=mock(ApplicationEventPublisher.class);
+        when(engine.parseModel(any())).thenReturn(FlowDefModel.parse(mapper,def.getContentJson()));
+        lifecycle=new FlowInstanceService(instances,defs,tasks,branches,engine,publisher);
+        api=new OapiFlowService(defs,instances,tasks,mock(FlwCcRepository.class),mock(FlwCallbackRegRepository.class),lifecycle,mock(FlowTaskService.class),engine,mock(AssigneeResolver.class),mapper,mock(OpenApiUserClient.class),apps,mock(DiagramTokenService.class),mock(ObjectProvider.class));
+        api.setUsageGrantGuard(guard);
+        ReflectionTestUtils.setField(api,"sourcePrincipalResolver",new FlowSourcePrincipalResolver(apps));
+        rows=new HashMap<>();AtomicLong seq=new AtomicLong(100);
+        when(instances.findBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdAndLegacySlot(anyLong(),anyString(),anyString(),anyString(),eq(1)))
+                .thenAnswer(c -> Optional.ofNullable(rows.get(c.getArgument(1))));
+        when(instances.saveAndFlush(any())).thenAnswer(c -> {FlwInstance i=c.getArgument(0);if(i.getId()==null)i.setId(seq.incrementAndGet());rows.put(i.getSourcePrincipalId(),i);return i;});
+        when(instances.findById(anyLong())).thenAnswer(c -> rows.values().stream().filter(i -> i.getId().equals(c.getArgument(0))).findFirst());
+        when(instances.findFirstBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdOrderByApplyRoundDesc(anyLong(),anyString(),anyString(),anyString()))
+                .thenAnswer(c -> Optional.ofNullable(rows.get(c.getArgument(1))));
+    }
+    OapiModels.ApplyBody body() {
+        OapiModels.ApplyBody r=new OapiModels.ApplyBody();r.setFlowGuid("flow");r.setBizType("type");r.setBizId("same-id");r.setSubmitterId(5);return r;
+    }
+    FlowApplyRetryModels.ApplyRequestV2 v2(String token) {
+        FlowApplyRetryModels.ApplyRequestV2 r=new FlowApplyRetryModels.ApplyRequestV2();r.setFlowGuid("flow");r.setBizType("type");r.setBizId("same-id");r.setSubmitterId(5);r.setRequestToken(token);r.setAttempt(1);return r;
+    }
+    void noWrites() {verify(instances,never()).saveAndFlush(any());verifyNoInteractions(tasks,branches,engine,publisher);}
+    @Test void bothGatesRequiredAndSameSourceIsIdempotent() {
+        long a=api.apply(27L,"app-a",body()).getInstanceId();
+        assertThat(api.apply(27L,"app-a",body()).getInstanceId()).isEqualTo(a);
+        assertThat(rows).hasSize(1);verify(engine,times(1)).startAdvance(any(),any());
+        assertThat(rows.get(A).getSourcePrincipalId()).isEqualTo(A);
+    }
+    @Test void distinctSourcesCreateIndependentInstancesAndNeverRestartOthers() {
+        long a=api.apply(27L,"app-a",body()).getInstanceId();rows.get(A).setStatus(30);
+        long b=api.apply(27L,"app-b",body()).getInstanceId();
+        assertThat(b).isNotEqualTo(a);assertThat(rows.get(A).getStatus()).isEqualTo(30);
+        assertThat(rows).hasSize(2);
+        assertThat(api.apply(27L,"app-a",body()).getInstanceId()).isEqualTo(a);
+        assertThat(rows.get(A).getStatus()).isEqualTo(10);
+        assertThat(rows.get(B).getId()).isEqualTo(b);
+        verify(instances,never()).findBySchIdAndBizTypeAndBizId(anyLong(),anyString(),anyString());
+    }
+    @Test void missingGrantRejectsWithoutAnySideEffects() {
+        when(grants.findBySchIdAndFlowGuidAndAppId(anyLong(),anyString(),anyInt())).thenReturn(Optional.empty());
+        assertThatThrownBy(() -> api.apply(27L,"app-a",body())).isInstanceOf(BizException.class);noWrites();
+    }
+    @Test void inactiveOrRevokedSchoolRejectsEvenWithGrant() throws Exception {
+        when(outbound.get(anyString(),anyString(),anyMap(),any())).thenReturn(mapper.readTree("{\"appId\":1,\"schoolId\":27,\"activated\":false}"));
+        assertThatThrownBy(() -> api.apply(27L,"app-a",body())).isInstanceOf(BizException.class);noWrites();
+    }
+    @Test void unavailableAuthorityRejects() {
+        when(outbound.get(anyString(),anyString(),anyMap(),any())).thenThrow(new RuntimeException("offline"));
+        assertThatThrownBy(() -> api.apply(27L,"app-a",body())).isInstanceOf(BizException.class);noWrites();
+    }
+    @Test void malformedAuthorityResponseRejects() throws Exception {
+        when(outbound.get(anyString(),anyString(),anyMap(),any())).thenReturn(mapper.readTree("{\"appId\":2,\"schoolId\":27,\"activated\":true}"));
+        assertThatThrownBy(() -> api.apply(27L,"app-a",body())).isInstanceOf(BizException.class);noWrites();
+    }
+    @Test void missingSchoolSourceOrGuardRejects() {
+        assertThatThrownBy(() -> api.apply(null,"app-a",body())).isInstanceOf(BizException.class);
+        assertThatThrownBy(() -> api.apply(0L,"app-a",body())).isInstanceOf(BizException.class);
+        assertThatThrownBy(() -> api.apply(27L,null,body())).isInstanceOf(BizException.class);
+        api.setUsageGrantGuard(null);
+        assertThatThrownBy(() -> api.apply(27L,"app-a",body())).isInstanceOf(BizException.class);noWrites();
+    }
+    @Test void sourceLookupUnavailableOrUnknownRejects() throws Exception {
+        when(apps.getAppByKey("app-a")).thenReturn(mapper.readTree("{\"id\":1}"));
+        assertThatThrownBy(() -> api.apply(27L,"app-a",body())).isInstanceOf(BizException.class);
+        when(apps.getAppByKey("app-a")).thenThrow(new RuntimeException("offline"));
+        assertThatThrownBy(() -> api.apply(27L,"app-a",body())).isInstanceOf(BizException.class);noWrites();
+    }
+    @Test void mismatchedGrantSourceRejects() {
+        FlwUsageGrant g=new FlwUsageGrant();g.setEnabled(1);g.setSourcePrincipalId(B);
+        when(grants.findBySchIdAndFlowGuidAndAppId(anyLong(),anyString(),anyInt())).thenReturn(Optional.of(g));
+        assertThatThrownBy(() -> api.apply(27L,"app-a",body())).isInstanceOf(BizException.class);noWrites();
+    }
+    @Test void v2ExactReceiptSurvivesRevocationButNewCommandDoesNot() {
+        long id=api.applyV2(27L,"app-a",v2("token-1")).getInstanceId();
+        when(grants.findBySchIdAndFlowGuidAndAppId(anyLong(),anyString(),anyInt())).thenReturn(Optional.empty());
+        assertThat(api.applyV2(27L,"app-a",v2("token-1")).getInstanceId()).isEqualTo(id);
+        assertThatThrownBy(() -> api.applyV2(27L,"app-a",v2("new-token"))).isInstanceOf(BizException.class);
+        assertThatThrownBy(() -> api.applyV2(27L,"app-b",v2("token-1"))).isInstanceOf(BizException.class);
+    }
+    @Test void v2IndependentSourcesAndConflictRetryUseScopedLookup() {
+        long a=api.applyV2(27L,"app-a",v2("a-token")).getInstanceId();
+        long b=api.applyV2(27L,"app-b",v2("b-token")).getInstanceId();assertThat(a).isNotEqualTo(b);
+        verify(instances,never()).findBySchIdAndBizTypeAndBizId(anyLong(),anyString(),anyString());
+    }
+    @Test void v1ConflictRecoveryCannotReturnOtherSourcesRow() {
+        long a=api.apply(27L,"app-a",body()).getInstanceId();
+        doAnswer(new org.mockito.stubbing.Answer<FlwInstance>() {boolean first=true;public FlwInstance answer(org.mockito.invocation.InvocationOnMock c) {
+            if(first){first=false;throw new DataIntegrityViolationException("race");}FlwInstance i=c.getArgument(0);i.setId(999L);rows.put(i.getSourcePrincipalId(),i);return i;
+        }}).when(instances).saveAndFlush(any());
+        assertThat(api.apply(27L,"app-b",body()).getInstanceId()).isNotEqualTo(a);
+    }
+    @Test void otherSchoolOrFlowCannotUseGrant() {
+        assertThatThrownBy(() -> api.apply(28L,"app-a",body())).isInstanceOf(BizException.class);
+        OapiModels.ApplyBody r=body();r.setFlowGuid("not-granted");
+        assertThatThrownBy(() -> api.apply(27L,"app-a",r)).isInstanceOf(BizException.class);noWrites();
+    }
+    @Test void v2ConflictRetryNeverRecoversAnotherSource() {
+        long a=api.applyV2(27L,"app-a",v2("a-token")).getInstanceId();
+        doAnswer(new org.mockito.stubbing.Answer<FlwInstance>() {boolean first=true;public FlwInstance answer(org.mockito.invocation.InvocationOnMock c) {
+            if(first){first=false;throw new DataIntegrityViolationException("race");}FlwInstance i=c.getArgument(0);i.setId(999L);rows.put(i.getSourcePrincipalId(),i);return i;
+        }}).when(instances).saveAndFlush(any());
+        FlowApplyRetryModels.ApplyResultV2 result=api.applyV2(27L,"app-b",v2("b-token"));
+        assertThat(result.getInstanceId()).isNotEqualTo(a);
+        assertThat(result.isDuplicated()).isFalse();
+    }
+    @Test void businessReadsAndExplicitInstanceAccessAreSourceScopedEvenWithFormalModeOff() throws Exception {
+        long a=api.apply(27L,"app-a",body()).getInstanceId();
+        long b=api.apply(27L,"app-b",body()).getInstanceId();
+        FlowOapiSourceScope scope=new FlowOapiSourceScope(new FlowSourcePrincipalResolver(apps),instances,tasks);
+        org.springframework.mock.web.MockHttpServletRequest req=new org.springframework.mock.web.MockHttpServletRequest("GET","/oapi/flow/instance");
+        req.setAttribute("yh.app.auth","app-b");
+        scope.preHandle(req,new org.springframework.mock.web.MockHttpServletResponse(),new Object());
+        org.springframework.web.context.request.RequestContextHolder.setRequestAttributes(new org.springframework.web.context.request.ServletRequestAttributes(req));
+        try {assertThat(api.instanceByBiz(27L,"type","same-id").getInstanceId()).isEqualTo(b);}
+        finally {org.springframework.web.context.request.RequestContextHolder.resetRequestAttributes();}
+        req.setParameter("instanceId",String.valueOf(a));
+        assertThatThrownBy(() -> scope.preHandle(req,new org.springframework.mock.web.MockHttpServletResponse(),new Object())).isInstanceOf(BizException.class);
+    }
+    @Test void v1UsesExistingCallbackIdentityFieldsWithoutChangingEnvelopeContract() {
+        api.apply(27L,"app-a",body());
+        assertThat(rows.get(A).getApplyRequestToken()).isNotBlank();
+        assertThat(rows.get(A).getApplyPayloadHash()).hasSize(64);
+        assertThat(rows.get(A).getApplyRound()).isEqualTo(1);
+    }
+    @Test void legacyWriterCannotDuplicateAnExistingFormalCoordinate() {
+        FlwInstance formal=new FlwInstance();formal.setId(99L);formal.setSourcePrincipalId(A);formal.setLegacySlot(null);
+        when(instances.findFirstBySchIdAndSourcePrincipalIdAndBizTypeAndBizIdOrderByApplyRoundDesc(27L,A,"type","same-id"))
+                .thenReturn(Optional.of(formal));
+        assertThatThrownBy(() -> api.apply(27L,"app-a",body())).isInstanceOf(BizException.class);noWrites();
+    }
+}
diff --git a/src/test/java/com/yunhai/flowcenter/service/FlUsageGrantTest.java b/src/test/java/com/yunhai/flowcenter/service/FlUsageGrantTest.java
index b0437ae..f0bf0f5 100644
--- a/src/test/java/com/yunhai/flowcenter/service/FlUsageGrantTest.java
+++ b/src/test/java/com/yunhai/flowcenter/service/FlUsageGrantTest.java
@@ -70,11 +70,11 @@ class FlUsageGrantTest {
     // ==================== Guard：新发起资格 ====================
 
     @Test
-    @DisplayName("enforce 关闭：直通且不出站（灰度期存量行为不变）")
-    void enforceOffPassesThrough() {
+    @DisplayName("enforce 关闭仍不得绕过授权")
+    void enforceOffCannotBypassAuthorization() {
         ReflectionTestUtils.setField(activationClient, "enforce", false);
 
-        assertThat(guard.requireNewApplyGrant(SCH, FLOW, APP_KEY)).isNull();
+        assertThatThrownBy(() -> guard.requireNewApplyGrant(SCH, FLOW, APP_KEY)).isInstanceOf(BizException.class);
         verify(grantRepository, never()).findBySchIdAndFlowGuidAndAppId(anyLong(), anyString(), anyInt());
     }
 
@@ -195,6 +195,7 @@ class FlUsageGrantTest {
         when(appClient.getAppByKey(APP_KEY)).thenReturn(registration(5001));
         when(grantRepository.findBySchIdAndFlowGuidAndAppId(SCH, FLOW, 5001)).thenReturn(Optional.empty());
         when(grantRepository.save(any())).thenAnswer(c -> c.getArgument(0));
+        stubActivation(5001, true);
 
         FlwUsageGrant saved = admin.grant(SCH, FLOW, APP_KEY, "首次授权", "admin");
 
@@ -224,6 +225,7 @@ class FlUsageGrantTest {
     private JsonNode registration(int appId) {
         Map<String, Object> row = new HashMap<>();
         row.put("id", appId);
+        row.put("sourcePrincipalId", "11111111-1111-1111-1111-111111111111");
         row.put("appKey", APP_KEY);
         row.put("appName", "测试应用");
         return mapper.valueToTree(row);
@@ -246,6 +248,7 @@ class FlUsageGrantTest {
         g.setAppId(appId);
         g.setAppKeySnapshot(APP_KEY);
         g.setEnabled(enabled);
+        g.setSourcePrincipalId("11111111-1111-1111-1111-111111111111");
         return g;
     }