Experiment 5-12: Permission-Embedded Data Objects / 实验 5-12：权限内嵌的数据对象（★★★）¶

This project is the implementation companion for the dynamic software discussion in Chapter 5. It is adapted from the PermissionEmbeddedDataObjects prototype: the implementation code, scenarios, tests, and the targeted generated-code evaluator are included here; the paper, PDF, website, and large result files are intentionally left out.

English¶

Goal¶

Show how an application whose business code may be generated or rewritten by an Agent can still enforce authorization and data integrity. The experiment makes the application layer deliberately small: generated code calls a stable object store, while permissions, validators, relationships, and consequences are declared with the data type and checked by the store on every operation.

The deterministic demo exercises three cases:

a valid hiring-pipeline update is accepted;
generated code that skips a candidate status transition or writes an out-of-range salary is rejected by the data-layer validator;
a cross-tenant read is rejected by the permission boundary.

Technical plan¶

The prototype is a Python middleware layer over PostgreSQL:

pedo/core/models.py defines DataObject, ObjectType, PermissionRule, AccessContext, relationships, and reaction declarations;
pedo/core/store.py implements the three-tier pipeline: synchronous permission checks and validators, persistence and referential-integrity mechanics, then asynchronous reactions with a bounded depth;
pedo/scenarios/ registers realistic hiring, project-management, and other multi-tenant schemas with state machines and cross-object validators;
run_targeted_eval.py is an optional live comparison that asks models to generate code for raw SQL and PEDO APIs on adversarial prompts, then checks the resulting database state.

The key comparison is not whether the generated handler contains a correct if statement. It is whether the same request is accepted or rejected when it reaches the stable data layer. The generated layer receives a scoped AccessContext; it does not receive a privileged database connection.

Run the deterministic demo¶

PostgreSQL must be running and the database named by PEDO_DSN must be reachable. The default is dbname=pedo_test.

cd chapter5/permission-embedded-data-objects
python -m pip install -r requirements.txt
createdb pedo_test                 # if the database does not exist yet
python demo.py
pytest -q

Use another connection string with, for example, PEDO_DSN='dbname=pedo_test host=localhost user=postgres'.

The optional live evaluator needs provider SDKs and credentials in addition to the core requirements:

python -m pip install anthropic openai
DATAGUARDBENCH_DSN="$PEDO_DSN" python run_targeted_eval.py

Run that evaluator only in an isolated test database. It executes model- generated code by design and is not a production security boundary.

中文¶

实验目标¶

验证业务代码可以动态生成或重写时，系统仍能保证权限和数据完整性。实验把应用层故意做得很薄：生成的代码只调用稳定的对象存储接口；权限规则、校验器、对象关系和后果声明附着在数据类型上，由对象存储在每次操作时统一检查。

确定性演示包含三类操作：合法的招聘流程更新应当成功；跳过候选人状态机或写入超出职位范围的工资应由数据层拒绝；跨租户读取应由权限边界拒绝。

技术方案¶

项目是运行在 PostgreSQL 之上的 Python 中间层。models.py 定义数据对象、对象类型、权限规则和访问上下文；store.py 实现三层流水线：同步执行权限检查与校验器，完成持久化和引用完整性处理，再以受控深度异步执行 reactions（后果反应）。scenarios/ 提供招聘、项目管理等带状态机、跨对象校验和多租户隔离的示例 schema。run_targeted_eval.py 则是可选的在线评测：让模型分别为裸 SQL 和 PEDO 接口生成代码，再用对抗性请求检查最终数据库状态。

这个实验关注的不是生成的 handler 有没有写出一条正确的 if，而是同一请求到达稳定数据层后能否被可靠接受或拒绝。生成代码只能携带受限的 AccessContext，不能拿到可绕过规则的高权限数据库连接。

运行¶

先启动 PostgreSQL，并准备 pedo_test 数据库，然后执行：

cd chapter5/permission-embedded-data-objects
python -m pip install -r requirements.txt
createdb pedo_test
python demo.py
pytest -q

可通过 PEDO_DSN 指定其他 PostgreSQL 连接串。在线评测还需要安装 anthropic、openai 并配置对应的 API 凭证；它会在隔离测试库中执行模型生成的代码，不应直接指向生产数据库。

文件¶

demo.py：无需调用 LLM 的确定性演示；
pedo/core/：权限内嵌对象模型和三层对象存储；
pedo/scenarios/：招聘、项目管理及其他多租户场景；
tests/：核心权限、校验、租户隔离和反应机制测试；
run_targeted_eval.py：可选的 Agent 生成代码安全对照评测。