using-archipy-models

A set of rules for organising ArchiPy data models, including database entities, data-transfer objects, types, and domain errors. Data-transfer objects carry structured data between parts of an application.

In plain words
What is it for?
Choosing model folders, naming input and output DTOs, defining repository commands and queries, and creating ArchiPy-based errors.
Why use it?
It keeps data structures separate from input/output work and business rules, making service boundaries and model names consistent.

Cursor rule

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/syntaxarc/archipy-plugin/using-archipy-models
Clone the repo
git clone --depth 1 https://github.com/SyntaxArc/archipy-plugin
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 447 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00447
Opus 5 $0.00000 $0.00224
Sonnet 5 $0.00000 $0.00089
Haiku 4.5 $0.00000 $0.00045

Measured yesterday against content hash 6a960b6599d7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

using-archipy-models scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

rules/using-archipy-models.mdc · 49 lines

What it actually says

Using ArchiPy Models

Data structures only — no I/O, no business rules.

Live: https://syntaxarc.github.io/ArchiPy/getting-started/project_structure/

Layout

models/
├── entities/                 # SQLAlchemy BaseEntity subclasses
├── errors/                   # Domain errors extending ArchiPy BaseError hierarchy
├── types/                    # Optional enums / aliases
└── dtos/{domain}/
    ├── domain/v{n}/          # Versioned — cross service boundary
    └── repository/           # Internal — never versioned

DTO Naming

Kind Pattern Example
Domain input {Op}InputDTO UserRegistrationInputDTO
Domain output {Op}OutputDTO UserRegistrationOutputDTO
Repository command {Action}CommandDTO CreateUserCommandDTO
Repository query {Action}QueryDTO GetUserByIdQueryDTO
Repository response {Domain}ResponseDTO UserResponseDTO

DTOs use Pydantic BaseModel. Prefer ArchiPy base entities where applicable.

Errors

  • Subclass ArchiPy errors from archipy.models.errors (e.g. AlreadyExistsError, NotFoundError).
  • Raise with context: raise NotFoundError(...) from e.
  • Never raise bare Exception for domain failures.
  • With AppUtils.create_fastapi_app exception handlers, ArchiPy errors map to HTTP status automatically — see https://syntaxarc.github.io/ArchiPy/tutorials/error_handling/

Do Not

  • Put adapters, DB sessions, or HTTP/gRPC types in models.
  • Version repository DTOs.
  • Import repositories, logics, or services from models.
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 49 lines · 447 tokens per session scan A 6a960b6599d7

Subscribe to this mod's changes

using-archipy-models is a cursor rule published in the GitHub repository SyntaxArc/archipy-plugin (2 stars, last pushed 8d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 447 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.