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.
npx agentmods add rules/first-fluke/fullstack-starter/backendgit clone --depth 1 https://github.com/first-fluke/fullstack-starterWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/rules/first-fluke/fullstack-starter/backend)<a href="https://agentmods.dev/rules/first-fluke/fullstack-starter/backend"><img src="https://agentmods.dev/badge/rules/first-fluke/fullstack-starter/backend.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00015 | $0.00485 |
| Opus 5 | $0.00008 | $0.00243 |
| Sonnet 5 | $0.00003 | $0.00097 |
| Haiku 4.5 | $0.00002 | $0.00049 |
Grade A, and why
backend 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 today.
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.
How it starts
The opening of the file, as written. The whole thing — 39 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Backend Coding Standards
Core Rules
- Clean architecture: router -> service -> repository -> models
- No business logic in route handlers
- All inputs validated with your stack's validation library
- Parameterized queries only (never string interpolation)
- JWT + Argon2id for auth (bcrypt acceptable for legacy compatibility); rate limit auth endpoints
- Async where supported; type annotations on all signatures
- Custom exceptions via centralized error module (not raw HTTP exceptions)
- Explicit ORM loading strategy: do not rely on default relation loading when query shape matters
- Explicit transaction boundaries: group one business operation into one request/service-scoped unit of work
- Safe ORM lifecycle: do not share mutable ORM session/entity manager across concurrent work unless ORM explicitly supports it
- Config from environment, with graceful fallback: DB URLs, API keys, secrets from env vars or secret managers, never hardcode. When integrating a third-party API (OpenAI, Anthropic, Stripe, etc.), write BOTH paths: (a) real call when
process.env.<KEY>is present, (b) deterministic local fallback when absent. Mark the deferred branch with// TODO(oma-deferred): integrate <vendor> when key is provisioned. Shipping only the fallback (no env-conditional branch) leaves the spec unmet; shipping only the real call without fallback breaks demos when the key is missing. - Stateless services: no in-memory session or user state between requests — use external stores
- Backing services as resources: DB, queue, cache are swappable resources connected via config
Architecture
Router (HTTP) → Service (Business Logic) → Repository (Data Access) → Models
Principles
- DRY: Business logic in Service, data access in Repository
- Single Responsibility: Classes and functions should have one responsibility
- Dependency Inversion: Use your framework's DI mechanism
- KISS: Keep it simple and clear
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.
- today First seen · 39 lines · 15 tokens per session scan A bc88ca227b8a
backend is a cursor rule published in the GitHub repository first-fluke/fullstack-starter (222 stars, last pushed 3d ago), licensed MIT. It adds 15 tokens to every session and 485 once invoked, about $0.0001 per session on Opus 5. 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 2026-09-03.
Other cursor rules, from other repositories
avoid_source_deduplication
name: avoid-source-deduplication description: Preserve unique source entries in search results to maintain proper citation tracking globs: ['/connectorservice.py', '/searchservice.py'] alwaysApply: true.
consistent_container_image_sources
name: consistent-container-image-sources description: Maintain consistent image sources in Docker compose files using authorized registries globs: ['/docker-compose.yml', '/docker-compose..yml'] alwaysApply: true.
no_env_files_in_repo
name: no-env-files-in-repo description: Prevent committing environment and configuration files containing sensitive credentials globs: ['/.env', '/.env.', '/config/.yml', '/config/.yaml'] alwaysApply: true.
require_unique_id_props
name: require-unique-id-props description: Ensure unique key props are provided when mapping arrays to React elements globs: ['/.tsx', '/.jsx'] alwaysApply: true.
cursorrules
use pnpm as default package manager.
cursorrules
Cursor rule "cursorrules" from sseshachala/conductai, covering conductguard policy and agent booster — context-efficient reads.