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/luxvil/ai-coding-rules/91-api-routesgit clone --depth 1 https://github.com/Luxvil/ai-coding-rulesWhat 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 | $0.00000 | $0.00819 |
| Opus 5 | $0.00000 | $0.00409 |
| Sonnet 5 | $0.00000 | $0.00164 |
| Haiku 4.5 | $0.00000 | $0.00082 |
Grade A, and why
91-api-routes 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 2d ago.
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.
This is a copy
100% identical to 91-api-routes — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.
🔌 API Routes Rules
Auto-activated for files in
/api/or/routes/directories.
Route Structure
api/
├── users/
│ ├── route.ts # Next.js App Router
│ ├── [id]/route.ts # Dynamic route
│ └── schema.ts # Zod validation
├── middleware.ts # Auth, rate limiting
└── types.ts # Shared types
Rules
1. Input Validation (STRICT)
// ✅ ALWAYS validate all inputs
import { z } from 'zod';
const CreateUserSchema = z.object({
email: z.string().email(),
name: z.string().min(2).max(100),
age: z.number().int().positive().optional(),
});
export async function POST(request: Request) {
const body = await request.json();
const result = CreateUserSchema.safeParse(body);
if (!result.success) {
return Response.json({ error: result.error.flatten() }, { status: 400 });
}
// Use result.data (validated)
}
2. Error Handling (STRICT)
// ✅ Consistent error envelope
interface ApiResponse<T> {
data?: T;
error?: {
code: string;
message: string;
details?: unknown;
};
}
// ✅ Proper status codes
// 200 - Success
// 201 - Created
// 400 - Bad Request (validation failed)
// 401 - Unauthorized
// 403 - Forbidden
// 404 - Not Found
// 500 - Internal Server Error
3. Authentication (STRICT)
// ✅ ALWAYS check auth before processing
export async function GET(request: Request) {
const session = await getServerSession(authOptions);
if (!session) {
return Response.json({ error: { code: 'UNAUTHORIZED' } }, { status: 401 });
}
// Check authorization (permissions)
if (!hasPermission(session.user, 'users:read')) {
return Response.json({ error: { code: 'FORBIDDEN' } }, { status: 403 });
}
// Process request...
}
4. Rate Limiting
// ✅ Apply rate limiting for public endpoints
import { rateLimit } from '@/lib/rate-limit';
const limiter = rateLimit({
interval: 60 * 1000, // 1 minute
uniqueTokenPerInterval: 500,
});
export async function POST(request: Request) {
try {
await limiter.check(5, 'API_ROUTE_NAME'); // 5 requests per minute
} catch {
return Response.json({ error: { code: 'RATE_LIMITED' } }, { status: 429 });
}
}
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.
- 2d ago First seen · 138 lines · 0 tokens per session scan A d5a8783c1c18
91-api-routes is a cursor rule published in the GitHub repository Luxvil/ai-coding-rules (3 stars, last pushed 3d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 819 tokens. A static security scan graded it A with 0 findings. It is 100% identical to 91-api-routes, differing in 0 lines, and is treated as a copy.
Other cursor rules, from other repositories
exam-answer-format
Guidelines for writing exam-style answers in a practical, conversational style with definitions first followed by real-world examples.
lecture-reference-linking
Guidelines for including course materials lists and inline references when writing exam answers or documentation that references course materials.
mermaid-diagrams
Guidelines for adding Mermaid diagrams to exam answers and documentation with automatic SVG generation support.
short-answer-version
Guidelines for creating short/concise versions of detailed answers.
documentation-formatting
Guidelines for formatting markdown documentation to improve readability and scannability.
human-writing-style
Rules for writing naturally and authentically - avoid robotic AI tone in documentation, code comments, error messages, and explanations. Write like a human colleague, not a customer service bot.