senior-engineer

senior-engineer is a cursor rule for Cursor from kensaurus/cursor-kenji. It costs 50 tokens per session (328 once invoked), scanned A, original, MIT.

Senior-engineer defaults are project rules for building and refactoring Next.js, React, and Supabase applications. They cover state management, file structure, validation, access checks, rate limits, and verification.

In plain words
What is it for?
Use them when adding features, restructuring code, choosing where logic belongs, protecting server actions, or checking a change in the browser and database.
Why use it?
They provide consistent decisions for common application problems and make security and completion checks part of the workflow.

Cursor rule for Cursor

Written for Cursor: a Cursor rule (.mdc).

Good fit Use them when adding features, restructuring code, choosing where logic belongs, protecting…

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/kensaurus/cursor-kenji/senior-engineer
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.

Clone the repo
git clone --depth 1 https://github.com/kensaurus/cursor-kenji

Made for: Cursor.

Wrote 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.

agentmods badge for senior-engineer

README.md
[![agentmods](https://agentmods.dev/badge/rules/kensaurus/cursor-kenji/senior-engineer.svg)](https://agentmods.dev/rules/kensaurus/cursor-kenji/senior-engineer)
Your own site
<a href="https://agentmods.dev/rules/kensaurus/cursor-kenji/senior-engineer"><img src="https://agentmods.dev/badge/rules/kensaurus/cursor-kenji/senior-engineer.svg" alt="Measured on agentmods" height="20"></a>
Per session 50 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 328 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00050 $0.00328
Opus 5 $0.00025 $0.00164
Sonnet 5 $0.00010 $0.00066
Haiku 4.5 $0.00005 $0.00033

Measured 3d ago against content hash 821c9e46d36f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

senior-engineer 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 3d 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.

rules/senior-engineer.mdc · 26 lines

What it actually says

Senior Engineer Defaults — Next.js/Supabase stack

  • Scan README.md, package.json, and existing code first; reuse existing @/components/ui primitives; match established naming and structure. Never block waiting on context — proceed with stack defaults and note the assumption.
  • State/data routing: server/async → TanStack Query · client UI → Zustand · URL params → nuqs · forms → React Hook Form + Zod. Simple mutations → Server Actions; webhooks/external APIs → Route Handlers.
  • Separation of concerns: types in types.ts, Zod schemas in schemas.ts, server actions in server/actions.ts, reusable logic in hooks/use-{name}.ts; components stay UI-only. Split files over ~300 lines. Strict TypeScript — no any.
  • Security non-negotiables: Zod validation on the server for all inputs, RLS on every table, an auth check in every Server Action, rate limits on actions and edge functions, service-role key server-side only, env validation with T3 Env.
  • Verify before claiming done: exercise the UI in a browser with a clean console, and confirm DB state/schema matches what the code assumes.
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. 3d ago First seen · 26 lines · 50 tokens per session scan A 821c9e46d36f

Subscribe to this mod's changes

senior-engineer is a cursor rule published in the GitHub repository kensaurus/cursor-kenji (9 stars, last pushed 8d ago), licensed MIT. It adds 50 tokens to every session and 328 once invoked, about $0.0003 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.