Next.js Best Practices

Next.js Best Practices is an instructions file for GitHub Copilot from agutinbaigo28/financial-agent-api. It costs 3,641 tokens per session, scanned A, original, no licence file.

Development rules for Next.js, a framework for building web applications with JavaScript or TypeScript. They cover code structure, performance, security, testing, and common mistakes.

In plain words
What is it for?
It helps organize Next.js code, avoid common pitfalls, improve performance and security, and plan testing.
Why use it?
It gives the coding agent consistent guidance for building and reviewing Next.js applications.

Instructions file for GitHub Copilot

Written for GitHub Copilot: a Copilot chat mode or prompt.

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 instructions/agutinbaigo28/financial-agent-api/next-js
Clone the repo
git clone --depth 1 https://github.com/agutinbaigo28/financial-agent-api

Made for: GitHub Copilot.

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 Next.js Best Practices

README.md
[![agentmods](https://agentmods.dev/badge/instructions/agutinbaigo28/financial-agent-api/next-js.svg)](https://agentmods.dev/instructions/agutinbaigo28/financial-agent-api/next-js)
Your own site
<a href="https://agentmods.dev/instructions/agutinbaigo28/financial-agent-api/next-js"><img src="https://agentmods.dev/badge/instructions/agutinbaigo28/financial-agent-api/next-js.svg" alt="Measured on agentmods" height="20"></a>
Per session 3,641 This file is loaded in full into every session.
When invoked 3,641 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.03641 $0.03641
Opus 5 $0.01820 $0.01820
Sonnet 5 $0.00728 $0.00728
Haiku 4.5 $0.00364 $0.00364

Measured 6d ago against content hash ec370efcaec4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

Next.js Best Practices 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 6d 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.

.github/instructions/next-js.instructions.md · 287 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 6d ago First seen · 287 lines · 3,641 tokens per session scan A ec370efcaec4

Subscribe to this mod's changes

Next.js Best Practices is an instructions file published in the GitHub repository agutinbaigo28/financial-agent-api (129 stars, last pushed 2d ago), with no licence file. It adds 3,641 tokens to every session, about $0.0182 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 2026-08-30.

Related

Other instructions, from other repositories