Next.js is a React framework for building applications that run across the browser and Node.js, including server-rendered applications. It is used by developers building web applications with React components.
Borrowing it
Nothing to install: this file belongs to vercel/next.js. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/vercel/next.js/canary/AGENTS.mdgit clone --depth 1 https://github.com/vercel/next.jsWrote 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/instructions/vercel/next.js/agents-md)<a href="https://agentmods.dev/instructions/vercel/next.js/agents-md"><img src="https://agentmods.dev/badge/instructions/vercel/next.js/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/vercel/next.js/agents-md"><img src="https://agentmods.dev/badge/instructions/vercel/next.js/agents-md.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.07257 | $0.07257 |
| Opus 5.5 | $0.02903 | $0.02903 |
| Sonnet 5.5 | $0.01451 | $0.01451 |
| Haiku 4.5 | $0.00726 | $0.00726 |
Grade A, and why
next.js AGENTS.md scanned grade A with 1 finding 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
**External API calls (gh, curl):** How it starts
The opening of the file, as written. The whole thing — 536 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Next.js Development Guide
Codebase structure
Monorepo Overview
This is a pnpm monorepo containing the Next.js framework and related packages.
next.js/
├── packages/ # Published npm packages
├── turbopack/ # Turbopack bundler (Rust) - git subtree
├── crates/ # Rust crates for Next.js SWC bindings
├── test/ # All test suites
├── examples/ # Example Next.js applications
├── docs/ # Documentation
└── scripts/ # Build and maintenance scripts
Core Package: packages/next
The main Next.js framework lives in packages/next/. This is what gets published as the next npm package.
Source code is in packages/next/src/.
Key entry points:
- Dev server:
src/cli/next-dev.ts→src/server/dev/next-dev-server.ts - Production server:
src/cli/next-start.ts→src/server/next-server.ts - Build:
src/cli/next-build.ts→src/build/index.ts
Compiled output goes to packages/next/dist/ (mirrors src/ structure).
Other Important Packages
packages/create-next-app/- Thecreate-next-appCLI toolpackages/next-swc/- Native Rust bindings (SWC transforms)packages/eslint-plugin-next/- ESLint rules for Next.jspackages/font/-next/fontimplementationpackages/third-parties/- Third-party script integrations
README files
Before editing or creating files in any subdirectory (e.g., packages/*, crates/*), read all README.md files in the directory path from the repo root up to and including the target file's directory. This helps identify any local patterns, conventions, and documentation.
Example: Before editing turbopack/crates/turbopack-ecmascript-runtime/js/src/nodejs/runtime/runtime-base.ts, read:
turbopack/README.md(if exists)turbopack/crates/README.md(if exists)turbopack/crates/turbopack-ecmascript-runtime/README.md(if exists)turbopack/crates/turbopack-ecmascript-runtime/js/README.md(if exists - closest to target file)
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.
- yesterday Changed · +12 lines · +300 tokens per session 8d5d085ec926
- 2d ago Changed · +3 lines · +138 tokens per session babf58b4ca17
- 6d ago Changed · +14 tokens per session 718351e2e576
- 13d ago Changed · -7 lines · -180 tokens per session 07c35e7d11ff
- 21d ago Changed · +5 lines · +62 tokens per session b092e770678a
- 23d ago Changed · -2 lines · -26 tokens per session 378188e2ba4d
- 28d ago Changed · -36 lines · -347 tokens per session 01f52b62e25e
- 1mo ago First seen · 561 lines · 7,296 tokens per session scan A cd6cb00dca2d
next.js AGENTS.md is an instructions file published in the GitHub repository vercel/next.js (143,028 stars, last pushed today), licensed MIT. It adds 7,257 tokens to every session, about $0.0290 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
generative-ai-for-beginners AGENTS.md
AGENTS.md instructions for microsoft/generative-ai-for-beginners, covering agents.md, project overview, setup commands, initial repository setup and clone the repository.