agentmods.dev

react-router AGENTS.md

A development guide for React Router, a library for connecting web-page URLs with the screens and data in a React application.

In plain words
What is it for?
Use it to build, test, type-check, lint, document, and clean the project, or to determine which of React Router's five modes a feature supports.
Why use it?
It collects the commands, architectural modes, and testing practices needed to change the project without overlooking mode-specific behavior.

Instructions file for CodexOpenCode

57k 5d ago A scan 1,820 tokens original MIT
View the source file remix-run/react-router
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/remix-run/react-router/agents-md
Clone the repo
git clone --depth 1 https://github.com/remix-run/react-router

Made for: Codex, OpenCode.

Per session 1,820 This file is loaded in full into every session.
When invoked 1,820 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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 $0.01820 $0.01820
Opus 5 $0.00910 $0.00910
Sonnet 5 $0.00364 $0.00364
Haiku 4.5 $0.00182 $0.00182

Measured 3d ago against content hash 26d0b881712b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

react-router AGENTS.md 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.

AGENTS.md · 159 lines

How it starts

The opening of the file, as written. The whole thing — 159 lines — stays where its author put it; the contents beside it link to each section on GitHub.

React Router Development Guide

Commands

  • Build: pnpm build (all packages) or pnpm run --filter <package> build (single package)
  • Test (Jest): pnpm test (all packages), pnpm test packages/<package>/ (single package), pnpm test packages/react-router/__tests__/router/fetchers-test.ts (single file), or pnpm test -- -t "action fetch" (tests matching name)
  • Integration tests (Playwright): pnpm test:integration --project chromium (build + test all), pnpm test:integration:run --project chromium (test only, all), pnpm test:integration:run integration/middleware-test.ts --project chromium (single file), or pnpm test:integration:run --project chromium -g "middleware" (tests matching name)
  • Typecheck: pnpm run typecheck
  • Lint: pnpm run lint
  • Docs generation: pnpm run docs (regenerates API docs from JSDoc)
  • Type generation: pnpm run typegen (Framework Mode only)
  • Clean: pnpm run clean (git clean -fdX)

Modes

Five distinct modes: Declarative, Data, Framework, RSC Data (unstable), RSC Framework (unstable). Always identify which mode(s) a feature applies to.

  1. Declarative: <BrowserRouter>, <Routes>, <Route>
  2. Data: createBrowserRouter() with loader/action, <RouterProvider>
  3. Framework: Vite plugin + routes.ts + Route Module API (route exports like loader, action, default) + type generation + SSR/SPA
  4. RSC Data (unstable): RSC runtime APIs, manual bundler setup, runtime route config
  5. RSC Framework (unstable): Framework Mode with unstable_reactRouterRSC Vite plugin

RSC mode differences:

  • RSC Framework: unstable_reactRouterRSC plugin, @vitejs/plugin-rsc, different entry points/format
  • RSC Data: Manual bundler, runtime route config typically in src/routes.ts, unstable_RSCRouteConfig, different runtime APIs, setupRscTest in integration/rsc/

Architecture

  • Monorepo: pnpm workspace, packages in packages/
  • Key packages:
    • react-router: Core (all modes) - lib/components.tsx, lib/hooks.tsx, lib/router/, lib/dom/, lib/rsc/
    • @react-router/dev: Framework tooling - vite/plugin.ts (Framework), vite/rsc/plugin.ts (RSC Framework), typegen/
    • @react-router/node, @react-router/cloudflare, @react-router/express: Server adapters
    • @react-router/serve: Minimal server for Framework Mode
    • @react-router/fs-routes: File-system routing (flatRoutes())

Read the full file on GitHub · 159 lines

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 · 159 lines · 1,820 tokens per session scan A 26d0b881712b

Subscribe to this mod's changes

react-router AGENTS.md is an instructions file published in the GitHub repository remix-run/react-router (56,575 stars, last pushed 5d ago), licensed MIT. It adds 1,820 tokens to every session, about $0.0091 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.

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