Tanstack Start

What it does

When your agent uses it

• Tasks that involve React components
• Tasks that involve Backend development
• Tasks that involve End-to-end testing

Example prompts

• “/tanstack-start”

What it can do on your machine

Read from SKILL.md and the folder at commit 0a7169e. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • node
  • pnpm

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md. Its commands use pnpm, which can reach the network depending on how they are called.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names these keys or tokens, usually read from environment variables:

  • COGNITO_TEST_PASSWORD

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Tanstack Start loads about 2.9k tokens when it runs, and up to ~4.5k if it reads all its reference files. Until then it costs about 219 tokens; SKILL.md has 855 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~219

When it runs · the whole SKILL.md, loaded when a task matches

~2.9k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~4.5k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

• NoteMentions a .env fileSKILL.md:275

  # apps/.../.env (committed)

• NoteMentions a .env fileSKILL.md:282

  # apps/.../.env.local (gitignored); Vite still bakes VITE_* in at build time

• NoteMentions a .env fileSKILL.md:291

  `.env.local` (or CI secrets). Gate the auth Playwright projects on the creds being

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from asmyshlyaev177/test-proxy-recorder at commit 0a7169e, republished under its MIT licence (© asmyshlyaev177). 855 words, ~2,856 tokens.

name

tanstack-start

description

Record and replay TanStack Start SSR with test-proxy-recorder. Tag server-side fetches (route loaders, server functions, server routes) with the x-test-rcrd-id session header so parallel replay stays correct. Lead with registerProxyFetch (patch global fetch once at the top of src/router.tsx); createHeadersWithRecordingId and getRecordingId are the patch-free per-call options. Covers the vite build + node .output/server/index.mjs vs vite dev caveat, TEST_PROXY_RECORDER_ENABLED, the server BACKEND_URL vs browser import.meta.env.VITE_API_URL split, TanStack Query SSR prefetch (ensureQueryData / useSuspenseQuery), and the real-auth pattern (transparent-mode login, Bearer redaction, localStorage-token vs cookie session). Load this when setting up test-proxy-recorder in a TanStack Start (Vite + Nitro) app that makes server-side or authenticated API calls.

requires

test-proxy-recorder/proxy-setup

sources

asmyshlyaev177/test-proxy-recorder:README.md, asmyshlyaev177/test-proxy-recorder:packages/test-proxy-recorder/src/tanstack-start/registerProxyFetch.ts…

metadata.type

framework

metadata.library

test-proxy-recorder

metadata.library_version

1.3.1

metadata.framework

tanstack-start

// src/router.tsx
import { QueryClient } from '@tanstack/react-query';
import { createRouter } from '@tanstack/react-router';
import { registerProxyFetch } from 'test-proxy-recorder/tanstack-start';

import { routeTree } from './routeTree.gen';

registerProxyFetch(); // no-op on the client / in production unless TEST_PROXY_RECORDER_ENABLED=true

export function getRouter() {
  const queryClient = new QueryClient();
  return createRouter({ routeTree, context: { queryClient } });
}

// src/lib/api.ts
function apiBase(): string {
  if (typeof window === 'undefined') {
    return process.env.BACKEND_URL ?? 'http://localhost:8100'; // server only
  }
  return import.meta.env.VITE_API_URL ?? 'http://localhost:8100'; // browser
}

// src/routes/index.tsx
export const Route = createFileRoute('/')({
  loader: ({ context }) => context.queryClient.ensureQueryData(todosQueryOptions),
  component: TodoApp, // uses useSuspenseQuery(todosQueryOptions)
});

import { createHeadersWithRecordingId } from 'test-proxy-recorder/tanstack-start';

const res = await fetch('http://localhost:8100/todos', {
  headers: await createHeadersWithRecordingId({ 'Content-Type': 'application/json' }),
});

{ "scripts": { "start": "vite dev --port 3000" } }

{
  "scripts": {
    "build:test": "TEST_PROXY_RECORDER_ENABLED=true vite build",
    "start": "TEST_PROXY_RECORDER_ENABLED=true node .output/server/index.mjs"
  }
}

vite build && node .output/server/index.mjs   # NODE_ENV=production → helpers no-op

TEST_PROXY_RECORDER_ENABLED=true vite build
TEST_PROXY_RECORDER_ENABLED=true node .output/server/index.mjs

// The server has no localStorage, so the loader can't send the Bearer token —
// the prefetch hits the protected API unauthenticated and 401s.
export const Route = createFileRoute('/dashboard')({
  loader: ({ context }) => context.queryClient.ensureQueryData(protectedTodosQuery),
});

// Read the token after mount and fetch on the client (recorded via HAR).
const token = getToken(); // localStorage — client only
const { data } = useQuery({ ...protectedTodosQueryOptions(token), enabled: !!token });

// src/routes/index.tsx — a route module doesn't reliably run before the SSR
// fetches of other routes, so the global patch may not be installed in time.
registerProxyFetch();

// src/router.tsx — runs on the server for every SSR request, before route work.
registerProxyFetch();

const API_BASE = process.env.BACKEND_URL ?? 'http://localhost:8100'; // client bundle

const API_BASE =
  typeof window === 'undefined'
    ? process.env.BACKEND_URL ?? 'http://localhost:8100'
    : import.meta.env.VITE_API_URL ?? 'http://localhost:8100';

# apps/.../.env (committed)
VITE_COGNITO_REGION=eu-north-1
VITE_COGNITO_CLIENT_ID=7mrh9ih3ccmr2jis2ebtai8ta9

# apps/.../.env.local (gitignored); Vite still bakes VITE_* in at build time
VITE_COGNITO_REGION=...
VITE_COGNITO_CLIENT_ID=...
COGNITO_TEST_EMAIL=...
COGNITO_TEST_PASSWORD=...

© asmyshlyaev177, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file (references) in packages/test-proxy-recorder/skills/tanstack-start of asmyshlyaev177/test-proxy-recorder.

• SKILL.md
• references/auth-and-isr.md

Open the folder on GitHubat commit 0a7169e