Use when the user wants to persist a preference, skill, or knowledge. Use when it would aid future val development to store a memory of how best to build something.
Use when a val needs to ship JavaScript that runs in the browser — React apps, vanilla DOM scripts, canvas/games, htmx/Alpine, or any client-side module beyond a single inline snippet. Explains how Val Town serves transpiled .ts/.tsx/.jsx modules with no build step, how the browser resolves their imports, and how to load third-party deps.
Use when building an HTTP val — a web endpoint, API route, webhook receiver, or any val that responds to HTTP requests. Covers the handler signature, Hono usage, the endpoint URL, CORS behavior, redirects, and Val Town-specific limitations.
Use when a val needs simple key/value persistence — JSON documents, cached responses, uploaded files, or binary assets. Covers the std/blob API, listing and deleting keys, account-global or val scoping, and storage limits.
Use when a val needs to require login with a Val Town account — gating routes behind authentication, identifying the current user, building user-specific dashboards. Covers std/oauth's `oauthMiddleware` and `getOAuthUserData`, the auto-managed `/auth/*` routes, and session behavior. For third-party OAuth providers (Google, GitHub, etc.) see the `third-party-integrations` skill instead.
Use when a val sends email, receives email, or is triggered by an incoming email. Covers email-type vals (the Email handler shape, attachment limits, the assigned val email address) and sending mail via std/email.
Use when a val needs to store structured or relational data. Covers the std/sqlite API, parameterized queries, transactions, and the val-scoped vs organization-scoped database distinction.
Use when a val talks to an external service — Slack, Discord, Telegram, Stripe, GitHub, Gmail, Google Sheets, Postgres/Supabase/Upstash/Neon, browser automation (Playwright, Browserbase, Kernel, Steel), web scraping, PDF generation, push notifications, RSS, or any other third-party API. Covers the required workflow (fetch the Val Town guide, get credentials, test, store secrets) and the catalog of available guides.