Geistdocs agent instructions

This app uses the packaged Geistdocs architecture. The @vercel/geistdocs package owns shared runtime behavior; this app owns local content, configuration, adapters, and site-specific routes.

Use these instructions when an AI coding agent edits this project.

Architecture

• Runtime features come from @vercel/geistdocs, including the docs page renderer, layout helpers, MDX components, search, Ask AI, markdown routes, proxy helpers, and source helpers.
• @vercel/geistdocs owns the Ask AI client, server route behavior, and AI SDK v6 runtime dependencies. Do not fork package internals to fit an older app-level ai version.
• Local files are user-owned adapters. They should stay thin and call public package exports from @vercel/geistdocs/*.
• Do not copy package internals into the app to make a customization. Prefer configuring an adapter file or upgrading @vercel/geistdocs.
• Do not deep import from @vercel/geistdocs/dist or edit files in node_modules/@vercel/geistdocs.
• Do not edit generated directories such as .source/, .next/, node_modules/, or build output.

Package Docs For Agents

• When package API behavior is unclear, read the installed package docs in node_modules/@vercel/geistdocs/docs before guessing.
• Start with node_modules/@vercel/geistdocs/docs/agents.md and node_modules/@vercel/geistdocs/docs/sitemap.md to identify the relevant focused page.
• Use node_modules/@vercel/geistdocs/docs/pages/*.md for task-specific guidance and node_modules/@vercel/geistdocs/docs/llms.txt only when you need broad package context.
• These package docs are read-only generated artifacts. Do not edit files under node_modules/@vercel/geistdocs; change local adapter files or update the package instead.

Common edit targets

Content guidelines

• Put docs in content/docs unless the project has added another source in lib/geistdocs/source.ts.
• Add each new page to content/docs/meta.json so it appears in the sidebar.
• Use MDX frontmatter with at least title and description for documentation pages. Set navTitle only when the navigation label should differ from the page heading.
• Keep slugs stable unless the task explicitly includes redirects or link updates.
• When adding translated content, follow the existing locale suffix pattern, such as page.cn.mdx.
• Use CopyPrompt when a page should give readers a prompt they can copy into a coding agent.

Routing and proxy guidelines

• Keep App Router route files as thin adapters around package helpers such as createDocsPage, createChatRoute, createLlmsRoute, and createProxy.
• Keep cacheComponents: true and partialPrefetching: true in next.config.ts. Do not export dynamic, revalidate, or fetchCache from App Router pages or route handlers.
• Read [lang] from next/root-params in Server Components (via lib/geistdocs/root-params.ts). Keep route context params in Route Handlers and Server Actions.
• Use prefetch={true} for app-owned links to fully static documentation pages so navigation does not stop at the generic route shell.
• Keep export const config in proxy.ts as a static object. Next.js must parse proxy matchers at build time.
• Use proxy matcher exclusions that only match /api and /api/..., such as api(?:/|$). Do not exclude broad prefixes like api, because that also excludes routes such as /api-reference.
• Preserve markdown negotiation unless the task explicitly changes AI-readable output. Geistdocs serves /agents.md, /llms.txt, /.well-known/mcp.json, and per-page Markdown for .md, .mdx, Accept: text/markdown, and AI-agent requests.
• The homepage rewrite (/ to /[lang]/home/[code]) lives in a createProxy after hook so it never preempts markdown negotiation.
• When adding custom proxy behavior, prefer before, after, and markdownRoutes options on createProxy instead of replacing the proxy.
• Use explicit markdownRoutes for root-mounted docs or any site where homepage/app routes coexist with docs routes.
• Keep source URLs, navigation links, getPageUrl, and markdownRoutes app-local when config.basePath is set. Geistdocs derives public page-action and Markdown URLs separately.

Ask AI and Vertex proxy guidelines

• Leave GEISTDOCS_CHAT_PROXY_URL unset and ai.eveAgent unconfigured to use the default AI Gateway path. In that mode, app/api/chat/route.ts calls createChatRoute without a proxy option and uses the local docs search tool during the AI SDK streamText loop.
• Set ai.eveAgent: { url } in geistdocs.tsx to answer Ask AI with a hosted eve framework agent instead. The URL flows through the config object; the route file needs no changes. Requests authenticate with a per-request Vercel OIDC bearer token by default; pass server-only headers through the eveAgent option on createChatRoute for custom auth. Never put auth material in geistdocs.tsx. Configuring both proxy and an eve agent throws at route creation.
• Geistdocs Ask AI targets AI SDK v6: ai v6 and @ai-sdk/react v3. Keep those dependencies on the generated package versions unless a @vercel/geistdocs release changes them.
• If the app uses ai or @ai-sdk/react for product code outside Geistdocs, migrate that app code separately or let the package manager install separate versions. Do not downgrade Geistdocs Ask AI to match unrelated app code.
• Set GEISTDOCS_CHAT_PROXY_URL only when Ask AI should route through the central Vertex-backed proxy. The value must include the /vertex route, such as https://<geistdocs-platform-deployment>/vertex.
• Do not add Vertex credentials to a Geistdocs site. The central platform proxy forwards the Vercel OIDC token in x-vercel-trusted-oidc-idp-token; the Vertex deployment should trust the platform Vercel project through Deployment Protection Trusted Sources.
• Use GEISTDOCS_CHAT_PROXY_TOKEN only for a custom proxy that requires bearer authentication. The default Geistdocs platform /vertex proxy does not require it.
• Keep app/api/chat/route.ts as a thin adapter around createChatRoute. Prefer configuring GEISTDOCS_CHAT_PROXY_URL and GEISTDOCS_CHAT_PROXY_TOKEN over forking the package chat route.

Migration guidelines

• When migrating from Fumadocs or a custom Geist docs site, inventory source.config.ts, route files, middleware.ts or proxy.ts, public/llms.txt, OG routes, Tailwind CSS setup, and required environment variables before editing.
• Inventory direct app usage of ai and @ai-sdk/react. Package-owned Ask AI uses AI SDK v6; migrate local AI SDK code separately from Geistdocs route adapters.
• Import source-config helpers from @vercel/geistdocs/source-config in source.config.ts. Do not import runtime component entry points from source config.
• Move existing middleware.ts behavior into createProxy({ before }) or createProxy({ after }) hooks.
• Set openGraph.images in createDocsPage only when the app includes the Geistdocs OG route, or override metadata to avoid broken /og/... URLs.
• Add Tailwind CSS v4 @source entries for @vercel/geistdocs and related runtime dependencies when migrating styles.
• Add local fallbacks for production-only environment variables so migration builds do not require production secrets.

Package updates

• Use pnpm exec geistdocs update to update package-based Geistdocs projects.
• geistdocs update updates the @vercel/geistdocs dependency. It does not overwrite local adapter files.
• Review dependency changes and run the verification commands before committing an update.

Commands

Run commands from the repository root unless noted:

• Start development: pnpm dev -F docs
• Build for production: pnpm build -F docs
• Start the built app: pnpm start -F docs
• Regenerate Fumadocs output after dependency installation: pnpm postinstall -F docs
• Update Geistdocs: pnpm -F docs exec geistdocs update
• Run translations if configured: pnpm translate -F docs

Verification

• Run pnpm build -F docs after changing routes, config, source setup, MDX components, or package versions.
• Run pnpm dev -F docs and open the changed pages when visual layout, navigation, or MDX rendering changes.
• Check both /docs and AI-readable routes such as /agents.md, /.well-known/mcp.json, /llms.txt, or a page-level .md URL when changing content routing or proxy behavior.
• Confirm no secrets were added to source files. Use .env.local for local values and keep it out of Git.

This is NOT the Next.js you know

This version has breaking changes — APIs, conventions, and file structure may all differ from your training data. Read the relevant guide in node_modules/next/dist/docs/ (resolved from this file's directory; in monorepos the next package may not be visible from the repo root) before writing any code. Heed deprecation notices.

This block is written and re-added by next dev — verify at node_modules/next/dist/server/lib/generate-agent-files.js. Removing it from a diff only re-creates the uncommitted change; committing it with your work keeps the tree clean.