if an ai requests the docs, send them llms.txt

Author: 0xngmi

examples/web/vite.config.ts

@@ -3,9 +3,49 @@ import { defineConfig } from 'vite'
 import path from 'path'
 import fs from 'fs'
 
+const llmsTxtPath = path.resolve(__dirname, '../../llms.txt')
+
+/**
+ * Vite plugin that serves llms.txt for API requests to the root page.
+ * When a request to "/" comes in without an "Accept: text/html" header
+ * (e.g., curl, LLM agents, API clients), we return the llms.txt content
+ * instead of the SPA HTML.
+ */
+function llmsTxtPlugin() {
+  return {
+    name: 'llms-txt',
+    configureServer(server: any) {
+      server.middlewares.use((req: any, res: any, next: any) => {
+        const isLlmsTxtPath = req.url === '/llms.txt'
+        const isRoot = req.url === '/' || req.url === ''
+
+        if (!isLlmsTxtPath && !isRoot) {
+          return next()
+        }
+
+        // Always serve llms.txt at /llms.txt, and at / only for non-browser requests
+        if (isRoot) {
+          const accept = req.headers['accept'] || ''
+          if (accept.includes('text/html')) {
+            return next()
+          }
+        }
+
+        try {
+          const content = fs.readFileSync(llmsTxtPath, 'utf-8')
+          res.setHeader('Content-Type', 'text/plain; charset=utf-8')
+          res.end(content)
+        } catch {
+          next()
+        }
+      })
+    },
+  }
+}
+
 // https://vitejs.dev/config/
 export default defineConfig({
-  plugins: [vue()],
+  plugins: [llmsTxtPlugin(), vue()],
   server: {
     port: 5050,
     open: true,