[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"playground-nextjs-weekly-middleware-to-proxy-network-boundary":3,"verticals":19,"search-suggestions":58},{"slug":4,"title":5,"summary":6,"html":7,"css":8,"js":9,"config":10,"doc":13},"nextjs-weekly-middleware-to-proxy-network-boundary","Next.js proxy.ts vs middleware.ts — interactive playground",null,"\u003Cdiv class=\"pg\">\n    \u003Ch1 class=\"pg-title\">🎮 proxy.ts vs middleware.ts — the network boundary\u003C\u002Fh1>\n    \u003Cp class=\"pg-sub\">\n      This is a \u003Cstrong>model\u003C\u002Fstrong> of the documented behavior, not a live Next.js server.\n      Pick which file handles the request, whether the visitor has a session cookie, and whether\n      the boundary tries a Node-only API — then send the request and watch where it goes.\n    \u003C\u002Fp>\n\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">1\u003C\u002Fspan> Controls\u003C\u002Fdiv>\n\n      \u003Cdiv class=\"addr\">\n        \u003Cspan class=\"dots\">\u003Cspan>\u003C\u002Fspan>\u003Cspan>\u003C\u002Fspan>\u003Cspan>\u003C\u002Fspan>\u003C\u002Fspan>\n        \u003Ccode>https:\u002F\u002Fapp.example.com\u002Fdashboard\u003C\u002Fcode>\n      \u003C\u002Fdiv>\n\n      \u003Cdiv class=\"wrap-controls\">\n        \u003Cdiv class=\"field\">\n          \u003Cspan class=\"ctl-label\">Boundary file\u003C\u002Fspan>\n          \u003Cdiv class=\"seg\" id=\"fileSeg\">\n            \u003Cbutton aria-pressed=\"true\" data-file=\"proxy\">proxy.ts (Node.js)\u003C\u002Fbutton>\n            \u003Cbutton aria-pressed=\"false\" data-file=\"middleware\">middleware.ts (Edge)\u003C\u002Fbutton>\n          \u003C\u002Fdiv>\n        \u003C\u002Fdiv>\n      \u003C\u002Fdiv>\n\n      \u003Cdiv class=\"btn-row\" style=\"margin-top:12px\">\n        \u003Clabel class=\"toggle\">\n          \u003Cinput type=\"checkbox\" id=\"hasCookie\" checked \u002F>\u003Cspan class=\"switch\">\u003C\u002Fspan>\n          \u003Cspan>Visitor has a valid session cookie\u003C\u002Fspan>\n        \u003C\u002Flabel>\n      \u003C\u002Fdiv>\n      \u003Cdiv class=\"btn-row\" style=\"margin-top:8px\">\n        \u003Clabel class=\"toggle\">\n          \u003Cinput type=\"checkbox\" id=\"usesNodeApi\" \u002F>\u003Cspan class=\"switch\">\u003C\u002Fspan>\n          \u003Cspan>Boundary calls a Node-only API (e.g. \u003Ccode>crypto.createHmac\u003C\u002Fcode>)\u003C\u002Fspan>\n        \u003C\u002Flabel>\n      \u003C\u002Fdiv>\n\n      \u003Cdiv class=\"btn-row\" style=\"margin-top:14px\">\n        \u003Cbutton class=\"btn primary\" id=\"send\">Send request\u003C\u002Fbutton>\n        \u003Cbutton class=\"btn ghost\" id=\"reset\">Reset\u003C\u002Fbutton>\n      \u003C\u002Fdiv>\n\n      \u003Cdiv class=\"presets\" style=\"margin-top:12px\">\n        \u003Cbutton class=\"btn sm\" data-preset=\"guest\">Guest visits \u002Fdashboard\u003C\u002Fbutton>\n        \u003Cbutton class=\"btn sm\" data-preset=\"authed\">Signed-in visits \u002Fdashboard\u003C\u002Fbutton>\n        \u003Cbutton class=\"btn sm\" data-preset=\"nodeapi\">Old middleware.ts tries a Node API\u003C\u002Fbutton>\n      \u003C\u002Fdiv>\n    \u003C\u002Fdiv>\n\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">2\u003C\u002Fspan> Request path (model)\u003C\u002Fdiv>\n      \u003Cdiv class=\"flow\" id=\"flow\">\n        \u003Cdiv class=\"box\" id=\"boxRequest\">\u003Cspan class=\"ico\">📨\u003C\u002Fspan>Request\u003Cspan class=\"sub\">GET \u002Fdashboard\u003C\u002Fspan>\u003C\u002Fdiv>\n        \u003Cdiv class=\"box\" id=\"boxBoundary\">\u003Cspan class=\"ico\">🛡️\u003C\u002Fspan>Boundary\u003Cspan class=\"sub\" id=\"boundarySub\">proxy.ts — Node.js runtime\u003C\u002Fspan>\u003C\u002Fdiv>\n        \u003Cdiv class=\"arrow\" id=\"arrowText\">↓\u003C\u002Fdiv>\n        \u003Cdiv class=\"box wide\" id=\"boxOutcome\">\u003Cspan class=\"ico\">…\u003C\u002Fspan>\u003Cspan id=\"outcomeText\">Waiting to send\u003C\u002Fspan>\u003C\u002Fdiv>\n      \u003C\u002Fdiv>\n\n      \u003Cdiv class=\"status\" id=\"status\" style=\"margin-top:12px\">\n        \u003Cspan class=\"dot info\" id=\"dot\">\u003C\u002Fspan>\u003Cspan id=\"statusText\">Ready — configure the request and send it.\u003C\u002Fspan>\n      \u003C\u002Fdiv>\n      \u003Cp class=\"hint\" id=\"hint\">Pick a file, a cookie state, and whether the check reaches for a Node-only API, then send.\u003C\u002Fp>\n\n      \u003Cdiv class=\"log\" id=\"log\" style=\"margin-top:10px\" aria-live=\"polite\">\u003C\u002Fdiv>\n    \u003C\u002Fdiv>\n  \u003C\u002Fdiv>","\u002F*\n * Shared playground design system — daily-post\n * ============================================\n * Link it from any post's playground\u002Findex.html (no per-post boilerplate):\n *\n *   \u003Clink rel=\"stylesheet\" href=\"..\u002F..\u002F..\u002Fplayground\u002Fassets\u002Fbase.css\" \u002F>\n *\n * The relative path resolves the same locally (posts\u002F\u003Cbase>\u002Fplayground\u002F) and on\n * the deployed host (public\u002Fposts\u002F\u003Cbase>\u002Fplayground\u002F), because build-site.js\n * mirrors this file to public\u002Fplayground\u002Fassets\u002Fbase.css. For a CodeSandbox\n * --embed, playground.js inlines this file so the single-file sandbox still styles.\n *\n * Then write ONLY the demo-specific CSS in your inline \u003Cstyle>. Everything below\n * — tokens, layout, panels, buttons, toggles, sliders, code blocks, status\u002Flog,\n * banners, presets — comes for free and looks consistent across every post.\n *\n * Theme-aware: dark by default, light via prefers-color-scheme AND a\n * [data-theme] override on \u003Chtml> (so a toggle can force either). Accessible:\n * real focus rings, adequate contrast, reduced-motion honored.\n *\u002F\n\n\u002F* ---------- design tokens ---------- *\u002F\n:root {\n  --bg: #0d1117;\n  --bg-grid: #ffffff0a;\n  --panel: #161b22;\n  --panel-2: #0b0e14;\n  --card: #0b0e14;\n  --ink: #e8ebf2;\n  --muted: #9aa4b2;\n  --faint: #6b7688;\n  --line: #232a35;\n  --line-soft: #ffffff12;\n  --accent: #7c9cff;\n  --accent-ink: #0b0e14;\n  --good: #3fb950;\n  --warn: #f0883e;\n  --bad: #f85149;\n  --info: #58a6ff;\n  --radius: 14px;\n  --radius-sm: 9px;\n  --shadow: 0 8px 30px #0006;\n  --shadow-sm: 0 4px 14px #0005;\n  --mono: ui-monospace, SFMono-Regular, \"SF Mono\", Menlo, Consolas, \"Liberation Mono\", monospace;\n  --sans: ui-sans-serif, system-ui, -apple-system, \"Segoe UI\", Roboto, \"Helvetica Neue\", sans-serif;\n  color-scheme: dark;\n}\n\n\u002F* Light theme — system preference, overridable by [data-theme] on \u003Chtml>. *\u002F\n@media (prefers-color-scheme: light) {\n  :root:not([data-theme=\"dark\"]) {\n    --bg: #f4f6fb;\n    --bg-grid: #00000008;\n    --panel: #ffffff;\n    --panel-2: #f0f3f9;\n    --card: #f7f9fc;\n    --ink: #131722;\n    --muted: #5b6472;\n    --faint: #8a93a3;\n    --line: #e2e7f0;\n    --line-soft: #00000010;\n    --accent: #2f6df0;\n    --accent-ink: #ffffff;\n    --good: #1a7f37;\n    --warn: #bc4c00;\n    --bad: #cf222e;\n    --info: #0969da;\n    --shadow: 0 8px 30px #0000001f;\n    --shadow-sm: 0 4px 14px #00000014;\n    color-scheme: light;\n  }\n}\n:root[data-theme=\"light\"] {\n  --bg: #f4f6fb;\n  --bg-grid: #00000008;\n  --panel: #ffffff;\n  --panel-2: #f0f3f9;\n  --card: #f7f9fc;\n  --ink: #131722;\n  --muted: #5b6472;\n  --faint: #8a93a3;\n  --line: #e2e7f0;\n  --line-soft: #00000010;\n  --accent: #2f6df0;\n  --accent-ink: #ffffff;\n  --good: #1a7f37;\n  --warn: #bc4c00;\n  --bad: #cf222e;\n  --info: #0969da;\n  --shadow: 0 8px 30px #0000001f;\n  --shadow-sm: 0 4px 14px #00000014;\n  color-scheme: light;\n}\n\n\u002F* ---------- reset & base ---------- *\u002F\n*, *::before, *::after { box-sizing: border-box; }\n\nbody {\n  margin: 0;\n  min-height: 100vh;\n  font-family: var(--sans);\n  color: var(--ink);\n  background:\n    radial-gradient(circle at 1px 1px, var(--bg-grid) 1px, transparent 0) 0 0 \u002F 24px 24px,\n    var(--bg);\n  display: flex;\n  justify-content: center;\n  align-items: flex-start;\n  padding: clamp(14px, 3vw, 26px);\n  line-height: 1.55;\n  -webkit-font-smoothing: antialiased;\n  text-rendering: optimizeLegibility;\n}\n\n\u002F* The single content column. *\u002F\n.pg {\n  width: 100%;\n  max-width: 860px;\n}\n\n\u002F* ---------- header ---------- *\u002F\n.pg-title {\n  font-size: clamp(1.15rem, 1rem + 1vw, 1.4rem);\n  font-weight: 800;\n  letter-spacing: -0.02em;\n  margin: 0 0 4px;\n  display: flex;\n  align-items: center;\n  gap: 9px;\n}\n.pg-sub {\n  color: var(--muted);\n  font-size: 0.92rem;\n  line-height: 1.5;\n  margin: 0 0 16px;\n  max-width: 66ch;\n}\n.pg-sub strong, .pg-sub b { color: var(--ink); font-weight: 700; }\n.pg-sub code { font-family: var(--mono); background: var(--line-soft); color: var(--accent);\n  padding: 1px 6px; border-radius: 6px; font-size: 0.85em; }\n\n\u002F* ---------- panels ---------- *\u002F\n.panel {\n  background: var(--panel);\n  border: 1px solid var(--line);\n  border-radius: var(--radius);\n  padding: 16px 18px;\n  margin-bottom: 14px;\n  box-shadow: var(--shadow-sm);\n}\n.panel-label {\n  font-size: 0.7rem;\n  text-transform: uppercase;\n  letter-spacing: 0.08em;\n  color: var(--muted);\n  font-weight: 800;\n  margin: 0 0 13px;\n  display: flex;\n  align-items: center;\n  gap: 8px;\n}\n.panel-label .n {\n  display: inline-grid; place-items: center;\n  width: 18px; height: 18px; border-radius: 50%;\n  background: var(--accent); color: var(--accent-ink);\n  font-size: 0.66rem; font-weight: 800;\n}\n\n\u002F* ---------- layout helpers ---------- *\u002F\n.row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }\n.row.between { justify-content: space-between; }\n.col { display: flex; flex-direction: column; gap: 10px; }\n.grow { flex: 1 1 0; min-width: 0; }\n.wrap-controls { display: flex; flex-wrap: wrap; gap: 16px 24px; align-items: flex-end; }\n.field { display: flex; flex-direction: column; gap: 7px; min-width: 0; }\n.field > .label, .ctl-label {\n  font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.04em;\n  color: var(--muted); font-weight: 800;\n}\n\n\u002F* ---------- buttons ---------- *\u002F\n.btn {\n  font: inherit; font-weight: 650; font-size: 0.88rem;\n  cursor: pointer; user-select: none;\n  border: 1px solid var(--line);\n  background: var(--card); color: var(--ink);\n  padding: 9px 15px; border-radius: var(--radius-sm);\n  display: inline-flex; align-items: center; gap: 8px;\n  transition: background .15s ease, border-color .15s ease, transform .05s ease, color .15s ease;\n}\n.btn:hover { background: var(--line-soft); border-color: var(--muted); }\n.btn:active { transform: translateY(1px); }\n.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }\n.btn[disabled] { opacity: 0.45; cursor: not-allowed; }\n.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }\n.btn.primary:hover { filter: brightness(1.08); background: var(--accent); }\n.btn.good { background: var(--good); border-color: var(--good); color: #04140a; }\n.btn.bad  { background: var(--bad);  border-color: var(--bad);  color: #fff; }\n.btn.ghost { background: transparent; }\n.btn.sm { padding: 6px 11px; font-size: 0.82rem; }\n\n.btn-row { display: flex; flex-wrap: wrap; gap: 9px; }\n\n\u002F* Segmented control — a row of buttons where one is active (aria-pressed). *\u002F\n.seg { display: inline-flex; background: var(--card); border: 1px solid var(--line);\n  border-radius: var(--radius-sm); padding: 3px; gap: 3px; }\n.seg button {\n  font: inherit; font-weight: 650; font-size: 0.84rem; cursor: pointer;\n  border: none; background: transparent; color: var(--muted);\n  padding: 7px 13px; border-radius: 7px;\n  transition: background .15s ease, color .15s ease;\n}\n.seg button:hover { color: var(--ink); }\n.seg button[aria-pressed=\"true\"] { background: var(--accent); color: var(--accent-ink); }\n.seg button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }\n\n\u002F* Preset chips — worked-example shortcuts. *\u002F\n.presets { display: flex; flex-wrap: wrap; gap: 8px; }\n.presets .btn { background: var(--panel-2); }\n\n\u002F* ---------- toggle switch ---------- *\u002F\n.toggle { display: inline-flex; align-items: center; gap: 10px; cursor: pointer;\n  font-size: 0.88rem; font-weight: 600; user-select: none; }\n.toggle input { position: absolute; opacity: 0; width: 0; height: 0; }\n.switch { position: relative; width: 44px; height: 25px; border-radius: 999px; flex: none;\n  background: var(--line); border: 1px solid var(--line); transition: background .18s ease; }\n.switch::after { content: \"\"; position: absolute; top: 2px; left: 2px; width: 19px; height: 19px;\n  border-radius: 50%; background: #cfd6e4; transition: transform .18s ease; box-shadow: 0 1px 3px #0006; }\n.toggle input:checked + .switch { background: var(--good); border-color: var(--good); }\n.toggle input:checked + .switch::after { transform: translateX(19px); background: #fff; }\n.toggle input:focus-visible + .switch { outline: 2px solid var(--accent); outline-offset: 2px; }\n\n\u002F* ---------- range slider ---------- *\u002F\ninput[type=\"range\"] {\n  -webkit-appearance: none; appearance: none; width: 100%; height: 6px;\n  background: var(--line); border-radius: 999px; outline: none; cursor: pointer; margin: 8px 0;\n}\ninput[type=\"range\"]::-webkit-slider-thumb {\n  -webkit-appearance: none; appearance: none; width: 19px; height: 19px; border-radius: 50%;\n  background: var(--accent); border: 2px solid var(--panel); box-shadow: var(--shadow-sm); cursor: pointer;\n}\ninput[type=\"range\"]::-moz-range-thumb {\n  width: 19px; height: 19px; border-radius: 50%; background: var(--accent);\n  border: 2px solid var(--panel); box-shadow: var(--shadow-sm); cursor: pointer;\n}\ninput[type=\"range\"]:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }\n\n\u002F* ---------- text inputs \u002F selects ---------- *\u002F\ninput[type=\"text\"], input[type=\"number\"], input[type=\"search\"], select, textarea {\n  font: inherit; color: var(--ink); background: var(--card);\n  border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 8px 11px; width: 100%;\n}\ntextarea { font-family: var(--mono); font-size: 0.85rem; line-height: 1.6; resize: vertical; }\ninput:focus-visible, select:focus-visible, textarea:focus-visible {\n  outline: 2px solid var(--accent); outline-offset: 1px; border-color: var(--accent);\n}\n\n\u002F* ---------- status \u002F output \u002F log ---------- *\u002F\n.status {\n  display: flex; align-items: center; gap: 9px; flex-wrap: wrap;\n  font-size: 0.9rem; font-weight: 600;\n  padding: 11px 14px; border-radius: var(--radius-sm);\n  background: var(--panel-2); border: 1px solid var(--line); color: var(--ink);\n}\n.status.good { border-color: color-mix(in srgb, var(--good) 55%, var(--line)); }\n.status.warn { border-color: color-mix(in srgb, var(--warn) 55%, var(--line)); }\n.status.bad  { border-color: color-mix(in srgb, var(--bad) 55%, var(--line)); }\n.dot { width: 9px; height: 9px; border-radius: 50%; background: var(--muted); flex: none; }\n.dot.good { background: var(--good); } .dot.warn { background: var(--warn); }\n.dot.bad { background: var(--bad); } .dot.info { background: var(--info); }\n\n.output { background: var(--panel-2); border: 1px solid var(--line); border-radius: var(--radius-sm);\n  padding: 13px 15px; }\n.log { font-family: var(--mono); font-size: 0.8rem; line-height: 1.7; background: var(--card);\n  border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 11px 14px;\n  max-height: 220px; overflow-y: auto; white-space: pre-wrap; }\n\n\u002F* ---------- code block + syntax tokens ---------- *\u002F\n.code {\n  font-family: var(--mono); font-size: 0.82rem; line-height: 1.7;\n  background: var(--panel-2); border: 1px solid var(--line); border-radius: var(--radius-sm);\n  padding: 13px 15px; overflow-x: auto; white-space: pre; tab-size: 2;\n}\n.code .tok-sel  { color: var(--accent); }\n.code .tok-prop { color: #86e29b; }\n.code .tok-kw   { color: #ff9bcb; }\n.code .tok-str  { color: #f0c674; }\n.code .tok-num  { color: #f0883e; }\n.code .tok-cmt  { color: var(--faint); font-style: italic; }\n.code .hl { background: color-mix(in srgb, var(--good) 22%, transparent); border-radius: 4px; padding: 0 3px; }\n\n\u002F* ---------- hint \u002F caption ---------- *\u002F\n.hint { font-size: 0.83rem; color: var(--muted); line-height: 1.55; margin: 10px 0 0; }\n.hint code { font-family: var(--mono); color: var(--ink); background: var(--line-soft);\n  padding: 1px 5px; border-radius: 5px; font-size: 0.86em; }\n.hint strong { color: var(--ink); }\n\n\u002F* ---------- banner (feature-support \u002F notices) ---------- *\u002F\n.banner {\n  display: none; margin-bottom: 14px; padding: 11px 14px; border-radius: 11px;\n  font-size: 0.85rem; line-height: 1.5;\n  color: var(--ink); background: color-mix(in srgb, var(--warn) 12%, var(--panel));\n  border: 1px solid color-mix(in srgb, var(--warn) 45%, var(--line));\n}\n.banner.show { display: block; }\n.banner.info { background: color-mix(in srgb, var(--info) 12%, var(--panel));\n  border-color: color-mix(in srgb, var(--info) 45%, var(--line)); }\n.banner code { font-family: var(--mono); background: var(--line-soft); padding: 1px 5px; border-radius: 5px; }\n\n\u002F* ---------- misc atoms ---------- *\u002F\n.pill { display: inline-flex; align-items: center; gap: 6px; font-size: 0.75rem; font-weight: 700;\n  padding: 3px 9px; border-radius: 999px; background: var(--line-soft); color: var(--muted); }\n.pill.good { color: var(--good); background: color-mix(in srgb, var(--good) 16%, transparent); }\n.pill.bad  { color: var(--bad);  background: color-mix(in srgb, var(--bad) 16%, transparent); }\n.mono { font-family: var(--mono); }\n.muted { color: var(--muted); }\n.big-num { font-family: var(--mono); font-size: 1.6rem; font-weight: 800; letter-spacing: -0.02em; }\n\n\u002F* Optional theme toggle button (top-right). Wire it in JS if you want it. *\u002F\n.theme-btn { position: fixed; top: 12px; right: 12px; z-index: 20; }\n\n\u002F* ---------- responsive ---------- *\u002F\n@media (max-width: 560px) {\n  .panel { padding: 14px; }\n  .wrap-controls { gap: 14px; }\n  .btn { padding: 9px 13px; }\n}\n\n\u002F* ---------- reduced motion ---------- *\u002F\n@media (prefers-reduced-motion: reduce) {\n  *, *::before, *::after { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; }\n}\n\n\n\u002F* Demo-specific only — base.css owns tokens, panels, buttons, status, log, toggle. *\u002F\n  .addr {\n    display: flex; align-items: center; gap: 8px;\n    padding: 8px 10px;\n    border: 1px solid var(--line);\n    border-radius: var(--radius-sm);\n    background: var(--panel-2);\n    font-size: 0.78rem;\n    margin-bottom: 10px;\n  }\n  .addr .dots { display: flex; gap: 4px; }\n  .addr .dots span { width: 7px; height: 7px; border-radius: 50%; background: var(--line); display: inline-block; }\n  .addr code { color: var(--ink); }\n  .flow {\n    display: grid;\n    grid-template-columns: 1fr 1fr;\n    gap: 8px;\n  }\n  .box {\n    padding: 10px 8px;\n    text-align: center;\n    border-radius: var(--radius-sm);\n    border: 1px solid var(--line);\n    background: var(--panel-2);\n    font-size: 0.76rem;\n    line-height: 1.35;\n    transition: background .25s, border-color .25s, transform .2s;\n  }\n  .box .ico { display: block; font-size: 1.15rem; margin-bottom: 3px; }\n  .box .sub { display: block; margin-top: 3px; font-size: 0.68rem; color: var(--muted); }\n  .box.wide { grid-column: 1 \u002F -1; }\n  .box.dim { opacity: .38; }\n  .box.active { border-color: var(--accent); background: color-mix(in oklab, var(--accent) 18%, var(--panel-2)); transform: translateY(-2px); }\n  .box.good { border-color: color-mix(in oklab, #34d399 55%, var(--line)); background: color-mix(in oklab, #34d399 14%, var(--panel-2)); }\n  .box.info { border-color: color-mix(in oklab, #58a6ff 55%, var(--line)); background: color-mix(in oklab, #58a6ff 14%, var(--panel-2)); }\n  .box.bad { border-color: color-mix(in oklab, #f85149 55%, var(--line)); background: color-mix(in oklab, #f85149 14%, var(--panel-2)); }\n  .arrow { text-align: center; font-size: 0.85rem; color: var(--muted); grid-column: 1 \u002F -1; margin: -2px 0; }\n  @media (max-width: 560px) {\n    .flow { grid-template-columns: 1fr; }\n  }","\"use strict\";\n  const $ = (id) => document.getElementById(id);\n  let file = \"proxy\"; \u002F\u002F \"proxy\" | \"middleware\"\n\n  function setStatus(text, kind = \"info\") {\n    $(\"statusText\").textContent = text;\n    $(\"dot\").className = \"dot \" + kind;\n  }\n\n  function log(line) {\n    const el = $(\"log\");\n    const row = document.createElement(\"div\");\n    row.textContent = line;\n    el.appendChild(row);\n    el.scrollTop = el.scrollHeight;\n  }\n\n  function clearBoxes() {\n    [\"boxRequest\", \"boxBoundary\", \"boxOutcome\"].forEach((id) => {\n      $(id).classList.remove(\"active\", \"good\", \"bad\", \"info\", \"dim\");\n    });\n  }\n\n  function paintBoundarySub() {\n    $(\"boundarySub\").textContent =\n      file === \"proxy\" ? \"proxy.ts — Node.js runtime (fixed)\" : \"middleware.ts — Edge runtime (fixed)\";\n  }\n\n  $(\"fileSeg\").addEventListener(\"click\", (e) => {\n    const btn = e.target.closest(\"button[data-file]\");\n    if (!btn) return;\n    file = btn.dataset.file;\n    [...$(\"fileSeg\").querySelectorAll(\"button\")].forEach((b) =>\n      b.setAttribute(\"aria-pressed\", String(b === btn))\n    );\n    paintBoundarySub();\n  });\n\n  function runRequest() {\n    clearBoxes();\n    $(\"log\").textContent = \"\";\n    const hasCookie = $(\"hasCookie\").checked;\n    const usesNodeApi = $(\"usesNodeApi\").checked;\n    const runtime = file === \"proxy\" ? \"Node.js\" : \"Edge\";\n\n    log(`→ Request hits the boundary: ${file === \"proxy\" ? \"proxy.ts\" : \"middleware.ts\"} (${runtime} runtime, fixed — not configurable).`);\n    $(\"boxRequest\").classList.add(\"info\");\n    $(\"boxBoundary\").classList.add(\"active\");\n\n    \u002F\u002F Step 1: does the boundary even manage to run its check?\n    if (usesNodeApi && runtime === \"Edge\") {\n      log(\"⚠ The boundary calls a Node-only API, but this runtime is Edge — that call would throw (simulated).\");\n      $(\"boxBoundary\").classList.add(\"bad\");\n      $(\"outcomeText\").textContent = \"❌ Boundary check never completes — Edge runtime has no Node built-ins\";\n      $(\"boxOutcome\").classList.add(\"bad\");\n      $(\"arrowText\").textContent = \"↓ (throws before continuing)\";\n      setStatus(\"Blocked: a Node-only call inside an Edge-runtime boundary fails before the auth check finishes.\", \"bad\");\n      $(\"hint\").textContent = \"This is why teams that ran middleware.ts on Edge stuck to Edge-safe libraries — the runtime never had crypto, fs, or most Node built-ins.\";\n      return;\n    }\n\n    if (usesNodeApi && runtime === \"Node.js\") {\n      log(\"✓ The boundary calls a Node-only API — this succeeds, because proxy.ts always runs on Node.js.\");\n    }\n\n    \u002F\u002F Step 2: the actual auth decision.\n    if (!hasCookie) {\n      log(\"✗ No valid session cookie found. The boundary redirects before the App Router resolves any route.\");\n      $(\"boxBoundary\").classList.add(\"info\");\n      $(\"outcomeText\").textContent = \"↪ Redirected to \u002Flogin — the page, layout, and Server Components never ran\";\n      $(\"boxOutcome\").classList.add(\"info\");\n      $(\"arrowText\").textContent = \"↓ redirect()\";\n      setStatus(\"Redirected: the boundary caught this before your app did any work.\", \"warn\");\n      $(\"hint\").textContent = \"That's the network-boundary model: the check happens once, in one place, before routing even starts.\";\n      return;\n    }\n\n    log(\"✓ Valid session cookie found. The boundary calls next() and the App Router takes over.\");\n    $(\"boxBoundary\").classList.add(\"good\");\n    $(\"outcomeText\").textContent = \"✓ Request reaches the App Router → Layout → Page\";\n    $(\"boxOutcome\").classList.add(\"good\");\n    $(\"arrowText\").textContent = \"↓ next()\";\n    setStatus(\"Allowed through — the boundary's job is done; the rest is ordinary rendering.\", \"good\");\n    $(\"hint\").textContent = \"Everything downstream (layouts, pages, Server Actions, cache reads) only runs once the boundary has already decided this request is welcome.\";\n  }\n\n  $(\"send\").addEventListener(\"click\", runRequest);\n\n  $(\"reset\").addEventListener(\"click\", () => {\n    clearBoxes();\n    $(\"log\").textContent = \"\";\n    $(\"outcomeText\").textContent = \"Waiting to send\";\n    $(\"arrowText\").textContent = \"↓\";\n    setStatus(\"Ready — configure the request and send it.\", \"info\");\n    $(\"hint\").textContent = \"Pick a file, a cookie state, and whether the check reaches for a Node-only API, then send.\";\n  });\n\n  function applyPreset(name) {\n    if (name === \"guest\") {\n      file = \"proxy\"; $(\"hasCookie\").checked = false; $(\"usesNodeApi\").checked = false;\n    } else if (name === \"authed\") {\n      file = \"proxy\"; $(\"hasCookie\").checked = true; $(\"usesNodeApi\").checked = false;\n    } else if (name === \"nodeapi\") {\n      file = \"middleware\"; $(\"hasCookie\").checked = true; $(\"usesNodeApi\").checked = true;\n    }\n    [...$(\"fileSeg\").querySelectorAll(\"button\")].forEach((b) =>\n      b.setAttribute(\"aria-pressed\", String(b.dataset.file === file))\n    );\n    paintBoundarySub();\n    runRequest();\n  }\n\n  document.querySelectorAll(\"[data-preset]\").forEach((btn) => {\n    btn.addEventListener(\"click\", () => applyPreset(btn.dataset.preset));\n  });\n\n  paintBoundarySub();",{"height":11,"autorun":12},520,true,{"slug":4,"title":14,"excerpt":15,"coverUrl":16,"vertical":17},"Next.js proxy.ts Explained (with Cheat Sheet)","Next.js 16 renamed middleware.ts to proxy.ts and locked it to the Node.js runtime. Learn the network-boundary model, matcher config, and the migration path.","\u002Fmedia\u002Fcovers\u002Fnextjs-weekly-middleware-to-proxy-network-boundary.png",{"slug":18},"dev",[20,34,46],{"id":21,"slug":18,"name":22,"tagline":23,"description":24,"accentFrom":25,"accentTo":26,"icon":27,"defaultLocale":28,"locales":29,"features":31,"position":33},"019fe637-3d33-714b-b57f-23e163ffca0c","Web Development","Read it. Run it. Prove it.","A post a day on modern web development — most with an editable playground and a quiz that explains every answer. Free, no account needed.","violet-500","cyan-400","◇","en",[28,30],"fa",{"courses":12,"paths":12,"articles":12,"exams":32,"flashcards":32,"packages":12,"community":12,"certificates":12,"teams":12,"commerce":12},false,0,{"id":35,"slug":36,"name":37,"tagline":38,"description":39,"accentFrom":40,"accentTo":25,"icon":41,"defaultLocale":28,"locales":42,"features":44,"position":45},"019fe637-3dc2-754c-8657-0f175bfee7c6","lang","Languages","Learn a language the way you learn a codebase.","Grammar explained the way good documentation explains an API — one idea at a time, each with a quiz.","amber-400","⌘",[28,30,43],"es",{"courses":32,"paths":32,"articles":12,"exams":32,"flashcards":12,"packages":32,"community":12,"certificates":12,"teams":32,"commerce":32},2,{"id":47,"slug":48,"name":49,"tagline":50,"description":51,"accentFrom":52,"accentTo":53,"icon":54,"defaultLocale":28,"locales":55,"features":56,"position":57},"7b3c16f2-931d-410e-802e-e1fa4edab7de","soft","Soft Skills","The half of the job nobody wrote documentation for.","Weekly, on the parts of working life that decide more than your code does — first weeks, meetings, interviews, promotions, and the people around you. Written from what actually happens, and recorded as a podcast you can listen to on the walk.","emerald-400","teal-300","◉",[28],{"courses":32,"paths":32,"articles":12,"exams":32,"flashcards":32,"packages":32,"community":12,"certificates":32,"teams":32,"commerce":32},3,[59,63,67,71,75,79,83,87,91,95,98,102],{"slug":60,"name":61,"articles":62},"webdev","Webdev",107,{"slug":64,"name":65,"articles":66},"javascript","Javascript",89,{"slug":68,"name":69,"articles":70},"frontend","Frontend",72,{"slug":72,"name":73,"articles":74},"css","Css",36,{"slug":76,"name":77,"articles":78},"tutorial","Tutorial",35,{"slug":80,"name":81,"articles":82},"typescript","Typescript",15,{"slug":84,"name":85,"articles":86},"react","React",13,{"slug":88,"name":89,"articles":90},"performance","Performance",12,{"slug":92,"name":93,"articles":94},"browser","Browser",9,{"slug":96,"name":97,"articles":94},"node","Node",{"slug":99,"name":100,"articles":101},"html","Html",7,{"slug":103,"name":104,"articles":101},"accessibility","Accessibility"]