{"record":{"id":"45d2c56df81ad639","repo":"sveltejs/kit","slug":"could-not-determine-clientaddress","errorCode":null,"errorMessage":"Could not determine clientAddress","messagePattern":"Could not determine clientAddress","errorType":"exception","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"packages/kit/src/exports/vite/dev/index.js","lineNumber":431,"sourceCode":"\t\t\t\t\t\t\t.replace(/%sveltekit\\.status%/g, String(status))\n\t\t\t\t\t\t\t.replace(/%sveltekit\\.error\\.message%/g, escape_html(message));\n\t\t\t\t\t};\n\n\t\t\t\t\tres.writeHead(500, {\n\t\t\t\t\t\t'Content-Type': 'text/html; charset=utf-8'\n\t\t\t\t\t});\n\t\t\t\t\tres.end(\n\t\t\t\t\t\terror_template({ status: 500, message: manifest_error.message ?? 'Invalid routes' })\n\t\t\t\t\t);\n\n\t\t\t\t\treturn;\n\t\t\t\t}\n\n\t\t\t\tconst rendered = await server.respond(request, {\n\t\t\t\t\tgetClientAddress: () => {\n\t\t\t\t\t\tconst { remoteAddress } = req.socket;\n\t\t\t\t\t\tif (remoteAddress) return remoteAddress;\n\t\t\t\t\t\tthrow new Error('Could not determine clientAddress');\n\t\t\t\t\t},\n\t\t\t\t\tread: (file) => {\n\t\t\t\t\t\tif (file in manifest.server_assets) {\n\t\t\t\t\t\t\treturn fs.readFileSync(from_fs(file));\n\t\t\t\t\t\t}\n\n\t\t\t\t\t\treturn fs.readFileSync(path.join(svelte_config.files.assets, file));\n\t\t\t\t\t},\n\t\t\t\t\tbefore_handle: async (event, config, prerender, handle) => {\n\t\t\t\t\t\t// we need to use .run because .enterWith() is not supported in Cloudflare Workers\n\t\t\t\t\t\t// see https://blog.cloudflare.com/workers-node-js-asynclocalstorage/\n\t\t\t\t\t\treturn await async_local_storage.run({ event, config, prerender }, handle);\n\t\t\t\t\t},\n\t\t\t\t\temulator\n\t\t\t\t});\n\n\t\t\t\tif (rendered.status === 404) {\n\t\t\t\t\t// @ts-expect-error","sourceCodeStart":413,"sourceCodeEnd":449,"githubUrl":"https://github.com/sveltejs/kit/blob/03f1687fe612ce3d2d9131139b5b188d9cf90c64/packages/kit/src/exports/vite/dev/index.js#L413-L449","documentation":"The dev server builds a `RequestEvent` with a `getClientAddress()` callback that reads `req.socket.remoteAddress`. If the socket has no remote address (e.g. already destroyed, or an unusual socket/handler setup), the callback throws this error instead of returning a bogus address.","triggerScenarios":"Request handled after the underlying socket was closed/destroyed, so `remoteAddress` is undefined; proxying or custom server plumbing that replaces the normal http socket; early-aborted requests.","commonSituations":"Client cancels a request mid-render; high-frequency polling with aborts; running behind unusual Unix-socket or in-memory transports where remoteAddress is not set.","solutions":["Guard request handling so aborted requests are not responded to","Check middleware/proxy setup that may detach the socket from the request","Upgrade SvelteKit/Vite — later versions handle aborted dev requests more gracefully","If you need the client IP, ensure the connection is a normal TCP socket (not a custom transport)"],"exampleFix":null,"handlingStrategy":"try-catch","validationCode":"// caller-side check before reading the address\nconst addr = req.socket?.remoteAddress;\nif (!addr) {\n  // request socket is gone; skip responding\n  return;\n}","typeGuard":"function hasClientAddress(socket) {\n  return typeof socket?.remoteAddress === 'string' && socket.remoteAddress.length > 0;\n}","tryCatchPattern":"try {\n  await render(request);\n} catch (err) {\n  if (/Could not determine clientAddress/.test(err.message)) {\n    // request aborted before response; safe to ignore\n    return;\n  }\n  throw err;\n}","preventionTips":["Don't cache or reuse RequestEvents whose socket may be destroyed","Handle client aborts promptly so dead requests aren't processed","Avoid custom transports that strip remoteAddress in dev","Keep SvelteKit updated; later versions tolerate aborted dev requests better"],"tags":["dev-server","socket","client-address"],"backgroundTag":"missing-client-address","analyzedSha":"03f1687fe612ce3d2d9131139b5b188d9cf90c64","analyzedAt":"2026-09-02T02:01:50.504Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-09T06:17:21.866Z"}