[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"skill:01M6EEQ4CV0RK46RGJB9D9TASX":3,"skill-same:01M6EEQ4CV0RK46RGJB9D9TASX":45},{"skillNo":4,"name":5,"nameZh":6,"description":6,"descriptionZh":6,"repositoryFullName":7,"ownerLogin":8,"ownerAvatarUrl":9,"ownerAccountNo":10,"ownerDisplayName":11,"repositoryNo":12,"starsCount":13,"licenseSpdxId":14,"licenseFileUrl":6,"sourceHtmlUrl":15,"categories":16,"keywords":17,"publishedAt":18,"linkOnly":19,"markdownContent":20,"markdownBody":20,"frontMatter":21,"refName":22,"commitSha":23,"skillDirectory":24,"forksCount":25,"repositoryHtmlUrl":26,"repositoryHomepageUrl":27,"ownerHtmlUrl":28,"ownerBlogUrl":6,"ownerDescription":29,"updatedAt":30,"install":31,"resources":44},"01M6EEQ4CV0RK46RGJB9D9TASX","cors",null,"ComeOnOliver\u002Fskillshub","ComeOnOliver","https:\u002F\u002Favatars.githubusercontent.com\u002Fu\u002F43215937?v=4","01M6E5JNFECJAAVFE0W7SMWWD2","Haoran Shu","01M6E5JNNDQS7AJZDYFQ8TPZCK",66,"MIT","https:\u002F\u002Fgithub.com\u002FComeOnOliver\u002Fskillshub\u002Fblob\u002Fmain\u002Fskills\u002FTerminalSkills\u002Fskills\u002Fcors\u002FSKILL.md",[],[5],"2026-11-10 10:12:30",false,"# CORS (Cross-Origin Resource Sharing)\n\n## Overview\n\nCORS controls which websites can call your API from a browser. Without proper CORS headers, browsers block cross-origin requests. Misconfigured CORS is either too restrictive (breaks your frontend) or too permissive (security risk). This skill covers correct configuration for common setups.\n\n## Instructions\n\n### Step 1: Express\n\n```typescript\n\u002F\u002F server.ts — CORS configuration for Express\nimport cors from 'cors'\nimport express from 'express'\n\nconst app = express()\n\n\u002F\u002F Production: whitelist specific origins\nconst allowedOrigins = [\n  'https:\u002F\u002Fmyapp.com',\n  'https:\u002F\u002Fadmin.myapp.com',\n  process.env.NODE_ENV === 'development' && 'http:\u002F\u002Flocalhost:3000',\n].filter(Boolean) as string[]\n\napp.use(cors({\n  origin: (origin, callback) => {\n    \u002F\u002F Allow requests with no origin (mobile apps, curl, server-to-server)\n    if (!origin) return callback(null, true)\n    if (allowedOrigins.includes(origin)) return callback(null, true)\n    callback(new Error(`Origin ${origin} not allowed by CORS`))\n  },\n  credentials: true,                    \u002F\u002F allow cookies\u002Fauth headers\n  methods: ['GET', 'POST', 'PUT', 'PATCH', 'DELETE'],\n  allowedHeaders: ['Content-Type', 'Authorization'],\n  maxAge: 86400,                         \u002F\u002F cache preflight for 24h\n}))\n```\n\n### Step 2: Next.js API Routes\n\n```typescript\n\u002F\u002F next.config.ts — CORS via Next.js headers\nconst nextConfig = {\n  async headers() {\n    return [\n      {\n        source: '\u002Fapi\u002F:path*',\n        headers: [\n          { key: 'Access-Control-Allow-Origin', value: 'https:\u002F\u002Fmyapp.com' },\n          { key: 'Access-Control-Allow-Methods', value: 'GET,POST,PUT,DELETE,OPTIONS' },\n          { key: 'Access-Control-Allow-Headers', value: 'Content-Type, Authorization' },\n          { key: 'Access-Control-Allow-Credentials', value: 'true' },\n          { key: 'Access-Control-Max-Age', value: '86400' },\n        ],\n      },\n    ]\n  },\n}\n```\n\n### Step 3: Manual Headers (Any Framework)\n\n```typescript\n\u002F\u002F middleware.ts — Manual CORS for any HTTP server\nexport function corsMiddleware(req, res, next) {\n  const origin = req.headers.origin\n  const allowed = ['https:\u002F\u002Fmyapp.com', 'https:\u002F\u002Fadmin.myapp.com']\n\n  if (allowed.includes(origin)) {\n    res.setHeader('Access-Control-Allow-Origin', origin)\n    res.setHeader('Access-Control-Allow-Credentials', 'true')\n  }\n\n  \u002F\u002F Handle preflight (OPTIONS) requests\n  if (req.method === 'OPTIONS') {\n    res.setHeader('Access-Control-Allow-Methods', 'GET,POST,PUT,DELETE')\n    res.setHeader('Access-Control-Allow-Headers', 'Content-Type,Authorization')\n    res.setHeader('Access-Control-Max-Age', '86400')\n    return res.status(204).end()\n  }\n\n  next()\n}\n```\n\n## Guidelines\n\n- NEVER use `Access-Control-Allow-Origin: *` with `credentials: true` — browsers reject this.\n- `*` origin is only safe for truly public APIs with no authentication.\n- Always set `Access-Control-Max-Age` to cache preflight responses (reduces OPTIONS requests).\n- CORS only applies to browser requests — server-to-server calls ignore CORS entirely.\n- If using cookies across domains, also set `SameSite=None; Secure` on cookies.\n",{},"main","def8531e65114c0fca8fb8551c1871ee0eed705c","skills\u002FTerminalSkills\u002Fskills\u002Fcors",24,"https:\u002F\u002Fgithub.com\u002FComeOnOliver\u002Fskillshub","https:\u002F\u002Fskillshub.wtf","https:\u002F\u002Fgithub.com\u002FComeOnOliver","AI & Blockchain Engineer\r\n","2026-06-24 22:07:19",{"source":7,"skillName":5,"commands":32,"prompt":42,"zipAvailable":43},[33,36,39],{"tool":34,"command":35},"npx","npx skills add ComeOnOliver\u002Fskillshub --skill cors",{"tool":37,"command":38},"bunx","bunx skills add ComeOnOliver\u002Fskillshub --skill cors",{"tool":40,"command":41},"pnpm","pnpm dlx skills add ComeOnOliver\u002Fskillshub --skill cors","安装技能，技能地址：https:\u002F\u002Fgithub.com\u002FComeOnOliver\u002Fskillshub\u002Fblob\u002Fmain\u002Fskills\u002FTerminalSkills\u002Fskills\u002Fcors\u002FSKILL.md",true,[],[46,60,70,79,85,92],{"skillNo":47,"name":48,"nameZh":6,"description":6,"descriptionZh":6,"repositoryFullName":7,"ownerLogin":8,"ownerAvatarUrl":9,"ownerAccountNo":10,"ownerDisplayName":11,"repositoryNo":12,"starsCount":13,"licenseSpdxId":14,"licenseFileUrl":6,"sourceHtmlUrl":49,"categories":50,"keywords":56,"publishedAt":18},"01M6FKJN13GMG4KY57J3QD8GY5","model-hierarchy-skill","https:\u002F\u002Fgithub.com\u002FComeOnOliver\u002Fskillshub\u002Fblob\u002Fmain\u002Fskills\u002Fzscole\u002Fmodel-hierarchy-skill\u002Fmodel-hierarchy-skill\u002FSKILL.md",[51],{"categoryNo":52,"categoryName":53,"taxonomyType":54,"taxonomyTypeDesc":55},"01JBSEEDCAT000000000000023","Skill与智能体开发","SCENARIO","使用场景",[57,58,59],"model","model hierarchy","model hierarchy skill",{"skillNo":61,"name":62,"nameZh":6,"description":6,"descriptionZh":6,"repositoryFullName":7,"ownerLogin":8,"ownerAvatarUrl":9,"ownerAccountNo":10,"ownerDisplayName":11,"repositoryNo":12,"starsCount":13,"licenseSpdxId":14,"licenseFileUrl":6,"sourceHtmlUrl":63,"categories":64,"keywords":66,"publishedAt":18},"01M6FKJJJ6GCAMR4PPPRD12M5X","zoom-mcp","https:\u002F\u002Fgithub.com\u002FComeOnOliver\u002Fskillshub\u002Fblob\u002Fmain\u002Fskills\u002Fzoom\u002Fskills\u002Fzoom-mcp\u002FSKILL.md",[65],{"categoryNo":52,"categoryName":53,"taxonomyType":54,"taxonomyTypeDesc":55},[67,68,69],"MCP","zoom","zoom mcp",{"skillNo":71,"name":72,"nameZh":6,"description":6,"descriptionZh":6,"repositoryFullName":7,"ownerLogin":8,"ownerAvatarUrl":9,"ownerAccountNo":10,"ownerDisplayName":11,"repositoryNo":12,"starsCount":13,"licenseSpdxId":14,"licenseFileUrl":6,"sourceHtmlUrl":73,"categories":74,"keywords":75,"publishedAt":18},"01M6FKJE3KYT3KPEZMEEHYKA6K","zoom-apps-sdk","https:\u002F\u002Fgithub.com\u002FComeOnOliver\u002Fskillshub\u002Fblob\u002Fmain\u002Fskills\u002Fzoom\u002Fskills\u002Fzoom-apps-sdk\u002FSKILL.md",[],[76,77,78,68],"sdk","zoom apps sdk","apps",{"skillNo":80,"name":81,"nameZh":6,"description":6,"descriptionZh":6,"repositoryFullName":7,"ownerLogin":8,"ownerAvatarUrl":9,"ownerAccountNo":10,"ownerDisplayName":11,"repositoryNo":12,"starsCount":13,"licenseSpdxId":14,"licenseFileUrl":6,"sourceHtmlUrl":82,"categories":83,"keywords":84,"publishedAt":18},"01M6FKJ9EDH9Q5VWDF8HAJRSP0","windows","https:\u002F\u002Fgithub.com\u002FComeOnOliver\u002Fskillshub\u002Fblob\u002Fmain\u002Fskills\u002Fzoom\u002Fskills\u002Fwindows\u002FSKILL.md",[],[81],{"skillNo":86,"name":87,"nameZh":6,"description":6,"descriptionZh":6,"repositoryFullName":7,"ownerLogin":8,"ownerAvatarUrl":9,"ownerAccountNo":10,"ownerDisplayName":11,"repositoryNo":12,"starsCount":13,"licenseSpdxId":14,"licenseFileUrl":6,"sourceHtmlUrl":88,"categories":89,"keywords":91,"publishedAt":18},"01M6FKJ666BEEFC3AE9GJ72Q93","whiteboard","https:\u002F\u002Fgithub.com\u002FComeOnOliver\u002Fskillshub\u002Fblob\u002Fmain\u002Fskills\u002Fzoom\u002Fskills\u002Fwhiteboard\u002FSKILL.md",[90],{"categoryNo":52,"categoryName":53,"taxonomyType":54,"taxonomyTypeDesc":55},[87],{"skillNo":93,"name":94,"nameZh":6,"description":6,"descriptionZh":6,"repositoryFullName":7,"ownerLogin":8,"ownerAvatarUrl":9,"ownerAccountNo":10,"ownerDisplayName":11,"repositoryNo":12,"starsCount":13,"licenseSpdxId":14,"licenseFileUrl":6,"sourceHtmlUrl":95,"categories":96,"keywords":97,"publishedAt":18},"01M6FKJ21WFCDGTJQ2Q91T9DVW","websockets","https:\u002F\u002Fgithub.com\u002FComeOnOliver\u002Fskillshub\u002Fblob\u002Fmain\u002Fskills\u002Fzoom\u002Fskills\u002Fwebsockets\u002FSKILL.md",[],[94]]