| name | vercel-functions |
| description | Vercel Functions expert guidance — Serverless Functions, Edge Functions, Fluid Compute, streaming, Cron Jobs, and runtime configuration. Use when configuring, debugging, or optimizing server-side code running on Vercel. |
| metadata | {"priority":8,"docs":["https://vercel.com/docs/functions","https://vercel.com/docs/functions/runtimes"],"sitemap":"https://vercel.com/sitemap/docs.xml","pathPatterns":["api/**/*.*","pages/api/**","src/pages/api/**","app/**/route.*","src/app/**/route.*","apps/*/api/**/*.*","apps/*/app/**/route.*","apps/*/src/app/**/route.*","apps/*/pages/api/**","vercel.json","apps/*/vercel.json"],"bashPatterns":["\\bvercel\\s+dev\\b","\\bvercel\\s+logs\\b"]} |
| validate | [{"pattern":"export\\s+default\\s+function","message":"Use named exports (GET, POST, PUT, DELETE) instead of default export for route handlers","severity":"error"},{"pattern":"NextApiRequest|NextApiResponse","message":"NextApiRequest/NextApiResponse are Pages Router types — use Web API Request/Response","severity":"error"},{"pattern":"from\\s+['\"](openai|@anthropic-ai/sdk|anthropic)['\"]|new\\s+(OpenAI|Anthropic)\\(","message":"Direct AI provider SDK detected in route handler. Use the Vercel AI SDK for streaming, tools, and provider abstraction.","severity":"recommended","upgradeToSkill":"ai-sdk","upgradeWhy":"Replace vendor-locked provider SDKs with @ai-sdk/openai or @ai-sdk/anthropic for unified streaming and tool support.","skipIfFileContains":"@ai-sdk/|from\\s+['\"](ai)['\"]|import.*from\\s+['\"](ai)['\"]|streamText|generateText"},{"pattern":"setTimeout\\s*\\(|setInterval\\s*\\(|await\\s+new\\s+Promise\\s*\\([^)]*setTimeout","message":"Long-running or polling logic detected in a serverless handler. Functions have execution time limits.","severity":"recommended","upgradeToSkill":"workflow","upgradeWhy":"Move delayed/polling logic to Vercel Workflow for durable execution with pause, resume, retries, and crash safety.","skipIfFileContains":"use workflow|use step|@vercel/workflow"},{"pattern":"writeFile(Sync)?\\(|createWriteStream\\(|from\\s+['\"](multer|formidable)['\"]|fs\\.writeFile","message":"Local filesystem write detected. Serverless functions have ephemeral, read-only filesystems.","severity":"error","upgradeToSkill":"vercel-storage","upgradeWhy":"Replace local filesystem writes with Vercel Blob, Neon, or Upstash for persistent, platform-native storage.","skipIfFileContains":"@vercel/blob|@upstash/|@neondatabase/"},{"pattern":"export\\s+(async\\s+)?function\\s+(GET|POST|PUT|PATCH|DELETE)\\b","message":"Route handler has no observability instrumentation. Add logging and error tracking for production debugging.","severity":"warn","upgradeToSkill":"observability","upgradeWhy":"Add structured logging, error tracking, and OTel instrumentation to route handlers.","skipIfFileContains":"console\\.error|logger\\.|captureException|Sentry|@vercel/otel|withTracing"},{"pattern":"from\\s+['\"\"](lru-cache|node-cache|memory-cache)['\"\"]|new\\s+(LRUCache|NodeCache|Map)\\(\\s*\\).*cache","message":"In-process memory cache detected in serverless function. Process memory is not shared across invocations.","severity":"recommended","upgradeToSkill":"runtime-cache","upgradeWhy":"Replace in-process caches with Vercel Runtime Cache (getCache from @vercel/functions) for region-aware caching that persists across invocations.","skipIfFileContains":"getCache|from\\s+['\"\"]\\@vercel/functions['\"\"]"},{"pattern":"maxRetries\\s*[=:]|retryCount\\s*[=:]|retry\\s*\\(\\s*|for\\s*\\([^)]*retry|while\\s*\\([^)]*retry","message":"Manual retry logic detected. Use Vercel Workflow DevKit for automatic retries with durable execution.","severity":"recommended","upgradeToSkill":"workflow","upgradeWhy":"Replace manual retry loops with Workflow DevKit steps that provide automatic retries, crash safety, and observability.","skipIfFileContains":"use workflow|use step|@vercel/workflow|from\\s+['\"\"](workflow)['\"\"]"},{"pattern":"from\\s+['\"](express)['\"\"]|require\\s*\\(\\s*['\"](express)['\"\"\\)]","message":"Express.js detected in a Vercel project. Vercel Functions use the Web Request/Response API — Express middleware, req/res, and app.listen() do not work in serverless.","severity":"recommended","upgradeToSkill":"vercel-functions","upgradeWhy":"Replace Express with Next.js route handlers (export async function GET/POST) or Vercel Functions using the Web Request/Response API.","skipIfFileContains":"export\\s+(async\\s+)?function\\s+(GET|POST|PUT|PATCH|DELETE)|from\\s+['\"\"](next/server|@vercel/functions)['\"\"]"}] |
| retrieval | {"aliases":["serverless functions","api routes","edge functions","lambda"],"intents":["create serverless function","configure function runtime","optimize cold starts","add api route"],"entities":["Serverless Functions","Edge Functions","Fluid Compute","streaming","Cron Jobs"]} |
| chainTo | [{"pattern":"from\\s+['\\\"](openai|@anthropic-ai/sdk|anthropic)['\"]|new\\s+(OpenAI|Anthropic)\\(","targetSkill":"ai-sdk","message":"Direct AI provider SDK in route handler — loading AI SDK guidance for unified streaming and tool support."},{"pattern":"setTimeout\\s*\\(|setInterval\\s*\\(|await\\s+new\\s+Promise\\s*\\([^)]*setTimeout","targetSkill":"workflow","message":"Long-running or polling logic in serverless handler — loading Workflow DevKit for durable execution."},{"pattern":"writeFile(Sync)?\\(|createWriteStream\\(|from\\s+['\\\"](multer|formidable)['\"]|fs\\.writeFile","targetSkill":"vercel-storage","message":"Local filesystem write in serverless function — loading Vercel Storage guidance for platform-native persistence."},{"pattern":"from\\s+['\"\"]@vercel/(postgres|kv)['\"\"]","targetSkill":"vercel-storage","message":"@vercel/postgres and @vercel/kv are sunset — loading Vercel Storage guidance for Neon and Upstash migration."},{"pattern":"generateObject\\s*\\(|streamObject\\s*\\(|toDataStreamResponse|maxSteps\\b|CoreMessage\\b","targetSkill":"ai-sdk","message":"Deprecated AI SDK v5 API detected — loading AI SDK v6 guidance for migration."},{"pattern":"while\\s*\\(\\s*true\\s*\\)\\s*\\{|for\\s*\\(\\s*;\\s*;\\s*\\)\\s*\\{|setInterval\\s*\\(\\s*async","targetSkill":"workflow","message":"Polling loop in serverless function detected — loading Workflow DevKit for durable, crash-safe execution with pause/resume.","skipIfFileContains":"use workflow|use step|from\\s+['\"]workflow['\"]"},{"pattern":"from\\s+['\"]express['\"]|require\\s*\\(\\s*['\"]express['\"]","targetSkill":"vercel-functions","message":"Express.js detected — loading Vercel Functions guidance for Web Request/Response API route handlers that replace Express middleware and routing.","skipIfFileContains":"export\\s+(async\\s+)?function\\s+(GET|POST|PUT|PATCH|DELETE)"},{"pattern":"from\\s+['\"\"](lru-cache|node-cache|memory-cache)['\"\"]|new\\s+(LRUCache|NodeCache|Map)\\(\\s*\\).*cache","targetSkill":"runtime-cache","message":"In-process memory cache in serverless function — loading Runtime Cache guidance for region-aware caching that persists across invocations.","skipIfFileContains":"getCache|from\\s+['\"\"]\\@vercel/functions['\"\"]"},{"pattern":"maxRetries\\s*[=:]|retryCount\\s*[=:]|retry\\s*\\(\\s*|for\\s*\\([^)]*retry|while\\s*\\([^)]*retry","targetSkill":"workflow","message":"Manual retry logic in serverless handler — loading Workflow DevKit guidance for automatic retries with durable execution.","skipIfFileContains":"use workflow|use step|@vercel/workflow|from\\s+['\"\"](workflow)['\"\"]"}] |
