Vercel KV / Upstash Redis Patterns

Quick Guide: Use @upstash/redis (the successor to @vercel/kv) for serverless, edge-compatible Redis via REST API. Key gotchas: REST adds ~5-15ms latency per call vs TCP Redis, all values are auto-serialized as JSON (objects round-trip transparently but Date objects become strings), pipeline/multi execute as single HTTP requests but pipeline is NOT atomic. Use Redis.fromEnv() for automatic connection. Always set TTLs -- serverless Redis is billed per command.

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CRITICAL: Before Using This Skill

All code must follow project conventions in CLAUDE.md (kebab-case, named exports, import ordering, import type, named constants)

(You MUST use @upstash/redis for new projects -- @vercel/kv was deprecated in December 2024 and all stores were migrated to Upstash Redis)

(You MUST set TTLs on all cached data -- serverless Redis is billed per command and has storage limits per plan)

(You MUST understand that this is a REST/HTTP client, NOT a TCP Redis client -- each command is an HTTP request with ~5-15ms overhead, so batch with pipelines when possible)

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