Redis Schema

Common Redis operations

import { redis } from '@devvit/web/server'

// String (simple values, flags)
await redis.set('key', 'value')
const value = await redis.get('key')           // string | null

// Numbers
await redis.incrBy('counter', 1)

// Hash (object/record)
await redis.hSet('user:t2_abc:stats', { solved: '5', bestTime: '120' })
const stats = await redis.hGetAll('user:t2_abc:stats')  // Record<string, string>

// Sorted set (leaderboard)
await redis.zAdd('leaderboard:wins', { member: 'alice', score: 100 })
const top10 = await redis.zRange('leaderboard:wins', 0, 9, { by: 'score', reverse: true })

// Expiration
await redis.expire('session:abc', 3600)  // seconds

// Batch reads (prefer over multiple round trips)
const [a, b] = await redis.mGet(['key1', 'key2'])

Platform limits to design around

• 500MB total storage per subreddit install
• 1,000 commands/second max
• 4MB max request payload
• Prefer hGetAll over multiple hGet calls
• Prefer mGet over multiple get calls

Null safety (noUncheckedIndexedAccess is on)

const value = await redis.get('key')
if (value === null) {
  // handle missing key — don't assume it exists
}

const stats = await redis.hGetAll('user:t2_abc:stats')
const solved = stats['solved']  // string | undefined — must check
if (solved !== undefined) {
  const count = parseInt(solved, 10)
}

Checklist before finishing

• Tests written FIRST in __tests__/ using bun:test and devvit-mocks for Redis operations
• Keys follow {entity}:{id}:{field} pattern
• All Redis values are strings — parse numbers with parseInt/parseFloat
• Null/undefined handled after every get / hGet
• Batch reads used where multiple keys needed
• Expiration set on ephemeral data (sessions, temp state)
• Total storage estimate documented if significant
• bun run test passes with zero failures