API: Cache markets for 15 seconds at least

web/pages/api/v0/market/[id]/index.ts

@@ -4,6 +4,7 @@ import { listAllComments } from 'web/lib/firebase/comments'
 import { getContractFromId } from 'web/lib/firebase/contracts'
 import { applyCorsHeaders, CORS_UNRESTRICTED } from 'web/lib/api/cors'
 import { FullMarket, ApiError, toFullMarket } from '../../_types'
+import { marketCacheStrategy } from '../../markets'
 
 export default async function handler(
   req: NextApiRequest,
@@ -24,6 +25,6 @@ export default async function handler(
     return
   }
 
-  res.setHeader('Cache-Control', 'max-age=0')
+  res.setHeader('Cache-Control', marketCacheStrategy)
   return res.status(200).json(toFullMarket(contract, comments, bets))
 }

web/pages/api/v0/market/[id]/lite.ts

@@ -2,6 +2,7 @@ import { NextApiRequest, NextApiResponse } from 'next'
 import { getContractFromId } from 'web/lib/firebase/contracts'
 import { applyCorsHeaders, CORS_UNRESTRICTED } from 'web/lib/api/cors'
 import { ApiError, toLiteMarket, LiteMarket } from '../../_types'
+import { marketCacheStrategy } from '../../markets'
 
 export default async function handler(
   req: NextApiRequest,
@@ -18,6 +19,6 @@ export default async function handler(
     return
   }
 
-  res.setHeader('Cache-Control', 'max-age=0')
+  res.setHeader('Cache-Control', marketCacheStrategy)
   return res.status(200).json(toLiteMarket(contract))
 }

web/pages/api/v0/markets.ts

@@ -6,6 +6,8 @@ import { toLiteMarket, ValidationError } from './_types'
 import { z } from 'zod'
 import { validate } from './_validate'
 
+export const marketCacheStrategy = 's-maxage=15, stale-while-revalidate=45'
+
 const queryParams = z
   .object({
     limit: z
@@ -39,7 +41,7 @@ export default async function handler(
   try {
     const contracts = await listAllContracts(limit, before)
     // Serve from Vercel cache, then update. see https://vercel.com/docs/concepts/functions/edge-caching
-    res.setHeader('Cache-Control', 's-maxage=1, stale-while-revalidate')
+    res.setHeader('Cache-Control', marketCacheStrategy)
     res.status(200).json(contracts.map(toLiteMarket))
   } catch (e) {
     res.status(400).json({