Postgres FATAL: remaining connection slots are reserved / too many clients (53300)

Serverless functions or parallel agent workers opening direct TCP Postgres connections exhaust max_connections without PgBouncer transaction pooling or HTTP driver.

1. Immediate Code & SKU Fix

Replace With SKU: @neondatabase/serverless (HTTP/WebSocket pooler) or Supabase Supavisor (:6543?pgbouncer=true)

Install Command: npm install @neondatabase/serverless

Required Env Vars: DATABASE_URL

import { neon } from "@neondatabase/serverless"; const sql = neon(process.env.DATABASE_URL!); // Uses pooled HTTP fetch

2. Verified Hot-Swap Fallback Route

JTBD: serverless-postgres

Primary: neon → Fallback: supabase

liveHealth: operational · autoActOk: false

Corpus/QPS exceeds comfortable Postgres vector range — Qdrant/Milvus/Turbopuffer.

GET /api/rescue JSON (<2 KB)Falsify Pick (/api/falsify)

Matched Error String Signatures (5)

remaining connection slots are reservedsorry, too many clients already53300MaxClientsInSessionModeP1001: Can't reach database server

curl -s "https://getagentdepot.com/api/rescue?q=remaining%20connection%20slots%20are%20reserved"

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