🐛 retry once on connection error

[ianardee]

Description

Hi Mindee Team,

We are using the Mindee Node.js SDK (mindeeClient.enqueue()) in a Next.js / Vercel Serverless environment. We are consistently hitting an UND_ERR_SOCKET ("other side closed") error on our API routes. Because Vercel pauses serverless execution between invocations, Keep-Alive sockets in the connection pool go stale. When the function wakes up for the next request, undici grabs a pooled socket that the Mindee API (or its load balancer) has already closed, resulting in an immediate crash at bytesWritten: 0.

We have tried multiple aggressive workarounds to completely disable connection reuse and Keep-Alive, but the SDK seems to bypass or ignore them:

1. Using the SDK's dispatcher option

We passed a custom undici Agent to strictly disable pipelining and keep-alive pools:

import * as mindee from "mindee";
import { Agent } from "undici";

const mindeeClient = new mindee.Client({
  apiKey: process.env.MINDEE_API_KEY!,
  dispatcher: new Agent({
    pipelining: 0,
    keepAliveTimeout: 1,
    keepAliveMaxTimeout: 1
  }),
});

Result: Still throws "other side closed"

2. Monkey-patching https.request

We tried intercepting Node's underlying https module to force keepAlive: false:

const noKeepAliveAgent = new https.Agent({ keepAlive: false });
const originalHttpsRequest = https.request;
(https as any).request = function (url: any, options: any, cb: any) {
  if (typeof options === "object") options.agent = noKeepAliveAgent;
  return originalHttpsRequest(url, options, cb);
};

Result: Still throws "other side closed"

3. Setting Environment Variables

We also added MINDEE_REQUEST_TIMEOUT=60 and NODE_TLS_REJECT_UNAUTHORIZED=0 to our Vercel environment.

Despite all of this, the SDK continues to grab closed sockets from a pool somewhere and fails.

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Requires a change to the official Guide documentation.