hcengineering/platform · error · HttpError

Internal Server Error

Error message

Internal Server Error

What it means

The link-preview pod's errorHandler is the final middleware: for errors that carry a numeric err.code it echoes that status, but for anything else it calls Analytics.handleError and returns HTTP 500 with err.message ?? 'Internal Server Error'. So this message is the fallback for any unexpected exception thrown by link-preview request handling.

Source

Thrown at pods/link-preview/src/middleware.ts:72

export interface ErrorHandlerOptions {
  ctx: MeasureContext
}

export const errorHandler = (options: ErrorHandlerOptions): ErrorRequestHandler => {
  const { ctx } = options

  return (err: any, req: Request, res: Response, _next: NextFunction): void => {
    ctx.error(err.message, { code: err.code, message: err.message })

    if (err instanceof HttpError) {
      res.status(err.code).json({ message: err.message })
      return
    }

    Analytics.handleError(err)

    res.status(500).json({ message: err.message ?? 'Internal Server Error' })
  }
}

View on GitHub (pinned to 63e28dc964)

Solutions

1. Check server logs / Analytics for the underlying error recorded by Analytics.handleError to find the real cause
2. Verify the target URL is reachable from the server (firewall, DNS, TLS) — not just from your browser
3. Retry the request; transient fetch/parse failures of the target page are the most common cause
4. If reproducible for one URL, inspect that page's markup for parser-breaking content and report/upgrade the preview parser

Example fix

// before
res.status(500).json({ message: err.message ?? 'Internal Server Error' })
// after (caller side)
try {
  const preview = await fetchPreview(url)
} catch (e) {
  if (e.status === 500) return retryWithBackoff(() => fetchPreview(url))
  throw e
}

const parsed = new URL(targetUrl)
if (!['http:', 'https:'].includes(parsed.protocol)) {
  throw new Error('unsupported preview target')
}

function isHttpError(err: unknown): err is { code: number; message: string } {
  return typeof err === 'object' && err !== null && typeof (err as any).code === 'number'
}

try {
  preview = await getLinkPreview(url)
} catch (err) {
  if (isHttpError(err)) throw err // surface 4xx as-is
  await backoffRetry(() => getLinkPreview(url), 3)
}

When it happens

Trigger: Any thrown/uncaught error inside a link-preview route (e.g. parseLinkPreviewDetails throwing on fetch/parse failures) that is not an HttpError with a status code — network failures fetching the URL, HTML parsing exceptions, timeouts.

Common situations: Preview target URL unreachable or returns malformed HTML; upstream fetch timeouts; dependency bugs inside the preview parser; config problems surfacing as generic exceptions.

Understand the failure class

• HTTP status errors: handling 4xx and 5xx responses — how to handle 4xx and 5xx responses properly.

Related errors

• err.message
• err.message
• err.message
• err.message
• Internal server error

AI-assisted analysis of hcengineering/platform@63e28dc964 (2026-08-29). Data as JSON: /api/errors/1d1d513ac3b65e4a. Report an issue: GitHub.