## TL;DR

Fixed in @mergeapi/merge-node-client 4.0.4. Upgrade and pass expand values as the SDK documents; the serialized query now matches the comma-separated format the API expects.

## Fix

1. Fixed in @mergeapi/merge-node-client 4.0.4.
   Expected: You get the expected result; the problem is gone.
2. Upgrade and pass expand values as the SDK documents; the serialized query now matches the comma-separated format the API expects.
   Expected: You get the expected result; the problem is gone.

## When to use

- You are dealing with this situation.
- The symptom matches: Merge Node SDK v4 corrupts multiple expand query params.

## When NOT to use

- Unrelated issues with a different cause.
- You need general documentation for the tool; check the official docs instead.

## Compatibility

Reported per the linked source (mentions 4.0.4).

## Variant phrasings

### Merge Node SDK v4 corrupts multiple expand query params

## Why it happens

GitHub issue on merge-api/merge-node-client: Merge REST requires multiple expand values comma-separated, but the v4 SDK sent them in a way the API rejected, breaking multi-expand list calls.

## Edge cases

- If your error message differs even slightly, this is probably a different issue; search the exact text.
- Behavior can change between releases; the linked source reflects the versions above.
- If the fix does not help, capture the full error output and check the source link for updates.