# X_CLIENT_RECORD_ENVELOPE_INVALID

## Means

a response marked as a records envelope has the wrong shape

## Typical cause

a response carried `x-ultimate-records: 1`, and its body is not `{ data, records?, removed? }`: no own `data`, `records` not record type → record key → row, or `removed` not record type → list of keys. The cause names the position and never echoes the body

## Fix

build the body with `encodeRecordEnvelope()` from `@ultimat3/core` in the handler that set the header, or stop setting the header

[Core and runtime](/error-codes#core-and-runtime)