# X_OUTBOUND_RETRY_UNSAFE

## Means

a retry was asked for on a write that is not idempotent

## Typical cause

outbound() was given retry on a POST or PATCH without idempotent: true. A replayed write is a second charge, so the call is refused before anything is sent

## Fix

add `idempotent: true` to the `outbound()` call with the vendor's idempotency-key header, or drop `retry`

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