429 Rate Limit Error – Clarifying Idempotency Key Scope and Lifetime for LinkedIn Campaign Creation

When the LinkedIn Marketing API returns a 429 rate‑limit error or a transient 5xx response during campaign creation, clients must retry the request without creating duplicate campaign objects. The intended safe‑retry approach is to include an idempotency key so that a retried call maps to the existing resource instead of generating a new one.

Public documentation does not clarify the effective scope of that key—whether it is tied to the advertiser account, the calling application, or is globally unique—and it does not state how long LinkedIn retains the key for deduplication. This lack of detail leaves implementers unsure whether a key can be safely reused after a delay or across different contexts.

What is the exact scope (advertiser, application, or global) of an idempotency key for campaign creation endpoints? How long does LinkedIn retain the key for deduplication before it expires? Does the scope or retention differ between sandbox and production environments?