G2A's public seller page describes import and export API access following account creation and verification. Confirm the permissions and current documentation available to your account before developing an integration.

Define the system of record

Decide where stock, product mappings and order state live. If your warehouse owns the key ledger, the marketplace quantity should be a projection of available stock. It should not become a second independent ledger that can sell the same units twice.

Write down when a key moves from available to reserved to delivered. Include the recovery path for a failed network request. A timeout means the result may be unknown; it does not prove that the platform rejected the operation.

Start with read-only reconciliation

Before enabling writes, fetch a small set of offers and compare product identifiers, region restrictions, prices and quantities with your internal records. Record differences. Avoid immediately overwriting live quantities based on a partially imported catalog.

When adding writes, scope the pilot to a small inventory segment. Use the current API's supported identifiers and response semantics. Do not invent endpoints from an old tutorial or assume a rate limit applies to every account.

Failure handling

  • Keep an operation log with timestamps, local references and platform response IDs.
  • Retry only when the documented operation is safe to repeat.
  • Reconcile uncertain writes before sending another fulfillment request.
  • Alert an operator when repeated failures leave live stock inconsistent.
  • Define a way to pause offers during a prolonged integration outage.

Delivering a second unused key to compensate for an uncertain first response can double your loss. Keep fulfillment idempotent within your own system and verify remote state before deciding what happened.

Credential lifecycle

Store API secrets on the server, outside front-end code and support screenshots. Limit production access and rotate credentials after an operator or integration change. Test whether rotation interrupts stock updates and plan the handover accordingly.

For account acquisition, ask whether API access is enabled for the specific listing and whether it must be reapproved after a permitted transfer. An API label on an old screenshot does not answer those questions.

Read G2A verification, explore shared inventory controls, and check the G2A product specifications.

Sources and scope

G2A official reference.

Public sources reviewed on 3 October 2026. Operational checklists and hypothetical examples are KeyMerchantHub planning guidance. Confirm account-specific requirements and current commercial terms with the marketplace.