2. Listing VCUs on the Marketplace (User Journey)

User Action (Tero Platform): A Tero Carbon user (Project Owner/Holder) decides to list VCUs on your Marketplace. They initiate a manual transfer of the desired VCU quantity from their Tero account to your Marketplace's designated Tero Carbon custody account address using the Tero Platform interface.

Tero Action: Tero Carbon administrators approve the transfer (if required by policy). Upon confirmation, Tero:

Records the transfer on the Polygon blockchain (generating a Transfer NFT certificate).

Updates its internal registry: decrements the user's balance, increments the Marketplace custody account balance.

Crucially: Marks the transferred VCU tokens in its system as "Externalized" or "In External Custody". This is Tero's internal "destokenization" step, preventing the native Tero token from being actively traded while under external custody.

Sends notifications (e.g., email) to the user and the Marketplace.

[Webhook] Sends a webhook notification to the Marketplace confirming the deposit into custody.

Marketplace Action (Triggered by Webhook/Confirmation):

The Marketplace verifies the VCU deposit.

The Marketplace must tokenizes the received VCUs within its own internal system. This creates the representation that will be traded on the Marketplace platform.

Notification to Tero: The Marketplace calls the reportTransaction endpoint with operation: Tokenization, providing details of the VCUs tokenized internally (quantity, source issuance ID, link to internal representation if available).

Tero Action:

Receives the Tokenization notification (202 Accepted).

Admin reviews the notification details for consistency.

[Webhook] If approved, Tero may send a webhook confirming the notification was processed. The VCU remains marked as "Externalized" in Tero's system.

[Webhook] If rejected (e.g., inconsistent data), Tero sends a rejection webhook. The Marketplace must investigate and potentially reverse its internal tokenization or correct and resubmit the notification.

Marketplace Action: Once the internal tokenization is confirmed and the notification (implicitly or explicitly) approved, the Marketplace uses getProjectData, getIssuanceData, getUnitsData (querying its custody account) to fetch details and list the internally tokenized VCUs for sale on its platform.