Pay on Behalf on TT-web

Pay on Behalf on TT-web (the TradeTrust web application) lives on the TT Verify page. The PlatformPaymaster input field appears on that page once the connected wallet is confirmed to have EIP-7702 delegation enabled.

Token Registry v5 only

Pay on Behalf only applies to documents issued from Token Registry v5 (TR v5) registries. It has no effect on earlier registry versions.

Disclaimer

Pay on Behalf is one possible way to sponsor a user's transaction costs. The TT-web implementation is built and tested against Pimlico as an example bundler/paymaster provider. This is not an endorsement of, or dependency on, Pimlico specifically — any ERC-4337-compatible provider that supports EIP-7702 can be used, as long as it's wired up through the same Setup steps.

User experience

On the TT Verify page, once a document is loaded:

1. TT-web checks whether the connected wallet already has EIP-7702 delegation enabled. The PlatformPaymaster input field only appears once this check passes.

   

2. The user enters the platform's PlatformPaymaster address (provided by the issuer) into that input field.

3. TT-web checks the connected wallet against that paymaster's whitelist and reports back whether the wallet is eligible (whitelisted) for sponsored transactions.

   

4. If eligible, supported actions (minting, transferring, etc.) prompt the user's wallet for a signature (of the UserOperation) instead of the usual gas-payment transaction confirmation — no ETH is required from the user.

   

5. If not eligible, TT-web surfaces this so the user knows to request access from their platform admin — admins grant eligibility by whitelisting the address via setUserWhitelist (see Setup).

6. If delegation was not already enabled in step 1, the one-time EIP-7702 delegation happens transparently as part of the user's first sponsored action.

See Overview for a diagram of the full admin-setup vs. user-experience flow, and Operations for the underlying SDK calls TT-web makes on the user's behalf.