B20 has two variants. Both share the base ERC-20-compatible B20 surface, roles, policy scopes, memos, pausing, supply caps, and permit.
Decision table
Multiplier
Asset tokens expose a WAD-precision multiplier for scaled UI balances. Raw balances remain unchanged; scaled balances are derived at read time.
For Asset tokens, balanceOf(account) returns the raw ERC-20 balance. scaledBalanceOf(account) returns the multiplier-adjusted display balance. Choose one view for your integration and label it clearly.
updateMultiplier is an emergency override.
Announcements
announce(internalCalls, id, description, uri) emits Announcement, executes internal calls, then emits EndAnnouncement. Announcement IDs are unique forever. Non-panic inner reverts are wrapped in InternalCallFailed.
Use announcements to wrap holder-impacting operations such as batch minting or multiplier changes.
Batch mint
batchMint(recipients, amounts) mints to multiple recipients atomically. Any failing element reverts the whole batch. It is gated by MINT_ROLE and should be wrapped in announce when disclosure is required.
Asset tokens can store issuer-defined string key/value metadata. Setting an empty value deletes the entry.
Stablecoin currency
Stablecoin tokens expose currency(), set once at creation. The code must contain uppercase A-Z characters only.
B20 validates the currency code format, not the issuer’s claim. A token can set currency() to USD, but B20 does not verify reserves, legal status, or registration with an external currency registry.
