Capabilities

A capability is a named feature that a handle may or may not have. Generic code checks bc.supports(capability) and adapts; a call that needs a missing capability throws UnsupportedCapabilityError (UNSUPPORTED_CAPABILITY) before anything is stored. Chains, families and drivers explains where capabilities come from.

What each one means

Capability	The handle can…	Used by
tokens	Send and read tokens: ERC-20, TRC-20, SPL, jettons	transfer({ asset }), getBalance(address, asset)
memo	Attach a public memo or comment to a transfer	transfer({ memo })
batch-transfer	Pay several outputs in one transaction	transfer({ outputs: [...] })
replace-fee	Replace a pending transaction with a higher fee, in the same slot	bc.replace(id, { fee })
cancel	Cancel a pending transaction with a conflicting one	bc.cancel(id)
expiry	Prove a transaction expired, and re-issue it	bc.rebuild(id)
block-scan	Read blocks in order for deposits	bc.scanner(…)
address-history	List an address's transactions	bc.history(address)
hd-public-derivation	Derive addresses from an xpub	bc.deriveAddress(wallet, index)
finality-tag	Read finality from a finalized block tag rather than by depth	Verdicts and mode: 'final' scans
fee-market-1559	Price fees with an EIP-1559 base fee and tip	estimateFee, fee overrides
contract-read	Read contract state (reserved: no built-in family has it yet)

KNOWN_CAPABILITIES lists these names. A plugin may add its own.

Which chains have which

Every network of a chain has the same capabilities. test/docs/capabilities.test.ts checks this table against the library.

Chain	tokens	memo	batch-transfer	replace-fee	cancel	expiry	block-scan	address-history	hd-public-derivation	finality-tag	fee-market-1559
ethereum	✓			✓	✓		✓		✓	✓	✓
bsc	✓			✓	✓		✓		✓	✓
polygon	✓			✓	✓		✓		✓	✓	✓
avalanche (C-Chain)	✓			✓	✓		✓		✓		✓
arbitrum	✓						✓		✓	✓	✓
optimism	✓			✓	✓		✓		✓	✓	✓
base	✓			✓	✓		✓		✓	✓	✓
bitcoin			✓	✓	✓		✓	✓	✓
tron	✓	✓				✓	✓	with an indexer	✓
solana	✓	✓				✓	✓	✓
ton	✓	✓				✓		✓
avalanche-x		✓	✓				✓	✓	✓
avalanche-p			✓				✓	✓	✓
fakechain (testing)		✓		✓	✓		✓		✓	✓
fakeexpiry (testing)		✓				✓	✓		✓	✓
fakeseqno (testing)		✓					✓		✓	✓

A few things the table cannot show:

• Arbitrum has no public mempool, so nothing can be replaced or cancelled there.
• Tron serves address history through an indexer provider (trongrid or public as the handle's indexer); without one, history() is unsupported.
• Bitcoin, TON and the Avalanche X-Chain and P-Chain always need an indexer; Solana serves history from its RPC.
• TON has no block scan, because its chain is sharded: read deposits with history().
• The EVM chains have no address history yet: it needs an indexer the family does not use yet.
• Expiry and seqno chains (Tron, Solana, TON) have no replace or cancel: a transaction that does not land expires, and rebuild re-issues it once the expiry is proven. TON's seqno ordering reports expiry too, since its messages also carry a deadline.

Each family page in Networks gives the details.