smc-101.txt

TON Smart Contracts

Receiving internal messages

When internal message is received by smart contract function recv_internal (id=0) is called
Signature:

() recv_internal(int smc_balance, int msg_value, cell msg, slice msg_body)

Where:

smc_balance - balance of smart contract after crediting the value of the inbound message in nanograms
msg_value   - balance of the message in nanograms
msg         - serialized message cell
msg_body    - message body


SMC Introspection

Highly inspired by
https://eips.ethereum.org/EIPS/eip-165

In order to support Introspection SMC should implement supports_interface method:
(int) supports_interface(int interface)

Which returns true if interface supported.

Interfaces are represented by bitwise XOR of function selectors of interface.
Function selectors:

For GET methods
selector = (crc16(<function_name>) & 0xffff) | 0x10000
(same is used in FunC)

For internal message queries
selector = (crc16(<function_formal_definition>) & 0xffff) | 0x10000

Where function_formal_definition is some sort of definition of query e.g. TL or TL-B

Any Smart Contract supporting introspection should also return true when checked for support of supports_interface method