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Memo Length Reduction

Reducing Memo Size

Given the complexity of memos, they can become very long, beyond the limits of chains like Bitcoin. Various methods have been developed to significantly shorten memo length. Example:
  1. 1.
    SWAP:ETH.ETH:0xe6a30f4f3bad978910e2cbb4d97581f5b5a0ade0:1612345678:thor1el4ufmhll3yw7zxzszvfakrk66j7fx0tvcslym:10
    can be reduced to =:e:dx:161e6:t:10
  2. 2.
    SWAP:ETH.USDT-0xdac17f958d2ee523a2206206994597c13d831ec7:0xe6a30f4f3bad978910e2cbb4d97581f5b5a0ade0:10012345678:thor1el4ufmhll3yw7zxzszvfakrk66j7fx0tvcslym:10
    can be reduced to =:ETH.USDT:dx:100e7:t:10
The examples below use the following features to reduce memo length:

Shortened Asset Names

Native asset names can be shortened to reduce the length of the memo. The exact list is here.
Shorten Asset
Asset Notation
r
THOR.RUNE
a
AVAX.AVAX
b
BTC.BTC
c
BCH.BCH
e
ETH.ETH
n
BNB.BNB
s
BSC.BNB
d
DOGE.DOGE
e
ETH.ETH
l
LTC.LTC
Example Swaps:
  • =:ETH.ETH:0x388C818CA8B9251b393131C08a736A67ccB19297 is reduced to =:e:0x388C818CA8B9251b393131C08a736A67ccB19297, Swap for Ether.
  • =:r:thor1el4ufmhll3yw7zxzszvfakrk66j7fx0tvcslym - Swap to RUNE.

Asset Abbreviations

Assets can be abbreviated using fuzzy logic. The following will all be matched appropriately. If there are conflicts, then the deepest pool is matched to prevent attacks.
Notation
ETH.USDT
ETH.USDT-ec7
ETH.USDT-6994597c13d831ec7
ETH.USDT-0xdac17f958d2ee523a2206206994597c13d831ec7

THORNames

THORNames allows a custom name to be assigned to an address, like an alias, so the address does not need to be specified.
Example:
  • thor1nt2d4kmj0xd6xxm3m82tac3d20y05dm0vv7ur3 can be specified as tr.
See the THORName Creation Guide to create your own. This is used greatly to specify the affiliate address.

Shortened Functions

Memos contain functions such as Swap or Add, which describe the user's intent and are sent along with specific parameters. Functions can be reduced in the following way:
Function
Abbreviated
Recommended
Swap
s
=
Add / Deposit
+
Withdraw
wd
-
Loan Open
Loan+
$+
Loan Close
Loan-
$-
THORName
name, n
~
Limit Order
Limitto
lo
Example:
=SWAP:e:0x388C818CA8B9251b393131C08a736A67ccB19297 is reduced to =:e:0x388C818CA8B9251b393131C08a736A67ccB19297

Scientific Notation

In THORChain memos and the state machine, asset amounts are expressed as Base in 1e8 format requiring many digits to express an amount. E.g. 0.01 BTC is expressed as 1000000 and 5 Ether is expressed as 500000000.
To help save space in memos, scientific notation can shorten memos by specifying both significant digits and the amount of trailing zeros. Note that using scientific notation in memos always leads to a loss of precision, so ensure enough significant digits are used to express the amount properly. For example, using 161e6 to represent 1612345678 results in a loss of precision.
Examples:
  • In memo: 1e8 -> THORChain reads: 100000000
  • In memo: 51e7 -> THORChain reads: 510000000
Full Memo Example:
  • SWAP:ETH.ETH:0x388C818CA8B9251b393131C08a736A67ccB19297:1612341234:thor19emplkuphjk2y9gkkv06m8vcstc0ufn4pevv5u:10
    is reduced to =:e:0x388C818CA8B9251b393131C08a736A67ccB19297:161e6:t:10