dai is a simple single-collateral stablecoin that is dependent on a
trusted oracle address and has a kill-switch.
See the developer documentation for a more technical overview.
There are four tokens in the system:
gem: externally valuable token e.g. ETHgov: governance token e.g. MKRpeth: a claim to lockedgemsdai: the stablecoin, a variable claim on some quantity ofgems
Collateral holders deposit their collateral using join and receive
peth tokens proportional to their deposit. peth can be redeemed for
collateral with exit. You will get more or less gem tokens for each
peth depending whether the system made a profit or loss while you
were exposed.
The oracle updates the GEM:REF and GOV:REF price feeds. These are the only external real-time input to the system.
peth is used as the direct backing collateral for CDPs. A prospective
issuer can open an empty position, lock some peth and then draw
some dai. Debt is covered with wipe. Collateral can be reclaimed
with free as long as the CDP remains "safe".
If the value of the collateral backing the CDP falls below the
liquidation ratio mat, the CDP is vulnerable to liquidation via
bite. On liquidation, the CDP peth collateral is sold off to cover
the dai debt.
Under-collateralized CDPs can be liquidated with bite. Liquidation is
immediate: backing peth is taken to cover the dai debt at the time of
bite, plus a liquidation fee (axe); any excess remains in the CDP.
peth seized from bad CDPs can be purchased with bust, in exchange for
dai at the s2s price. This dai pays down the bad CDP debt.
Any remaining Dai surplus (joy) can be purchased with boom, in
exchange for peth at the s2s price. This peth is burned.
Stability fee is continuously charged on all open cups according to tax.
It makes their debt (tab) increase over time.
Governance fee is continuously charged on all open cups according to fee.
It makes their debt (rap) increase over time.
dai can be shut down at a given price with cage, after which dai
and peth can be exchanged for gems via cash. All outstanding cups
are liquidated and the entire pool of gem is tapped to redeem dai
at their face value, as if the boom/bust trades were instantly settled
at the cage price. Any remaining gems are shared between peth
holders.
Practically this means that if the system is undercollateralized on
cage, holders of free peth will have their gem share diluted as
much as necessary to make dai whole. In other words, peth is a
risk bearing token.
Excess collateral contained within a single cup can be reclaimed with
bite(cup).
Actions:
bite initiate liquidation of an undercollateral cup
boom buy some amount of dai to process joy (surplus)
bust sell some amount of dai to process woe (bad debt)
cage lock the system and initiate settlement
cash cash in dai balance for gems after cage
cupi get the last cup id
cups list cups created by you
draw issue the specified amount of dai stablecoins
drip recalculate the internal debt price
exit sell PETH for gems
free remove excess PETH collateral from a cup
give transfer ownership of a cup
heal cancel debt
help print help about dai(1) or one of its subcommands
join buy PETH for gems
lock post additional PETH collateral to a cup
open create a new cup (collateralized debt position)
prod recalculate the accrued holder fee (par)
safe determine if a cup is safe
setAxe update the liquidation penalty
setFee update the governance fee
setCap update the debt ceiling
setMat update the liquidation ratio
setTapGap update the spread on `boom` and `bust`
setTax update the stability fee
setTubGap update the spread on `join` and `exit`
setWay update the holder fee (interest rate)
shut close a cup
vent process a caged tub
wipe repay some portion of your existing dai debt
Vars, Getters, Utils:
air get the amount of backing collateral
axe get the liquidation penalty
caged get time of cage event (= 0 if system is not caged)
chi get the internal debt price
cup show the cup info
fee get the governance fee
fit get the gem per peth settlement price
fix get the gem per dai settlement price
fog get the amount of peth pending liquidation
gem get the collateral token
gov get the governance token
cap get the debt ceiling
ice get the good debt
ink get the amount of peth collateral locked in a cup
joy get the amount of surplus dai
lad get the owner of a cup
mat get the liquidation ratio
off get the cage flag
out get the post cage exit flag
par get the accrued holder fee (ref per dai)
per get the current entry price (gem per peth)
pie get the amount of raw collateral
pep get the gov price feed
pip get the gem price feed
pit get the liquidator vault
rap get the amount of governance debt in a cup
ray parse and display a 27-decimal fixed-point number
rho get the time of last drip
rhi get the internal debt price (governance included)
s2s get the peth per dai rate (for boom and bust)
dai get the dai token
sin get the sin token
peth get the peth token
tab get the amount of debt in a cup
tag get the reference price (ref per peth)
tapAsk get the amount of peth in dai for bust
tapBid get the amount of peth in dai for boom
tapGap get the spread on `boom` and `bust`
tau get the time of last prod
tax get the stability fee
tubAsk get the amount of peth in gem for join
tubBid get the amount of peth in gem for exit
tubGap get the spread on `join` and `exit`
vox get the target price engine
wad parse and display a 18-decimal fixed-point number
way get the holder fee (interest rate)
woe get the amount of bad debt
$ export ETH_FROM=0x(...)
$ export DAI_TUB=0x(...)
# Give the system access to our GEM (W-ETH), PETH and DAI balances
# so we can join()/exit() and also draw()/wipe() dai
$ token approve $(dai gem) $(dai tub) $(seth --to-wei 1000000000 ETH)
$ token approve $(dai peth) $(dai tub) $(seth --to-wei 1000000000 ETH)
$ token approve $(dai dai) $(dai tub) $(seth --to-wei 1000000000 ETH)
# If we also plan on using boom() and bust(), a different component
# (called `tap`) will need to have access to our PETH and DAI balances
$ token approve $(dai peth) $(dai tap) $(seth --to-wei 1000000000 ETH)
$ token approve $(dai dai) $(dai tap) $(seth --to-wei 1000000000 ETH)
# We need to have some GEM (W-ETH) balance to start with
$ token balance $(dai gem) $ETH_FROM
2.467935274974511817
# Join the system by exchanging some GEM (W-ETH) to PETH
$ dai join 2.2
Generating 2.200000000000000000 PETH depositing GEM...
$ token balance $(dai gem) $ETH_FROM
0.267935274974511817
$ token balance $(dai peth) $ETH_FROM
2.200000000000000000
# Open a new cup
$ dai open
Opening cup...
Opened cup 62
# We can list our cups at all times
$ dai cups
Cups created by you...
62
# Lock some PETH collateral in the cup and then draw some DAI from it
$ dai --cup 62 lock 1.5
Locking 1.500000000000000000 PETH in cup 62...
$ dai --cup 62 draw 89.0
Drawing 89.000000000000000000 DAI from cup 62...
$ token balance $(dai peth) $ETH_FROM
0.700000000000000000
$ token balance $(dai dai) $ETH_FROM
89.000000000000000000
# We can examine the cup details, `tab` and `ink` representing
# the amount of debt and the amount of collateral respectively
$ dai --cup 62 cup
cup id 62...
lad: 0x(...)
ink: 1.500000000000000000
tab: 89.000000000000000000
rap: 0.000000000000000000
# We can check whether the cup is still safe
# (ie. whether the value of collateral locked is high enough)
$ dai --cup 62 safe
true
# At some point we will want to wipe our DAI debt
# which means we can also free the PETH collateral
$ dai --cup 62 wipe 59.0
Wiping 59.000000000000000000 DAI from cup 62...
$ dai --cup 62 free 1.1
Freeing 1.100000000000000000 PETH from cup 62...
$ token balance $(dai peth) $ETH_FROM
1.800000000000000000
$ token balance $(dai dai) $ETH_FROM
30.000000000000000000
# The `tab` and `ink` values have changed
$ dai --cup 62 cup
cup id 62...
lad: 0x(...)
ink: 0.400000000000000000
tab: 30.000000000000000000
rap: 0.000000000000000000
# We can also `wipe` and `free` outstanding balances of DAI and PETH by calling `shut`
$ dai --cup 62 shut
Closing cup 62...
$ dai --cup 62 cup
cup id 62...
lad: 0x0000000000000000000000000000000000000000
ink: 0.000000000000000000
tab: 0.000000000000000000
rap: 0.000000000000000000
# Exit the system by exchanging PETH back to GEM (W-ETH)
$ dai exit 2.2
Sending 2.200000000000000000 PETH to TUB...
$ token balance $(dai gem) $ETH_FROM
2.467935274974511817
$ token balance $(dai peth) $ETH_FROM
0.000000000000000000v3.0:
# TODO: ADD NEW ADDRESSES (load-env)
export DAI_MULTISIG=0x2305576962e33102b01d8f3dfda2fa640137b15e# TODO: ADD NEW ADDRESSES (load-env)
export DAI_MULTISIG=0xf24888d405776cc56d29e70448172380708bb7a5