So, let’s look at one we can see of Djed in Cardanoscan:
The main contract is: https://cardanoscan.io/address/addr1z8ru2k4eqtwrf95fvmgxu04pugezz7xg8l3jrrq9mhgh5agm5kjdmrpmng059yellupyvwgay2v0lz6663swmds7hp0q4jak04
DJED and SHEN Tokens
There are almost a trillion of “DjedMicroUSD” and “ShenMicroUSD” in this contract. They have been pre-minted and are not minted and burned during the operation of Djed. So, if the Djed paper https://iohk.io/en/research/library/papers/djed-a-formally-verified-crypto-backed-pegged-algorithmic-stablecoin/ talks about “minting” and “burning”, in this implementation it is rather given out by the contract address and given back to the contract address.
If we look at their policy https://cardanoscan.io/tokenPolicy/8db269c3ec630e06ae29f74bc39edd1f87c819f1056206e879a1cd61, we see a very uninformative total supply of one trillion each. To get the real circulating DJED and SHEN we have to subtract the tokens residing on the contract address from this. And we arrive at roughly 750 000 DJED and roughly 9.2 million SHEN circulating at the time of writing (probably already more at the time of publishing).
There is also a “DjedStableCoinNFT”, minted under the same policy and also held by the contract address, which is probably a technicality needed by one of the Plutus scripts.
The contract address belongs to the stake https://cardanoscan.io/stakeKey/stake1uyd6tfxa3sae586zjvll7qjx8ywj9x8l3dddgc8dkc0tshssd5g6e, which is delegated to the pool WAV1 https://cardanoscan.io/pool/e985b5698de1386439e62b5b7ab2cc9f814b91b4a1fef5970f38694d. As announced in https://cotinetwork.medium.com/djed-update-economics-of-the-djed-stablecoin-and-delegation-rewards-53f732851b29 and https://cotinetwork.medium.com/djed-update-jan-30th-c64ed7099728, it is a pool managed by Wave.
Up to a few epochs ago, it was a private pool with 100% margin. Then, it was first set to 8% and then to 5% consistent with the announcements by COTI. I don’t know why they didn’t just use a private pool with a deal with the pool operator.
There are two more addresses with funds on them that belong to the same stake: https://cardanoscan.io/address/addr1q9qf60kgctthflcakjyufu2z39qcy80cr7lz3gk4uvf4f6qm5kjdmrpmng059yellupyvwgay2v0lz6663swmds7hp0q8v9ugf, which holds the collected operational fees which will be converted to COTI and put in their treasury from time to time, and https://cardanoscan.io/address/addr1q8sefdq99nlv0wefzprjvp5h9mw2l3jvhvgy4tl20kszdlcm5kjdmrpmng059yellupyvwgay2v0lz6663swmds7hp0q8dklg8, which pays for the updates of the oracle (I’d guess, they plan to refill this address from time to time, since the transaction fees will slowly deplete it).
The oracle lives on the contract address https://cardanoscan.io/address/addr1wxxx5uc8t8mphyyf7qmse7vx5fm469puha6uru06djfj4vql8unkl and is updated roughly every 12 minutes.
In such an update transaction, we see the datum living at the only UTxO of that address to be updated: https://cardanoscan.io/transaction/58b6e3ecc266b9e1e8cdd7f87aa3da3c519e7482e7eed6220c33c8f71721ce31?tab=contracts
In a quick analysis, I couldn’t find out what format this datum is in. Doesn’t seem to be ASCII, UTF-8, or CBOR, as far as I can see.
Orders and Batching
If you place an order on djed.xyz, you sign a transaction to the contract address https://cardanoscan.io/address/addr1wxy49hzx86ch868hr3uz98lqw8p7ef55j6x8ras7udy3a0gm8cdla which serves as an order queue, which is then processed by transactions involving the “real” reserve address.
- Buy 5001 SHEN: https://cardanoscan.io/transaction/934427a02c4aebcea2f6e47511e8c66b86864e14e09d52c8c92a14fc98b88778?tab=utxo
Processed by: https://cardanoscan.io/transaction/df241e5e5f894096fe66f9de98fc40dc84354c9b19eaad6fcbda85fb4842e20d?tab=utxo
- Sell 5001 SHEN: https://cardanoscan.io/transaction/5988ce604d855f12e000c165503879e7c4a188db0a62bb75f2fbd5b8517bc099?tab=utxo
Processed by: https://cardanoscan.io/transaction/0ecf58aceeb18e6377d0f8f60badc0a5a6247478df7f0e0f149ec1b60489b6a6?tab=utxo
- Buy 5001 DJED: https://cardanoscan.io/transaction/d9573bcb96b80ecedfa9e7d9f2976a0c9ed5dfb64a1e28b6a036a732ec19c018?tab=utxo
Processed by: https://cardanoscan.io/transaction/0795bc2c4cb4ddaaa8de5339c7ed7346ef50dec4b9f7775b0996a6fe8d2b50b3?tab=utxo
- Sell 5001 DJED: https://cardanoscan.io/transaction/a08687019da49eb6fafc5b2846522283746f01ba73c9942d55d58e2e5c4f4168?tab=utxo
Processed by: https://cardanoscan.io/transaction/6196ec5678f64861f6ed0806b040b347008b30704baa54774724cd27a8679ee2?tab=utxo
In all of these examples you can see the changes on the main contract address as well as 100 ADA each operational fee going out to the contract address https://cardanoscan.io/address/addr1wx8vgeyxzyrm9qu6ju9fh4useecga8njlwtmqa2357luj3clkzzzx. From that address, they are periodically forwarded in transactions like https://cardanoscan.io/transaction/83af9af5cea65ecf258c344c5410a6c36bf124a6579a0acd0fda4c064be51de6?tab=utxo to the operational fee collection address we have seen earlier.
Further analysis of the involved contracts and datums should be really interesting.