ddnode

README

DDChain

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Mirror

This repo mirrors from DDChain Gitlab to Github. To contribute, please contact the team and commit to the Gitlab repo:

https://gitlab.com/digitaldollar/ddnode

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DDChain is a decentralised liquidity network built with CosmosSDK.

DDNodes

The DDNode software allows a node to join and service the network, which will run with a minimum of four nodes. The only limitation to the number of nodes that can participate is set by the minimumBondAmount, which is the minimum amount of capital required to join. Nodes are not permissioned; any node that can bond the required amount of capital can be scheduled to churn in.

DDChain comes to consensus about events observed on external networks via witness transactions from nodes. Swap and liquidity provision logic is then applied to these finalised events. Each event causes a state change in DDChain, and some events generate an output transaction which require assets to be moved (outgoing swaps or bond/liquidity withdrawals). These output transactions are then batched, signed by a threshold signature scheme protocol and broadcast back to the respective external network. The final gas fee on the network is then accounted for and the transaction complete.

This is described as a "1-way state peg", where only state enters the system, derived from external networks. There are no pegged tokens or 2-way pegs, because they are not necessary. On-chain Bitcoin can be swapped with on-chain Ethereum in the time it takes to finalise the confirmed event.

All funds in the system are fully accounted for and can be audited. All logic is fully transparent.

Churn

DDChain actively churns its validator set to prevent stagnation and capture, and ensure liveness in signing committees. Churning is also the mechanism by which the DDNode software can safely facilitate non-contentious upgrades.

Every 50000 blocks (3 days) DDChain will schedule the oldest and the most unreliable node to leave, and rotate in two new nodes. The next two nodes chosen are simply the nodes with the highest bond.

During a churn event the following happens:

• The incoming nodes participate in a TSS key-generation event to create new Asgard vault addresses
• When successful, the new vault is tested with a on-chain challenge-response.
• If successful, the vaults are rolled forward, moving all assets from the old vault to the new vault.
• The outgoing nodes are refunded their bond and removed from the system.

Bifröst

The Bifröst faciliates connections with external networks, such as Binance Chain, Ethereum and Bitcoin. The Bifröst is generally well-abstracted, needing only minor changes between different chains. The Bifröst handles observations of incoming transactions, which are passed into DDChain via special witness transactions. The Bifröst also handles multi-party computation to sign outgoing transactions via a Genarro-Goldfeder TSS scheme. Only 2/3rds of nodes are required to be in each signing ceremony on a first-come-first-serve basis, and there is no log of who is present. In this way, each node maintains plausible deniabilty around involvement with every transaction.

Adding a New Chain

To add a new chain, the process and guidelines defined in this doc must be followed.

Removing a Chain

To remove a chain, nodes can stop witnessing it. If a super-majority of nodes do not promptly follow suit, the non-witnessing nodes will attract penalties during the time they do not witness it. If a super-majority of nodes stop witnessing a chain it will invoke a chain-specific Ragnörok, where all funds attributed to that chain will be returned and the chain delisted.

Transactions

The DDChain facilitates the following transactions, which are made on external networks and replayed into the DDChain via witness transactions:

• ADD LIQUIDITY: Anyone can provide assets in pools. If the asset hasn't been seen before, a new pool is created.
• WITHDRAW LIQUIDITY: Anyone who is providing liquidity can withdraw their claim on the pool.
• SWAP: Anyone can send in assets and swap to another, including sending to a destination address, and including optional price protection.
• BOND: Anyone can bond assets and attempt to become a Node. Bonds must be greater than the minimumBondAmount, else they will be refunded.
• LEAVE: Nodes can voluntarily leave the system and their bond and rewards will be paid out. Leaving takes 6 hours.
• RESERVE: Anyone can add assets to the Protocol Reserve, which pays out to Nodes and Liquidity Providers. 220,447,472 Karma will be funded in this way.

Continuous Liquidity Pools

The Provision of liquidity logic is based on the CLP Continuous Liquidity Pool algorithm.

Swaps The algorithm for processing assets swaps is given by: y = (x * Y * X) / (x + X)^2, where x = input, X = Input Asset, Y = Output Asset, y = output

The fee paid by the trader is given by: fee = ( x^2 * Y ) / ( x + X )^2

The slip-based fee model has the following benefits:

• Resistant to manipulation
• A proxy for demand of liquidity
• Asymptotes to zero over time, ensuring pool prices match reference prices
• Prevents Impermanent Loss to liquidity providers

Provide Liquidity The provier units awarded to a liquidity provider is given by: liquidityUnits = ((R + T) * (r * T + R * t))/(4 * R * T), where r = Karma Provided, R = Karma Balance, T = Token Balance, t = Token Provided

This allows them to provide liquidity asymmetrically since it has no opinion on price.

Incentives

The system is safest and most capital-efficient when 67% of Karma is bonded and 33% is provided liquidity in pools. At this point, nodes will be paid 67% of the System Income, and liquidity providers will be paid 33% of the income. The Sytem Income is the block rewards (blockReward = totalReserve / 6 / 6311390) plus the liquidity fees collected in that block.

An Incentive Pendulum ensures that liquidity providers receive 100% of the income when 0% is provided liquidity (inefficent), and 0% of the income when totalLiquidity >= totalBonded (unsafe). The Total Reserve accumulates the transactionFee, which pays for outgoing gas fees and stabilises long-term value accrual.

Governance

There is strictly minimal goverance possible through DDNode software. Each DDNode can only generate valid blocks that is fully-compliant with the binary run by the super-majority.

The best way to apply changes to the system is to submit a DDChain Improvement Proposal (TIP) for testing, validation and discussion among the DDChain developer community. If the change is beneficial to the network, it can be merged into the binary. New nodes may opt to run this updated binary, signalling via a semver versioning scheme. Once the super-majority are on the same binary, the system will update automatically. Schema and logic changes can be applied via this approach.

Changes to the Bifröst may not need coordination, as long as the changes don't impact DDChain schema or logic, such as adding new chains.

Emergency changes to the protocol may be difficult to coordinate, since there is no ability to communicate with any of the nodes. The best way to handle an emergency is to invoke Ragnarök, simply by leaving the system. When the system falls below 4 nodes all funds are paid out and the system can be shut-down.

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Setup

Install dependencies, you may skip packages you already have.

Linux:

apt-get update
apt-get install -y git make golang-go protobuf-compiler

Mac:

brew install golang coreutils binutils diffutils findutils gnu-tar gnu-sed gawk grep make git protobuf

# Follow post-setup instructions...
# Your $PATH should look something like this
export PATH=/opt/homebrew/opt/make/libexec/gnubin:/opt/homebrew/opt/gnu-sed/libexec/gnubin:opt/homebrew/opt/libpq/bin:/opt/homebrew/opt/findutils/libexec/gnubin:$GOPATH/bin:/usr/local/bin:$PATH

Install Docker and Docker Compose V2.

Ensure you have a recent version of go (scripts/check-env.sh) and enabled go modules.
Add GOBIN to your PATH.

export GOBIN=$GOPATH/bin

Automated Install Locally

Clone repo

git clone https://gitlab.com/digitaldollar/ddnode.git
cd ddnode

Install via this make command.

make go-generate openapi protob-docker install

Once you've installed ddnode, check that they are there.

ddnode help

Start Standalone Full Stack

For development and running a full chain locally (your own separate network), use the following command on the project root folder:

make run-mocknet

See build/docker/README.md for more detailed documentation on the DDNode images and local mocknet environment.

Simulate Local Churn

# reset mocknet cluster
make reset-mocknet-cluster

# increase churn interval as desired from the default 60 blocksmake go-generate openapi protob-docker
make cli-mocknet
> ddnode tx ddchain mimir CHURNINTERVAL 1000 --from dog $TX_FLAGS

# bootstrap vaults from smoke test add liquidity transactions
make mocknet-bootstrap

# verify vault balances
curl -s localhost:1317/ddchain/vaults/asgard | jq '.[0].coins'

# watch logs for churn
make logs-mocknet

# verify active nodes
curl -s localhost:1317/ddchain/nodes | jq '[.[]|select(.status=="Active")]|length'

# disable future churns if desired
make cli-mocknet
> ddnode tx ddchain mimir CHURNINTERVAL 1000000 --from dog $TX_FLAGS

See build/docker/README.md for more detailed documentation on the DDNode images and local mocknet environment.

Smoke Tests

The smoke tests compare a mocknet against a simulator implemented in python. Changes to ddnode, particularly to the calculations, will require also updating the python simulator, and subsequently the unit-tests for the simulator.

The smoke-test currently requires that all synth balances be cleared be liquidity is withdrawn at the end of the smoke-test, so it is possible the transactions in test/smoke/data/smoke_test_transactions.json may need to be changed.

Run Smoke Tests

make smoke-protob-docker
make smoke

Update Balances and Events

EXPORT=data/smoke_test_balances.json EXPORT_EVENTS=data/smoke_test_events.json make smoke-unit-test

Format code

make format

Build all

make all

Test

Run tests

make test

Regression Tests

We expose a testing framework that allows the definition of test cases and suites using a DSL in YAML. Providing a regular expression to the RUN environment variable will match against files in test/regression/suites to filter tests to run.

make test-regression

# with more detailed logs
DEBUG=1 make test-regression

# with specific test filters
RUN=core make test-regression
RUN=mimir/deprecate-ilp test-regression

# overwrite export state
EXPORT=1 make test-regression

Ledger CLI Support

cd cmd/ddnode
go build -tags cgo,ledger
./ddnode keys add ledger1 --ledger

How to contribute

• Create an issue or find an existing issue on https://gitlab.com/digitaldollar/ddnode/-/issues
• About to work on an issue? Start a conversation at #ddnode-dev channel on discord
• Assign the issue to yourself
• Create a branch using the issue id, for example if the issue you are working on is 600, then create a branch call 600-issue , this way , gitlab will link your PR with the issue
• Raise a PR , Once your PR is ready for review , post a message in #ddnode-dev channel in discord , tag @ddnode-team for review
• Make sure the pipeline is green
• Once PR get approved, you can merge it

Current active branch is develop , so when you open PR , make sure your target branch is develop

Vulnerabilities and Bug Bounties

If you find a vulnerability in DDNode, please submit it for a bounty according to these guidelines.

the semantic version and release

DDNode manage changelog entry the same way like gitlab, refer to (https://docs.gitlab.com/ee/development/changelog.html) for more detail. Once a merge request get merged into master branch, if the merge request upgrades the version, then a new release will be created automatically, and the repository will be tagged with the new version by the release tool.

New Chain Integration

The process to integrate a new chain into DDChain is multifaceted. As it requires changes to multiple repos in multiple languages (golang, python, and javascript).

To learn more about how to add a new chain, follow this doc

To learn more about creating your own private chain as a testing and development environment, follow this doc