Cardano Ledger

This repository contains the formal specifications, executable models, and implementations of the Cardano Ledger.

The documents are built in our CI and can be readily accessed using the following links:

Other Documents:

• Non-integer calculations specification: details on the parts of the Shelley specification that use real numbers.
• Stake pool ranking specification: details for a robust stake pool ranking mechanism.
• Explanation of the small-step-semantics framework: a guide to the notation and style used by our ledger rules.

In addition, there is a formalization of the Ledger Specification in Isabelle/HOL which can be found here.

Some user documentation is published on Read the Docs

Repository structure

The directory structure of this repository is as follows:

• byron
  • ledger
    • formal-spec
    • executable-spec
    • implementation
  • chain
    • formal-spec
    • executable-spec
  • cddl
• shelley
  • design-spec
  • formal-spec
  • implementation
  • tests
  • cddl
• Timelocks and Multi-Assets
  • formal-spec
  • implementation
  • tests
• Smart Contracts
  • formal-spec
  • implementation
  • tests
• Libraries

Building

It is recommended to use nix for building everything in this repository. Haskell files can be built with cabal inside of a nix shell.

Nix Cache

When using nix it is recommended that you setup the cache, so that it can reuse built artifacts, reducing the compilation times dramatically:

If you are using NixOS add the snippet below to your /etc/nixos/configuration.nix:

nix.settings = {
  experimental-features = [ "nix-command" "flakes" ];
  substituters = [
    "https://cache.nixos.org"
    "https://cache.iog.io"
  ];
  trusted-public-keys = [
    "hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ="
  ];
};

If you are using the nix package manager next to another operating system put the following in /etc/nix/nix.conf:

experimental-features = nix-command flakes
substituters        = https://cache.iog.io https://cache.nixos.org/
trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=

Building the LaTeX documents and executable specifications

When using nix the documents and Haskell code can be readily built by running:

nix build

The LaTeX documents will be places inside directories named result*, e.g.:

result-2/ledger-spec.pdf
result-3/delegation_design_spec.pdf
result-4/non-integer-calculations.pdf
result-5/small-step-semantics.pdf
result-6/ledger-spec.pdf
result/blockchain-spec.pdf

Building individual LaTeX documents

Change to the latex directory where the latex document is (e.g. eras/shelley/formal-spec for the ledger specification corresponding to the Shelley release, or eras/byron/ledger/formal-spec for the ledger specification corresponding to the Byron release). Then, build the latex document by running:

nix-shell --pure --run make

For a continuous compilation of the LaTeX file run:

nix-shell --pure --run "make watch"

Updating dependencies

When updating the pinned hackage index-state (for example, in order to get a new version of a package), it's necessary to make sure that hackage.nix pin points to a later date than the index-state, in order to avoid an error like this:

error: Unknown index-state 2021-08-08T00:00:00Z, the latest index-state I know about is 2021-08-06T00:00:00Z. You may need to update to a newer hackage.nix.

You can update the sources.json file using niv:

niv update hackage

Submitting an issue

Issues can be filed in the GitHub Issue tracker.

However, note that this is pre-release software, so we will not usually be providing support.

Contributing

See CONTRIBUTING.