celestia-core is a fork of cometbft/cometbft, an implementation of the Tendermint protocol, with the following changes:

1. Early adoption of the ABCI++ methods: PrepareProposal and ProcessProposal because they haven't yet landed in a CometBFT release.
2. Modifications to how DataHash in the block header is determined. In CometBFT, DataHash is based on the transactions included in a block. In Celestia, block data (including transactions) are erasure coded into a data square to enable data availability sampling. In order for the header to contain a commitment to this data square, DataHash was modified to be the Merkle root of the row and column roots of the erasure coded data square. See ADR 008 for the motivation or celestia-app/pkg/da/data_availability_header.go for the implementation. Note on the implementation: celestia-app computes the hash in prepare_proposal and returns it to CometBFT via blockData.Hash so a modification to celestia-core isn't strictly necessary but comments were added.

See ./docs/celestia-architecture for architecture decision records (ADRs) on Celestia modifications.

                ^  +-------------------------------+  ^
                |  |                               |  |
                |  |  State-machine = Application  |  |
                |  |                               |  |   celestia-app (built with Cosmos SDK)
                |  |            ^      +           |  |
                |  +----------- | ABCI | ----------+  v
Celestia        |  |            +      v           |  ^
validator or    |  |                               |  |
full consensus  |  |           Consensus           |  |
node            |  |                               |  |
                |  +-------------------------------+  |   celestia-core (fork of CometBFT)
                |  |                               |  |
                |  |           Networking          |  |
                |  |                               |  |
                v  +-------------------------------+  v

See https://github.com/celestiaorg/celestia-app#install

See https://github.com/celestiaorg/celestia-app#usage

This repo intends on preserving the minimal possible diff with cometbft/cometbft to make fetching upstream changes easy. If the proposed contribution is

• specific to Celestia: consider if celestia-app is a better target
• not specific to Celestia: consider making the contribution upstream in CometBFT

1. Install Go 1.22.5+
2. Fork this repo
3. Clone your fork
4. Find an issue to work on (see good first issues)
5. Work on a change in a branch on your fork
6. When your change is ready, push your branch and create a PR that targets this repo

# Build a new CometBFT binary and output to build/comet
make build

# Install CometBFT binary
make install

# Run tests
make test

# If you modified any protobuf definitions in a `*.proto` file then
# you may need to lint, format, and generate updated `*.pb.go` files
make proto-lint
make proto-format
make proto-gen

The canonical branches in this repo are based on CometBFT releases. For example: v0.34.x-celestia is based on the CometBFT v0.34.x release branch and contains Celestia-specific changes.

Releases are formatted: v<CELESTIA_CORE_VERSION>-tm-v<TENDERMINT_CORE_VERSION> For example: v1.4.0-tm-v0.34.20 is celestia-core version 1.4.0 based on CometBFT 0.34.20. CELESTIA_CORE_VERSION strives to adhere to Semantic Versioning.

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