# Centralized Sequencer

centralized-sequencer is an implementation of the [Generic Sequencer interface](https://github.com/rollkit/go-sequencing)
for modular blockchains. It runs a gRPC service,
which can be used by rollup clients to sequence transactions to DA layer.

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## Minimum requirements

| Requirement | Notes          |
| ----------- |----------------|
| Go version  | 1.22 or higher |

## Installation

```sh
git clone https://github.com/rollkit/centralized-sequencer.git
cd centralized-sequencer
make build
./build/centralized-sequencer -h
```

## Usage

centralized-sequencer exposes a gRPC service that can be used with any gRPC
client to sequence rollup transactions to a DA layer.

## Example

Run centralized-sequencer by specifying DA network details:

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```sh
    ./build/centralized-sequencer -da_address <da_address> -da_auth_token <da_auth_token> -da_namespace $(openssl rand -hex 10)
```
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## Flags

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| Flag                         | Usage                                   | Default                     |
| ---------------------------- |-----------------------------------------|-----------------------------|
| `batch-time`            | time in seconds to wait before generating a new batch | 2 seconds |
| `da_address`              | DA address | `http:////localhost:26658`|
| `da_auth_token`               | auth token for the DA | `""` |
| `da_namespace`              | DA namespace where the sequencer submits transactions | `""` |
| `host`                | centralized sequencer host            | localhost |
| `port`             | centralized sequencer port | 50051 |
| `listen-all` |listen on all network interfaces (0.0.0.0) instead of just localhost|disabled|
| `metrics` |enable prometheus metrics|disabled|
| `metrics-address` |address to expose prometheus metrics|`":8080"`|
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See `./build/centralized-sequencer --help` for details.

### Tools

1. Install [golangci-lint](https://golangci-lint.run/welcome/install/)
1. Install [markdownlint](https://github.com/DavidAnson/markdownlint)
1. Install [hadolint](https://github.com/hadolint/hadolint)
1. Install [yamllint](https://yamllint.readthedocs.io/en/stable/quickstart.html)

## Helpful commands

```sh
# Print centralized-sequencer commands
centralized-sequencer --help

# Run unit tests
make test-unit

# Run all tests including integration tests
make test

# Run linters (requires golangci-lint, markdownlint, hadolint, and yamllint)
make lint
```

## Contributing

We welcome your contributions! Everyone is welcome to contribute, whether it's
in the form of code, documentation, bug reports, feature
requests, or anything else.

If you're looking for issues to work on, try looking at the [good first issue
list](https://github.com/rollkit/centralized-sequencer/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22).
Issues with this tag are suitable for a new external contributor and is a great
way to find something you can help with!