# Herald

Herald is a Gitea bot that performs automated AI-powered code reviews on pull requests using [OpenRouter](https://openrouter.ai/).

## Features

- Listens for Gitea webhook events and triggers code reviews on pull request comments
- Streams reviews back to Gitea as PR comments
- Concurrent review processing with configurable parallelism
- Graceful shutdown — in-progress reviews finish before the process exits
- Error tracking via Sentry
- Tiny memory footprint (~4MB) thanks to Rust

## Installation

**Requirements:** Rust toolchain ([rustup.rs](https://rustup.rs))

```sh
cargo build --release
./target/release/herald
```

Herald reads its configuration from environment variables (a `.env` file is supported):

| Variable | Description |
|---|---|
| `HTTP_PORT` | Port to listen on |
| `BOT_NAME` | The bot's Gitea username (used to detect mentions) |
| `WEBHOOK_SIG_HEADER_SECRET` | Gitea webhook secret for signature verification |
| `OPEN_ROUTER_API_KEY` | OpenRouter API key |
| `OPEN_ROUTER_MODEL` | Model to use (e.g. `deepseek/deepseek-v4-flash`) |
| `OPEN_ROUTER_TIMEOUT` | OpenRouter request timeout in seconds |
| `BOT_MAX_CONCURRENT` | Maximum number of concurrent reviews |
| `GITEA_URL` | Base URL of your Gitea instance |
| `GITEA_TOKEN` | Gitea API token |
| `GITEA_TIMEOUT` | Gitea API request timeout in seconds |
| `SENTRY_DSN` | *(optional)* Sentry DSN for error tracking |
| `RUST_LOG` | *(optional)* Log level, defaults to `info` |

## Development

The easiest way to get started is with the provided [Dev Container](https://containers.dev/) (VS Code or Zed with the dev container extension).

Open the project and reopen it in the container — the Rust toolchain is pre-installed.

**Without Dev Container**, you just need a Rust toolchain:

```sh
rustup toolchain install stable
cargo run
```

Copy `.env.example` to `.env` and fill in your values before running.