# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Project Overview

alerttonotify receives Alertmanager HTTP webhooks and forwards them as notifications via NATS to a dbus notify service. Written in Go (1.23.3).

## Build & Development

```bash
# Build
go build -v ./...

# Lint (available in nix devshell)
golangci-lint run

# Enter dev environment (requires nix with flakes)
nix develop

# Build with nix
nix build
```

No tests exist yet. The project uses direnv (`.envrc`) to auto-load the nix devshell.

## Architecture

**main.go** — Entry point. Reads config from environment variables, sets up NATS connection, creates the HTTP server, handles graceful shutdown on SIGINT.

**server/server.go** — HTTP server with two routes:
- `GET /` — health check
- `POST /alert` — receives Alertmanager webhook payloads (`AlertMessage`/`Alert` structs), builds a summary, and publishes via `NotificationService`

**server/notify.go** — `NotificationService` wraps a NATS connection. Serializes `BusNotification` (summary, body, timeout) to JSON and publishes to subject `home2rjusnet.notifications`. Uses NKey authentication.

## Configuration

All config is via environment variables:
- `NATS_URL` (required) — NATS server URL
- `NATS_NKEY` or `NATS_NKEY_FILE` (required) — NKey seed for NATS auth
- `ALERTTONOTIFY_ADDR` (optional, default `:5001`) — HTTP listen address

## Nix

The flake builds with `buildGoModule`. The `vendorHash` in `flake.nix` must be updated when Go dependencies change.