Mixer

A social posting platform built with Elixir/Phoenix, Ash Framework, and React. Users can post, reply, like, follow each other, and upload media/avatars. Metrics are tracked in ClickHouse.

Stack

• Backend: Elixir 1.15+, Phoenix, Ash Framework (resources, policies, state machine, authentication)
• Frontend: React + TypeScript, bundled via esbuild, styled with Tailwind CSS + DaisyUI
• Databases: PostgreSQL (primary data), ClickHouse (metrics/analytics)
• Storage: S3-compatible object storage (MinIO locally, any S3-compatible service in prod)
• Email: Swoosh (local mailbox in dev, Brevo in prod)
• API layer: AshTypescript RPC (type-safe TS client auto-generated from Ash resources)

Dev environment setup

Prerequisites

• Elixir 1.15+ and Erlang/OTP (via asdf or system package manager)
• PostgreSQL running locally (default: postgres/postgres on localhost:5432)
• ClickHouse running locally (default: default/no password on localhost:8123, database mixer_metrics)
• MinIO running locally on localhost:9000 with credentials minioadmin/minioadmin

MinIO setup

Start MinIO and create the bucket before running the app:

# Start MinIO (adjust data dir as needed)
minio server /data --console-address ":9001"

# Create the bucket (using the MinIO CLI or the web console at http://localhost:9001)
mc alias set local http://localhost:9000 minioadmin minioadmin
mc mb local/mixer-bucket
mc anonymous set public local/mixer-bucket

First-time setup

# Install Elixir dependencies and set up both databases
mix setup

mix setup runs mix deps.get, creates and migrates both the PostgreSQL and ClickHouse databases, and seeds initial data.

Running the server

mix phx.server

Visit http://localhost:4000. The frontend assets (esbuild + Tailwind) are compiled and watched automatically.

Email in development

Magic-link sign-in emails are delivered to the local Swoosh mailbox. View them at http://localhost:4000/dev/mailbox.

Regenerating the TypeScript RPC client

After changing Ash resource actions or attributes, regenerate the typed TS client:

mix ash_typescript.generate

The output goes to assets/js/ash_rpc.ts.

Production environment variables

Variable	Description
DATABASE_URL	PostgreSQL connection URL (ecto://user:pass@host/db)
SECRET_KEY_BASE	Phoenix secret key (generate with mix phx.gen.secret)
TOKEN_SIGNING_SECRET	Ash authentication token signing secret
CLICKHOUSE_URL	ClickHouse connection URL (or use individual vars below)
CLICKHOUSE_HOST	ClickHouse host
CLICKHOUSE_PORT	ClickHouse port (default 8123)
CLICKHOUSE_DATABASE	ClickHouse database name (default mixer_metrics)
CLICKHOUSE_USERNAME	ClickHouse username (default default)
CLICKHOUSE_PASSWORD	ClickHouse password
S3_ACCESS_KEY_ID	S3 access key
S3_SECRET_ACCESS_KEY	S3 secret key
S3_HOST	S3 host (e.g. s3.amazonaws.com)
S3_BUCKET	S3 bucket name
S3_ASSET_HOST	Public base URL for serving assets (e.g. https://cdn.example.com)
S3_SCHEME	S3 scheme (default https://)
S3_PORT	S3 port (default 80)
S3_VIRTUAL_HOST	Use virtual-hosted S3 URLs (default false)
BREVO_API_KEY	Brevo (Sendinblue) API key for transactional email
PHX_HOST	Public hostname (default mixer.jimweaver.com)
PORT	HTTP port (default 4000)
PHX_SERVER	Set to true to start the HTTP server in a release