CertStream Server

Aggregates and broadcasts SSL certificates as they're issued live by watching Certificate Transparency logs. Provides a simple Docker container to easily set up your own server. Updated for slightly more resiliance and ease-of-use.

Setup (Docker — recommended)

1. Install Docker and Docker Compose
2. Clone the repo and enter the directory:

   git clone https://github.com/jzurner1/certstream-server.git
   cd certstream-server

3. Build and start the server:

   docker compose up --build

4. The server is available at http://localhost:4000

Setup (local)

1. Install Elixir (1.14+)
2. Fetch dependencies:

   mix deps.get

3. Run the server:

   mix run --no-halt

Endpoints

Endpoint	Description
ws://localhost:4000/	WebSocket stream (no DER cert data)
ws://localhost:4000/full-stream	WebSocket stream with DER-encoded certificates
ws://localhost:4000/domains-only	WebSocket stream of domain names only
http://localhost:4000/latest.json	Most recent 25 certificates (JSON)
http://localhost:4000/example.json	Most recent certificate (JSON)
http://localhost:4000/stats	Server stats and connected clients

Environment Variables

Variable	Default	Description
PORT	4000	Port the server listens on
LOG_LEVEL	info	Log verbosity (debug, info, warn, error)
HONEYBADGER_API_KEY	(empty)	API key for Honeybadger error reporting (optional)
STATSD_HOST	localhost	StatsD host for metrics (optional, uses UDP — safe to leave unset)
STATSD_PORT	8125	StatsD port
STATS_URL	stats	URL path for the stats endpoint