Deployment¶

Deployment Options¶

media-downloader supports local stdio, a loopback-only development listener, a least-privilege stdio container, and a remote authenticated HTTPS boundary. Provider endpoint, credential, selector, identity, and trust material are supplied at runtime through AgentConfig; none is stored in this repository.

Installed stdio process¶

{
  "mcpServers": {
    "media-downloader": {
      "command": "media-downloader-mcp",
      "args": [],
      "env": {"MCP_TOOL_MODE": "intent"}
    }
  }
}

Loopback development listener¶

media-downloader-mcp --transport streamable-http --host 127.0.0.1 --port 8000

Do not expose this listener beyond loopback. Network deployments require direct TLS or an explicitly trusted TLS-terminating ingress, configured authentication, exact MCP_ALLOWED_HOSTS, and an exact trusted-proxy CIDR policy.

Least-privilege local container¶

docker run -i --rm \
  --read-only \
  --cap-drop=ALL \
  --security-opt=no-new-privileges \
  --pids-limit=256 \
  --tmpfs /tmp:rw,noexec,nosuid,nodev,size=64m \
  -e TRANSPORT=stdio \
  registry.example.invalid/media-downloader@sha256:<digest> media-downloader-mcp

The operator projects the selected AgentConfig profile into the process at runtime; the image remains immutable and contains no environment connection profile.

Remote authenticated HTTPS endpoint¶

{
  "mcpServers": {
    "media-downloader": {"url": "https://service.example.invalid/mcp"}
  }
}

Store the real remote URL, outbound identity reference, and TLS-profile reference in AgentConfig, not in MCP client JSON or documentation.

This page covers running media-downloader as a long-lived server: the transports, a Docker Compose stack, putting it behind a Caddy reverse proxy, and giving it a DNS name with Technitium. It also documents the optional A2A agent server.

media-downloader ships an MCP server (console script media-downloader-mcp) and a Pydantic-AI agent server (console script media-downloader-agent). The agent connects to the MCP server over MCP_URL and exposes a conversational A2A interface with an optional web UI.

Run the MCP server¶

The transport is selected with --transport (or the TRANSPORT env var):

stdio (default)streamable-httpsse

media-downloader-mcp

For IDE / desktop MCP clients that launch the server as a subprocess.

media-downloader-mcp --transport streamable-http --host 0.0.0.0 --port 8000

A network server with a /health endpoint and /mcp route.

media-downloader-mcp --transport sse --host 0.0.0.0 --port 8000

Health check (HTTP transports):

curl -s http://localhost:8000/health        # {"status":"OK"}

Configuration (environment)¶

media-downloader is configured entirely from the environment. The required set is small — the downloader needs no external service. Copy .env.example to .env and fill in only what you use:

Var	Default	Meaning
`HOST`	`0.0.0.0`	Bind address for HTTP transports
`PORT`	`8000`	Listen port for HTTP transports
`TRANSPORT`	`stdio`	`stdio`, `streamable-http`, or `sse`
`YT_DLP_PATH`	`/usr/bin/yt-dlp`	Path to the `yt-dlp` binary
`BREW_INSTALL_CMD`	`brew install yt-dlp`	Install hint surfaced for macOS hosts
`ENABLE_OTEL`	`True`	Emit OpenTelemetry traces
`EUNOMIA_TYPE`	`none`	Authorization mode: `none`, `embedded`, or `remote`
`EUNOMIA_POLICY_FILE`	`mcp_policies.json`	Local policy file for `embedded` mode

Optional telemetry (OTEL_EXPORTER_OTLP_*) and Eunomia remote (EUNOMIA_REMOTE_URL) variables are documented inline in .env.example; each remains inactive when its credentials are absent.

Docker Compose¶

The repo ships docker/mcp.compose.yml. It reads a sibling .env and publishes the HTTP server on :8000:

services:
  media-downloader-mcp:
    image: example/media-downloader@sha256:<digest>
    container_name: media-downloader-mcp
    hostname: media-downloader-mcp
    restart: always
    env_file:
      - ../.env
    environment:
      - PYTHONUNBUFFERED=1
      - HOST=0.0.0.0
      - PORT=8000
      - TRANSPORT=streamable-http
    ports:
      - "8000:8000"
    healthcheck:
      test: ["CMD", "python3", "-c", "import urllib.request; urllib.request.urlopen('http://localhost:8000/health')"]
      interval: 30s
      timeout: 10s
      retries: 3

cp .env.example .env          # then edit values
docker compose -f docker/mcp.compose.yml up -d
docker compose -f docker/mcp.compose.yml logs -f

Agent server (A2A)¶

media-downloader also ships a Pydantic-AI agent. The console script media-downloader-agent connects to the MCP server over MCP_URL and serves a conversational A2A endpoint (with an optional web UI) on its own port:

export MCP_URL=http://localhost:8000/mcp
media-downloader-agent --provider openai --model-id gpt-4o --host 0.0.0.0 --port 9000

The repo ships docker/agent.compose.yml, which provisions the MCP server and the agent together. The agent waits on the MCP server and is wired to it by container name:

services:
  media-downloader-mcp:
    image: example/media-downloader@sha256:<digest>
    hostname: media-downloader-mcp
    environment:
      - HOST=0.0.0.0
      - PORT=8000
      - TRANSPORT=streamable-http
    ports: ["8000:8000"]

  media-downloader-agent:
    image: example/media-downloader@sha256:<digest>
    depends_on: [media-downloader-mcp]
    command: ["media-downloader-agent"]
    environment:
      - HOST=0.0.0.0
      - PORT=9000
      - MCP_URL=http://media-downloader-mcp:8000/mcp
      - PROVIDER=${PROVIDER:-openai}
      - MODEL_ID=${MODEL_ID:-gpt-4o}
      - ENABLE_WEB_UI=True
    ports: ["9000:9000"]

docker compose -f docker/agent.compose.yml up -d

Service	Port	Role
`media-downloader-mcp`	`8000`	MCP tool surface (`/mcp`, `/health`)
`media-downloader-agent`	`9000`	A2A agent + web UI, wired via `MCP_URL`

Behind a Caddy reverse proxy¶

Expose the HTTP server on a hostname with automatic TLS. Add to your Caddyfile:

# Internal (self-signed) — homelab .example.invalid zone
media-downloader.example.invalid {
    tls internal
    reverse_proxy media-downloader-mcp:8000
}

# Public — automatic Let's Encrypt
media-downloader.example.com {
    reverse_proxy media-downloader-mcp:8000
}

Reload Caddy:

docker compose -f services/caddy/compose.yml exec caddy caddy reload --config /etc/caddy/Caddyfile

DNS with Technitium¶

Point the hostname at the host running Caddy. Via the Technitium API:

curl -s "http://technitium.example.invalid:5380/api/zones/records/add" \
  --data-urlencode "token=$TECHNITIUM_DNS_TOKEN" \
  --data-urlencode "domain=media-downloader.example.invalid" \
  --data-urlencode "zone=arpa" \
  --data-urlencode "type=A" \
  --data-urlencode "ipAddress=192.0.2.10" \
  --data-urlencode "ttl=3600"

…or add an A record media-downloader.example.invalid → <caddy-host-ip> in the Technitium web console (http://technitium.example.invalid:5380). The ecosystem technitium-dns-mcp automates this as a tool.

Register with an MCP client¶

Add to your client's mcp_config.json:

{
  "mcpServers": {
    "media-downloader": {
      "command": "uv",
      "args": ["run", "media-downloader-mcp"],
      "env": {
        "DOWNLOAD_DIRECTORY": "/data/downloads",
        "AUDIO_ONLY": "False"
      }
    }
  }
}

For a remote HTTP server, point the client at http://media-downloader.example.invalid/mcp instead.