Paradex WebSocket via Subkey (Python SDK) — Quickstart

This repo is a minimal, working example to connect to Paradex Prod WebSocket price feeds using the official Paradex Python SDK (paradex-py), authenticated via a Trading Key (Subkey).

Goal: get from zero → streaming WS (perp-ticker) data in ~30–45 minutes, without digging through a large SDK repo structure.

Official SDK (reference / full functionality):

• https://github.com/tradeparadex/paradex-py

Related official docs:

• https://docs.paradex.trade/docs/trading/api-authentication#subkeys
• https://docs.paradex.trade/ws/general-information

DM me on X:

• https://x.com/cissora/status/2024335267365097743

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What this repo does

• Authenticates to Paradex Prod WS using your L2 Address + Trading Key (Subkey)
• Subscribes to:
  • markets_summary (ALL markets): mark + funding (often)
  • bbo (per market): best bid/ask
• Prints a clean periodic terminal snapshot

This is intended to be foundational plumbing you can build on:

• scanners
• execution
• REST calls
• risk dashboards
• hedging logic

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Confirmed Working Python Version

Python 3.11 is the baseline that is known to work here.
Newer Python versions might work, but are not guaranteed (dependency + async/websocket stacks can break on bleeding edge).

If you want “it just works,” use 3.11 (this repo’s Docker image uses Python 3.11).

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You MUST use a Trading Key (Subkey)

Paradex has different “keys”. For this setup you want a Trading Key / Subkey from the Paradex app.

Create a Trading Key (Subkey) in the Paradex UI

1. Go to: https://app.paradex.trade
2. Connect your wallet
3. Navigate to:
   • Settings
   • Key Management
4. You’ll typically see:
   • Read-only keys
   • Trading keys
5. Under Trading Keys, create / add a new key.

Important notes:

• This “Trading Key” may also be labeled as a “private key” in some UIs/exports.
• In practice, this is the safer key to use for automation than exposing a more sensitive primary key.
• Treat it like a secret anyway: do not paste it into videos, do not commit it, do not share it.

You’ll need:

• L2_ADDRESS (your Paradex L2 address)
• L2_SUBKEY (the trading key/subkey you generated)

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Quickstart (VS Code Dev Containers) (Optional)

This is the easiest path if you want a consistent environment and fewer OS issues.

1) Install prerequisites

Recommended:

• Docker Desktop (must be installed and running)
• VS Code
• VS Code extension: Dev Containers

Optional:

• Git (or download the repo ZIP manually)

2) Open the repo in VS Code

• File → Open Folder…
• Select the repo folder (the one containing Dockerfile + scan_ws.py)

3) Start the dev container

• Press Shift+Ctrl+P (Command Palette)
• Run: Dev Containers: Reopen in Container

If you changed requirements.txt or the Dockerfile:

• Shift+Ctrl+P → Dev Containers: Rebuild Container

4) Confirm you are inside the container

You should see BOTH:

• Bottom-left VS Code status bar shows something like: Dev Container: ...
• Terminal prompt typically looks like: root@<container_id>:/workspaces/<repo>#

If you do not see those, you are not inside the container yet.

5) Verify dependencies inside the container

python --version
python -c "import importlib.metadata as m; print('termcolor', m.version('termcolor'))"
python -c "import importlib.metadata as m; print('paradex-py', m.version('paradex-py'))"

6) Create your .env

Create .env in the repo root (same directory as scan_ws.py):

L2_ADDRESS=0x...
L2_SUBKEY=0x...

ENV=PROD
PARADEX_CHAIN_ID=PRIVATE_SN_PARACLEAR_MAINNET

7) Run the WebSocket scanner

python scan_ws.py

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Quickstart (Docker CLI)

Use this if you prefer the terminal instead of VS Code Dev Containers.

1) Build the image (from repo root)

docker build -t paradex-ws-quickstart .

2) Run the container (interactive)

This mounts your repo into the container so it can read .env and run scan_ws.py from the repo root:

docker run --rm -it \
  -v "$PWD:/repo" \
  -w /repo \
  paradex-ws-quickstart bash

3) Verify dependencies inside the container

python --version
python -c "import importlib.metadata as m; print('termcolor', m.version('termcolor'))"
python -c "import importlib.metadata as m; print('paradex-py', m.version('paradex-py'))"

4) Run the WebSocket scanner

python scan_ws.py