pyexch 0.0.1

Python CLI Exchange Rest Client

pyexch

EARLY PREVIEW RELEASE of a rudimentary python CLI based rest client for Coinbase

usage: pyexch [-h] [--method <get,post,>] [--url https://...]
              [--params params.json] [--call get_accounts] --keystore ks.json
              [--auth exch.auth]

Python Exchange CLI (pyexch)

optional arguments:
  -h, --help            show this help message and exit
  --method <get,post,>  rest http method (get<default>,post,put,delete)
  --url https://...     rest http url to perform actions upon
  --params params.json  json / json5 filename holding rest parameters / data
  --call get_accounts   call method in the default client
  --keystore ks.json    json / json5 filename where secrets are stored
                        (backup!)
  --auth exch.auth      the auth method to use from keystore.

NOTE: Must name either "--call" or "--url", but not both

Future Plans

• Add GET and POST methods for Coinbase
• Add OAuth2, API_v2 and API_v3 support for Coinbase
• Tag a (beta) release to reduce the nead to use the HEAD
• Release to PyPi for better CDN support
• Add PUT and DELETE methods for Coinbase
• Add Kraken as a supported Exchange
• Add Binance as a supported Exchange (from USA ?!?)
• Mask input on private data so it's is muted on screen

Install and Initial Setup

This utility allows you to use a Cryptocurrency Exchange's REST API to perform basic tasks and retrieve current and historical account data. You will need to setup API / OAuth2 access keys in your account to use this utility. The utility supports both GPG and Trezor-CipherKeyValue encryption. You will need either a GPG key pair installed, or a Trezor attached. As a fallback you can store API keys in naked JSON, but that is obviously not recommended.

Install with GIT / PIP

1. Get source: git clone https://github.com/brianddk/pyexch.git
2. Switch directories: cd pyexch
3. Install via pip: pip install .
4. Verify install (cli-mode): pyexch --help

Alternatively you can run it in module mode (python -m pyexch --help) or run the script directly (python pyexch.py --help).

Install without GIT

To install directly from GitHub, you can install from the tarball:

pip install https://github.com/brianddk/pyexch/archive/refs/tags/0.1.tar.gz

You won't get to documentation or templates, but all the code will land and functino

Building a Keystore

If you decide to use a naked JSON, you can simply modify the null values in the json_ks.json to fill in the key values. If you want to use encryption you will need to modify on of the encryption templates (trezor_ks.json or gnupg_ks.json) and update the unencrypted parameters. These all deal with various encryption settings. Note that for Trezor, zlib is the ONLY supported compression. Since the JSON keystore is self explanatory, I'll focus on building the encrypted keystores.

Building a GnuPG encrypted Keystore:

Start with the GnuPG template gnupg_ks.json, and change the recipient to the key-id of your GnuPG key. This can be the UID (email), or the short or long key hex.

{
  "format": "gnupg",
  "gnupg": {
    "recipient": "TYPE_YOUR_GPG_PUBLIC_KEY_HERE"
  }
}

Once you have populate the recipient, you can update the secrets interactively to keep them off of your filesystem and out of your process viewer. This uses the update_keystore command which takes a JSON template as a parameter. Any null value will trigger prompting on the console. Input is not masked or muted, so you may want to run a clear-screen after to keep reduce the amount of time it is in the console buffer.

1. Pick a authorization method to use (coinbase.oauth2, coinbase.v2_api, coinbase.v3_api)
2. Fill in your template data, leave null values for prompting (ex: coinbase_oauth2.json)
3. Run the update_keystore command to prompt and encrypt secrets

Template:

{
  "format": "json",
  "coinbase": {
    "oauth2": {
      "auth_url": "https://api.coinbase.com/oauth/authorize",
      "token_url": "https://api.coinbase.com/oauth/token",
      "revoke_url": "https://api.coinbase.com/oauth/token",
      "redirect_url": "http://localhost:8000/callback",
      "scope": "wallet:user:read,wallet:accounts:read",
      "id": null,
      "secret": null
    }
  }
}

With both the GnuPG and OAuth2 templates, the update_keystore call will prompt for the null fields, and encrypt the resultant merge with GnuPG

pyexch --call update_keystore --params coinbase_oauth2.json --keystore gnupg_ks.json --auth coinbase.auth2

If you choose OAuth2, you will need to create / authorize your app to get a grant token

pyexch --uri https://www.coinbase.com/oauth/authorize --keystore gnupg_ks.json --auth coinbase.auth2

This will launch your web-browser and web-server to service the request and store the keys in your keystore. You can display the keys on console using print_keystore call. Note that since this get takes secret params, the auth_url is treated special and the parameters are built internally for processing to avoid the need for an encrypted params.json file.

pyexch --call print_keystore --keystore gnupg_ks.json

Note that since OAuth tokens are short lived, you will need to refresh the tokens about every hour. To refresh to token post to the token_url to get a new token. Note that since this get takes secret params, the token_url is treated special and the parameters are built internally for processing to avoid the need for an encrypted params.json file.

pyexch --method post --uri https://api.coinbase.com/oauth/token --keystore gnupg_ks.json

Note: The --auth choice is cached in the keystore so the last choice used is assumed unless --auth is named again.

Making REST or Client calls

Once you have good API / AUTH tokens stored, you can start making calls to the API's or Clients directly. To determine which URLs are supported look at the API V2 documentation, and API V3 documentation. Note that OAuth2 works on both v2 and v3 URLs.

To learn which calls are supported, look at the V2 Client and V3 Client. All parameters needed for the call commands are taken from the JSON file pointed to in the --params argument.

For example, to exercise the V2-API Show Authorization Information endpoint, you can do the following

pyexch --url https://api.coinbase.com/v2/user/auth --keystore gnupg_ks.json

To call the [get_buy_price][] method from the V2-Client using BTC-USD trading pair (use \" with echo on certain shells)

echo {"currency_pair" : "BTC-USD"} > params.json
pyexch --call get_buy_price --params params.json --keystore gnupg_ks.json