Casper Python SDK

Python 3.9+ library for interacting with a CSPR node.

What is Casper Python SDK pycspr

The python client is published as pycspr: PYthon CaSPeR. It's goal is to streamline client side experience of interacting with a casper node.

How To: Install ?

It's recommend to create a virtual environment for your application:

$ cd path/to/your/project
$ virtualenv .venv  # if you just starting and need a venv anyway
$ source ./.venv/bin/activate  # launch your environment
$ pip install pycspr

If you want to take part in develeopment, follow the intallation instructions for development.

Usage

• Query a node See here.
• Transfer funds between 2 accounts See here.
• Delegate funds to a validator See here.
• Undelegate funds from a validator See here.
• Stake funds as a validator See here.
• Unstake funds as a validator See here.
• Install a smart contract See here.
• Invoke a smart contract See here.

NodeClient

Queries

Deploys

Events

Important modules

crypto

factory

serialisation

types

utils

Development

Architecture

                     ______________ Your APP needs to call the NodeClient to
                     | Your App   | make API calls. In addition you may need
                     |____________| some tools which can be found in factory,
                            X       crypto and utils.
                            |
=========================== | ================================================
                            V 
_____________        _______________      ______________ More complex
|           |        |             |      |            | operations and
| Deploys   |<------X|  NodeClient |X---->|EventsClient| simplification of
|           |   ----X|             |      |            | composed API/Client
-------------   |    ---------------      -------------- calls.
      X         |
===== | ======= | ============================================================
      V         V                       
_______________________________________ Supposes all API calls and additional   
|                    |                | methods, composed of basic API calls.
|        Client      |  pycspr.types  | Converts API response into pycspr.types.
|(client.QueryClient)|                | Extracts result from API response.
--------------------------------------- Checking and converting input params. 
            X
=========== | ==================================================================
            V               
___________________________ "Low Level" communication, REST and RPC Api calls.
|                         | Does all REST and RPC calls. All endpoints defined
|      CasperApi          | here. No converting or manipulation of output or
|     (pycspr.api)        | input params at all. All in all its a simple        
--------------------------- interface to the REST/RPC API.                      
            X                 
=========== | ==================================================================
            V
  ___________________________          ___________________________
  |                         |          |                         | 
  |   NodeConnectionInfo    |X-------> |      requests,          | 
  |      (pycspr.api)       |          |    jsonrpcclient, ...   | 
  ---------------------------          ---------------------------

Set up local test NCTL network

Installing Rust

Follow the Casper Documentation: Getting Started

Installing a local test NCTL network

See the Casper Documentation for installation: Local Network Testing

Running the local test network

$ nctl-assets-setup && nctl-start 

You can stop the server and delete created assets with nctl-assets-teardown.

Installing the SDK for Development

after cloning:

$ cd casper-python-sdk/
$ virtualenv .venv
$ source ./.venv/bin/activate
(.venv) $ pip install -r requirements-dev.txt

Pre Commit/PullRequest Actions

Always asure that the tests are running and that you follow the PEP.

Testing

Important Environment Variables

• NTCL default not set (ie: ~/casper-node/utils/nctl).
• PYCSPR_TEST_NODE_HOST" default set to "localhost")
• PYCSPR_TEST_NODE_PORT_REST default set to 14101)
• PYCSPR_TEST_NODE_PORT_RPC default set to 11101)
• PYCSPR_TEST_NODE_PORT_SSE default set to 18101)

Run Unit Tests

$ cd casper-python-sdk/
$ source .venv/bin/activate  # or pipenv shell
(.venv) $ export NCTL=/path/to/your/casper-node/utils/nctl
(.venv) $ pytest ./tests

TODO: Git pre-commit-hook needed.

Codestyle Guidelines

run flake8 (Style Guide Enforcement):

(.venv) $ cd casper-python-sdk/
(.venv) $ flake8 .

TODO: Git pre-commit-hook needed.

Additional Resources

• Json RPC Schema in resources/rpc_schema.json
• Casper Specifcation: https://caspernetwork.readthedocs.io/en/latest/implementation/
• Casper Documentation: https://docs.casperlabs.io/
• How to stake your CSPR: https://casper.network/network/blog/how-to-stake-your-cspr
• Python Enhancement Proposals(PEP): https://www.python.org/dev/peps/