Python Plugins

This folder contains everything needed to build and run a Python plugin (other than the rippled code).

Build & Run

pip install xrpl-plugin
plugin-build path/to/plugin.py
# edit rippled.cfg to include the plugin.xrplugin in a [plugins] stanza
# run rippled with the `plugin` branch and submit plugin transactions to it

Concepts

Keylet

A Keylet identifies a key in the state map and its ledger entry type. Keylet is a portmanteau of the key and LET, an acronym for LedgerEntryType.

LedgerEntryType

Each ledger object requires a unique type identifier, which is stored within the object itself; this makes it possible to iterate the entire ledger, determine each object's type and verify that the object you retrieved from a given hash matches the expected type.

Notes

pybind11 is a lightweight header-only library that exposes C++ types in Python and vice versa, mainly to create Python bindings of existing C++ code. The plugin exposes the code in main.cpp as python bindings.

Then we can use in our plugin the following:

• models (classes):

  • Transactor
  • SType (it has a parse_value method)
  • TERCode
  • LedgerObject
  • InvariantCheck
  • InnerObject

• sfields (ST fields, serialized fields that can be included in transactions and ledger objects):

  • SF_ACCOUNT
  • SF_AMOUNT
  • SF_UINT8
  • ...

• stypes (all STObjects, serialized types):

  • STAmount
  • STObject
  • STArray
  • ...

• return_codes (Existing TER return codes):

  • tesSUCCESS
  • temMALFORMED
  • ...

• basic_types (basic/fundamental types):

  • AccountID
  • XRPAmount
  • Seed
  • IOUAmount
  • ...

• keylets (as per definition above):

  • account_keylet
  • escrow_keylet
  • trustline_keylet
  • offer_keylet
  • ...

• ledger_objects (for ledger object manipulation):

  • LedgerEntryType
  • LedgerSpecificFlags

• transactors (contexts and other classes used in transaction processing):

  • Rules
  • Fees
  • TimePoint
  • LedgerInfo

• build (for the build process)

• nfts (utility methods for working with NFTs)