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Intelligent Contracts
Your First Intelligent Contract

Your First Intelligent Contract

An Intelligent Contract in GenLayer can contain non-deterministic blocks: regular Python functions with no arguments that may return arbitrary values and must be invoked through gl.eq_principle.*. For blockchain integrity reasons, non-determinism must be contained within these special non-deterministic blocks, and the blocks have two important limitations:

  • Storage is inaccessible from non-deterministic blocks
  • State of the Python interpreter is not passed back to the deterministic code (for instance, you won't see changes in global variables)

Simple Case

To illustrate how non-deterministic blocks work, this example gets a webpage as plain HTML and verifies that it has a link to the owner:

example_web_address = 'https://example.org'
def my_non_deterministic_block():
    web_data = gl.nondet.web.render(example_web_address, mode='html')
    return 'iana' in web_data
 
print(gl.eq_principle.strict_eq(my_non_deterministic_block))

Here are a few important parts:

  1. It is mandatory to call gl.nondet.web.render (or gl.nondet.web.get) from a function invoked via gl.eq_principle.*, otherwise it will give an error
  2. Type annotations are not required
  3. example_web_address gets captured without the need to specify it explicitly
  4. We are getting the page in plain HTML, because we want text from a link (<a> HTML tag), which is not visible in the text representation
  5. We are using gl.eq_principle.strict_eq because we return a bool (True or False), so there is no need to run LLMs or other complex computations: validators will agree if they both get the exactly the same result, which makes sense for our case. However, if you wish to return more complex data (such as a text summary), you should use other gl.eq_principle methods. More on this topic on the next page

As a Full Contract

# { "Depends": "py-genlayer:1jb45aa8ynh2a9c9xn3b7qqh8sm5q93hwfp7jqmwsfhh8jpz09h6" }
 
from genlayer import *
 
class Contract(gl.Contract):
    had_iana: bool
 
    def __init__(self):
        example_web_address = 'https://example.org'
        def my_non_deterministic_block():
            web_data = gl.nondet.web.render(example_web_address, mode='html')
            return 'iana' in web_data
        self.had_iana = gl.eq_principle.strict_eq(my_non_deterministic_block)
Contract StorageEquivalence Principle