Using agents storage function

Introduction

Agents will need to store data for later use, uAgents has an inbuilt function to store data to json file, this is done with ctx.storage. Data is stored in key:value format. ctx object’s storage attribute has different function like get and set to use agent’s storage.

Overview

We can store simple integers like :

ctx.storage.set("Messages_sent", 1)

Or strings:

ctx.storage.set("Passkey", "#-eiwfwrign")

Complex data can also be stored:

Record1 = {"name":ctx.name, "address":ctx.address}
ctx.storage.set("Record1", Record1)

We can access these values like so:

ctx.logger.info(ctx.storage.get("Record1"))
ctx.logger.info(ctx.storage.get("Messages_sent"))
ctx.logger.info(ctx.storage.get("Passkey"))

Expected Output:

INFO:     [Receiver]: {"name": "Receiver", "address": "agent1qdlcar9glcm6f9rpzway3xqaw4clfltxdhtwflxrjz3ahy98ep5dx7xy6x7"}
INFO:     [Receiver]: 2
INFO:     [Receiver]: "#-eiwfwrign"

Locally, this will be stored as a json file:

{
"Messages_sent" : 2,
"Record1" : {"name" : "Receiver", "address" : "agent1qdlcar9glcm6f9rpzway3xqaw4clfltxdhtwflxrjz3ahy98ep5dx7xy6x7"},
"Passkey" : "#-eiwfwrign"
}

Generally, any object that is compatible with pydantic Models will be fine with uAgents.

Prerequisites

Make sure you have read the following resources before going on with this guide:

• Creating your first agent
• Agent Handlers

Imports needed

• uAgents (opens in a new tab)

Walk-through

In this walkthrough, we want to show how storage functions are called and how to use them. We want to create an agent which gets a value from the storage (starting from 0) every second. Then prints it, and puts the new value back into the storage but increased by 1 unit.

1. To start let's create a Python script and name it storage.py, we can do this in terminal with the following command:

   windows
   echo. > storage.py

2. Then, we need to open the script in the text editor of choice and import the necessary classes, Agent and Context, from the uagents library.

3. Let's then create an agent named alice which logs a message every second using the .on_interval() decorator, indicating the current count. The on_interval() function takes a Context object as a parameter: the Context object contains a storage attribute, which is used to store and retrieve data between method calls:

storage.py
 
from uagents import Agent, Context
 
alice = Agent(name="alice", seed="alice recovery phrase")
 
@alice.on_interval(period=1.0)
async def on_interval(ctx: Context):
    current_count = ctx.storage.get("count") or 0
 
    ctx.logger.info(f"My count is: {current_count}")
 
    ctx.storage.set("count", current_count + 1)
 
if __name__ == "__main__":
    alice.run()
 

Here, the on_interval() function retrieves the current count from the storage attribute using the ctx.storage.get() method. It prints the current_count value, and then increments it by 1, and stores the updated count back to the storage attribute using the ctx.storage.set() method. The current count is then logged using the ctx.logger.info() method.

4. Save the script.

Run the script

On your terminal, make sure you activated the virtual environment.

Run the script: python storage.py

The output should look as follows:

INFO:     [alice]: Starting server on http://0.0.0.0:8000 (Press CTRL+C to quit)
INFO:     [alice]: My count is: 1
INFO:     [alice]: My count is: 2
INFO:     [alice]: My count is: 3
...