solsim

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Introduction

solsim is the Solana complex systems simulator. It simulates behavior of dynamical systems—DeFi protocols, DAO governance, cryptocurrencies, and more—built on the Solana blockchain.

Philosophy

Define your system how you see fit.

solsim will simulate its behavior and collect its results in a structured, straightforward manner.

Usage

1. Implement initial_step and step methods.
2. From each, return the current state, i.e. a dictionary mapping variables to current values.
3. Specify the variables you'd like to "watch."
4. Instantiate a Simulation, call .run().
5. Receive a pandas DataFrame containing values of "watched" variables at each step in time.

With Solana

from anchorpy import Context
from solana.keypair import Keypair
from solsim.simulation import Simulation

class SomeSolanaSystem(BaseSolanaSystem):
    def __init__(self):
        super().__init__("path/to/workspace")
        self.account = Keypair()
        self.pubkey = self.account.public_key
        self.program = self.workspace["my_anchor_program"]  # solsim gives a Anchor program workspace (self.workspace).

    async def initial_step(self):
        self.program.rpc["initialize"]()  # Make RPC calls to your Anchor program.
        await self.client.request_airdrop(self.pubkey, 10)  # solsim gives you a Solana API client (self.client).
        return {"balance": await self.client.get_balance(self.pubkey)}

    async def step(self, state, history):
        self.program.rpc["submit_uniswap_trade"](
            ctx=Context(accounts={"account": self.pubkey}, signers=[self.account])
        )
        return {"balance": await self.client.get_balance(self.account)}


simulation = Simulation(system=SomeSolanaSystem(), watchlist=("balance"))
results = simulation.run(steps_per_run=5)  # Returns pandas DataFrame of results.

Without Solana

class SomeSystem(BaseSystem):
    def __init__(self, population):
        self.pop = population

    def initial_step(self):
        return {"population": self.pop}

    def step(self, state, history):
        return {"population": state["population"] * 1.1}


simulation = Simulation(system=SomeSystem(), watchlist=("population"))
results = simulation.run(steps_per_run=5)

CLI

Simulations can also be run via CLI. Instead of calling simulation.run(), simply:

1. Call simulation.cli()
2. Run your simulation as e.g. python path/to/file.py run --num-runs 3

Results Explorer

solsim gives you a streamlit app to explore results, e.g.

To automatically start this app following simulation, invoke one of the following:

• simulation.run(visualize_results=True)
• --viz-results flag in the CLI runner, e.g. python path/to/file.py run --viz-results

Installation

First, install Anchor.

Library

pip install solsim

Development

Install poetry. Then,

git clone --recurse-submodules https://github.com/cavaunpeu/solsim.git
cd solsim
poetry install
poetry shell

Detailed Usage

With Solana

First, write your Solana program. solsim prefers you do this in Anchor. Then,

1. Write a system class that inherits from BaseSolanaSystem.
2. Call super().__init__("path/to/program") in its __init__.
3. Implement initial_step and step methods. (Since you'll interact with Solana asynchronously, these methods should be async.)

In 2., solsim exposes the following attributes to your system instance:

• self.workspace: IDL clients for the Solana programs that comprise your system (via anchorpy).

For example, these clients let you interact with your respective programs' RPC endpoints.

• self.client: a general Solana client (via solana-py).

This client lets you interact with Solana's RPC endpoints. Documentation here.

Finally,

1. Define a watchlist: variables (returned in initial_step and step) you'd like to "watch."
2. Instantiate and run your simulation, e.g. Simulation(MySystem(), watchlist).run(steps_per_run=10).

Without Solana

1. Write a system class that inherits from BaseSystem.
2. Implement initial_step and step methods.
3. Define a watchlist.
4. Instantiate and run your simulation.

Examples

Drunken Escrow

Agents are randomly paired to exchange random amounts of foo_coin and bar_coin via an Anchor escrow contract in each timestep.

• Run: python -m examples.drunken_escrow.
• Code: here.
• Expected output (numbers may vary):

(.venv) ➜  solsim git:(main) $ python -m examples.drunken_escrow
Waiting for Solana localnet cluster to start (~10s) ...
Steps completed: 100%|████████████████████████████████████████████████████████████████████████████████████| 4/4 [00:27<00:00,  6.82s/it]
   step  mean_balance_spread  mean_swap_amount  num_swaps
0    -1            40.000000         30.666667          3
1     0            58.000000         12.000000          3
2     1            60.666667          4.000000          3
3     2            83.333333         21.500000          2

Lotka-Volterra

The Lotka-Volterra model is a classic dynamical system in the field of ecology that tracks the evolution of interdependent predator and prey populations.

• Run: python -m examples.lotka_volterra.
• Code: here.
• Expected output:

(.venv) ➜  solsim git:(main) ✗ python -m examples.lotka_volterra
Steps completed: 100%|█████████████████████████████████████████████████████████████████████████████████| 4/4 [00:00<00:00, 28581.29it/s]
   step  food_supply  population_size
0    -1     1000.000            50.00
1     0      995.000            60.00
2     1      989.000            69.95
3     2      982.005            79.84

This implementation inspired by cadCAD Edu.

Inspiration

solsim humbly builds on the shoulders of the giants that are cadCAD and tokenspice, among others.