Plutus examples

Math Bounty Contract

Description

This is a simple smart contract which locks deposited funds under a math bounty (specifically figuring out what number squared matches a given value). The user who locks their ada under this contract provides a target which is the number that must be the result of the squaring.

In other words:

x * x = target

This target is an integer and is placed within the script Datum of the locked output UTXO.

Once the funds are locked under the contract with the datum, anyone can solve the math bounty by providing the correct number (providing the correct x).

They do this by submitting a transaction with their answer for x as the Redeemer. If their answer is correct, then they get to spend the locked bounty UTXO, and take the funds from within it.

Code

NOTE: use plutus-app commit 4edc082309c882736e9dec0132a3c936fe63b4ea

Code

• MathBounty: first version
• MathBountyFilter: fix consuming wrong datum contracts
• MathBount2: just consumes one utxo in another way

Playground test cases

• Wallet 1 make a bounty, and Wallet 2 consumes it
• Wallet 1 make 2 bounties in the same slot, Wallet 2 consumes the existen one
• Wallet 1 make 2 bounties same datum in the different slots, Wallet 2 consumes them
• Wallet 1 and 2 makes 2 bounties with same datum in the same slot, Wallet 2 consumes all
• Wallet 1 and 2 makes 2 bounties with different datums in the same slot, Wallet tries to consume
• Introduce MathBountyFilter fixing previous problem, and test again previous case

Guessing Game Contract

This is the same guessing the secret word game contract as the example in the Plutus Playground, but hiding datum by hashing it.

Playground test cases

• Wallet 1 make locks, and Wallet 2 guesses
• Wallet 1 and Wallet 2 locks 2 equal secrets in the same slot, Wallet 2 guesses
• Wallet 1 and Wallet 2 locks 2 different secrets in the same slot, Wallet 2 guesses, propose as homework fix the problem as done with Math Bounty

Multi-Stage Protocol - Math Bounty Into Pin Lock

This is combination of the math bounty contract (as stage 1) and the pin/pass lock contract (as stage 2). Do note, this example only provides the off-chain logic to perform the transition between the stages and to go in/out of the protocol. There is no on-chain check that forces the user to go from stage 1 (math bounty) to stage 2 (pin/pass lock), and as such this is not a "true" multi-stage protocol. Future examples will cover how to specifically enforce this on-chain.

This example showcases how to use a different script once a certain condition is met (note that the change is made off-chain).

First, a user locks deposited funds under a math bounty (specifically figuring out what number squared matches a given value). The user who solves the problem then locks the awarded funds into a password protected contract that can be collected later by providing the unlock password.

The user who locks their ada under this contract provides a target which is the number that must be the result of the squaring.

In other words:

x * x = target

This target is an integer and is placed within the Datum of the locked output UTXO.

Once the funds are locked under the contract with the datum, anyone can solve the math bounty by providing the correct number (providing the correct x). They do this by submitting a transaction with their answer for x as the Redeemer and a lock password. If their answer is correct and the UTXO can be spent, the endpoint will lock the funds into a new contract that will validate that the hash of the passwords match, and then they get to spend the locked bounty UTXO, and take the funds from within it.

This application three endpoints:

• Publish the problem and prize (Math bounty contract)
• Send a solution to the bounty, and lock the funds under a secret word (Guessing game)
• Unlock the funds that were originally

Run playground

Run nix-shell in plutus-app repository

cd plutus-app
git checkout 4edc082309c882736e9dec0132a3c936fe63b4ea
nix-shell

Run playground

Inside a two plutus-app's nix-shells run:

cd plutus-playground-client
plutus-playground-server

And:

cd plutus-playground-client
npm start

Playground should be accesible at: https://0.0.0.0:8009/

Run documentation

Inside a plutus-app's nix-shell run:

build-and-serve-docs

Playground should be accesible at: http://localhost:8002/haddock