Saya - Persistent mode

saya

In persistent mode, Saya will fetch the blocks from Katana and will verify the proof and update the state of the core contract on the settlement layer.

The core contract currently used on Starknet is Piltover.

Setup Katana

Katana needs to be configured in provable mode to work with Saya. Katana is available in provable mode with all the new options starting Dojo 1.3.0.

Initialize a new Katana chain spec:

katana init --id per1 \
    --settlement-chain <Sepolia|Mainnet> \
    --settlement-account-address <ADDRESS> \
    --settlement-account-private-key <PRIVATE_KEY>

This will automatically deploy a fresh core contract on the settlement layer.

If you want to use a specific facts registry contract, set it via the settlement-facts-registry argument.

katana init --id per1 \
    --settlement-chain <Sepolia|Mainnet> \
    --settlement-account-address <ADDRESS> \
    --settlement-account-private-key <PRIVATE_KEY>
    --settlement-facts-registry <ADDRESS>

✓ Deployment successful (0x7059b8519965f0587a2d3892ce747d79d256e98e1021a7b993f86d6a3f62d22) at block #605518

When working with Katana in provable mode, two additional parameters are required:

block time: since every block is proven, it is recommended to use a block time instead of the default mode where a block is mined for each transaction.
block max cairo steps: in the current implementation of Katana, there's a limitation where the cairo steps in a block are capped at 16 million. This is to prevent the proving step to fail. Once this limitation will be lifted, the maximum will be 40 million.

katana --chain sov1 \
    --block-time 30000 \
    --sequencing.block-max-cairo-steps 16000000

Running Saya

If you didn't already, consult the Herodotus guide to get an account and an API key.

To ease the configuration, Saya can be run with environment variables (which can be overridden by command line arguments).

If you are not running Saya in docker, you can download the SNOS program and the Layout Bridfge program from the Saya releases.

If you are running Saya in docker, the programs are already present in the /programs directory.

# .env.persistent file
 
# The number of blocks to process in parallel in Saya.
BLOCKS_PROCESSED_IN_PARALLEL=4
 
# The database directory, to ensure long running queries are tracked
# and not re-run if Saya is restarted.
DB_DIR=/tmp/saya_persistent
 
# The Atlantic key, obtained from https://herodotus.cloud.
ATLANTIC_KEY=
 
# The path to the compiled SNOS program to be run against each block.
SNOS_PROGRAM=./programs/snos.json
 
# The path to the compiled layout bridge program to be run against each block.
LAYOUT_BRIDGE_PROGRAM=./programs/layout_bridge.json
 
# In persistent mode, the rollup RPC to pull the blocks from.
ROLLUP_RPC=http://0.0.0.0:5050
 
# Integrity verifier contract address.
# https://github.com/HerodotusDev/integrity/blob/main/deployed_contracts.md
SETTLEMENT_INTEGRITY_ADDRESS=0x04ce7851f00b6c3289674841fd7a1b96b6fd41ed1edc248faccd672c26371b8c
 
# Settlement chain.
SETTLEMENT_RPC=https://api.cartridge.gg/x/starknet/sepolia
SETTLEMENT_PILTOVER_ADDRESS=
SETTLEMENT_ACCOUNT_ADDRESS=
SETTLEMENT_ACCOUNT_PRIVATE_KEY=

Export those variables in your shell by sourcing the file or running:

export $(grep -v '^#' .env.persistent | xargs)

Then, you can start Saya with:

saya persistent start