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Adding Archival Checks

🧑‍🎓 Instructions for adding new archival check configurations by following an example for Polygon zkEVM 🧑‍🎓

Table of Contents ​

Overview​

The process of configuring archival checks for a new chain is manual but only needs to be performed once per chain.

Service QoS Configurations​

QoS configurations are stored in path/config/service_qos_config.go.

Adding an Archival Check By Example: Polygon zkEVM​

This example uses the Polygon zkEVM chain (F029).

0. Find a Block Explorer​

Firstly, find a publically accessible block explorer for the chain. Most EVM chain block explorers use a similar format for their browser UI.

Block Explorer for Polygon zkEVM: zkevm.polygonscan.com/

1. Go to the chain's block explorer​

Go to the chain's block explorer and search for Top Account in the Blockchain dropdown.

HowToArchival1

2. Choose a top account​

Find an account with lots of activity and click on the Address.

HowToArchival2

3. Find the contract creation block​

Under the Filters section, select View Contract Creation.

HowToArchival3

Take note of the block number of the first transaction for that address.

HowToArchival4

4. Add the new archival check configuration​

In the path/config/service_qos_config.go file, add a new entry to the shannonServices array.

The configuration MUST be entered in this exact format:

// Polygon zkEVM
evm.NewEVMServiceQoSConfig("F029", "0x44d", evm.NewEVMArchivalCheckConfig(
   // https://zkevm.polygonscan.com/address/0xee1727f5074e747716637e1776b7f7c7133f16b1
   "0xee1727f5074E747716637e1776B7F7C7133f16b1",
   // Contract start block
   111,
)),

It must contain the following elements in evm.NewEVMArchivalCheckConfig, exactly as shown above.

LineDescriptionExample
1A comment containing the URL for the contract address on the block explorer as a comment// https://zkevm.polygonscan.com/address/
0xee1727f5074e747716637e1776b7f7c7133f16b1
2The contract address as the first parameter"0xee1727f5074E747716637e1776B7F7C7133f16b1"
3A comment containing // Contract start block// Contract start block
4A block number just slightly higher than the first transaction for that address as the second parameter111

5. Send a test request​

Configure PATH for the service you want to test, and run make path_run to start PATH from a local binary.

Pocket Network Cheat Sheet

For information on how to configure PATH for a service, see the Shannon Cheat Sheet.

Then send a request to validate that data is returned correctly for the requested block.

Example eth_getBalance Request
  • The example contract address: 0xee1727f5074E747716637e1776B7F7C7133f16b1
  • A randomly selected block hash (ideally close to the first transaction for that address): 0x15E (350)

Request:

curl http://localhost:3069/v1 \
  -H "Target-Service-Id: F029" \
  -d '{
     "jsonrpc": "2.0",
     "method": "eth_getBalance",
     "id": 1,
     "params": [
        "0xee1727f5074E747716637e1776B7F7C7133f16b1",
        "0x15E"
     ]
  }'

Expect Response:

{
  "id": 1,
  "jsonrpc": "2.0",
  "result": "0x247a76d7647c0000"
}

Additional Resources​