fetch-blocks

name	fetch-blocks
description	Use to fetch Ethereum mainnet blocks from an RPC URL and save them on a local directory. Use it to acquire blocks for later execution/proving.
allowed-tools	Bash, Read, Glob

Fetch Ethereum Blocks from RPC URL and Save to Local Directory

Overview

The z6m_prover command with --service option runs a service fetching blocks at the tip or specified range and execute.

Command Syntax

prover/target/release/z6m_prover --service --rpc-url <URL> --data-dir temp/mainnet --save-all-responses [other-flags] > temp/mainnet/fetch.log 2>&1

Required Flags

• --rpc-url: URL of the RPC server to fetch blocks from (required). Use the $RPC_URL environment variable, which should be configured in .claude/settings.local.json under the env key. If $RPC_URL is not set, ask the user for the URL.

Usage Patterns

Fetch and Execute Blocks at the Tip Until Stopped

prover/target/release/z6m_prover --service --rpc-url <URL> --data-dir temp/mainnet --save-all-responses > temp/mainnet/fetch.log 2>&1

Fetch Blocks at the Tip Executing One In Every Million Until Stopped

prover/target/release/z6m_prover --service --rpc-url <URL> --data-dir temp/mainnet --save-all-responses --execute-every 1000000 > temp/mainnet/fetch.log 2>&1

Fetch Blocks Range Without Executing

prover/target/release/z6m_prover --service --rpc-url <URL> --data-dir temp/mainnet --save-all-responses --start-block 24620000 --end-block 24620199 --execute-every 1000 > temp/mainnet/fetch.log 2>&1

Important Considerations

Fetching Without Executing

When specifying both --start-block and --end-block, you can use a value for --execute-every greater than the block range size to only fetch blocks without ever executing.

Before Running

1. Ensure z6m_prover binary is built: run make z6m_prover to build it

Workflow

When the user wants to fetch Ethereum blocks and save them to a local directory:

1. Confirm parameters

   • Ask for target RPC URL if not already known from context

2. Run command

Error Handling

Common issues:

• "Failed to get initial block number after retries": Verify the RPC URL is correct

Examples

Example 1: Fetch Blocks at the Tip From Public Reth Until Stopped

prover/target/release/z6m_prover --service --rpc-url $RPC_URL --data-dir temp/mainnet --save-all-responses --execute-every 1000000 > temp/mainnet/fetch.log 2>&1

Example 2: Fetch Blocks Range [24620000, 24620199] Without Executing

prover/target/release/z6m_prover --service --rpc-url $RPC_URL --data-dir temp/mainnet --save-all-responses --start-block 24620000 --end-block 24620199 --execute-every 1000 > temp/mainnet/fetch.log 2>&1

Tips

• If building from source, use make z6m_prover within the project home folder to build the binary at prover/target/release/z6m_prover