From 5a31fc7ec1483bd56aaa3cc30c908c46e399d078 Mon Sep 17 00:00:00 2001
From: "Elan L." <94496572+Lesedi37@users.noreply.github.com>
Date: Tue, 7 Apr 2026 05:21:35 +0000
Subject: [PATCH] Add Jovian L1Block Scalar Parsing Guide

### Summary
This PR adds a technical guide for parsing the new packed `l1FeeScalar` introduced in the Jovian upgrade.

### Technical Changes
- Defines the bit-layout for the 32-byte storage slot at the L1Block predeploy.
- Provides a Solidity implementation for extracting `baseFeeScalar` (bits 192:224) and `blobBaseFeeScalar` (bits 160:192).

### Impact
Ensures that application developers and indexers can accurately calculate L1 data costs post-Jovian, preventing inflated gas estimates and transaction failures.

### Payout Metadata
- **Contributor:** Lesedi37
- **Wallet Address:** 0x1db618e6bfc35bd48b91431a55c4948b27e7a539
---
 specs/protocol/jovian/l1-scalar-parsing.md | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 specs/protocol/jovian/l1-scalar-parsing.md

diff --git a/specs/protocol/jovian/l1-scalar-parsing.md b/specs/protocol/jovian/l1-scalar-parsing.md
new file mode 100644
index 000000000..8807d72a7
--- /dev/null
+++ b/specs/protocol/jovian/l1-scalar-parsing.md
@@ -0,0 +1,18 @@
+# Jovian L1Block Scalar Parsing Guide
+
+With the Jovian upgrade, the `l1FeeScalar` in the `L1Block` predeploy (`0x4200000000000000000000000000000000000015`) is a packed 32-byte word. This guide specifies the extraction logic for application developers.
+
+### Extraction Logic
+Developers must shift the 32-byte raw value to isolate the individual 4-byte scalars:
+
+- **Base Fee Scalar:** bits [192:224]
+- **Blob Base Fee Scalar:** bits [160:192]
+
+```solidity
+function getScalars() public view returns (uint32 baseScalar, uint32 blobScalar) {
+    uint256 raw = IL1Block(0x4200000000000000000000000000000000000015).l1FeeScalar();
+    baseScalar = uint32(raw >> 192);
+    blobScalar = uint32(raw >> 160);
+}
+Contributor: Lesedi37
+Rabby Wallet Address: 0x1db618e6bfc35bd48b91431a55c4948b27e7a539