restructure base-chain sidebar and file organization

docs/base-chain/infrastructure/overview.mdx

@@ -0,0 +1,16 @@
+---
+title: Infrastructure & Operations
+sidebarTitle: Overview
+description: Running, operating, and integrating with Base Chain infrastructure.
+---
+
+This section covers everything required to operate Base infrastructure: running nodes, configuring execution clients, understanding the sequencer and batcher, and integrating with Flashblocks for low-latency block access.
+
+| Topic | Description |
+| :--- | :--- |
+| **Block Building** | How the sequencer constructs and orders transactions |
+| **Node Operators** | Running, configuring, troubleshooting, and upgrading Base nodes |
+| **Flashblocks** | 200ms incremental block updates — overview, integration, and architecture |
+| **Batcher Spec** | How transaction batches are written to L1 |
+| **Consensus & Derivation** | How the L2 chain is derived from L1 data |
+| **P2P Networking** | Peer discovery and gossip protocol for the Base network |

docs/base-chain/network-information/bridges.mdx → docs/base-chain/network-information/bridges/overview.mdx

@@ -1,7 +1,7 @@
 ---
 title: Bridges
+sidebarTitle: Overview
 description: Documentation for bridging assets to Base. This page covers how to bridge assets between Ethereum, Solana, Bitcoin, and Base.
-
 ---
 
 Base supports bridging assets from multiple chains including Ethereum, Solana, and Bitcoin. While the bridge on bridge.base.org has been deprecated, there are many bridges that support moving assets between Base and other chains.

docs/base-chain/quickstart/base-solana-bridge.mdx → docs/base-chain/network-information/bridges/solana-bridge.mdx

@@ -1,5 +1,5 @@
 ---
-title: "Base-Solana Bridge"
+title: "Solana Bridge"
 description: "Bridge tokens and messages between Base and Solana Mainnet"
 ---
 

docs/base-chain/network-information/overview.mdx

@@ -0,0 +1,16 @@
+---
+title: Network Information
+sidebarTitle: Overview
+description: The trust model, economic structure, and network-level guarantees of Base Chain.
+---
+
+This section covers the core properties of Base Chain: fee markets, finality windows, bridge mechanics, and network security governance.
+
+| Topic | Description |
+| :--- | :--- |
+| **Fees & Gas** | EIP-1559 base fee, priority fee, and L1 data cost components |
+| **Transaction Finality** | Soft confirmation, hard confirmation, and L1-finalized settlement windows |
+| **Contract Addresses** | Canonical protocol and ecosystem contract addresses on mainnet and testnet |
+| **Network Faucets** | Testnet ETH faucets for Base Sepolia development |
+| **Bridges** | How the canonical bridge moves ETH and ERC-20s between Base and Ethereum, including deposit, withdrawal, and messenger specifications |
+| **Security** | Security Council governance, bug bounty program, and vulnerability reporting |

docs/base-chain/api-reference/rpc-overview.mdx → docs/base-chain/protocol-api/json-rpc/overview.mdx

@@ -1,6 +1,6 @@
 ---
 title: 'Base RPC Overview'
-sidebarTitle: 'Overview'
+sidebarTitle: 'RPC Overview'
 description: 'Complete reference for all JSON-RPC and Flashblocks methods available on Base nodes.'
 ---
 
@@ -171,3 +171,28 @@ All requests are HTTP POST with `Content-Type: application/json`.
 | `"finalized"` | Latest finalized block | Latest finalized block |
 | `"earliest"` | Genesis block | Genesis block |
 | `"0x<n>"` | Specific block by number | Specific block by number |
+
+## Rollup Node API
+
+The rollup node exposes one additional RPC method not part of the standard Ethereum JSON-RPC API. It is used internally by the fault proof system to retrieve L2 output roots.
+
+### `optimism_outputAtBlock`
+
+Returns an output root and associated metadata for a given L2 block number. The output root is a 32-byte commitment used by the fault proof proposer to anchor disputed L2 state on L1.
+
+**Parameters**
+
+| Name | Type | Description |
+| :--- | :--- | :--- |
+| `blockNumber` | `QUANTITY`, 64 bits | L2 integer block number |
+
+**Returns**
+
+| Name | Type | Description |
+| :--- | :--- | :--- |
+| `version` | `DATA`, 32 Bytes | Output root version number, beginning with `0` |
+| `outputRoot` | `DATA`, 32 Bytes | The output root |
+| `blockRef` | `Object` | L2 block reference — hash, number, parentHash, timestamp, l1origin, sequenceNumber |
+| `withdrawalStorageRoot` | `DATA`, 32 Bytes | Storage root of the `L2ToL1MessagePasser` contract |
+| `stateRoot` | `DATA`, 32 Bytes | The state root |
+| `syncStatus` | `Object` | Snapshot of the rollup driver sync state across L1 and L2 heads |

docs/base-chain/protocol-api/overview.mdx

@@ -0,0 +1,20 @@
+---
+title: Protocol & API
+sidebarTitle: Overview
+description: The complete API reference and protocol specification for Base Chain.
+---
+
+This section is the authoritative technical reference for Base Chain. It covers every RPC endpoint, the full execution and consensus specifications, the EVM environment, fault proof mechanics, and the complete history of network upgrades.
+
+| Topic | Description |
+| :--- | :--- |
+| **Ethereum JSON-RPC API** | Standard `eth_*` methods supported by Base, with examples |
+| **Flashblocks API** | WebSocket subscription methods for 200ms pre-confirmation streams |
+| **Debug API** | `debug_trace*` methods for transaction-level execution tracing |
+| **Protocol Specifications** | High-level architecture, execution engine, and consensus derivation |
+| **Execution & EVM** | Execution engine spec, precompiles, predeploys, and preinstalls |
+| **Fault Proofs** | Full specification for the dispute game, bond incentives, and Cannon VM |
+| **Network Upgrades** | Per-upgrade changelogs from Canyon through Jovian |
+| **Configuration** | All consensus, policy, admin, and service role parameters, plus a changelog of network config changes |
+| **BCPs** | Base Chain Proposals — the governance specification process |
+| **Glossary** | Canonical definitions for Base and OP Stack terminology |

docs/base-chain/protocol-api/specs/protocol/execution/evm/precompiles.mdx

@@ -0,0 +1,61 @@
+---
+title: "Precompiles"
+description: "Specification of precompiled contracts on Base, including native EVM implementations available at predefined addresses."
+---
+
+## Overview
+
+[Precompiled contracts](../../../reference/glossary#precompiled-contract-precompile) exist on Base at
+predefined addresses. They are similar to predeploys but are implemented as native code in the EVM as opposed to
+bytecode. Precompiles are used for computationally expensive operations, that would be cost prohibitive to implement
+in Solidity. Where possible predeploys are preferred, as precompiles must be implemented in every execution client.
+
+Base contains the [standard Ethereum precompiles](https://www.evm.codes/precompiled) as well as a small
+number of additional precompiles. The following table lists each of the additional precompiles. The system version
+indicates when the precompile was introduced.
+
+| Name       | Address                                    | Introduced |
+|------------| ------------------------------------------ |------------|
+| P256VERIFY | 0x0000000000000000000000000000000000000100 | Fjord      |
+
+## P256VERIFY
+
+The `P256VERIFY` precompile performs signature verification for the secp256r1 elliptic curve. This curve has widespread
+adoption. It's used by Passkeys, Apple Secure Enclave and many other systems.
+
+It is specified as part of [RIP-7212](https://github.com/ethereum/RIPs/blob/master/RIPS/rip-7212.md) and was added to
+the Base protocol in the Fjord release. The op-geth implementation is
+[here](https://github.com/ethereum-optimism/op-geth/blob/optimism/core/vm/contracts.go#L1161-L1193).
+
+Address: `0x0000000000000000000000000000000000000100`
+
+## Opcode Differences
+
+Base uses the standard Ethereum opcode set with the following modifications:
+
+| Opcode | Hex | Behavior on Base |
+| :--- | :--- | :--- |
+| `ORIGIN` | `0x32` | For L1→L2 deposits from contracts, returns the [aliased](#address-aliasing) L1 address. For EOA-initiated deposits, returns the actual origin. |
+| `CALLER` | `0x33` | For L1→L2 deposits initiated by contracts, returns the aliased L1 contract address. |
+| `COINBASE` | `0x41` | Returns the [`SequencerFeeVault`](/base-chain/specs/protocol/execution/evm/predeploys#sequencerfeevault) address (`0x4200000000000000000000000000000000000011`). |
+| `DIFFICULTY` / `PREVRANDAO` | `0x44` | Returns the `prevrandao` value from the L1 origin block, per [EIP-4399](https://eips.ethereum.org/EIPS/eip-4399). |
+| `BASEFEE` | `0x48` | Returns the current L2 base fee. |
+| `BLOBBASEFEE` | `0x4A` | Always returns `1`. EIP-4844 blob transactions are disabled on L2; Base does not process blobs. |
+
+## Address Aliasing
+
+When a contract on L1 calls a contract on L2 (via the `L1CrossDomainMessenger` or directly through a deposit transaction), the L1 sender address is aliased on L2 to prevent address collisions between identically-addressed contracts on L1 and L2.
+
+The alias is computed by adding a fixed offset to the L1 address:
+
+```
+L2_alias = L1_address + 0x1111000000000000000000000000000000001111
+```
+
+This applies to `CALLER` and `ORIGIN` within the context of those L1-initiated transactions. Externally owned accounts (EOAs) are **not** aliased — aliasing only applies to contract callers.
+
+To recover the original L1 address from an aliased address, subtract the same offset:
+
+```
+L1_address = L2_alias - 0x1111000000000000000000000000000000001111
+```

docs/base-chain/specs/protocol/fault-proof/index.mdx → docs/base-chain/protocol-api/specs/protocol/fault-proofs/overview.mdx

@@ -1,5 +1,5 @@
 ---
-title: "Fault Proof"
+title: "Overview"
 description: "Overview of the Base fault proof system, describing the program, virtual machine, and interactive dispute game components that verify L2 state."
 ---
 

docs/base-chain/specs/reference/configurability.mdx → docs/base-chain/protocol-api/specs/reference/configurability.mdx

@@ -69,3 +69,35 @@ There are four categories of Base configuration:
 | Guardian | Pauses L1 withdrawals, blacklists dispute games, sets respected game type in `OptimismPortal`. [0x09f7150D8c019BeF34450d6920f6B3608ceFdAf2](https://etherscan.io/address/0x09f7150D8c019BeF34450d6920f6B3608ceFdAf2) | [L1 Proxy Admin](#admin-roles) |
 | [Proposer](../protocol/fault-proof/stage-one/bridge-integration#permissioned-faultdisputegame) | Creates permissioned dispute games on L1. Active only when respected game type is `PERMISSIONED_CANNON`. | [L1 Proxy Admin](#admin-roles) |
 | [Sequencer P2P Signer](glossary#unsafe-block-signer) | Signs unsafe/pre-submitted blocks at the P2P layer | [System Config Owner](#admin-roles) |
+
+## Changelog
+
+This section tracks configuration changes to the Base networks, including updates to block building, network fees, and other network parameters.
+
+### Base Mainnet
+
+| Date | Change | Documentation |
+|------|--------|---------------|
+| February 19, 2026 | Increased Minimum Base Fee to 5,000,000 wei | [Minimum Base Fee](/base-chain/network-information/network-fees#minimum-base-fee) |
+| February 4, 2026 | Increased EIP-1559 Denominator to 125 | [EIP-1559 Fee Parameters](/base-chain/network-information/network-fees#eip-1559-fee-parameters) |
+| February 2, 2026 | Increased Minimum Base Fee to 2,000,000 wei | [Minimum Base Fee](/base-chain/network-information/network-fees#minimum-base-fee) |
+| January 22, 2026 | Increased Minimum Base Fee to 1,000,000 wei | [Minimum Base Fee](/base-chain/network-information/network-fees#minimum-base-fee) |
+| December 18, 2025 | Increased Minimum Base Fee to 500,000 wei | [Minimum Base Fee](/base-chain/network-information/network-fees#minimum-base-fee) |
+| December 4, 2025 | Enabled Minimum Base Fee (200,000 wei) | [Minimum Base Fee](/base-chain/network-information/network-fees#minimum-base-fee) |
+| September 17, 2025 | Enabled Per-Transaction Gas Maximum | [Per-Transaction Gas Maximum](/base-chain/infrastructure/block-building#per-transaction-gas-maximum) |
+| September 11, 2025 | Ended testing Per-Transaction Gas Maximum | [Per-Transaction Gas Maximum](/base-chain/infrastructure/block-building#per-transaction-gas-maximum) |
+| September 10, 2025 | Started testing Per-Transaction Gas Maximum | [Per-Transaction Gas Maximum](/base-chain/infrastructure/block-building#per-transaction-gas-maximum) |
+| July 7, 2025 | Enabled Flashblocks | [Flashblocks](/base-chain/infrastructure/flashblocks/overview) |
+| May 15, 2025 | Ended testing Flashblocks | [Flashblocks](/base-chain/infrastructure/flashblocks/overview) |
+| May 15, 2025 | Started testing Flashblocks | [Flashblocks](/base-chain/infrastructure/flashblocks/overview) |
+
+### Base Sepolia
+
+| Date | Change | Documentation |
+|------|--------|---------------|
+| February 19, 2026 | Increased Minimum Base Fee to 5,000,000 wei | [Minimum Base Fee](/base-chain/network-information/network-fees#minimum-base-fee) |
+| February 10, 2026 | Increased EIP-1559 Denominator to 125 | [EIP-1559 Fee Parameters](/base-chain/network-information/network-fees#eip-1559-fee-parameters) |
+| February 10, 2026 | Increased Minimum Base Fee to 2,000,000 wei | [Minimum Base Fee](/base-chain/network-information/network-fees#minimum-base-fee) |
+| November 20, 2025 | Enabled Minimum Base Fee (200,000 wei) | [Minimum Base Fee](/base-chain/network-information/network-fees#minimum-base-fee) |
+| September 3, 2025 | Enabled Per-Transaction Gas Maximum | [Per-Transaction Gas Maximum](/base-chain/infrastructure/block-building#per-transaction-gas-maximum) |
+| February 25, 2025 | Enabled Flashblocks | [Flashblocks](/base-chain/infrastructure/flashblocks/overview) |