docs.base.org

# Base Documentation

> Build on Base — Coinbase's Ethereum L2. Smart Wallet, OnchainKit, MiniKit, Base Chain RPCs, and AI Agents. This index points AI assistants at the canonical page for each topic; follow the links for full context.

## Get Started

### Quickstart

- [Base](https://docs.base.org/get-started/base): The blockchain for global finance.

- [Connect to Base](https://docs.base.org/get-started/connect-to-base): Network details for Base Mainnet and Base Sepolia: RPC endpoints, chain IDs, and block explorers.

- [Get Funds](https://docs.base.org/get-started/get-funds): Fund an address on Base: withdraw from a Coinbase account, bridge from another chain, or use a testnet faucet.

- [Make a Transaction](https://docs.base.org/get-started/make-a-transaction): Send your first transaction on Base with viem: connect, sign, and confirm in seconds for a fraction of a cent.

- [Bridge to Base](https://docs.base.org/base-chain/network-information/ecosystem-bridges): Move ETH, stablecoins, and tokens to and from Base — from a Coinbase account, Ethereum, Solana, or Bitcoin.

### Solutions

- [Integrate DeFi](https://docs.base.org/get-started/integrate-defi): Add trading, direct lending, collateralized borrowing, or a vault-based earn product to your app with third-party protocols on Base.

- [Tokenize Assets](https://docs.base.org/get-started/issue-rwa): Represent and operate real-world assets on Base with the B20 Asset standard: configurable precision, issuer roles, holder controls, and distributions through one ERC-20-compatible surface.

- [Issue a Stablecoin](https://docs.base.org/get-started/issue-stablecoins): Run a fiat-backed stablecoin on Base with minting, compliance, and reconciliation built into the chain.

- [Accept Payments](https://docs.base.org/get-started/accept-payments): Choose an onchain payment lifecycle for checkout, agentic payments, reconciliation, refunds, and payouts on Base.

### Coding Agents

- [Resources for AI Agents](https://docs.base.org/get-started/resources-for-ai-agents): Base-first resources for AI agents, including docs indexes, MCP access, skills, and recommended starting points

- [MCP Server](https://docs.base.org/get-started/docs-mcp): Connect your AI coding assistant to Base documentation using Model Context Protocol for real-time access.

- [Static Docs Files](https://docs.base.org/get-started/docs-llms): Use llms.txt and llms-full.txt to give AI assistants access to Base documentation.

### Get Funding

- [Base Batches](https://docs.base.org/get-started/base-batches): Apply to Base Batches, an accelerator with investment, mentorship, and a demo day for early-stage teams building on Base.

- [Base Ecosystem Fund](https://docs.base.org/get-started/base-ecosystem-fund): The Base Ecosystem Fund backs pre-seed and seed teams building onchain businesses on Base, in partnership with Coinbase Ventures.

- [Base Services Hub](https://docs.base.org/get-started/base-services-hub): A collection of services for building on Base.

### References

- [Base Protocol](https://docs.base.org/get-started/base-chain): Explore Base as a chain: connect to its networks, use native primitives, understand transactions and network systems, and operate infrastructure.

- [SDKs & APIs](https://docs.base.org/get-started/sdks-and-apis): Choose the Base SDK, API, or CLI that matches what you are building.

## Build on Base

### Overview

- [Overview](https://docs.base.org/build-on-base/overview): Build financial products on Base by outcome: integrate DeFi, tokenize assets, issue stablecoins, or accept payments.

- [Test on Vibenet](https://docs.base.org/build-on-base/test-on-vibenet): Build and test against Base's newest chain-level features on Vibenet, Base's experimental preview network, and track what's live at chain.base.org/vibenet.

- [Assign User Attributes](https://docs.base.org/build-on-base/assign-user-attributes): Choose Builder Codes for transaction attribution or Base Verify for verified user traits, identity deduplication, and eligibility policies.

### Integrate DeFi

- [Integrate Trading](https://docs.base.org/build-on-base/integrate-defi/integrate-trading): Let users swap tokens on Base with executable routes from the 0x Swap API.

- [Integrate Lending](https://docs.base.org/build-on-base/integrate-defi/integrate-lending): Let users supply USDC directly to Morpho or Aave lending markets on Base.

- [Integrate Borrowing](https://docs.base.org/build-on-base/integrate-defi/integrate-borrowing): Let users borrow USDC against WETH collateral with Morpho or Aave on Base.

- [Integrate an Earn Product](https://docs.base.org/build-on-base/integrate-defi/integrate-earn-product): Give users a one-deposit USDC earn experience with Morpho vaults on Base.

- [List Tokenized Stocks](https://docs.base.org/build-on-base/integrate-defi/list-tokenized-stocks): Let users trade Coinbase-issued tokenized stocks on your app.

### Tokenize Assets

- [Create an Asset Token](https://docs.base.org/build-on-base/issue-rwa/create-an-asset-token): Create a six-decimal B20 Asset token with issuer roles, a supply ceiling, and issuer-defined metadata. This example configures a stock token.

- [Issue Units to Holders](https://docs.base.org/build-on-base/issue-rwa/issue-units): Distribute B20 Asset units to multiple approved holders in one batch.

- [Restrict Eligible Holders](https://docs.base.org/build-on-base/issue-rwa/restrict-eligible-holders): Keep units within an approved set of holders by binding a B20 allowlist to issuance and transfers.

- [Cancel Blocked Units](https://docs.base.org/build-on-base/issue-rwa/cancel-blocked-units): Cancel units from a holder after removing the holder from a B20 sender allowlist.

- [Announce a Distribution](https://docs.base.org/build-on-base/issue-rwa/announce-a-distribution): Wrap a holder-impacting action with an onchain disclosure using the B20 Asset announce function.

- [Apply a Multiplier](https://docs.base.org/build-on-base/issue-rwa/apply-a-multiplier): Schedule a B20 Asset multiplier update so displayed share counts change at a future time without rewriting raw balances. A stock split is one example.

- [Pause Transfers](https://docs.base.org/build-on-base/issue-rwa/pause-transfers): Pause transfers on a B20 Asset token during an incident while leaving minting and burning available.

### Issue Stablecoins

- [Issue Your Stablecoin](https://docs.base.org/build-on-base/issue-stablecoins/issue-your-stablecoin): Create a fiat-backed stablecoin on Base with one B20 factory call.

- [Mint Supply](https://docs.base.org/build-on-base/issue-stablecoins/mint-supply): Issue new stablecoin supply on Base as reserves grow, gated by a minter role and an optional supply cap.

- [Burn Supply](https://docs.base.org/build-on-base/issue-stablecoins/burn-supply): Retire stablecoin supply on Base when a holder redeems for fiat, keeping circulating supply matched to reserves.

- [Restrict Who Can Hold It](https://docs.base.org/build-on-base/issue-stablecoins/restrict-who-can-hold): Limit transfers of your stablecoin to accounts your KYC program has approved, using B20 transfer policies.

- [Block an Account](https://docs.base.org/build-on-base/issue-stablecoins/block-an-account): Stop a specific address from moving your stablecoin when a compliance hold requires it, without affecting other holders.

- [Recover Funds](https://docs.base.org/build-on-base/issue-stablecoins/recover-funds): Reclaim and reissue stablecoin from a blocked account on Base, for lost keys or a legal hold.

- [Pause Activity](https://docs.base.org/build-on-base/issue-stablecoins/pause-activity): Halt transfers, mints, or burns on your stablecoin independently during an incident, then resume when it's resolved.

- [Reconcile with Memos](https://docs.base.org/build-on-base/issue-stablecoins/reconcile-with-memos): Tag stablecoin operations with an onchain reference so you can match them to offchain records at scale.

### Accept Payments

#### Take a Payment

- [Request a Payment](https://docs.base.org/build-on-base/accept-payments/request-a-payment): Request an immediately settled USDC or memo-enabled B20 payment from a wallet on Base.

- [Authorize a Payment](https://docs.base.org/build-on-base/accept-payments/authorize-a-payment): Ask a buyer to sign a USDC authorization that your merchant backend can capture later on Base.

- [Capture an Authorization](https://docs.base.org/build-on-base/accept-payments/capture-an-authorization): Settle a stored USDC authorization from the merchant account with receiveWithAuthorization.

- [Capture a Partial Amount](https://docs.base.org/build-on-base/accept-payments/capture-a-partial-amount): Authorize a maximum USDC amount and capture the final total through a constrained one-use checkout contract.

- [Void an Authorization](https://docs.base.org/build-on-base/accept-payments/void-an-authorization): Expire an unused USDC authorization or cancel its nonce onchain with the buyer's signature.

- [Charge on a Schedule](https://docs.base.org/build-on-base/accept-payments/charge-on-a-schedule): Charge a smart account on a recurring schedule within a buyer-approved period allowance.

#### Confirm and Reconcile

- [Verify a Payment](https://docs.base.org/build-on-base/accept-payments/verify-a-payment): Verify USDC or B20 settlement on your backend and claim each transaction exactly once before fulfillment.

- [Watch for Payments](https://docs.base.org/build-on-base/accept-payments/watch-for-payments): Watch token Transfer logs, backfill missed blocks, and process confirmed payments idempotently.

- [Reconcile Payments](https://docs.base.org/build-on-base/accept-payments/reconcile-payments): Build a merchant settlement report from token transfers and optional B20 memo events.

#### Return and Pay Out

- [Refund a Payment](https://docs.base.org/build-on-base/accept-payments/refund-a-payment): Return tokens to the verified payer and keep partial or repeated refunds within the captured balance.

- [Send a Payout](https://docs.base.org/build-on-base/accept-payments/send-a-payout): Send a referenced batch of token payouts in one transaction without leaving funds in the payout contract.

- [Split a Payment](https://docs.base.org/build-on-base/accept-payments/split-a-payment): Split one token amount across marketplace recipients with exact basis-point accounting and no stranded dust.

#### Accept Agentic Payments

- [Charge for an API](https://docs.base.org/build-on-base/accept-payments/charge-for-an-api): Protect a fixed-price API route with the x402 exact scheme on Base.

- [Settle Usage-Based Payments](https://docs.base.org/build-on-base/accept-payments/settle-usage-based-payments): Authorize a maximum x402 payment and settle the actual API usage after the handler succeeds.

- [Batch High-Frequency Payments](https://docs.base.org/build-on-base/accept-payments/batch-high-frequency-payments): Verify cumulative x402 vouchers per request and settle high-frequency API usage in batches.

- [Call a Paid Service](https://docs.base.org/build-on-base/accept-payments/call-a-paid-service): Call an x402 service from an agent while enforcing network, token, per-request, and session spend limits.

## Specifications

### Specifications

- [Overview](https://docs.base.org/specifications/overview): Base protocol specifications — tokens, bridging, transactions, consensus, execution, and proofs.

#### Base Protocol

- [Overview](https://docs.base.org/specifications/base-protocol/overview): High-level overview of the Base Chain protocol — network participants, system architecture, core components, and user flows.

##### Consensus

- [Specification](https://docs.base.org/specifications/base-protocol/consensus/specification): Specification of the Base rollup node, describing its components and role in L2 block derivation and consensus.

- [Derivation](https://docs.base.org/specifications/base-protocol/consensus/derivation): Specification of the L2 chain derivation pipeline, describing how L2 blocks are deterministically derived from L1 data and sequencer batches.

- [P2P](https://docs.base.org/specifications/base-protocol/consensus/p2p): Specification of the rollup node peer-to-peer network, covering node discovery, gossip protocol, and unsafe block propagation.

- [RPC](https://docs.base.org/specifications/base-protocol/consensus/rpc): Specification of the rollup node RPC interface, including the optimism_outputAtBlock method for retrieving L2 output roots.

##### Execution

- [L2 Execution Engine](https://docs.base.org/specifications/base-protocol/execution/l2-execution-engine): Specification of the L2 execution engine, detailing EIP-1559 parameters, fee vaults, Engine API usage, and execution layer behavior.

- [Precompiles](https://docs.base.org/specifications/base-protocol/execution/precompiles): Specification of precompiled contracts on Base, including native EVM implementations available at predefined addresses.

- [Predeploys](https://docs.base.org/specifications/base-protocol/execution/predeploys): Specification of predeployed smart contracts on Base, including system contracts deployed at predetermined addresses in genesis state.

- [Preinstalls](https://docs.base.org/specifications/base-protocol/execution/preinstalls): Specification of preinstalled smart contracts on Base, including utility contracts deployed in genesis state that run directly in the EVM.

##### Bridging

- [Standard Bridges](https://docs.base.org/specifications/base-protocol/bridging/standard-bridges): Specification of the standard bridge contracts enabling cross-domain ETH and ERC-20 token transfers between L1 and L2 on Base.

- [Deposits](https://docs.base.org/specifications/base-protocol/bridging/deposits): How deposits work on Base — from user experience to the protocol-level deposit transaction type and guaranteed gas market.

- [Withdrawals](https://docs.base.org/specifications/base-protocol/bridging/withdrawals): How withdrawals work on Base — the standard 3-step flow, the 7-day challenge period, faster options, and the full protocol specification.

- [Cross Domain Messengers](https://docs.base.org/specifications/base-protocol/bridging/cross-domain-messengers): Specification of the cross-domain messenger contracts, providing a higher-level API for sending messages between L1 and L2 on Base.

- [Base-Solana Bridge](https://docs.base.org/specifications/base-protocol/bridging/base-solana-bridge): Bridge tokens and messages between Base and Solana Mainnet

- [Batcher](https://docs.base.org/specifications/base-protocol/batcher): Specification of the batcher (batch submitter), the component responsible for posting L2 sequencer data to L1 for data availability.

##### Proofs

- [Proofs](https://docs.base.org/specifications/base-protocol/proofs/overview): Overview of the offchain services and onchain contracts that make L2 checkpoint proposals verifiable from Ethereum in the Azul proof system.

- [Challenger](https://docs.base.org/specifications/base-protocol/proofs/challenger): Specification of the challenger, an offchain service that detects invalid AggregateVerifier games and submits dispute transactions on L1 to nullify them.

- [Proposer](https://docs.base.org/specifications/base-protocol/proofs/proposer): Specification of the proposer, an offchain service that turns canonical L2 checkpoint ranges into AggregateVerifier games on L1.

- [Registrar](https://docs.base.org/specifications/base-protocol/proofs/registrar): Specification of the registrar, an offchain service that maintains the onchain registry of accepted TEE signer identities via attestation ZK proofs.

- [TEE Prover](https://docs.base.org/specifications/base-protocol/proofs/tee-prover): Specification of the TEE prover, an offchain service that re-executes L2 block ranges inside AWS Nitro Enclaves to produce signed proof material for AggregateVerifier games.

- [ZK Prover](https://docs.base.org/specifications/base-protocol/proofs/zk-prover): Specification of the ZK prover, an offchain service that uses SP1 programs to produce permissionless proofs for checkpoint proposals and disputes.

- [Proof Contracts](https://docs.base.org/specifications/base-protocol/proofs/proof-contracts): Specification of the onchain contracts that verify proof material, track game state, and release withdrawals for the Azul proof system.

- [Design Goals](https://docs.base.org/specifications/base-protocol/design-goals): Design philosophy and lineage of the Base Chain protocol specification.

#### B20

- [B20 Specification](https://docs.base.org/specifications/b20/specification-overview): Normative Beryl specification for Base's B20 native token standard, precompile registries, policy scopes, factory, and variants.

##### Interfaces

- [IActivationRegistry Reference](https://docs.base.org/specifications/b20/reference/interfaces/i-activation-registry/index): Generated B20 reference for IActivationRegistry functions, events, and errors.

- [IB20 Reference](https://docs.base.org/specifications/b20/reference/interfaces/ib20/index): Generated B20 reference for IB20 functions, events, and errors.

- [IB20Asset Reference](https://docs.base.org/specifications/b20/reference/interfaces/ib20-asset/index): Generated B20 reference for IB20Asset functions, events, and errors.

- [IB20Factory Reference](https://docs.base.org/specifications/b20/reference/interfaces/ib20-factory/index): Generated B20 reference for IB20Factory functions, events, and errors.

- [IB20Stablecoin Reference](https://docs.base.org/specifications/b20/reference/interfaces/ib20-stablecoin/index): Generated B20 reference for IB20Stablecoin functions, events, and errors.

- [IPolicyRegistry Reference](https://docs.base.org/specifications/b20/reference/interfaces/i-policy-registry/index): Generated B20 reference for IPolicyRegistry functions, events, and errors.

- [Constants & Addresses](https://docs.base.org/specifications/b20/reference/constants-addresses): Copy B20 precompile addresses, roles, policy scopes, variant bytes, policy IDs, and supply-cap constants.

- [Errors & Events Index](https://docs.base.org/specifications/b20/reference/errors-events): Reverse lookup B20 errors and events by selector or topic.

- [B20 Invariants and Test Cases](https://docs.base.org/specifications/b20/reference/invariants-tests): Normative invariants the B20 precompiles guarantee, and the conformance test cases that exercise them.

- [Changelog](https://docs.base.org/specifications/b20/changelog): Per-hardfork, per-feature migration notes for the B20 token standard, newest first, including new methods, deprecations, and activation dates.

- [Native Account Abstraction](https://docs.base.org/specifications/native-account-abstraction): EIP-8130 reference for Base: vibenet chain details, client setup, transaction structure, account configuration, authenticators, and payers.

#### Transactions

- [Transaction Ordering](https://docs.base.org/specifications/transactions/transaction-ordering): Transactions are ordered based priority fee and arrival time, which determines which Flashblock they are included in.

- [Transaction Finality](https://docs.base.org/specifications/transactions/transaction-finality): Detailed information about transaction finality on Base.

- [Network Fees](https://docs.base.org/specifications/transactions/network-fees): Documentation about network fees on Base. This page covers details of the two-component cost system involving L2 execution fees and L1 security fees, and offers insights on fee variations and cost-saving strategies.

- [Throughput and Limits](https://docs.base.org/specifications/transactions/throughput-and-limits): Gas limits and throughput-related network parameters on Base.

- [Troubleshooting Transactions](https://docs.base.org/specifications/transactions/troubleshooting-transactions): Guide to diagnosing and resolving transaction issues on Base.

- [Flashblocks](https://docs.base.org/specifications/flashblocks): Reference for Flashblocks on Base — key concepts, architecture, and frequently asked questions about block building, WebSocket data, RPC usage, and node setup.

#### Builder Codes

- [Base Builder Codes](https://docs.base.org/specifications/builder-codes/overview): Attribute onchain activity to your app, wallet or agent with Builder Codes.

- [Builder Codes for App Developers](https://docs.base.org/specifications/builder-codes/for-app-developers): Integrate Builder Codes into your app using Wagmi or Viem to attribute onchain activity.

- [Builder Codes for Wallet Developers](https://docs.base.org/specifications/builder-codes/for-wallet-developers): Implement the dataSuffix capability in your wallet to enable Builder Code attribution.

- [Builder Codes for Agent Developers](https://docs.base.org/specifications/builder-codes/for-agent-developers): Attribute your AI agent's onchain transactions to your identity on Base and unlock analytics and leaderboard features.

#### Validity Transactions

- [Overview](https://docs.base.org/specifications/build-transaction/validity-transactions): Submit signed transactions that Base considers when onchain conditions match.

- [Build a Validity Transaction](https://docs.base.org/specifications/build-transaction/build-a-validity-transaction): Sign and submit a validity transaction with Viem.

- [Validity Transaction RPC](https://docs.base.org/specifications/build-transaction/base_sendRawTransactionValidity): Submit a signed raw transaction with validity predicates.

- [Fees, Ordering, and Lifecycle](https://docs.base.org/specifications/build-transaction/fees-ordering-and-lifecycle): Understand fees, expiry, and replacement for validity transactions.

- [Predicates and Safety](https://docs.base.org/specifications/build-transaction/predicates-and-safety): Use validity predicates safely.

- [Troubleshooting](https://docs.base.org/specifications/build-transaction/troubleshooting): Diagnose validity transaction submission and inclusion issues.

### Reference

- [Contract Addresses](https://docs.base.org/specifications/reference/base-contracts): A comprehensive list of contract addresses for Base Mainnet and Base Testnet, including links to their respective blockchain explorers.

- [Smart Contracts](https://docs.base.org/specifications/reference/smart-contracts): How smart contracts work on Base, why Base needs its own Foundry build, and how to deploy a contract to Base Sepolia with base-anvil.

- [Configuration](https://docs.base.org/specifications/reference/configuration): Reference for Base Chain configuration parameters across consensus, policy, admin, and sequencer categories.

- [Glossary](https://docs.base.org/specifications/reference/glossary): Glossary of terms and definitions used throughout the Base Chain protocol specification.

### Node Operators

- [Run a Node](https://docs.base.org/specifications/node-operators/run-a-node): A tutorial that teaches how to set up and run a Base Node.

- [Node Performance](https://docs.base.org/specifications/node-operators/performance-tuning): Hardware specifications, storage requirements, client recommendations, and configuration settings for running a performant Base node.

- [Node Snapshots](https://docs.base.org/specifications/node-operators/snapshots): Download and restore Base node snapshots to significantly reduce initial sync time for nodes.

- [Node Troubleshooting](https://docs.base.org/specifications/node-operators/troubleshooting): Solutions to common issues when setting up and running a Base node, covering sync problems, networking, snapshots, and performance.

### Security

- [Security Council for Base](https://docs.base.org/specifications/security/security-council-for-base): This page outlines the purpose, goals, structure, and responsibilities of the Security Council for Base.

- [How to Avoid Getting Your App Flagged as Malicious](https://docs.base.org/specifications/security/avoid-malicious-flags): The Base bug bounty program and procedures for reporting vulnerabilities.

- [Reporting Vulnerabilities](https://docs.base.org/specifications/security/report-a-vulnerability): The Base procedures for reporting vulnerabilities.

## SDKs & APIs

### Overview

- [SDKs & APIs](https://docs.base.org/sdks/overview): SDKs, APIs, and command-line tools for identity verification, local development, and direct Base chain access.

### CLIs

- [base-anvil CLI](https://docs.base.org/sdks/base-anvil): Base's Foundry build: install base-forge, base-cast, and base-anvil, which teach Foundry about Base's native precompiles.

### Base Chain API

- [Base RPC Overview](https://docs.base.org/base-chain/api-reference/rpc-overview): Complete reference for all JSON-RPC and Flashblocks methods available on Base nodes.

#### Ethereum JSON-RPC API

- [eth_blockNumber](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_blockNumber): Returns the number of the most recently mined block.

- [eth_call](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_call): Executes a message call without creating a transaction. Use pending to simulate against pre-confirmed state.

- [eth_chainId](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_chainId): Returns the chain ID of the current network.

- [eth_estimateGas](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_estimateGas): Estimates the gas required for a transaction. Use pending to estimate against pre-confirmed state.

- [eth_feeHistory](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_feeHistory): Returns historical base fees and priority fee percentiles for a range of blocks.

- [eth_gasPrice](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_gasPrice): Returns the current gas price in wei.

- [eth_getBalance](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getBalance): Returns the ETH balance of an account at a given block. Use the pending tag for 200ms pre-confirmed balances.

- [eth_getBlockByHash](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getBlockByHash): Returns block information by block hash.

- [eth_getBlockByNumber](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getBlockByNumber): Returns block information by number. On Flashblocks endpoints, the pending tag returns the live pre-confirmed block updated every ~200ms.

- [eth_getBlockReceipts](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getBlockReceipts): Returns all transaction receipts for a block. Use pending for pre-confirmed receipts.

- [eth_getBlockTransactionCountByHash](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getBlockTransactionCountByHash): Returns the number of transactions in a block by block hash.

- [eth_getBlockTransactionCountByNumber](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getBlockTransactionCountByNumber): Returns the number of transactions in a block by block number.

- [eth_getCode](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getCode): Returns the contract bytecode at an address. Use pending to detect newly deployed contracts before block finalization.

- [eth_getLogs](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getLogs): Returns logs matching a filter. Use pending to query logs from pre-confirmed transactions.

- [eth_getStorageAt](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getStorageAt): Returns the value of a storage slot at an address. Use pending for pre-confirmed storage reads.

- [eth_getTransactionByBlockHashAndIndex](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getTransactionByBlockHashAndIndex): Returns a transaction by block hash and index position.

- [eth_getTransactionByBlockNumberAndIndex](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getTransactionByBlockNumberAndIndex): Returns a transaction by block number and index position.

- [eth_getTransactionByHash](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getTransactionByHash): Returns a transaction by its hash.

- [eth_getTransactionCount](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getTransactionCount): Returns the number of transactions sent from an address (the nonce). Use pending to get the pre-confirmed nonce.

- [eth_getTransactionReceipt](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getTransactionReceipt): Returns the receipt for a mined transaction. Receipts are only available after a transaction is included in a block.

- [eth_maxPriorityFeePerGas](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_maxPriorityFeePerGas): Returns the suggested EIP-1559 priority fee (tip) per gas.

- [eth_sendRawTransaction](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_sendRawTransaction): Submits a pre-signed transaction to the network. All Base endpoints are Flashblocks-enabled, providing 200ms pre-confirmation.

- [eth_subscribe](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_subscribe): Creates a real-time WebSocket subscription for new blocks, logs, and pending transactions.

- [eth_syncing](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_syncing): Returns the sync status of the node.

- [eth_unsubscribe](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_unsubscribe): Cancels an active WebSocket subscription.

- [net_version](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/net_version): Returns the current network ID as a string.

- [web3_clientVersion](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/web3_clientVersion): Returns the current client version string.

#### Flashblocks API

- [Overview](https://docs.base.org/base-chain/api-reference/flashblocks-api/flashblocks-api-overview): Flashblocks-specific RPC methods, WebSocket subscriptions, and the infrastructure stream schema for Base pre-confirmations.

- [base_transactionStatus](https://docs.base.org/base-chain/api-reference/flashblocks-api/base_transactionStatus): Checks whether a transaction is in the node mempool. Only available on Flashblocks endpoints.

- [eth_simulateV1](https://docs.base.org/base-chain/api-reference/flashblocks-api/eth_simulateV1): Simulates one or more transaction bundles against the current pre-confirmed Flashblock state. Only available on Flashblocks endpoints.

- [newFlashblockTransactions](https://docs.base.org/base-chain/api-reference/flashblocks-api/newFlashblockTransactions): Subscribe to receive each transaction as it is pre-confirmed into a Flashblock. Only available on Flashblocks WebSocket endpoints.

- [newFlashblocks](https://docs.base.org/base-chain/api-reference/flashblocks-api/newFlashblocks): Subscribe to receive full Flashblock payload stream as each pre-confirmed block is built. Only available on Flashblocks WebSocket endpoints.

- [pendingLogs](https://docs.base.org/base-chain/api-reference/flashblocks-api/pendingLogs): Subscribe to logs from pre-confirmed transactions matching an optional filter. Only available on Flashblocks WebSocket endpoints.

#### Debug API

- [debug_traceTransaction](https://docs.base.org/base-chain/api-reference/debug-api/debug_traceTransaction): Returns the full EVM execution trace for a transaction. Requires a node with debug APIs enabled.

- [debug_traceBlockByHash](https://docs.base.org/base-chain/api-reference/debug-api/debug_traceBlockByHash): Returns EVM execution traces for all transactions in a block by block hash.

- [debug_traceBlockByNumber](https://docs.base.org/base-chain/api-reference/debug-api/debug_traceBlockByNumber): Returns EVM execution traces for all transactions in a block by block number.

### Base Verify API

- [Base Verify API](https://docs.base.org/sdks/base-verify/overview): Use Base Verify APIs and contracts to prove verified account ownership, prevent duplicate participation, and enforce eligibility policies.

- [Verify Social Accounts](https://docs.base.org/sdks/base-verify/verify-social-accounts): Use Base Verify to let users prove ownership of verified accounts (X, Coinbase, Instagram, TikTok) without sharing credentials, enabling Sybil-resistant airdrops, gated content, and identity-based rewards.

- [Verify Users Onchain](https://docs.base.org/sdks/base-verify/verify-users-onchain): Enforce Sybil resistance and policy gating inside any Base contract. Base Verify signs a short-lived verification your contract checks in the same transaction as a claim, deposit, or vote, so one real identity counts once and only wallets that meet your bar can participate.

### Migrated Documentation

- [Base Account and Base MCP Have Moved](https://docs.base.org/sdks/migrated-products): Find the Base Account SDK and Base MCP documentation now maintained on Coinbase Developer Platform.

## Upgrades

### Overview

- [Upgrades](https://docs.base.org/upgrades/overview): Track Base network upgrades, activation dates, and the protocol changes included in each release.

- [Configuration Changelog](https://docs.base.org/base-chain/network-information/configuration-changelog): A log of configuration changes to the Base networks.

### Denim

- [Overview](https://docs.base.org/upgrades/denim/overview): Denim introduces native blocks at a 200ms cadence, onchain millisecond time through BaseTime, and millisecond-resolution RPC timestamps.

- [200ms Native Blocks](https://docs.base.org/upgrades/denim/200ms-blocks): Specification for Denim's canonical 200ms blocks, including BaseTime, derivation, validation, and RPC behavior.

- [Migrate From Flashblocks](https://docs.base.org/upgrades/denim/migrate-from-flashblocks): Migrate your Flashblocks integration to 200ms blocks.

### Cobalt

- [Overview](https://docs.base.org/upgrades/cobalt/overview): Cobalt improves the B20 token standard, adds validity transactions, introduces dynamic node upgrades, and migrates Base to a Trusted Execution Environment.

- [Dynamic Upgrades](https://docs.base.org/upgrades/cobalt/dynamic-upgrades): An Ethereum smart contract stores upgrade timestamps for Base nodes, allowing forks to activate at the scheduled time with no client restart.

- [B20: Beryl to Cobalt Migration](https://docs.base.org/base-chain/specs/reference/b20/changelog/02-cobalt-b20asset-multiplier): B20 Asset multiplier becomes ERC-8056 conformant at Cobalt, with a scheduled multiplier setter for corporate actions. Every Beryl selector stays dialable.

- [B20: Seize Surface and burnBlocked Deprecation](https://docs.base.org/base-chain/specs/reference/b20/changelog/02-cobalt-b20-seize): The B20 seize surface at Cobalt and the deprecation of burnBlocked. Migration notes for teams integrated against the Beryl seize path.

- [PolicyRegistry: Composite Policies (UNION / INTERSECT)](https://docs.base.org/base-chain/specs/reference/b20/changelog/02-cobalt-policyregistry-composite-policy): Cobalt adds UNION and INTERSECT composite policies to PolicyRegistry so B20 integrations can combine simple authorization policies without flattening their member lists.

- [Validity Transactions](https://docs.base.org/upgrades/cobalt/validity-transactions): Validity transactions ship with the Cobalt upgrade. Read the full specification in the Specifications tab.

### Beryl

- [Overview](https://docs.base.org/upgrades/beryl/overview): Beryl makes Base a first-class issuance platform with B20 tokens, more capital efficient with reduced withdrawal delays, and more scalable with Reth V2.

- [Reth V2](https://docs.base.org/upgrades/beryl/reth-v2): Ships Reth V2 as the reference execution client for Base nodes, delivering significant sync speed and throughput improvements.

- [Faster Withdrawals](https://docs.base.org/upgrades/beryl/reducing-canonical-withdrawal-delay): The single-proof dispute game finalization window is reduced from 7 days to 5 days. The dual-proof fast path (TEE + ZK) introduced in Azul remains at 1 day.

- [B20 Native Token Standard](https://docs.base.org/upgrades/beryl/b20): Learn how B20, Base's native token standard, serves stablecoin issuers, real-world asset (RWA) and equity issuers, and long-tail token creators.

### Azul

- [Overview](https://docs.base.org/upgrades/azul/overview): Azul is Base's first independent network upgrade. It focuses on increasing security and decentralization, accelerating the path to 1 gigagas/s, and improving developer experience.

- [Node Upgrade Guide](https://docs.base.org/upgrades/azul/node-upgrade): Migrate your Base node to base-reth-node and base-consensus for Azul.

- [Execution Engine](https://docs.base.org/upgrades/azul/exec-engine): Execution engine changes in the Azul hardfork, including the EIP-7825 transaction gas limit cap and secp256r1 precompile cost updates.

- [Proof System](https://docs.base.org/upgrades/azul/proofs): Specification of the Azul multi-proof system, replacing the single output proposer with an AggregateVerifier contract for L2 checkpoint security.

### Optimism

#### Jovian

- [Jovian](https://docs.base.org/upgrades/jovian/overview): Overview of the Jovian hardfork, introducing a configurable minimum base fee and a DA footprint gas scalar for improved fee market stability.

- [Jovian: Execution Engine](https://docs.base.org/upgrades/jovian/exec-engine): Execution engine changes in the Jovian upgrade, introducing a configurable minimum base fee via SystemConfig to reduce priority-fee auction durations.

- [Derivation](https://docs.base.org/upgrades/jovian/derivation): Derivation changes in the Jovian upgrade, specifying activation block rules and gas computation behavior at hardfork activation.

- [L1 Block Attributes](https://docs.base.org/upgrades/jovian/l1-attributes): L1 attributes transaction changes in the Jovian upgrade, extending calldata to include the DA footprint gas scalar.

- [Jovian: System Config](https://docs.base.org/upgrades/jovian/system-config): SystemConfig changes in the Jovian upgrade, adding a minimum base fee configuration variable for the EIP-1559 fee market.

#### Isthmus

- [Isthmus](https://docs.base.org/upgrades/isthmus/overview): Overview of the Isthmus hardfork, incorporating Ethereum Pectra EIPs and introducing the operator fee mechanism for sequencer revenue.

- [L2 Execution Engine](https://docs.base.org/upgrades/isthmus/exec-engine): Execution engine changes in the Isthmus upgrade, including L2ToL1MessagePasser storage root in block headers and operator fee collection.

- [Isthmus L2 Chain Derivation Changes](https://docs.base.org/upgrades/isthmus/derivation): Derivation changes in the Isthmus upgrade, specifying network upgrade automation transactions executed at hardfork activation.

- [L1 Block Attributes](https://docs.base.org/upgrades/isthmus/l1-attributes): L1 attributes transaction changes in the Isthmus upgrade, extending calldata to include operator fee scalar and constant parameters.

- [Predeploys](https://docs.base.org/upgrades/isthmus/predeploys): Predeploy changes in the Isthmus upgrade, including updates to L1Block and the new OperatorFeeVault contract.

- [Isthmus: System Config](https://docs.base.org/upgrades/isthmus/system-config): SystemConfig changes in the Isthmus upgrade, adding operatorFeeScalar and operatorFeeConstant configuration variables.

#### Holocene

- [Holocene](https://docs.base.org/upgrades/holocene/overview): Overview of the Holocene hardfork, introducing dynamic EIP-1559 parameters configurable via SystemConfig and stricter block derivation rules.

- [L2 Execution Engine](https://docs.base.org/upgrades/holocene/exec-engine): Execution engine changes in the Holocene upgrade, enabling dynamic EIP-1559 parameters encoded in block headers and configured via SystemConfig.

- [Holocene L2 Chain Derivation Changes](https://docs.base.org/upgrades/holocene/derivation): Derivation changes in the Holocene upgrade, introducing stricter pipeline rules that simplify derivation and improve fault proof worst-case behavior.

- [System Config](https://docs.base.org/upgrades/holocene/system-config): SystemConfig changes in the Holocene upgrade, adding dynamic EIP-1559 parameter configuration via ConfigUpdate events.

#### Granite

- [Granite](https://docs.base.org/upgrades/granite/overview): Overview of the Granite hardfork, adding bn256Pairing precompile input size restrictions and CHANNEL_TIMEOUT parameter changes.

- [L2 Execution Engine](https://docs.base.org/upgrades/granite/exec-engine): Execution engine changes in the Granite upgrade, restricting bn256Pairing precompile input size to prevent unbounded gas consumption.

- [Granite L2 Chain Derivation Changes](https://docs.base.org/upgrades/granite/derivation): Derivation changes in the Granite upgrade, updating the CHANNEL_TIMEOUT protocol parameter.

#### Fjord

- [Fjord](https://docs.base.org/upgrades/fjord/overview): Overview of the Fjord hardfork, introducing FastLZ-based L1 fee estimation, the RIP-7212 secp256r1 precompile, and brotli channel compression.

- [L2 Execution Engine](https://docs.base.org/upgrades/fjord/exec-engine): Execution engine changes in the Fjord upgrade, replacing the L1 cost fee estimator with a FastLZ-based compression model.

- [Fjord L2 Chain Derivation Changes](https://docs.base.org/upgrades/fjord/derivation): Derivation changes in the Fjord upgrade, updating protocol parameters for max sequencer drift, channel bank size, and adding brotli compression support.

- [Predeploys](https://docs.base.org/upgrades/fjord/predeploys): Predeploy changes in the Fjord upgrade, adding FastLZ fee computation constants to the GasPriceOracle contract.

#### Ecotone

- [Ecotone](https://docs.base.org/upgrades/ecotone/overview): Overview of the Ecotone hardfork, integrating Ethereum Dencun changes including EIP-4844 blob transactions and EIP-4788 beacon block roots.

- [Derivation](https://docs.base.org/upgrades/ecotone/derivation): Derivation changes in the Ecotone upgrade, extending the retrieval stage to support EIP-4844 blobs as an additional data availability source.

- [Ecotone L1 Attributes](https://docs.base.org/upgrades/ecotone/l1-attributes): L1 attributes transaction changes in the Ecotone upgrade, updating calldata format to support the new blob-based fee calculation model.

#### Delta

- [Delta](https://docs.base.org/upgrades/delta/overview): Overview of the Delta hardfork, introducing span batches to reduce L1 data costs by compressing multiple L2 blocks into single batcher transactions.

- [Span-Batches](https://docs.base.org/upgrades/delta/span-batches): Specification of span batches introduced in Delta, a new batch format that compresses sequences of L2 blocks for more efficient L1 data posting.

- [Canyon](https://docs.base.org/upgrades/canyon/overview): Overview of the Canyon hardfork, bringing Ethereum Shanghai EIPs (EIP-3651, EIP-3855, EIP-3860) to the Base execution layer.

## Optional
- [Base MCP server](https://docs.base.org/mcp): Direct AI access to Base documentation
- [Base skills](https://github.com/base/skills): Installable agent skills (`npx skills add base/base-skills`)
- [Full context (llms-full.txt)](https://docs.base.org/llms-full.txt): Same index plus cross-cutting concept guides