Account Abstraction by Account Configuration

Abstract

This proposal introduces a new EIP-2718 transaction type and an onchain Account Configuration system that together provide account abstraction — custom authentication, call batching, and gas sponsorship. Accounts register owners with onchain verifier contracts. Transactions declare which verifier to use, enabling nodes to filter transactions without executing wallet code. No EVM changes are required. The contract infrastructure is designed to be shared across chains as a common base layer for account management.

Motivation

Account abstraction proposals that delegate validation to wallet code force nodes to simulate arbitrary EVM before accepting a transaction. This requires full state access, tracing infrastructure, and reputation systems to bound the cost of invalid submissions.

This proposal separates verification from account logic. Each transaction explicitly declares its verifier — a contract that takes a hash and signature data and returns the authenticated owner. This makes validation predictable: wallets know the rules, and nodes can see exactly what computation a transaction requires before executing it. Nodes may optionally filter on verifier identity, accepting only known verifiers (ECDSA, P256, WebAuthn, multisig, post-quantum) and rejecting the rest without execution.

New signature algorithms are introduced through verifier contracts and standardized through the canonical verifier set.

Specification

Constants

Account Configuration

Each account can authorize a set of owners through the Account Configuration Contract at ACCOUNT_CONFIG_ADDRESS. This contract handles owner authorization, account creation, change sequencing, and delegates signature verification to onchain Verifiers.

Owners are identified by their ownerId, a 32-byte identifier derived by the verifier from public key material. The protocol does not enforce a derivation algorithm — each verifier defines its own convention (see ownerId Conventions). Owners can be modified via calls within EVM execution by calling the authenticated config change functions.

Default behavior: The EOA owner is implicitly authorized by default but can be revoked on the contract.

Storage Layout

Each owner occupies a single owner_config slot containing the verifier address (20 bytes) and a scope byte (1 byte) with 11 bytes reserved. The scope byte controls which authentication contexts the owner is valid for (see Owner Scope). Non-EOA owners are revoked by deleting the owner_config slot. The implicit EOA owner (ownerId == bytes32(bytes20(account))) is revoked by overwriting the slot with verifier = REVOKED_VERIFIER (type(uint160).max), making it distinguishable from an empty (implicitly authorized) slot.

Implicit EOA authorization: An unregistered owner (owner_config slot is empty) is implicitly authorized if ownerId == bytes32(bytes20(account)). The empty slot’s scope byte is 0x00 (unrestricted), granting full permissions by default. This allows every existing EOA to send AA transactions immediately without prior registration. When the implicit rule applies, the protocol verifies using native ecrecover rather than calling an external verifier contract. The implicit authorization is revoked by writing REVOKED_VERIFIER (type(uint160).max) to the verifier field, making the slot non-empty and blocking re-authorization. The EOA owner can also be explicitly registered with ECRECOVER_VERIFIER (address(1)) to set a custom scope while retaining native ecrecover verification.

Owner Scope

The scope byte in owner_config is a permission bitmask that restricts which authentication contexts an owner can be used in. A value of 0x00 means unrestricted — the owner is valid in all contexts. Any non-zero value restricts the owner to contexts where the corresponding bit is set.

The protocol checks scope after verifier execution: scope == 0x00 || (scope & context_bit) != 0.

The protocol validates signatures by reading owner_config directly and delegating authentication to Verifiers — see Validation for the full flow. Owner enumeration is performed off-chain via OwnerAuthorized / OwnerRevoked event logs. No owner count is enforced on-chain — gas costs naturally bound owner creation.

2D Nonce Storage

Nonce state is managed by a precompile at NONCE_MANAGER_ADDRESS. The protocol reads and increments nonce slots directly during AA transaction processing; the precompile exposes a read-only getNonce() interface to the EVM.

The transaction carries two nonce fields: nonce_key (uint256) selects the nonce channel, and nonce_sequence (uint64) is the expected sequence number within that channel.

Nonce-Free Mode (NONCE_KEY_MAX)

When nonce_key == NONCE_KEY_MAX, the protocol does not read or increment nonce state. nonce_sequence MUST be 0. Replay protection relies on expiry, which MUST be non-zero.

Nodes SHOULD reject NONCE_KEY_MAX transactions from the mempool if expiry exceeds a short window (e.g., 10 seconds from current time). Replay protection is handled by transaction hash.

Account Lock

Account lock state is stored in a single packed 32-byte slot:

When locked is set, all config changes are rejected — both config change entries in account_changes and applySignedOwnerChanges() via EVM. The lock cannot be removed without a timelock delay.

Lock operations are called directly by the account (msg.sender) on the Account Configuration Contract.

Lifecycle:

1. Lock: Call lock(unlockDelay). Sets locked = true with the specified unlockDelay (seconds).
2. Initiate unlock: Call initiateUnlock(). Sets unlocks_at = block.timestamp + unlock_delay.
3. Effective unlock: Once block.timestamp >= unlocks_at, the account is effectively unlocked — config changes are permitted.

Delegation Indicator

This proposal uses the same delegation indicator behavior as EIP-7702 on 8130 chains, even if EIP-7702 transactions are not enabled. An account is delegated when its code is exactly 0xef0100 || target, where target is a 20-byte address. Delegated accounts MAY originate transactions, and all code-executing operations targeting a delegated account MUST load code from target instead of the indicator.

Verifiers

Each owner is associated with a verifier, a contract that performs signature verification. The verifier address is stored in owner_config. All verifiers implement IVerifier.verify(hash, data). Stateful verifiers MAY read transaction context (sender address, calls, payer) from the Transaction Context precompile at TX_CONTEXT_ADDRESS (see Transaction Context). The protocol validates the returned ownerId against owner_config and checks the owner’s scope against the authentication context.

Verifiers are executed via STATICCALL. Verifier addresses MUST NOT be delegated accounts — reject if the code at the verifier address starts with the delegation indicator (0xef0100). Execution is metered (see Mempool Acceptance for rules).

On the 8130 path, nodes MAY enshrine canonical verifier execution and charge standard gas targets for those verifiers. Enshrined execution MUST produce identical results to the corresponding verifier contract.

ECRECOVER_VERIFIER (address(1)) is a protocol-reserved address for native secp256k1 verification. When the protocol encounters this address as a verifier in auth data, it performs ecrecover directly rather than making a STATICCALL. The data portion is interpreted as raw ECDSA (r || s || v), and the returned ownerId is bytes32(bytes20(recovered_address)). Owners can be explicitly registered with ECRECOVER_VERIFIER to use native ecrecover with a custom scope, without requiring a deployed verifier contract.

Any contract implementing IVerifier can be permissionlessly deployed and registered as an owner’s verifier.

Canonical Verifier Set

This specification defines a canonical verifier set which is the set of signature algorithms that compliant nodes MUST accept. The initial canonical set includes:

The canonical verifier set and corresponding contract addresses are maintained in a companion ERC and deployed at deterministic CREATE2 addresses across chains. The canonical set is expected to grow as new algorithms are adopted (e.g., post-quantum) through the companion ERC process.

Nodes MUST include all canonical verifiers in their allowlist and SHOULD NOT extend the allowlist with non-canonical verifiers. The 8130 path is intended to use a small, standard set of signature algorithms; accepting additional verifiers is a divergence from this specification.

Account Types

This proposal supports three paths for accounts to use AA transactions:

AA Transaction Type

A new EIP-2718 transaction with type AA_TX_TYPE:

AA_TX_TYPE || rlp([
  chain_id,
  sender,             // Sender address (20 bytes) | empty for EOA signature
  nonce_key,          // uint256: nonce channel selector
  nonce_sequence,     // uint64: sequence number
  expiry,             // Unix timestamp (seconds)
  max_priority_fee_per_gas,
  max_fee_per_gas,
  gas_limit,
  account_changes,    // Account creation, config change, and/or delegation operations | empty
  calls,              // [[{to, data}, ...], ...] | empty
  payer,              // empty = sender-paid, payer_address = specific payer
  sender_auth,
  payer_auth          // empty = sender-pay, verifier || data = sponsored (same format as sender_auth)
])

call = rlp([to, data])   // to: address, data: bytes

Field Definitions

Intrinsic Gas

sender_gas = AA_BASE_COST + tx_payload_cost + sender_auth_cost + nonce_key_cost + bytecode_cost + account_changes_cost + execution_gas_used
total_gas_charged = sender_gas + payer_auth_cost

All sender_gas components consume gas_limit; intrinsic costs are charged before call execution and the remaining gas is available to calls. Unused gas from gas_limit is refunded to the payer. payer_auth_cost is metered separately and charged to the payer, but does not consume gas_limit or reduce gas available to calls.

The sender verifier runs first, and its metered cost is included in gas_limit. This lets the payer sign a single maximum sender-side gas exposure without committing to the sender’s verifier choice. Payer authentication is chosen by the payer and metered separately.

sender_auth_cost: For EOA signatures (sender empty) or ECRECOVER_VERIFIER (address(1)) signatures: 6,000 gas (ecrecover + 1 SLOAD + overhead). For other configured owner signatures (sender set, address(2+) verifier): 1 SLOAD (owner_config) + cold code access + actual gas consumed by verifier execution.

payer_auth_cost: 0 for self-pay (payer empty). Otherwise, the same sender_auth_cost model applies to the payer’s verifier.

Signature Format

Signature format is determined by the sender field:

EOA signature (sender empty): Raw 65-byte ECDSA signature (r || s || v). The sender address is recovered via ecrecover.

Configured owner signature (sender set):

verifier (20 bytes) || data

The first 20 bytes identify the verifier address. When the verifier is ECRECOVER_VERIFIER, data is raw ECDSA (r || s || v) and the protocol handles ecrecover natively. For all other verifiers, data is verifier-specific — each verifier defines its own wire format.

Validation

1. Resolve sender: If sender empty, ecrecover derives the sender address (EOA path) with ownerId = bytes32(bytes20(sender)). If sender set, read the first 20 bytes of sender_auth as the verifier address.
2. Set transaction context: Populate the Transaction Context precompile with sender, payer, and calls (see Transaction Context).
3. Verify: Route by verifier address. For the EOA path (sender empty), ecrecover was already performed in step 1. For ECRECOVER_VERIFIER (address(1)), the protocol natively ecrecovers from data (as r || s || v), returning ownerId = bytes32(bytes20(recovered_address)). For all other verifiers (address(2+)), call verifier.verify(hash, data) via STATICCALL, returning ownerId (or bytes32(0) for invalid). Reject REVOKED_VERIFIER as a verifier address.
4. Authorize: SLOAD owner_config(sender, ownerId). Implicit EOA rule: if the slot is empty, ownerId == bytes32(bytes20(sender)), and verification in step 3 used the native secp256k1 path (the EOA path or ECRECOVER_VERIFIER), treat as implicitly authorized with scope 0x00. Otherwise, require that the stored verifier address matches the effective verifier and is not REVOKED_VERIFIER.
5. Check scope: Read the scope byte from owner_config (or 0x00 for the implicit case). Determine the context bit: 0x02 (SENDER) for sender_auth, 0x04 (PAYER) for payer_auth, 0x01 (SIGNATURE) for verifySignature(), 0x08 (CONFIG) for config change auth. Require scope == 0x00 || (scope & context_bit) != 0.

Signature Payload

Sender and payer use different type bytes for domain separation, preventing signature reuse attacks:

Sender signature hash — all tx fields through payer, excluding sender_auth and payer_auth:

keccak256(AA_TX_TYPE || rlp([
  chain_id, sender, nonce_key, nonce_sequence, expiry,
  max_priority_fee_per_gas, max_fee_per_gas, gas_limit,
  account_changes, calls,
  payer
]))

Payer signature hash — all tx fields through calls, excluding payer, sender_auth, and payer_auth:

keccak256(AA_PAYER_TYPE || rlp([
  chain_id, sender, nonce_key, nonce_sequence, expiry,
  max_priority_fee_per_gas, max_fee_per_gas, gas_limit,
  account_changes, calls
]))

The sender field in the payer signature hash MUST be the resolved sender address. In the EOA path (sender empty in the transaction wire format), the recovered sender address (from sender_auth ecrecover, see Validation step 1) MUST be substituted into the sender position before computing this hash; it MUST NOT be encoded as the empty wire-format value. This binds the payer’s signature to the specific resolved sender and prevents cross-sender replay of payer signatures (see Payer Security).

Payer Modes

Gas payment and sponsorship are controlled by two independent fields:

payer — the sender’s commitment regarding the gas payer, included in the sender’s signed hash:

payer_auth — uses the same verifier || data format as sender_auth:

Any authorized owner with SENDER scope can sign self-pay transactions.

Account Changes

The account_changes field is an array of typed entries for account creation and owner management:

Create and delegation entries are authorized by the transaction’s sender_auth — there is no separate authorization field. The initial ownerIds for create entries are salt-committed to the derived address. Delegation requires the sender to be the account’s implicit EOA owner with CONFIG scope. Config change entries carry their own auth and use a sequence counter for deterministic cross-chain ordering. Nodes SHOULD enforce a configurable per-transaction limit on the number of config change entries (mempool rule).

Create Entry

New smart contract accounts can be created with pre-configured owners in a single transaction. The code is placed directly at the account address — it is not executed during deployment. The account’s initialization logic runs via calls in the execution phase that follows:

rlp([
  0x00,               // type: create
  user_salt,          // bytes32: User-chosen uniqueness factor
  code,               // bytes: Runtime bytecode placed at account address
  initial_owners      // Array of [verifier, ownerId, scope] tuples
])

Initial owners are registered with their specified scope. Wallet initialization code can lock the account via calls in the execution phase (e.g., calling lock() on the Account Configuration Contract).

The code field contains runtime bytecode placed directly at the account address. For delegation, use a delegation entry (type 0x02) in account_changes after account creation.

[0x00, user_salt, runtimeBytecode, initial_owners]

Address Derivation

Addresses are derived using the CREATE2 address formula with the Account Configuration Contract (ACCOUNT_CONFIG_ADDRESS) as the deployer. The initial_owners are sorted by ownerId before hashing to ensure address derivation is order-independent (the same set of owners always produces the same address regardless of the order specified):

sorted_owners = sort(initial_owners, by: ownerId)

owners_commitment = keccak256(ownerId_0 || verifier_0 || scope_0 || ownerId_1 || verifier_1 || scope_1 || ... || ownerId_n || verifier_n || scope_n)

effective_salt = keccak256(user_salt || owners_commitment)
deployment_code = DEPLOYMENT_HEADER(len(code)) || code
address = keccak256(0xff || ACCOUNT_CONFIG_ADDRESS || effective_salt || keccak256(deployment_code))[12:]

The owners_commitment uses ownerId || verifier || scope (53 bytes) per owner — consistent with how the Account Configuration Contract identifies and configures owners.

DEPLOYMENT_HEADER(n) is a fixed 14-byte EVM loader that returns the trailing code (see Appendix: Deployment Header for the full opcode sequence). On non-8130 chains, createAccount() constructs deployment_code and passes it as init_code to CREATE2. On 8130 chains, the protocol constructs the same deployment_code for address derivation but places code directly (no execution). Both paths produce the same address — callers only provide code; the header is never user-facing.

Users can receive funds at counterfactual addresses before account creation.

Validation (Create Entry)

When a create entry is present in account_changes:

1. Parse [0x00, user_salt, code, initial_owners] where each entry is [verifier, ownerId, scope]
2. Reject if any duplicate ownerId values exist
3. Reject if code is empty
4. Sort by ownerId: sorted_owners = sort(initial_owners, by: ownerId)
5. Compute owners_commitment = keccak256(ownerId_0 || verifier_0 || scope_0 || ... || ownerId_n || verifier_n || scope_n)
6. Compute effective_salt = keccak256(user_salt || owners_commitment)
7. Compute deployment_code = DEPLOYMENT_HEADER(len(code)) || code
8. Compute expected = keccak256(0xff || ACCOUNT_CONFIG_ADDRESS || effective_salt || keccak256(deployment_code))[12:]
9. Require sender == expected
10. Require code_size(sender) == 0 (account not yet deployed)
11. Validate sender_auth against one of initial_owners (ownerId resolved from auth must match an entry’s ownerId)

Config Change Entry

Config change entries manage the account’s owners. Each entry includes a chain_id field where 0 means valid on any chain, allowing replay across chains to synchronize owner state.

Config Change Format

rlp([
  0x01,               // type: config change
  chain_id,           // uint64: 0 = valid on any chain
  sequence,           // uint64: monotonic ordering
  owner_changes,      // Array of owner changes
  auth                // Signature from an owner valid at this sequence
])

owner_change = rlp([
  change_type,          // uint8: operation type (see below)
  verifier,             // address: verifier contract (authorizeOwner only)
  ownerId,              // bytes32: owner identifier
  scope                 // uint8: permission bitmask (authorizeOwner only, 0x00 = unrestricted)
])

Operation types:

Config Change Authorization

Each config change entry represents a set of operations authorized at a specific sequence number. The auth must be valid against the account’s owner configuration at the point after all previous entries in the list have been applied. The authorizing owner must have CONFIG scope (see Owner Scope).

The sequence number is scoped by chain_id: 0 uses the multichain sequence channel (valid on any chain), while a specific chain_id uses that chain’s local channel.

Config Change Signature Payload

Entry signatures use ABI-encoded type hashing. Operations within an entry are individually ABI-encoded and hashed into an array digest:

TYPEHASH = keccak256("SignedOwnerChanges(address account,uint64 chainId,uint64 sequence,OwnerChange[] ownerChanges)OwnerChange(uint8 changeType,address verifier,bytes32 ownerId,uint8 scope)")

ownerChangeHashes = [keccak256(abi.encode(changeType, verifier, ownerId, scope)) for each ownerChange]
ownerChangesHash = keccak256(abi.encodePacked(ownerChangeHashes))

digest = keccak256(abi.encode(TYPEHASH, account, chainId, sequence, ownerChangesHash))

Domain separation from transaction signatures (AA_TX_TYPE, AA_PAYER_TYPE) is structural — transaction hashes use keccak256(type_byte || rlp([...])), which cannot produce the same prefix as abi.encode(TYPEHASH, ...).

The auth follows the same Signature Format as sender_auth (verifier || data), validated against the account’s owner state at that point in the sequence.

Account Config Change Paths

Owners can be modified through two portable paths:

Both paths share the same signed owner changes and change_sequence counters. applySignedOwnerChanges() parses the verifier address from auth, calls the verifier to get the ownerId, and checks owner_config. Anyone can call these functions; authorization comes from the signed operation, not the caller. All owner modification paths are blocked when the account is locked (see Account Lock).

Delegation Entry

Delegation entries set EIP-7702-style code delegation for the sender’s account, replacing the need for an authorization_list in the transaction. Delegation is authorized by the transaction’s sender_auth — no separate signature is required. The sender must be the account’s implicit EOA owner (ownerId == bytes32(bytes20(sender))) with CONFIG scope.

Delegation Format

rlp([
  0x02,               // type: delegation
  target              // address: delegate to this contract, or address(0) to clear
])

The delegation is only permitted when:

• code_size(sender) == 0 (empty account), or
• code(sender) starts with the delegation designator 0xef0100 (updating an existing delegation)

It will not replace non-delegation bytecode.

When target is address(0), the delegation indicator is cleared — the account’s code hash is reset to the empty code hash, restoring the account to a pure EOA.

On non-8130 chains, delegation uses standard EIP-7702 transactions (ECDSA authority).

For 8130 transactions, successful delegation updates emit a protocol-injected DelegationApplied(account, target) receipt log, where target is the delegated contract address (or address(0) when clearing delegation).

Execution (Account Changes)

account_changes entries are processed in order before call execution:

1. Create entry (if present): Register initial_owners in Account Config storage for sender — for each [verifier, ownerId, scope] tuple, write owner_config (verifier address and scope byte). Initialize lock state to safe defaults: locked = false, unlockDelay = 0, unlockRequestedAt = 0.
2. Config change entries (if any): Apply operations in entry order. Reject transaction if account is locked.
3. Delegation entries (if any): Require the sender’s resolved ownerId == bytes32(bytes20(sender)) (EOA owner) with CONFIG scope. Reject if account is locked. For each entry, set code(sender) = 0xef0100 || target (or clear if target is address(0)). Reject if account has non-delegation bytecode.
4. Code placement (if create entry present): Place code at sender. The runtime bytecode is placed directly — not executed.

Execution

Call Execution

The protocol dispatches calls directly from sender to each call’s to address:

Calls carry no ETH value. ETH transfers are initiated by the account’s wallet bytecode via the CALL opcode (see Why No Value in Calls?).

Phases execute in order from a single gas pool (gas_limit). Within each phase, calls execute in order and are atomic — if any call in a phase reverts, all state changes for that phase are discarded and remaining phases are skipped. Completed phases persist — their state changes are committed and survive later phase reverts.

Common patterns:

• Simple call: [[{to, data}]] — one phase, one call
• Atomic batch: [[call_a, call_b, call_c]] — one phase, all-or-nothing
• Sponsor + user: [[sponsor_payment], [user_action_a, user_action_b]] — sponsor in phase 0 (committed), user actions in phase 1 (atomic, skipped if sponsor fails)

Transaction Context

The Transaction Context precompile at TX_CONTEXT_ADDRESS provides read-only access to the current AA transaction’s metadata. The precompile reads directly from the client’s in-memory transaction state — protocol “writes” are effectively zero-cost. Gas is charged as a base cost plus 3 gas per 32 bytes of returned data, matching CALLDATACOPY pricing.

If the wallet needs the verifier address or scope, it calls getOwnerConfig(account, ownerId) on the Account Configuration Contract.

Non-8130 chains: No code at TX_CONTEXT_ADDRESS; STATICCALL returns zero/default values.

Portability

The system is split into storage and verification layers with different portability characteristics:

All contracts are deployed at deterministic CREATE2 addresses across chains.

Validation Flow

Mempool Acceptance

1. Parse and structurally validate sender_auth. Verify account_changes contains at most one create entry (type 0x00, must be first) and at most one delegation entry (type 0x02). Nodes SHOULD enforce a configurable limit on the number of config change entries (type 0x01).
2. Resolve sender: if sender set, use it; if empty, ecrecover from sender_auth
3. Determine effective owner state: a. If create entry present in account_changes: verify address derivation, code_size(sender) == 0, use initial_owners b. Else: read from Account Config storage
4. If config change or delegation entries present in account_changes: reject if account is locked (see Account Lock). For config change entries: simulate applying operations in sequence, skip already-applied entries. For delegation entries: verify code_size(sender) == 0 or existing delegation designator.
5. Validate sender_auth against resulting owner state (see Validation). Require SENDER scope on the resolved owner. If delegation entries are present, also require ownerId == bytes32(bytes20(sender)) (EOA owner) and CONFIG scope.
6. Resolve payer from payer and payer_auth:
   • payer empty and payer_auth empty: self-pay. Payer is sender. Reject if balance insufficient.
   • payer = 20-byte address (sponsored): payer_auth uses any verifier. Validate payer_auth against the payer address’s owner_config. Require PAYER scope on the resolved owner.
7. Verify nonce, payer ETH balance, and expiry:
   • Standard keys (nonce_key != NONCE_KEY_MAX): require nonce_sequence == current_sequence(sender, nonce_key).
   • Nonce-free key (nonce_key == NONCE_KEY_MAX): skip nonce check, require nonce_sequence == 0, require non-zero expiry, and nodes SHOULD reject if expiry exceeds a short window (e.g., 10 seconds). Deduplicate by transaction hash.
8. Mempool threshold: gas payer’s pending count below node-configured limits.

Nodes MUST maintain a verifier allowlist that includes all verifiers in the canonical verifier set (see Canonical Verifier Set).

Nodes SHOULD NOT extend their allowlist with additional non-canonical verifiers.

Nodes MAY apply higher pending transaction rate limits based on account lock state:

• Locked sender: A locked sender account has a stable signature if combined with a stateless verifier. Nodes can safely allow a higher sender rate.
• Locked payer with trusted bytecode: A locked payer account whose bytecode is recognized and restricts eth movement while locked provides an additional guarantee that ETH balance only decreases via gas fees. Nodes can safely allow a higher payer rate for such accounts.

Block Execution

1. If account_changes contains config change or delegation entries, read lock state for sender. Reject transaction if account is locked. If delegation entries are present, require the sender’s resolved ownerId == bytes32(bytes20(sender)) (EOA owner) with CONFIG scope.
2. ETH gas deduction from payer (sponsor for sponsored, sender for self-pay). Transaction is invalid if payer has insufficient balance.
3. If nonce_key != NONCE_KEY_MAX, increment nonce in Nonce Manager storage for (sender, nonce_key). If nonce_key == NONCE_KEY_MAX, skip (nonce-free mode).
4. If code_size(sender) == 0 and no create entry and no delegation entry is present in account_changes, auto-delegate sender to DEFAULT_ACCOUNT_ADDRESS (set code to 0xef0100 || DEFAULT_ACCOUNT_ADDRESS). This delegation persists.
5. Process account_changes entries in order (see Execution (Account Changes)).
6. Set transaction context on the Transaction Context precompile (sender, payer, ownerId, calls).
7. Execute calls per Call Execution semantics.

Unused gas from gas_limit is refunded to the payer. Intrinsic gas, excluding separately metered payer_auth_cost, consumes gas_limit before call execution. For step 5, the protocol SHOULD inject log entries into the transaction receipt (e.g., OwnerAuthorized, AccountCreated, DelegationApplied) matching the events defined in the IAccountConfiguration interface, following the protocol-injected log pattern established by EIP-7708. These protocol-injected logs are emitted only for 8130 transactions.

RPC Extensions

eth_getTransactionCount: Extended with optional nonceKey parameter (uint256) to query 2D nonce channels. Reads from the Nonce Manager precompile at NONCE_MANAGER_ADDRESS.

eth_getTransactionReceipt: AA transaction receipts include:

• payer (address): Gas payer address (sender for self-pay, specified payer for sponsored).
• status (uint8): 0x01 = all phases succeeded (or calls was empty), 0x00 = one or more phases reverted. Existing tools checking status == 1 remain correct for the success path.
• phaseStatuses (uint8[]): Per-phase status array. Each entry is 0x01 (success) or 0x00 (reverted). Phases after a revert are not executed and reported as 0x00. Empty if calls was empty.

Appendix: Storage Layout

The protocol reads storage directly from the Account Configuration Contract (ACCOUNT_CONFIG_ADDRESS) and Nonce Manager (NONCE_MANAGER_ADDRESS). The storage layout is defined by the deployed contract bytecode — slot derivation follows from the contract’s Solidity storage declarations. The final deployed contract source serves as the canonical reference for slot locations.

Appendix: Deployment Header

The DEPLOYMENT_HEADER(n) is a 14-byte EVM loader that copies trailing code into memory and returns it. The header encodes code length n into its PUSH2 instructions:

DEPLOYMENT_HEADER(n) = [
  0x61, (n >> 8) & 0xFF, n & 0xFF,     // PUSH2 n        (code length)
  0x60, 0x0E,                          // PUSH1 14       (offset: code starts after 14-byte header)
  0x60, 0x00,                          // PUSH1 0        (memory destination)
  0x39,                                // CODECOPY       (copy code from code[14..] to memory[0..])
  0x61, (n >> 8) & 0xFF, n & 0xFF,     // PUSH2 n        (code length)
  0x60, 0x00,                          // PUSH1 0        (memory offset)
  0xF3                                 // RETURN         (return code from memory)
]

The create entry only supports runtime bytecode. Delegation is set via delegation entries (type 0x02) in account_changes.

Rationale

Why Verifier Contracts?

Enables signature-algorithm extension through verifier contracts. The verifier returns the ownerId rather than accepting it as input, so the protocol never needs algorithm-specific logic. All verifiers share a single verify(hash, data) interface with no type-based dispatch. Owner scope provides protocol-enforced role separation without verifier cooperation.

Why 2D Nonce + NONCE_KEY_MAX?

Additional nonce_key values allow parallel transaction lanes without nonce contention between independent workflows.

NONCE_KEY_MAX enables nonce-free transactions where replay protection comes from short-lived expiry and node-level replay protection by transaction hash. This is useful for operations where nonce ordering coordination is undesirable.

Why a Nonce Precompile?

Nonce state is isolated in a dedicated precompile (NONCE_MANAGER_ADDRESS) because nonce writes occur on nearly every AA transaction, while owner config writes are relatively infrequent.

The Nonce Manager has no EVM-writable state and no portability requirement — a precompile is simpler than exposing nonce mutation through the account config contract.

Why a Transaction Context Precompile?

Transaction context (sender, payer, calls, gas) is immutable transaction metadata — it never changes during execution. ownerId is set after validation and available during execution only. A precompile is the natural fit:

• Zero protocol write cost: The precompile reads directly from the client’s in-memory transaction struct — no HashMap insert, no journaling, no rollback tracking.
• Pull model: Verifiers read only what they need. Pure verifiers pay nothing for context they don’t use.
• Forward compatible: New context fields are added as new precompile functions — no interface changes to IVerifier or existing verifier contracts.

Why CREATE2 for Account Creation?

The create entry uses the CREATE2 address formula with ACCOUNT_CONFIG_ADDRESS as the deployer address for cross-chain portability:

1. Deterministic addresses: Same user_salt + code + initial_owners produces the same address on any chain
2. Pre-deployment funding: Users can receive funds at counterfactual addresses before account creation
3. Portability: Same deployment_code produces the same address on both 8130 and non-8130 chains (see Address Derivation)
4. Front-running prevention: initial_owners in the salt prevents attackers from deploying with different owners (see Create Entry)

Smart Wallet Migration Path

Existing ERC-4337 smart accounts migrate to native AA without redeployment:

1. Import account: Call importAccount() on the Account Configuration Contract — this verifies via the account’s isValidSignature (ERC-1271) and registers initial owners. Existing ERC-4337 wallets already implement ERC-1271, so initial owner registration works without code changes.
2. Upgrade wallet logic: Update contract to delegate isValidSignature to the Account Configuration Contract’s verifySignature() function for owner and verifier infrastructure, and read getOwnerId() from the Transaction Context precompile during execution to identify which owner authorized the transaction
3. Backwards compatible: Wallet can still accept ERC-4337 UserOps via EntryPoint alongside native AA transactions

Why Call Phases?

Phases provide two atomic batching levels without per-call mode flags:

• Atomic batching: One phase, all-or-nothing.
• Sponsor protection: Payment in phase 0 persists even if user actions in phase 1 revert.
• Paymaster inspection: Verifiers can inspect calls via the Transaction Context precompile to validate payment terms.

Why Direct Dispatch?

The protocol dispatches each call directly to the specified to address with msg.sender = sender. Owners with SENDER scope are authorized to send transactions at the protocol level. Every account has wallet bytecode (via auto-delegation or explicit deployment), so calls route through the wallet for ETH-carrying operations.

Why No Value in Calls?

Since every account has wallet bytecode (auto-delegation or explicit deployment), ETH transfers route through wallet code via the CALL opcode — no capability is lost. Removing protocol-level value from calls means the protocol never moves ETH on behalf of the sender.

Why Delegation via Account Changes?

EIP-7702 introduced authorization_list as a transaction-level field for code delegation, with ECDSA authority. This proposal moves delegation into account_changes, authorized by the transaction’s sender_auth. Delegation is restricted to the account’s implicit EOA owner (ownerId == bytes32(bytes20(sender))) so that code delegation remains portable across non-8130 chains via standard EIP-7702 transactions. Eventually this can be expanded to all verifier types.

Why Account Lock?

Locked accounts have a frozen owner set, so the primary state that can invalidate a validated transaction is nonce consumption. This can enable nodes to cache owner state and apply higher mempool rate limits (see Mempool Acceptance). A per-owner lock alternative was considered but adds mempool tracking complexity — rate limits per (address, ownerId) pair rather than per address.

Why One Slot Per Owner?

The protocol reads everything it needs for authorization and scope checking in one SLOAD. Reserved bytes provide an extension path for future protocol-level owner policy.

Why Owner Scope?

Without scope, all owners have equal authority — any owner can sign as sender, approve gas payment, appear through ERC-1271, and authorize config changes. This is insufficient when accounts have owners serving different roles, like for example running a payer for ERC-20 tokens.

The 0x00 = unrestricted default ensures backward compatibility.

Why a Canonical Verifier Set?

Without a required verifier set, nodes could diverge on which signature algorithms they accept beyond ECRECOVER_VERIFIER. Wallets would face a fragmented network where each node accepts a different combination of algorithms, making it impossible to guarantee transaction delivery for non-k1 signature types.

The canonical set establishes a shared baseline: wallets that use canonical verifiers know their transactions will be accepted by any compliant node. The set is expected to remain small, with new algorithms added through the companion ERC process as they gain broad adoption.

Why No Public Key Storage?

Public keys are not stored in the Account Configuration Contract. Instead, owners are identified by ownerId (bytes32) and public key material is provided at signing time in the verifier-specific data portion of the signature. This design is motivated by three factors:

• State growth: Public key storage is permanent state growth. For PQ keys (1,000+ bytes), this means 40+ storage slots per owner. Calldata goes to data availability (temporary); storage is permanent. The trend is toward higher SLOAD costs and cheaper DA.
• Gas efficiency: Calldata is cheaper than cold SLOADs for all key sizes. P256: ~2,048 gas calldata vs ~6,300 gas cold SLOADs. PQ: ~21,000 gas calldata vs ~88,000 gas cold SLOADs.
• Simplicity: One storage slot per owner (owner_config). No variable-length public key encoding, no multi-slot reads, no length fields. Registration is a single SSTORE.

The protocol never needs to know how any algorithm works.

Why bytes32 ownerId?

The full 32-byte keccak256 output provides ~2^85 quantum collision resistance (vs ~2^53 for bytes20 via BHT), which is adequate for post-quantum keys. It also fits a single storage slot and aligns with keccak256 output without truncation.

ownerId Conventions

Each verifier defines how it derives ownerId from signature data.

Backwards Compatibility

No breaking changes. Existing EOAs and smart contracts function unchanged. Adoption is opt-in:

• EOAs continue sending standard transactions
• ERC-4337 infrastructure continues operating
• Accounts gain AA capabilities by configuring owners. EOAs sending their first AA transaction are auto-delegated to DEFAULT_ACCOUNT_ADDRESS if they have no code. EOAs MAY override with a delegation entry in account_changes (EOA-only authorization), a standard EIP-7702 transaction, or use a create entry in account_changes for custom wallet implementations

Reference Implementation

IAccountConfiguration

interface IAccountConfiguration {
    struct ChangeSequences {
        uint64 multichain; // chain_id 0
        uint64 local;      // chain_id == block.chainid
    }

    struct OwnerConfig {
        address verifier;
        uint8 scopes;      // 0x00 = unrestricted
    }

    struct Owner {
        bytes32 ownerId;
        OwnerConfig config;
    }

    struct OwnerChange {
        bytes32 ownerId;
        uint8 changeType;  // 0x01 = authorizeOwner, 0x02 = revokeOwner
        bytes configData;  // OwnerConfig for authorize, empty for revoke
    }

    event OwnerAuthorized(address indexed account, bytes32 indexed ownerId, OwnerConfig config);
    event OwnerRevoked(address indexed account, bytes32 indexed ownerId);
    event AccountCreated(address indexed account, bytes32 userSalt, bytes32 codeHash);
    event AccountImported(address indexed account);
    event DelegationApplied(address indexed account, address target);
    event AccountLocked(address indexed account, uint16 unlockDelay);
    event AccountUnlockInitiated(address indexed account, uint40 unlocksAt);

    // Account creation (factory)
    function createAccount(bytes32 userSalt, bytes calldata bytecode, Owner[] calldata initialOwners) external returns (address);
    function computeAddress(bytes32 userSalt, bytes calldata bytecode, Owner[] calldata initialOwners) external view returns (address);

    // Import existing account (ERC-1271 verification for initial owner registration)
    function importAccount(address account, Owner[] calldata initialOwners, bytes calldata signature) external;

    // Portable owner changes (direct verification via verifier + owner_config)
    function applySignedOwnerChanges(address account, uint64 chainId, OwnerChange[] calldata ownerChanges, bytes calldata auth) external;

    // Account lock (called by the account directly)
    function lock(uint16 unlockDelay) external;
    function initiateUnlock() external;

    // Signature verification
    function verifySignature(address account, bytes32 hash, bytes calldata signature) external view returns (bool verified);
    function verify(address account, bytes32 hash, bytes calldata auth) external view returns (uint8 scopes);

    // Storage views
    function isInitialized(address account) external view returns (bool);
    function isOwner(address account, bytes32 ownerId) external view returns (bool);
    function getOwnerConfig(address account, bytes32 ownerId) external view returns (OwnerConfig memory);
    function getChangeSequences(address account) external view returns (ChangeSequences memory);
    function isLocked(address account) external view returns (bool);
    function getLockStatus(address account) external view returns (bool locked, bool hasInitiatedUnlock, uint40 unlocksAt, uint16 unlockDelay);
}

IVerifier

interface IVerifier {
    function verify(
        bytes32 hash,
        bytes calldata data
    ) external view returns (bytes32 ownerId);
}

Stateful verifiers MAY read from the Transaction Context precompile or other state (see Transaction Context). When called outside of an 8130 transaction (e.g., verifySignature() in a legacy transaction), the Transaction Context precompile returns zero/default values, so verifiers that depend on it naturally reject those calls.

ITxContext (Precompile)

struct Call {
    address to;
    bytes data;
}

interface ITxContext {
    function getSender() external view returns (address);
    function getPayer() external view returns (address);
    function getOwnerId() external view returns (bytes32);
    function getCalls() external view returns (Call[][] memory);
    function getMaxCost() external view returns (uint256);
    function getGasLimit() external view returns (uint256);
}

Read-only. Gas is charged as a base cost plus 3 gas per 32 bytes of returned data.

INonceManager (Precompile)

interface INonceManager {
    function getNonce(address account, uint256 nonceKey) external view returns (uint64);
}

Read-only. The protocol manages nonce storage directly; there are no state-modifying functions.

Security Considerations

Validation Surface: For pure verifiers, invalidators are owner_config revocation and nonce consumption. Stateful verifiers additionally depend on traced state; invalidation tracking is a mempool concern.

Replay Protection: Transactions include chain_id, 2D nonce (nonce_key, nonce_sequence), and expiry. For NONCE_KEY_MAX (nonce-free mode), replay protection relies on short-lived expiry and transaction-hash deduplication. The mempool enforces a tight expiry window (e.g., 10-30 seconds) to bound the window. Block builders MUST NOT include duplicate NONCE_KEY_MAX transactions with the same hash.

Owner Scope: Protocol-enforced after verifier execution — a verifier cannot bypass scope checking.

Owner Management: Config change authorization requires CONFIG scope. The EOA owner is implicitly authorized with unrestricted scope; revocable via portable config change. All owner modification paths are blocked when the account is locked.

Implicit EOA Rule Scoping: The implicit EOA authorization rule only applies when authentication used the native secp256k1 path — either the EOA path (sender empty) or ECRECOVER_VERIFIER. Generic verifier contracts MUST NOT satisfy the implicit branch even if they return bytes32(bytes20(sender)), otherwise an arbitrary verifier could authenticate as any EOA whose implicit owner slot has never been written.

ownerId Binding: The protocol checks that the verifier’s returned ownerId maps back to that verifier in owner_config — preventing a malicious verifier from claiming ownership of another verifier’s owners.

Payer Security: AA_TX_TYPE vs AA_PAYER_TYPE domain separation prevents signature reuse between sender and payer roles. The payer field in the sender’s signed hash binds to a specific payer address. Scope enforcement adds a second layer — PAYER-only owners cannot be used as sender_auth, and vice versa. The payer’s exposure to sender-controlled gas is bounded by signed fee fields because gas_limit includes sender authentication, intrinsic costs, account changes, and call execution. Payer authentication uses the payer’s chosen verifier, is validated under PAYER scope, and is metered separately so the payer’s verifier choice cannot reduce gas available to calls.

Cross-sender Payer Replay: The payer signature hash binds to the resolved sender via the sender field (see Signature Payload). In the EOA path where sender is empty in the wire format, the recovered sender address MUST be substituted into the sender position before computing the hash. Without this substitution, two different EOAs that construct otherwise identical transaction data (same chain_id, nonce_key, nonce_sequence, expiry, fees, account_changes, calls) would produce identical payer hashes, allowing a second EOA to reuse a payer signature originally issued for the first and drain the payer’s gas deposit. The 2D nonce alone does not prevent this: nonce_key and nonce_sequence are fields in the transaction payload, so each attacker controls their own values. Substituting the recovered sender into the hash makes the payer’s commitment per-sender and closes this replay path. The configured-owner path is unaffected because sender is non-empty by definition.

Account Creation Security: initial_owners (verifier + ownerId + scope tuples) are salt-committed, preventing front-running of owner assignment. Wallet bytecode should be inert when uninitialized as it can be permissionlessly deployed.

Copyright

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