EIP-8130: Account Abstraction by Account Configuration

Enable account abstraction feature set through onchain account configurations and a new transaction type

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 actors with onchain authenticator contracts. Transactions declare which authenticator to use, enabling nodes to filter transactions without executing arbitrary 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 authentication from account logic. Each transaction explicitly declares its authenticator, a contract that takes a hash and signature data and returns the authenticated actor. This makes validation predictable: wallets know the rules, and nodes can see exactly what computation a transaction requires before executing it. Instead of simulating arbitrary code, nodes filter on authenticator identity, accepting transactions whose authenticator belongs to a small, standard canonical set and rejecting the rest.

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

Portability is also a top concern: the keystore lets accounts manage their authenticators and maintain cross-chain portability.

Specification

Overview

An account manages its authentication configuration via the keystore, a contract that maps an account to its configured authenticators and stores their authorizations. An actor on the account is one that has an authorization in the keystore. Each actor is bound to an authenticator, an onchain contract that checks a signature and returns the actor’s identity (actorId).

A new EIP-2718 transaction type (AA_TX_TYPE) names the authenticator that authenticates it. Because the authenticator is declared explicitly, a node can tell exactly what computation a transaction requires, and reject unknown authenticators before executing any code. Validation reads the account’s configuration, runs the named authenticator, and checks the resolved actor’s permissions; execution then dispatches the transaction’s calls.

The 8130 transaction type is not required for the accounts to work, and they are fully portable to other EVM-based chains. On chains that don’t support the 8130 transaction type, they must use an alternative transport mechanism such as ERC-4337. See Portability.

This EIP specifies the protocol surface: the transaction type, node validation and execution rules, intrinsic gas, and the authenticator model. The Keystore and the canonical authenticator/account contracts — including exact storage packing, typehashes, event ABIs, and function bodies — live in the canonical contracts repository (the base organization’s EIP-8130 repository on GitHub, src/Keystore.sol), which is authoritative for all contract internals. Where this document gives a byte layout or digest, it is a normative summary; the repository is the source of truth, and any implementation MUST match it (either by calling the deployed contracts or by reproducing their behavior with static/precomputed gas values).

The specification is organized around four pieces:

• Actors and Authenticators: the authentication and authorization model (see Authenticators).
• Account Configuration: onchain management of account and its actors (see Keystore and Account Configuration).
• AA Transaction Type: the wire format, signature payloads, and gas accounting (see AA Transaction Type).
• Account Changes: how accounts are created and how actors are added, revoked, or delegated (see Account Changes).

Account Types

8130 supports all account types, existing and newly created.

Adoption Profiles

8130 is specified once but adopted under one of two profiles. A chain MUST declare which profile it activates; the profile fixes the parameters this specification otherwise leaves open: the intrinsic-gas schedule, how the enshrined canonical authenticator set evolves, and whether the 8130 transaction path accepts authenticators outside that set. The canonical set is accepted on the transaction path under both profiles, always at a constant enshrined validation cost, so a wallet targeting the canonical set behaves identically everywhere; the profiles differ only in what else is allowed and how it changes, never in transaction semantics.

L1 profile (normative schedule, permissive acceptance). For a base layer, where the gas schedule is the specification and consensus validity MUST NOT depend on any out-of-band configuration. Under this profile:

• The intrinsic-gas schedule is normative. The component values in this document are protocol constants, identical for every node, and MAY change only through a hard fork. A node MUST NOT adopt a different schedule.
• Canonical authenticators are enshrined on the validation path with a constant validation cost (their fixed sender_auth_cost / payer_auth_cost component values); no EVM runs to authenticate a canonical actor, and the enshrined set changes only through a hard fork.
• Authenticator acceptance is permissive: the 8130 transaction path accepts any authenticator whose STATICCALL returns within MAX_AUTHENTICATION_GAS, canonical or not (see Authenticators). No allowlist is maintained; a base layer can afford this bounded, single-call validation.

Under the L1 profile 8130 is a single protocol: two independent implementations that agree on this document produce identical block validity.

L2 profile (configurable schedule, canonical-only path). For an L2 or any high-throughput EVM that wants to track a local cost model, move faster than L1 governance, and keep the transaction path to fixed-cost validation. Under this profile a chain MAY:

• adopt a different intrinsic-gas schedule (for example to mirror a future EVM repricing), provided it is fixed under that chain’s consensus and identical across its nodes;
• extend the enshrined constant-cost canonical set it accepts through the companion ERC process and node configuration.

Authenticator acceptance is canonical-only: the 8130 transaction path accepts only the enshrined canonical set (fixed validation cost, no arbitrary STATICCALL on the hot path). Non-canonical authenticators remain registrable and usable through the EVM (config-change calls, recovery flows, ERC-4337), just not on the 8130 transaction path. An L2-profile chain is still internally consistent; wallets that need cross-chain portability SHOULD rely only on the canonical set and the recommended schedule.

The gas-schedule policy and the acceptance policy are independent choices; the two profiles name the common pairings, and a chain MAY combine them differently. What is universal is the canonical set: every compliant chain accepts it on the 8130 transaction path at a constant enshrined cost, so a wallet can rely on canonical authenticators working everywhere. Additional authenticators may be registered on any chain (for example, recovery flows), but are usable on the 8130 transaction path only where a chain’s policy is permissive; otherwise they are reached through the EVM.

Throughout this specification, “recommended” values and schedules mean required under the L1 profile and default-but-overridable under the L2 profile; the normative structure (the gas-formula components, the authenticator interface, the canonical set) holds under both.

Authenticators

Each actor is associated with an authenticator, a contract that performs signature authentication. In the protocol’s terms, the authenticator authenticates the actor (it returns the actor’s actorId); scope and policy on the keystore then authorize what that authenticated actor may do. The authenticator address is stored in actor_config (see Keystore and Account Configuration). All authenticators implement IAuthenticator.authenticate(hash, data). After the authenticator authenticates the signature, the protocol validates the returned actorId against actor_config and authorizes the actor by checking its scope against the authorization context.

Canonical authenticators are enshrined on the validation path with a constant validation cost under both adoption profiles (their fixed sender_auth_cost / payer_auth_cost component values); no EVM is executed to authenticate them, and they are accepted on the 8130 transaction path on every compliant chain. When a canonical authenticator is enshrined, its execution MUST produce results identical to the corresponding authenticator contract.

Whether an authenticator outside the canonical set is accepted on the 8130 transaction path is the chain’s acceptance policy (see Adoption Profiles): a permissive chain (typically L1) authenticates it with a single STATICCALL, metered as ordinary EVM execution and bounded by MAX_AUTHENTICATION_GAS; a canonical-only chain (typically a high-throughput L2) does not accept it on the transaction path at all.

Any contract implementing IAuthenticator can be permissionlessly deployed and registered as an actor’s authenticator on any chain. Registration always makes the authenticator usable within EVM execution (for example, authenticating an actor against an arbitrary IAuthenticator via a config change call, enabling wallet-defined recovery methods); it becomes usable on the 8130 transaction path only on chains whose acceptance policy is permissive.

Canonical Authenticator Set

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

The canonical authenticator set and corresponding contract addresses are deployed at deterministic CREATE2 addresses across chains and catalogued in a companion ERC (number TBD). These are the authenticators enshrined on the validation path with a constant validation cost. How the enshrined set evolves depends on the chain’s adoption profile. Under the L1 profile the enshrined set is fixed by the protocol and changes only through a hard fork. Under the L2 profile the set MAY be extended as new algorithms are adopted (e.g., post-quantum) through the companion ERC process and node configuration.

The set is expected to grow over time to enshrine new canonical authenticators as signature algorithms mature. This does not disturb existing accounts. Actors reference their authenticator by address in actor_config, so an account stays bound to its keystore and its current actors while remaining free to adopt any newly canonical scheme: it simply authorizes a new actor pointing at the new authenticator, with no migration, redeployment, or address change. Accounts are therefore crypto-agile by construction, able to add, rotate to, or retire authenticators as the canonical set expands, without ever being locked to the algorithms enshrined at deployment time.

Nodes MUST accept all canonical authenticators on the 8130 transaction path; this is the universal baseline wallets can rely on everywhere. Whether an authenticator outside the canonical set is accepted on the transaction path is the chain’s acceptance policy (see Adoption Profiles): a permissive chain authenticates it with a single STATICCALL bounded by MAX_AUTHENTICATION_GAS, while a canonical-only chain does not accept it on the transaction path, so it must be reached through the EVM (config-change calls, ERC-4337, direct Keystore). The 8130 path is intended to use a small, standard set of signature algorithms, and wallets that need cross-chain portability SHOULD rely only on the canonical set.

Delegate Authenticator

The delegate authenticator lets one account act on behalf of another: account A registers a delegate actor with actorId = bytes32(uint256(uint160(B))), after which any key that can authenticate as account B may authenticate as A, bounded by the scope A grants that actor. Delegation MUST NOT chain (depth-1: the nested authenticator MUST NOT itself be the delegate authenticator) and the nested authenticator MUST be canonical, keeping total validation work bounded. The remaining details are defined in the canonical repository.

Keystore and Account Configuration

Each account can authorize a set of actors through the Keystore contract at KEYSTORE_ADDRESS. This contract handles actor authorization, account creation, change sequencing, and account lock, and delegates signature authentication to onchain Authenticators. Its full ABI, storage packing, typehashes, and events are defined in the canonical repository (src/Keystore.sol); this section specifies only the protocol-visible behavior and the state a node reads directly.

Actors are identified by their actorId, a 32-byte identifier derived by the authenticator from public key material. Each authenticator defines its own actorId derivation algorithm (see Canonical Authenticator Set). Actors can be modified via calls within EVM execution by calling the authenticated change function (applySignedAccountChanges).

Actor enumeration is performed off-chain via ActorAuthorized and ActorRevoked event logs.

Storage Layout

Each actor occupies a single actor_config slot containing the authenticator address, an optional expiry, and the scope bitmask. The protocol reads this slot directly during validation, so its packing is normative: authenticator(20) ‖ expiry(6) ‖ scope(2) ‖ reserved(4), where expiry is a uint48 Unix timestamp in seconds (0 = no expiry; the actor is invalid once block.timestamp > expiry) and scope is the uint16 permission bitmask (0x0000 = unrestricted, also the admin predicate; see Actor Scope). The exact slot derivation and byte offsets are defined in the canonical repository (src/Keystore.sol).

When scope includes POLICY (0x02), the actor also carries a signed policy commitment and a manager address in the separate policy slots policy_commitment/policy_manager (see Actor Policies). Actors are revoked by deleting the actor_config slot. The self-actor (actorId == bytes32(uint256(uint160(account)))) is the one exception: it is held inline in the packed account-state slot and resolved per Validation.

When scope & POLICY != 0, the actor’s policy is held in two additional slots:

policy_commitment(account, actorId) → bytes32   // set when POLICY is set
policy_manager(account, actorId)    → address   // set when POLICY is set

These slots are read only during execution (see Actor Policies); validity is decided by the single actor_config SLOAD giving cheap, predictable validation and invalidation.

Actor Scope

The scope field in actor_config is a uint16 permission bitmask of grants. A value of 0x00 means unrestricted (all contexts) and is also the account’s admin predicate: any check in this specification that requires an “admin” actor is exactly scope == 0x00. Any non-zero value grants only the contexts whose bits are set. Reads are fail-closed: a context is authorized only when scope == 0x00 or the corresponding grant bit is present. Unknown bits grant nothing. All future scope bits MUST be pure grants. An actor whose scope sets only unknown bits is stored verbatim but authorizes no context in the protocol.

Admin. Config-change authority (authorizeActor, revokeActor, applySignedAccountChanges, delegation) is exactly the admin predicate scope == 0x00: the same unrestricted root every other check already special-cases. Accounts are born with a scope-0 root (the implicit EOA, or an unrestricted actor named at create/import); everything below that root is granted.

Initiation grants. SENDER and POLICY compose: SENDER allows initiation to any call.to, POLICY allows gated initiation to the actor’s policy_manager. An actor may hold either or both; whenever POLICY is set the call is gated to the manager regardless of SENDER, so the gate always binds a policy-bearing actor. When both are set, SENDER conveys no additional authority; wallets SHOULD NOT set SENDER | POLICY. POLICY | SELF_PAYER and POLICY | NONCE compose likewise. POLICY | SPONSOR_PAYER also composes: the actor’s initiation is gated to its manager, but its sponsor authority is not gated and it may underwrite third-party gas off its policy gate. authorizeActor stores any scope combination verbatim; combination semantics are checked at the point of use.

Scope authorization is applied only after an authenticator authenticates the signature and returns an actorId: the protocol loads that actor’s scope and checks it against the context being authorized. For sender_auth, require scope == 0x00 || (scope & SENDER) != 0 || (scope & POLICY) != 0; when POLICY is set the actor is gated to its manager regardless of SENDER (see Actor Policies). For self-pay (payer account == sender account) require SELF_PAYER on the actor that authorizes payment, and for sponsorship (payer account ≠ sender) require SPONSOR_PAYER on the payer_auth-resolved actor (the respective bit, or unrestricted). For 2D nonce usage require NONCE and for config change auth require admin (scope == 0x00).

See Validation for the full flow.

Actor Expiry

The protocol enforces one rule: an actor is live at now (the inclusion block timestamp) iff expiry == 0 || now <= expiry (see Storage Layout), evaluated at inclusion. It checks only the acting key’s own expiry and never walks authorizer lineage, so a live admin’s authorization survives that admin’s own later expiry or revocation; removal requires an explicit revokeActor.

Note for wallets: expiry is set only by a config change (initial actors are always non-expiring), and SHOULD be placed only on non-admin actors, where a lapsed key simply stops working. Using it on an admin (scope == 0x00) can break valid change chains for cross-chain actor-change replay and account sync, so an admin SHOULD NOT expire unless the wallet owner deliberately plans for it and keeps a non-expiring owner in place.

Epoch System

To enable uncoordinated session-key, subscription, and JIT actor additions there is an epoch system. The local change channel carries an epoch (local_epoch) alongside its sequence counter (local_sequence); together they form the signed local word local_epoch(high 32) || local_sequence(low 32) (see Config Change Authorization). The epoch is a blunt cancellation control for the account’s own outstanding local signatures, distinct from actor expiry:

• IncrementLocalEpoch (an account change carried on either channel) increments local_epoch and resets local_sequence to 0. Every local batch signed at the prior epoch — sequenced or unsequenced/JIT — no longer matches the current local_epoch and is rejected with StaleEpoch; it can never land.
• The epoch does not revoke live actors or touch actor_config. An actor authorized in a landed batch stays authorized across an epoch bump; only unlanded local signatures are invalidated. Removing an actor is still an explicit RevokeActor.
• Multichain batches are unaffected: they carry no epoch and are ordered solely by the monotonic multichain counter.

This is what makes the unsequenced/JIT mode (UNSEQUENCED) safe to hand out: an unsequenced batch is intentionally replayable within its epoch, and the account durably retires it by bumping the epoch — typically batching the reducing RevokeActor/AuthorizeActor with IncrementLocalEpoch in one signed batch. See Why a Local Epoch?.

Actor Policies

Actor policies gate a key to a single manager contract that enforces application-defined authority on the account’s behalf, for example a session key limited to a spend cap or a small set of targets (see Why Actor Policies?).

POLICY selects whether an actor is gated; gating is determined by the scope bit alone. When set, policyData MUST be exactly manager (20 bytes) ‖ commitment (32 bytes), written verbatim to policy_manager / policy_commitment; neither field need be nonzero. A zero commitment is a valid “no parameters” value. A zero manager gates the key to address(0), leaving no productive call target. When unset, policyData MUST be empty and prior policy slots are cleared. Policy vocabulary lives in the commitment and manager logic.

A policy-bearing actor may call exactly one target: its configured manager. The contract at that target reads the actor’s commitment (via getPolicy), validates presented parameters against it, enforces what the call may do, and carries out the approved action. The protocol’s only responsibility is the single-target gate.

A key that should be enforced by the account’s own code rather than a separate contract sets manager = account. Because protocol dispatch originates the call from the account itself (msg.sender == account), this is only meaningful with policy-aware wallet code; code that implicitly trusts self-calls (e.g. a standard executeBatch) turns such a key into an unrestricted one (see Security Considerations).

Scope. POLICY is the gated initiation grant. How it composes with SENDER is defined in Actor Scope. It MAY combine with SELF_PAYER so a session key can self-pay gas (bounded by balance and expiry). It MAY also combine with NONCE so a policy key can use a sequenced nonce_key.

Reference flow (non-normative). One construction of a session-key policy:

1. Authorize. The account authorizes the key with POLICY, the manager, and a commitment. The key’s call authority is only the gate to its manager.
2. Use (each call). The protocol gate routes the key’s call to the manager; the manager enforces installed params and drives the account by checking the policy commitment.
3. Retire. revokeActor zeroes the commitment or expiry rejects further authentication.

Example (non-normative). A subscription session key limited to 5 USDC per 30-day period with a two-target allowlist. Authorized with POLICY. Over-budget transfers, wrong targets, expiry, or revoke all fail.

The commitment is signed, opaque, and protocol-stored. One signature fully describes the key’s manager and policy and travels with the portable actor-change path.

Enforcement. The gate is applied during Call Execution. Validity does not read policy_commitment or policy_manager.

Lifecycle. Policy state is keyed by (account, actorId); clearing on revocation and target-held parameters are covered under Policy State on Revocation.

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.

Actor Nonce Scope

NONCE (0x04) grants a restricted actor access to sequenced nonce_keys for sender-context transactions; it does not apply to payer_auth. The protocol enforces this during validation (see Validation):

Nonce-Free Mode (NONCE_KEY_MAX)

When nonce_key == NONCE_KEY_MAX, the protocol neither reads nor increments a nonce counter; nonce_sequence MUST be 0 and valid_before MUST be non-zero. Replay protection uses replay_id deduplication held in a fixed-capacity circular buffer that is consensus state, not per-node bookkeeping: a seen map (replay_id → valid_before) of live entries plus a ring that evicts the oldest entry once elapsed, so a still-live replay_id is rejected and a buffer full of still-live entries rejects the transaction. Because both checks decide block validity, the capacity is a protocol constant or explicit chain parameter (REPLAY_BUFFER_CAPACITY), identical for every node on the chain, and MUST be at least peak accepted nonce-free throughput × NONCE_FREE_EXPIRY_WINDOW so an entry always elapses before its ring slot is reused. Entries are ephemeral, so there is no permanent state growth. See nonce_key_cost in Intrinsic Gas.

The maximum validity window (valid_before − now) accepted for nonce-free transactions is likewise an explicit chain parameter (NONCE_FREE_EXPIRY_WINDOW), not a per-node choice, and MUST be sized together with REPLAY_BUFFER_CAPACITY so peak accepted nonce-free throughput × NONCE_FREE_EXPIRY_WINDOW stays within capacity. Replay protection is handled by the replay identifier defined below.

Replay Identifier

Nonce-free (NONCE_KEY_MAX) transactions have no nonce slot to key deduplication and replacement on, so each carries a replay identifier that names the logical transaction independent of its fees and authorization blobs. Standard and 2D transactions (nonce_key != NONCE_KEY_MAX) do not use replay_id; they are deduplicated and replaced by (sender, nonce_key, nonce_sequence) under the standard nonce rules (see Mempool Replacement).

REPLAY_ID_TYPE = 0x7901

replay_id = keccak256(REPLAY_ID_TYPE || rlp([
  chain_id, resolved_sender, valid_after, valid_before,
  account_changes, calls, metadata,
  payer
]))

nonce_key and nonce_sequence are omitted: a nonce-free transaction always has (NONCE_KEY_MAX, 0), so they carry no entropy and cannot distinguish two logical transactions.

resolved_sender is the sender address recovered via ecrecover (EOA path, where sender is empty in the wire format) or taken directly from the sender field (configured-actor path). Binding resolved_sender keeps the identifier unique per sender on the EOA path, where two distinct EOAs can sign identical transaction bodies.

replay_id deliberately excludes:

• max_fee_per_gas, max_priority_fee_per_gas, and gas_limit, so a fee bump on an otherwise-identical transaction does not change its identity.
• sender_auth and payer_auth, the authorization blobs, which are excluded both because they are non-deterministic (ECDSA signing is randomized and malleable) and because payer_auth can be freshly re-signed (e.g. on a fee bump) without changing the logical transaction.

It includes payer (the address field, not payer_auth): retargeting a transaction at a different payer is a change to the logical transaction, so it MUST produce a different replay_id.

The full transaction hash MUST NOT be used for nonce-free deduplication or mempool replacement (see Mempool Replacement below); the rationale for keying on replay_id instead is explained in Security Considerations.

Mempool Replacement

Fee-bump replacement is keyed differently depending on nonce mode:

• Standard and 2D transactions (nonce_key != NONCE_KEY_MAX): replacement follows the standard nonce rules. Two pending transactions from the same sender sharing the same (sender, nonce_key, nonce_sequence) are replacement candidates; replay_id plays no role. Nonce mechanics already prevent two transactions with the same (sender, nonce_key, nonce_sequence) from both being included, since inclusion increments the sequence.
• Nonce-free transactions (nonce_key == NONCE_KEY_MAX): replay_id drives replacement because there is no nonce slot. Two pending transactions from the same sender with the same replay_id are replacement candidates, and block builders MUST NOT include two transactions with the same (sender, replay_id) in the same block.

In both modes a replacement MUST increase max_priority_fee_per_gas by at least the node’s configured minimum bump (e.g., ≥10%), mirroring standard replace-by-fee conventions, and MUST be independently fully valid, including a fresh payer_auth when sponsored: payer_auth commits to max_fee_per_gas, max_priority_fee_per_gas, and gas_limit (see Signature Payload), so the payer must re-sign to authorize the bumped fees. For nonce-free transactions, changing payer yields a new replay_id (a new logical transaction) rather than a replacement of the old one.

Account Lock

Account lock state is stored in a single packed 32-byte account-state slot that also holds the change channels, an account-flags byte, and the inline default-EOA config. The protocol may read this slot’s raw layout directly for mempool rate-limit tiering, so its field order and widths are normative:

When LOCKED, all authority changes (authorize/revoke actor) and delegation are rejected on both paths (config entries in account_changes and applySignedAccountChanges). Only two changes remain permitted while locked: Unlock (which begins the timed release) and IncrementLocalEpoch (which cancels outstanding local signatures without touching actor authority — see Epoch System). Lock and unlock are themselves the only lock-state transitions, carried as standalone changes (below). The stored unlock_delay is bounded to the uint16 range (~18.2h max): lock exists for mempool permissioning, and a short ceiling prevents an account from self-bricking config rotations.

Lock Operations

Lock and unlock are local-only account changes carried in a signed batch through the single applySignedAccountChanges entry point; there is no separate lock function. Each is admin-authorized (scope == 0x00), binds chainId = block.chainid, and is consumed against the local channel like any sequenced local change. Lock and Unlock MUST each be the sole change in their batch, so a lock transition can never interleave with actor changes in the same signed batch. Anyone may relay; authorization comes from the signature. The signed digest and typehashes are defined in the canonical repository.

Lifecycle — lock, then unlock, with no other actions in between:

1. Lock: only from the unlocked state. Sets LOCKED and stores unlock_delay. Rejected if already locked (a zero delay is rejected); the delay cannot be changed while locked. Emits AccountLocked.
2. Unlock: only from LOCKED with no pending unlock. Sets UNLOCK_INITIATED and unlocks_at = block.timestamp + unlock_delay (from the stored delay). Emits AccountUnlockInitiated.
3. Effective unlock: once block.timestamp >= unlocks_at, the account is unlocked and config changes resume; the flags and lock_union are lazily cleared by the next op. Locking again requires a fresh lock.

Account Import

importAccount(address account, uint256 chainId, InitialActor[] calldata initialActors, bytes calldata signature) is a one-time call that registers an already-deployed account into the Keystore contract with an initial actor set. chainId is the replay domain of the import signature, mirroring applySignedAccountChanges: 0 = multichain (valid on every chain); otherwise it MUST equal block.chainid. The call is rejected when:

• chainId is neither 0 nor the current chain.
• The account already has 8130 state: either change-sequence channel is non-zero. Import is a one-time bootstrap, so it requires both the local and multichain channels empty. A locked account is always caught here: a lock is a signed local config change, so it has advanced local_sequence and the account is considered initialized (see Account Lock).
• The account has no bytecode (there is no contract to run the ERC-1271 signature check against), or its ERC-1271 check does not return the magic value.

The signature is validated against the account via ERC-1271 over a typed (EIP-712-style) ActorInitialization digest that omits the EIP-712 domain separator (anti-phishing) and binds the account’s own actorId (bytes32(uint256(uint160(account))), so it cannot be replayed against another account), chainId (matching the applySignedAccountChanges replay domain), and each initial actor with expiry = 0 (imported actors are always non-expiring; an actor-provided expiry MUST NOT be accepted). policyData follows authorizeActor’s rule and, unlike create, manager = account is expressible here. On success importAccount sets DEFAULT_EOA_REVOKED (parity with createAccount); to keep using the native key past import, include the self-actorId as a K1_AUTHENTICATOR entry in initialActors. Exact typehashes and digest construction are defined in the canonical repository (src/Keystore.sol).

Account Establishment

Both createAccount and importAccount set the CONTRACT_ESTABLISHED flag (flags bit 0) in the packed account-state slot, regardless of the account’s code shape (fresh deployment, plain contract, or EIP-7702 delegate). The flag is permanent, has no effect on authentication, and marks the account as keystore-established rather than backed by a proven address-bound key.

It exists because 8130 state can outlive code: an account established and SELFDESTRUCTed in the same transaction (EIP-6780) is left with empty code but retains its 8130 state. Consumers (and protocol logic that makes code-delegation decisions) therefore MUST NOT treat “empty code (or a delegate) plus 8130 state” as proof of a known EOA key; they check CONTRACT_ESTABLISHED instead. A future genuinely key-backed native path MAY deliberately leave the bit clear. The flag does not infer an address-bound key from code shape — delegate imports remain fully supported.

Delegation Indicator

The delegation indicator is the EIP-7702 mechanism for pointing an account’s code at a shared implementation contract. This proposal relies on it as the foundation for account code: an EOA sending its first AA transaction is auto-delegated to DEFAULT_ACCOUNT_ADDRESS when it has no code (see Block Execution), and accounts MAY set or clear delegation explicitly via a Delegation Entry in account_changes. Because 8130 depends on this behavior directly, the delegation indicator MUST be supported on 8130 chains even when standalone 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.

Signature Verification

The Keystore exposes one raw primitive, authenticateActor(account, hash, auth), which maps a hash and signature to a verified (actorId, scope). Wallet-originated flows — transactions, account changes, and other protocol paths — authenticate directly against it over their own digest.

Applications that instead request a signature (Sign-In with Ethereum, Permit, order flow) use validateSignature(account, hash, auth). This wraps authenticateActor with an identity binding that makes the signature replay-safe: replaySafeHash(account, chainId, hash) = keccak256(SIGNED_MESSAGE_TYPEHASH, account, chainId, hash) binds the signature to a specific account and chain (chainId = 0 binds all chains). The auth blob is sigType(1) ‖ authenticator(20) ‖ data, where sigType selects the Local (0x01) or Multichain (0x02) domain.

Because both methods return (actorId, scope) rather than a bare boolean, a consumer can attribute a signature to a specific key and make a granular authorization decision — the “who signed” and capability set that plain ERC-1271 discards, surfaced only when a consumer needs it.

This supersedes ERC-1271 while remaining backwards compatible: an 8130 account implements isValidSignature(hash, signature) on top of validateSignature, returning the magic value when the resolved actor is operational and treating any revert as invalid. The recommended wrapper is Scopes.isOperator (admin, or SENDER without POLICY; see Actor Scope); the canonical DefaultAccount in the contract repository ships this wrapper.

Precompiles and native signature verification. A precompile calling back into the EVM is both undesirable and unimplemented at the time of writing, so ERC-1271 — which verifies by calling the account’s isValidSignature — is unavailable for native or precompile-based checks. 8130 removes that dependency: the canonical authenticator set is small and enshrinable (see Canonical Authenticator Set) and authority lives in a flat actor_config slot, so validateSignature can run entirely in native code and be exposed as a precompile, producing identical results to EVM execution on non-8130 chains. Future applications may depend on this, as it replaces both ecrecover and ERC-1271 cleanly across all chain types.

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
  valid_after,        // uint64: Unix timestamp (ms or s, auto-detected); 0 = no lower bound
  valid_before,       // uint64: Unix timestamp (ms or s, auto-detected); 0 = no expiry
  max_priority_fee_per_gas,
  max_fee_per_gas,
  gas_limit,
  account_changes,    // Account creation, config change, and/or delegation operations | empty
  calls,              // [[call, ...], ...] where call = rlp([to, data]) | empty
  metadata,           // opaque attribution/annotation bytes | empty
  payer,              // empty = sender-paid, payer_address = specific payer
  sender_auth,        // raw ECDSA r||s||v (EOA, sender empty) | authenticator || data (configured actor)
  payer_auth          // empty = self-pay | authenticator || data = sponsored (same format as sender_auth)
])

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

Field Definitions

Millisecond window. The transaction window (valid_after/valid_before) is denominated in milliseconds, while on-chain actor and lock expiries are seconds; this split is deliberate and there is no second-denominated variant of these fields. Because block.timestamp has second granularity, the effective activation/expiry resolution equals the chain’s block-timestamp resolution (1 second on most chains today); the millisecond field exists for off-chain clock compatibility (e.g. Date.now(), sequencer clocks) and forward-compatibility with sub-second block times, not for finer resolution than the chain itself provides. Can easily be scaled on ingress.

Timestamp Normalization. valid_after and valid_before MAY be expressed in either seconds or milliseconds; a node accepts both at the same time and decides the unit per value, not per node or per chain. There is no mode flag: the unit is a fixed function of the value against the threshold TIMESTAMP_MS_THRESHOLD = 100_000_000_000 (10^11), applied independently to each field:

• a value below TIMESTAMP_MS_THRESHOLD is always interpreted as seconds and normalized to milliseconds as value * 1000;
• a value at or above TIMESTAMP_MS_THRESHOLD is always interpreted as milliseconds and used as-is;
• a 0 value means “no bound” and is not normalized.

This is unambiguous for every realistic value: a 64-bit Unix timestamp in seconds does not reach 10^11 until the year 5138, while any Unix timestamp in milliseconds has exceeded 10^11 since 1973. Because the rule is a pure function of the value, every node derives the same normalized timestamp, so this is consensus-safe (no node-local configuration affects block validity). All validity-window comparisons in this specification operate on the normalized millisecond value; wherever valid_after or valid_before appears in a comparison below, it denotes the normalized value.

Intrinsic Gas

Intrinsic gas follows the standard Ethereum meaning: the total cost to include the transaction. As in standard transactions it accounts for signature authentication, here both the sender’s authentication (sender_auth_cost) and the payer’s (payer_auth_cost) are included.

Full-EVM metering model (normative). The reference cost of an 8130 transaction is what its work costs when metered as ordinary EVM execution, over four phases:

1. Account changes. Apply account_changes in order: a create entry calls createAccount and config-change entries call applySignedAccountChanges (both metered as ordinary Keystore contract calls), and a delegation entry performs a standard EIP-7702 delegation, metered at the standard delegation cost.
2. Validation. Authenticate the transaction: STATICCALL the sender_auth authenticator, and (when sponsored) the payer_auth authenticator, each followed by the single actor_config SLOAD that resolves and authorizes the actor. Metered as ordinary STATICCALL execution.
3. Execution. Dispatch the transaction’s calls, metered as ordinary EVM execution.
4. Bound. The transaction’s total metered gas is bounded by effective_gas_limit (defined below), which is the gas limit for the transaction as a whole.

This model is the normative reference for results: whatever pricing a chain uses, a transaction MUST be accepted, authenticated, and executed to the same outcome and state changes that phases 1–3 produce under ordinary EVM. A chain MAY implement phases 1 and 2 (account-change application and authentication) as native code where applicable (for the enshrined canonical authenticator set and the Keystore reads it depends on), running no EVM for that work and instead charging a fixed gas cost per authenticator and per account-change operation (see Portability). The native path MUST match the Full-EVM model in results, but it need not match it in gas: its fixed schedule is its own consensus-fixed pricing, not a re-derivation of what EVM metering would charge. Whether phases 1–2 are metered pure-EVM or priced by a native fixed schedule is decided per chain (see Adoption Profiles); phase 3 is always ordinary EVM execution.

The per-component values below are that native fixed schedule for phases 1–2. They approximate the EVM access and data-availability costs (EIP-2929 / EIP-2028) at the time of writing, but a native chain charges them as flat costs rather than metering the underlying EVM. Their normative status follows the chain’s adoption profile:

• L1 profile: the values below are protocol constants (the gas schedule is part of the specification), identical for every node and changeable only through a hard fork. A chain MUST NOT adopt a different intrinsic-gas schedule under this profile.
• L2 profile: the values below are a recommended default. A chain MAY reprice them (for example to track a future EVM repricing or a local cost model), provided the schedule is fixed under that chain’s consensus and identical across its nodes.

The formula’s structure (its components and what each one accounts for) is normative under both profiles; only the absolute numbers may vary, and only under the L2 profile.

intrinsic_gas = AA_BASE_COST + tx_payload_cost + nonce_key_cost + bytecode_cost + account_changes_cost + auto_delegation_cost + sender_auth_cost + payer_auth_cost

Sender-intrinsic gas is intrinsic gas excluding payer authentication and is bounded by gas_limit. For self-pay transactions payer_auth_cost is 0, so sender-intrinsic gas equals intrinsic gas:

sender_intrinsic_gas = intrinsic_gas - payer_auth_cost
                     = AA_BASE_COST + tx_payload_cost + nonce_key_cost + bytecode_cost + account_changes_cost + auto_delegation_cost + sender_auth_cost

Intrinsic gas is charged before calls run. Since payer_auth_cost is metered outside gas_limit, the gas available to calls is:

execution_gas_available = gas_limit - sender_intrinsic_gas

payer_auth_cost is metered separately and charged to the payer on top of gas_limit; it does not draw from gas_limit and cannot reduce the gas available to calls. This isolation is required: payer_auth is excluded from both the sender and payer signature hashes (see Signature Payload) and is selected unilaterally by the payer. If it consumed gas_limit, a payer could choose an expensive authenticator to starve calls and alter execution behavior. Keeping it separate makes the gas available to calls a function of sender-signed fields alone. For the same reason the data-availability cost of the serialized payer_auth bytes is charged in payer_auth_cost rather than tx_payload_cost: those bytes are chosen by the payer and excluded from the signed hashes, so their cost is metered outside gas_limit and never reduces the sender’s execution budget. The payer reimburses payer_auth_cost regardless (the payer pays all gas).

Because payer_auth_cost sits outside gas_limit, total gasUsed can exceed gas_limit on a sponsored transaction. The overrun is bounded by an effective gas limit:

effective_gas_limit = gas_limit + MAX_AUTHENTICATION_GAS

MAX_AUTHENTICATION_GAS is the ceiling on a single authenticator’s execution: an authenticator outside the canonical set is STATICCALLed with at most this much gas, and it also bounds how much the payer’s authenticator (metered outside gas_limit) may add on top of the sender-signed gas_limit. Its suggested value is 100,000 gas. A transaction whose resolved payer_auth_cost exceeds MAX_AUTHENTICATION_GAS is rejected at Mempool Acceptance rather than metered, so gasUsed <= effective_gas_limit always holds and block-gas accounting stays bounded. For self-pay transactions payer_auth_cost is 0 and effective_gas_limit == gas_limit. Under the L1 profile MAX_AUTHENTICATION_GAS is fixed under consensus; under the L2 profile a chain MAY choose its own value (see Adoption Profiles).

sender_auth_cost, by contrast, is included in gas_limit: the sender chooses its own authenticator, and both sender and payer sign over gas_limit, so both commit to the full sender-side budget before inclusion.

sender_auth_cost: authenticator execution + 1 SLOAD (actor_config).

payer_auth_cost: 0 for self-pay (payer empty). Otherwise, the same sender_auth_cost model applies to the payer’s authenticator (authenticator execution + 1 actor_config SLOAD), plus the data-availability cost of the serialized payer_auth field itself (16 gas per non-zero byte, 4 per zero byte, per EIP-2028). These payer_auth bytes are excluded from tx_payload_cost and metered here instead, so the entire payer-authentication cost, execution and bytes alike, sits outside gas_limit and is paid by the payer.

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 actor signature (sender set):

authenticator (20 bytes) || data

The first 20 bytes identify the authenticator address. When the authenticator is K1_AUTHENTICATOR, data is raw ECDSA (r || s || v) and the protocol handles ecrecover natively. For all other authenticators, data is authenticator-specific; each authenticator defines its own wire format.

Validation

1. Resolve sender: If sender empty, ecrecover derives the sender address (EOA path) with actorId = bytes32(uint256(uint160(sender))). If sender set, read the first 20 bytes of sender_auth as the authenticator address.
2. Authenticate: Route by authenticator address. For the EOA path (sender empty), ecrecover was already performed in step 1. For K1_AUTHENTICATOR (address(1)), the protocol natively ecrecovers from data (as r || s || v), returning actorId = bytes32(uint256(uint160(recovered_address))). For all other authenticators, call authenticator.authenticate(hash, data) via STATICCALL, returning actorId (or bytes32(0) for invalid). address(0) is never a valid authenticator selector (it is the empty actor_config sentinel).
3. Authorize: Self-actor (native secp256k1) rule: if authentication in step 2 used the native secp256k1 path (the EOA path or K1_AUTHENTICATOR) and actorId == bytes32(uint256(uint160(sender))), resolve the self-actor from the inline default-EOA config in the packed account-state slot: reject if DEFAULT_EOA_REVOKED is set; otherwise take scope and expiry from the inline fields (all-zero = unrestricted, non-expiring full owner, i.e. admin). Otherwise SLOAD actor_config(sender, actorId), reject if its reserved bytes are nonzero (version gate, see Storage Layout), and require that the stored authenticator address matches the effective authenticator (this covers every other actor, including a non-secp256k1 self). In either case, if the resolved expiry is non-zero, also require block.timestamp <= expiry; an expired actor is rejected.
4. Check scope: Read the resolved scope byte (from the inline default-EOA config for the secp256k1 self-actor, or actor_config otherwise) and check it against the context being authorized per Actor Scope (for sender_auth: scope == 0x00 || (scope & (SENDER | POLICY)) != 0, with POLICY gating the actor to its manager). Payer scope is checked when the payer is resolved (see Validation Flow step 6).
5. Check nonce scope (sender-context only, when nonce_key != NONCE_KEY_MAX): require the resolved actor be admin or carry NONCE, per Actor Nonce Scope.

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, valid_after, valid_before,
  max_priority_fee_per_gas, max_fee_per_gas, gas_limit,
  account_changes, calls, metadata,
  payer
]))

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

keccak256(AA_PAYER_TYPE || rlp([
  chain_id, sender, nonce_key, nonce_sequence, valid_after, valid_before,
  max_priority_fee_per_gas, max_fee_per_gas, gas_limit,
  account_changes, calls, metadata,
  payer
]))

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). The payer field MUST also be included so the payer’s signature is bound to the account being charged; without it, a payer authorization could be redirected to any other account that authorizes the same actor with SPONSOR_PAYER scope (e.g., via the delegate authenticator).

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 authenticator || data format as sender_auth:

Transaction Metadata

The metadata field is optional opaque bytes for attaching attribution or annotation data to a transaction, for example builder/app attribution, a payment reference or memo, or a commitment to off-chain data. Legacy transactions carry such data as a “data suffix” appended to tx.input; because calls replace the single input blob, metadata provides the equivalent home.

metadata is part of the signed transaction (covered by both the sender and payer signature payloads) and is charged per byte through tx_payload_cost like any other transaction bytes. It does not affect validation or execution. Off-chain consumers (indexers, explorers) read it directly from the transaction. Producers MAY use any encoding.

Account Changes

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

Create and delegation entries are authorized by the transaction’s sender_auth and there is no separate authorization field. The initial actorIds for create entries are salt-committed to the derived address. Delegation requires the sender to be the account’s implicit EOA actor and admin (scope == 0x00). Config change entries carry their own admin auth and a channel/sequence for deterministic ordering and cross-chain replay (see Config Change Authorization). 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 actors 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_actors      // Array of [actorId, authenticator, scope, policyData] tuples
])

Each initial actor carries an actorId, authenticator, scope (uint16; 0x0000 = unrestricted admin), and policyData (empty, or manager ‖ commitment when POLICY is set), all committed to the derived address (see Address Derivation) so the counterfactual address binds each initial actor’s authority. Two things are not expressible here: expiry, and a self-referential manager = account (the account address is not yet known at commitment time). Both are added post-creation with a config change entry, which MAY accompany the create entry in the same account_changes array for atomic setup and, running after creation, resolves manager = account to a concrete address. For example, a subaccount is created with an admin actor (a delegate to the primary account, scope = 0x00) and a restricted app key (SENDER | SELF_PAYER, or POLICY with an external manager inline, or manager = account via an accompanying config change).

Address Derivation

Addresses are derived using the CREATE2 address formula with the Keystore contract (KEYSTORE_ADDRESS) as the deployer. The initial_actors MUST be provided already sorted by actorId in strictly ascending order. Requiring a single canonical ordering keeps address derivation deterministic (a given set of actors always produces the same address), and the strict ordering also rejects duplicate actorIds:

// initial_actors MUST already be sorted by actorId (strictly ascending); reject otherwise

// Hash each actor to a fixed-width leaf, then hash the ordered list of leaves
leaf_i           = keccak256(actorId_i || authenticator_i || scope_i || policyData_i)
actors_commitment = keccak256(leaf_0 || leaf_1 || ... || leaf_n)

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

This is the same hash-the-leaves-then-hash-the-list scheme used for the signed batch and import digests. Each actor’s leaf commits actorId || authenticator || scope || policyData: the 32-byte actorId, 20-byte authenticator, 2-byte scope, and the policyData bytes (empty when POLICY is unset, or exactly 52 bytes — manager (20) ‖ commitment (32) — when POLICY is set). Fixed-width 32-byte leaves make the commitment unambiguous by construction and linear in the actor count. Expiry does not participate (always 0 at create). The required strictly-ascending actorId ordering makes the commitment canonical.

Off-chain address prediction (computeAddress) MUST apply the same initial-actor validation as create — non-empty set, strictly ascending (non-zero, non-duplicate) actorIds, each authenticator >= K1_AUTHENTICATOR, and policyData length matching scope (52 bytes when POLICY is set, empty otherwise) — so a predicted address always corresponds to an actor set that create will accept. Otherwise an address could be derived and prefunded for a set a later create would reject, stranding the funds.

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. Callers only provide code, the header is never user-facing.

Validation (Create Entry)

When a create entry is present in account_changes:

1. Parse [0x00, user_salt, code, initial_actors] where each entry is [actorId, authenticator, scope, policyData]. scope is stored verbatim (unknown scope bits allowed, per Actor Scope). Apply authorizeActor’s frozen policyData rule: reject unless policyData is exactly manager (20) ‖ commitment (32) when scope & POLICY != 0, or empty otherwise. expiry is not accepted in the create entry
2. Require initial_actors are sorted by actorId in strictly ascending order; reject any unsorted set (strict ascending order also rejects duplicate actorId values).
3. Use initial_actors in the provided (sorted) order
4. Compute actors_commitment per Address Derivation
5. Compute effective_salt = keccak256(user_salt || actors_commitment)
6. Compute deployment_code = DEPLOYMENT_HEADER(len(code)) || code
7. Compute expected = keccak256(0xff || KEYSTORE_ADDRESS || effective_salt || keccak256(deployment_code))[12:]
8. Require sender == expected
9. Require the destination matches CREATE2 freshness: code_size(sender) == 0 and nonce(sender) == 0 (matching the conditions under which CREATE2 would be permitted to deploy)
10. Validate sender_auth against one of initial_actors (actorId resolved from auth must match an entry’s actorId and the auth authenticator must match that entry’s authenticator)

Config Change Entry

A config change entry carries a signed account-change batch — the same SignedAccountChanges structure applied by the Keystore’s single applySignedAccountChanges entry point. The batch binds a replay channel and a sequence, and applies its ordered list of changes atomically (any rejected change reverts the whole batch).

Config Change Format

rlp([
  0x01,               // type: config change
  channel,            // uint8: 0 = Local (binds block.chainid), 1 = Multichain (binds chain_id 0)
  sequence,           // uint64: Local  = local_epoch(high 32) || local_sequence(low 32)
                      //         Multichain = a plain monotonic counter
  changes,            // Array of account changes
  auth                // Admin (scope == 0x00) signature over the batch digest
])

change = rlp([
  change_type,        // uint8: 0 AuthorizeActor, 1 RevokeActor, 2 IncrementLocalEpoch, 3 Lock, 4 Unlock
  payload             // bytes: operation-specific, ABI-encoded (see below)
])

The operation-specific payload is an opaque bytes blob carried in the RLP envelope but encoded with the contract ABI, so the same blob is decoded identically whether the change is applied natively or via applySignedAccountChanges on the Keystore contract. It is also the value hashed (as keccak256(payload)) in the Config Change Signature Payload.

Change types:

Config Change Authorization

Each batch is authorized by a single admin signature (scope == 0x00; flat authorization, see Actor Scope) over the batch digest. The auth follows the same Signature Format as sender_auth (authenticator || data) and, when a batch is applied inside a list, must be valid against the account’s actor state after all previous entries have been applied. Anyone may relay; authorization comes from the signature.

The channel selects the replay domain and how sequence is interpreted:

• Multichain (chain_id 0): a plain monotonic uint64 counter, valid on any chain, for synchronizing actor state across chains. Each applied batch consumes the counter (sequence MUST equal the current value, then it increments). There is no epoch and no unsequenced mode on this channel, though a Multichain batch MAY still carry an IncrementLocalEpoch change that bumps the account’s local epoch.
• Local (block.chainid): sequence is the packed word local_epoch(high 32) || local_sequence(low 32). The batch is rejected with StaleEpoch unless its high half equals the current local_epoch. The low half selects one of two modes:
  • Sequenced (low half < UNSEQUENCED): the low half MUST equal the current local_sequence; on success local_sequence increments. This is the ordered, replay-once mode.
  • Unsequenced / JIT (low half == UNSEQUENCED, i.e. uint32 max): consumes no counter and does not increment local_sequence. It is permissive — any change may ride an unsequenced batch — and remains replayable until the epoch moves. Because it consumes no counter, ordering between two unsequenced batches is undefined. Retiring an unsequenced (JIT) authorization durably is done by bumping the epoch (IncrementLocalEpoch), typically batched with the reducing change. See Epoch System.

Expiry on AuthorizeActor is channel/mode-aware and never reverts. On the unsequenced/JIT path, an already-lapsed grant (a non-zero expiry that has passed per Actor Expiry) is silently skipped: the change is not applied and does not revert, and any live sibling changes in the same batch still apply. A JIT grant is replayable, so skipping a lapsed one keeps it from ever clobbering its slot — a renewed grant cannot be overwritten by replaying the old, expired one. A single-consume batch (any Multichain batch, or a Sequenced local batch) cannot be replayed, so an already-lapsed grant is instead installed inert — the actor_config slot is written (the actor is present and revocable) but the actor is not live, since authentication yields expired per Actor Expiry — and still consumes its sequence. Multichain relies on this: a chain catching up must replay a historical expiring grant’s slot (e.g. a periodically-renewed operator) in order to reach the current live grant, so dropping the stale slot would strand its counter. A zero expiry is the “no expiry” sentinel and is always accepted.

The combined local word (local_epoch || local_sequence) doubles as the initialized flag: creation and import set local_sequence = 1, so an all-zero word means uninitialized (only the implicit EOA is on the account).

Config Change Signature Payload

The batch digest is a typed (ABI-encoded, EIP-712-style) struct hash binding account, the resolved chainId (0 for Multichain, else block.chainid), the sequence word, and the ordered changes (each change hashed over its change_type and keccak256(payload)). Domain separation from transaction signatures (AA_TX_TYPE, AA_PAYER_TYPE) is structural: transaction hashes use keccak256(type_byte || rlp([...])), which cannot collide with the ABI-encoded struct hash. The exact typehash strings and digest construction are defined in the canonical repository (src/Keystore.sol).

Account Config Change Paths

The same signed batch (SignedAccountChanges) can be applied through two paths:

• account_changes (tx field): consumed by the protocol before code deployment on 8130 chains.
• applySignedAccountChanges (EVM): applied during EVM execution on any chain, including non-8130 chains and ERC-4337 deployments.

Both paths carry the same batch, share the same channels and counters, and are equally portable (Multichain for cross-chain, Local for chain-local). They differ only in transport. applySignedAccountChanges parses the authenticator from auth, resolves the admin actorId, verifies the batch digest, and applies each change in order per the change-type table. Anyone may call it; authorization comes from the signed batch, not the caller. Authority changes and delegation are blocked while the account is locked; only Unlock and IncrementLocalEpoch may be applied to a locked account (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 have been authenticated via the native secp256k1 path (the EOA path or K1_AUTHENTICATOR; mirroring the Implicit EOA Rule Scoping), with actorId == bytes32(uint256(uint160(sender))) and admin (scope == 0x00). A non-secp256k1 self authenticator that returns the self-actorId does not qualify, keeping delegation authority ECDSA/7702-portable.

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 and the account’s code hash is reset to the empty code hash.

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): apply the create entry (see Create Entry) — place code at sender, register initial_actors in Keystore storage, mark the account initialized (local channel = 1), initialize lock state to safe defaults, and set DEFAULT_EOA_REVOKED unless a self-actor is among initial_actors.
2. Config change entries (if any): Apply operations in entry order. Reject transaction if account is locked.
3. Delegation entries (if any): Require admin EOA-actor delegation authority (see Delegation Entry). 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.

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?).

Call Phases

calls is a two-level structure: an ordered array of phases, where each phase is an ordered array of individual calls ([[call, ...], [call, ...]]) — sequentially-committed atomic call groups. This gives two levels of atomicity where calls grouped within a phase are all-or-nothing, while phases commit independently in sequence.

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

Policy gate: When the transaction’s authenticating actor has POLICY set (and exclusivity checks passed), each call is gated before dispatch. The protocol resolves the actor’s allowed target (policy_manager(sender, actorId)) once at the start of calls execution, and that snapshot gates every call in every phase; a config change applied by an earlier call does not retarget the gate for later calls. If call.to is not that address, the call is not dispatched and fails deterministically with the protocol revert ActorPolicyViolation(bytes32 actorId, address target):

error ActorPolicyViolation(bytes32 actorId, address target);

The frame’s return data is abi.encodeWithSelector(ActorPolicyViolation.selector, actorId, call.to). This is a consensus-level result, not a validity error, so standard atomicity applies: the enclosing phase’s state changes roll back, later phases are skipped, and the phase is reported as failed in phaseStatuses. Only work already performed is charged (intrinsic gas plus the one policy_manager SLOAD); the undispatched call body costs nothing and the transaction is still included with its nonce consumed.

Common patterns:

• Simple call: [[call]], one phase, one call (call = rlp([to, data]))
• 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. It 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.

The static, sender-signed fields (sender, payer, calls, gas_limit) are populated during authentication and call execution, so a payer authenticator can inspect the transaction it is being asked to sponsor and decide onchain, at validation time, whether to pay. The authenticated actorId is resolved only after authentication succeeds, so it is available during execution only.

Under the L1 profile this getter set and its validation-time availability are normative; under the L2 profile a chain MAY populate the precompile during execution only.

If the wallet needs the authenticator address or scope, it calls getActorConfig(account, actorId) on the Keystore contract. A policy target reached as a call.to identifies which key it is acting for by combining getTransactionSender() and the authenticated getTransactionSenderActorId() from this precompile, then reads the actor’s gate target and signed commitment via getActor(account, actorId) in one call and validates the presented policy parameters against the commitment. The commitment lives in Keystore storage (where it is written and revoked), not the precompile, keeping the precompile to immutable transaction context.

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

Portability

The system is split into storage and authentication 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 actor state: a. If create entry present in account_changes: verify address derivation, code_size(sender) == 0, use initial_actors b. Else: read from Keystore 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 actor state (see Validation) and check scope per Actor Scope: SENDER (or POLICY) for the sender context, and admin or NONCE when nonce_key != NONCE_KEY_MAX. Payer scope (SELF_PAYER / SPONSOR_PAYER) is checked in step 6, not here — the sender actor is not required to carry a payer bit. If delegation entries are present, the resolved actor must additionally hold admin EOA-actor delegation authority (see Delegation Entry).
6. Resolve payer from payer and payer_auth:
   • payer empty and payer_auth empty: self-pay. Payer is sender; the resolved sender actor’s SELF_PAYER scope authorizes payment. Reject if balance insufficient.
   • payer = sender (explicit) with payer_auth: self-pay via a dedicated gas key. Payer account == sender; validate payer_auth against the account’s actor_config and require SELF_PAYER scope on the resolved actor. Reject if balance insufficient.
   • payer = a different 20-byte address (sponsored): payer_auth uses any authenticator. Validate payer_auth against the payer address’s actor_config. Require SPONSOR_PAYER scope on the resolved actor.
   • In every mode, reject the transaction if the resolved payer_auth_cost exceeds MAX_AUTHENTICATION_GAS, so total gas stays within effective_gas_limit = gas_limit + MAX_AUTHENTICATION_GAS (see Intrinsic Gas).
7. Verify nonce, payer ETH balance, and validity bounds. The transaction’s validity window and the resolved actor’s liveness are all checked and MUST hold: after normalizing valid_after/valid_before to milliseconds (see Timestamp Normalization), the transaction is valid only when valid_after == 0 || valid_after <= block.timestamp * 1000 and valid_before == 0 || block.timestamp * 1000 <= valid_before, and the resolved actor’s expiry (seconds) is unlapsed (expiry == 0 || block.timestamp <= expiry, per Actor Expiry and step 3). Any bound violated rejects the transaction. The transaction window is in milliseconds while on-chain actor/lock expiries are in seconds, a deliberate split that requires no sub-second timekeeping (see Field Definitions). Regardless of nonce mode, nodes MAY also reject a transaction whose valid_before is too near to be reliably included, and MAY reject (rather than hold) one whose valid_after is not yet active.
   • 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 valid_before, and reject if valid_before is farther out than NONCE_FREE_EXPIRY_WINDOW (the chain parameter bounded by REPLAY_BUFFER_CAPACITY, see Nonce-Free Mode). Deduplicate by the Replay Identifier (replay_id), not the full transaction hash.
8. Mempool threshold: gas payer’s pending count below node-configured limits.
9. Apply Mempool Replacement rules: for standard and 2D transactions (nonce_key != NONCE_KEY_MAX), when a pending transaction from the same sender shares this transaction’s (nonce_key, nonce_sequence); for nonce-free transactions (nonce_key == NONCE_KEY_MAX), when a pending transaction from the same sender shares this transaction’s replay_id.

Nodes recognize the enshrined canonical authenticator set and authenticate any other accepted authenticator via a single STATICCALL bounded by MAX_AUTHENTICATION_GAS, per the Canonical Authenticator Set rules.

Nodes MAY apply higher pending transaction rate limits based on account lock state. A node can cheaply read the packed account-state slot and grant the higher tier when the account is LOCKED, has no pending unlock (UNLOCK_INITIATED clear), and carries an unlock_delay at or above the node’s threshold (e.g. ≥ 6 hours) — the actor set is then frozen for at least that window:

• Locked sender: A locked sender account has a stable signature if combined with a stateless authenticator. Nodes can safely allow a higher sender rate.
• Locked payer with trusted bytecode: A locked payer account whose bytecode is recognized (e.g. a canonical account implementation that 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, supporting high-throughput payer/sponsor services.

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 admin EOA-actor delegation authority (see Delegation Entry).
2. ETH gas precharge from payer (sender for self-pay). The payer is precharged for the whole transaction, effective_gas_limit × max_fee_per_gas, which reserves gas_limit plus payer_auth_cost (payer authentication execution and its serialized payer_auth bytes, both metered outside gas_limit; see Intrinsic Gas). The block reserves effective_gas_limit against its gas target for the same reason. Transaction is invalid if the payer’s balance cannot cover the precharge.
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. A delegation entry that clears the indicator (target = address(0)) returns the account to code-less state, but auto-delegation re-applies on its next transaction: a code-less account cannot permanently opt out of auto-delegation without placing non-delegation bytecode (e.g. via a create entry).
5. Process account_changes entries in order (see Execution (Account Changes)).
6. Set the authenticated actorId on the Transaction Context precompile. The static sender-signed fields (sender, payer, calls, gas_limit) are already exposed from validation onward; actorId becomes readable from this point (execution).
7. Execute calls per Call Execution semantics.

Settlement charges the payer for gas actually used, sender-intrinsic gas plus executed calls (together bounded by gas_limit) plus payer_auth_cost (payer authentication execution and its serialized payer_auth bytes), and refunds the remainder of the precharge. Because payer_auth_cost is metered outside gas_limit, it is charged in full and is never part of the refundable unused-gas_limit amount; only the unspent portion of gas_limit is refunded to the payer. For step 5, the protocol SHOULD inject log entries into the transaction receipt (e.g., ActorAuthorized, ActorRevoked, AccountCreated, DelegationApplied) matching the events defined in the IKeystore 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. status == 0 does not imply “no state change.” Committed earlier phases (the sponsor pattern relies on this), auto-delegation, applied account_changes, nonce consumption, and gas payment all persist through a later phase revert. Consumers MUST NOT treat a failed AA receipt as a no-op. gasUsed includes payer_auth_cost (see Intrinsic Gas).
• 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.

eth_estimateGas / eth_call: Accept the AA transaction fields (sender, nonceKey, accountChanges, calls, validAfter, validBefore, metadata, payer, senderAuth, payerAuth) alongside the standard request object and price the request as an AA_TX_TYPE transaction. Because authentication gas is determined by the auth blob’s shape rather than a valid signature (see Intrinsic Gas), the request is priced from an unsigned representative blob; no signature is produced or verified. The sender is taken from sender or the standard from (equivalently) and if both are present they MUST be equal.

Constants

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 Authenticator Contracts?

Enables signature-algorithm extension through authenticator contracts. The authenticator returns the actorId rather than accepting it as input, so the protocol never needs algorithm-specific logic. All authenticators share a single authenticate(hash, data) interface with no type-based dispatch. Actor scope and policy provide protocol-enforced role separation without authenticator cooperation.

Why a Canonical Authenticator Set?

Without a required authenticator set, nodes could diverge on which signature algorithms they accept beyond K1_AUTHENTICATOR. 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 where wallets that use canonical authenticators 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 Two Adoption Profiles?

On a base layer the gas schedule and the set of consensus-relevant checks are the specification: if two nodes could disagree on the intrinsic-gas schedule, on which authenticators are accepted, or on how they are priced, they could disagree on block validity, a chain-split risk. Leaving those knobs “chain MAY choose” turns one specification into a family of subtly different protocols: acceptable for an L2 or application chain, but not for L1.

The two adoption profiles make that split explicit rather than implicit. The L1 profile enshrines every consensus-critical parameter (the gas schedule, the canonical authenticator set, and the pricing of enshrined authenticators), so that two independent implementations agreeing on this document produce identical block validity, and changing any of them requires a hard fork rather than an off-chain configuration or companion-ERC rollout. The L2 profile keeps the flexibility that lets a faster-moving chain track a local cost model or a future EVM repricing, at the cost of cross-chain uniformity. Because transaction semantics are identical across both, a wallet targeting the canonical set and the recommended schedule is portable regardless of which profile a chain runs.

Why Actor Policies?

Session keys often need narrow authority: only this token, only this much per day, only this action. POLICY makes gated initiation a first-class grant, distinct from ungated SENDER: the key may originate transactions, but only to a single call target, bound to a signed opaque commitment. The protocol’s only policy responsibility is the single-target gate plus storing the commitment. Allowing POLICY | SELF_PAYER lets a session key self-pay; note this exposes the account’s full ETH balance to gas spend (see Payer Modes).

Why a Local Epoch?

Session keys and just-in-time (JIT) authorizations want two things that pull against a shared counter: they should be usable in any order (no coordination), and the account should be able to cancel any it has handed out that have not yet landed. A single monotonic local_sequence gives ordering but forces every signature to burn the next slot, so parallel keys contend and a stale signature can still land later. Splitting the local word into local_epoch || local_sequence separates the two concerns: sequenced changes still consume local_sequence for ordered, replay-once semantics, while an epoch bump is a single blunt “cancel everything outstanding on the local channel” that resets the counter and invalidates every not-yet-landed local signature at the prior epoch (StaleEpoch). Crucially it cancels signatures, not authority — actors from landed batches survive — so bumping the epoch is cheap to reason about and cannot brick a live actor set. That is what makes the unsequenced/JIT mode (UNSEQUENCED) safe: a JIT batch is intentionally replayable within its epoch, and durable retirement is just an epoch bump batched with the reducing change (see Epoch System).

Why No Public Key Storage?

Authenticators receive the public key (or full credential) in transaction calldata and recover the actorId from it, rather than the protocol storing keys onchain. This keeps per-actor state to a single actor_config SLOAD regardless of key size, which matters most for large post-quantum credentials: storing them would add permanent state growth of tens of slots per actor. Calldata is also cheaper than cold storage for material read once per transaction — on the order of 2,048 vs 6,300 gas for a P256 key and 21,000 vs 88,000 gas for a PQ key — so the calldata-plus-recovery model is both smaller and cheaper than an onchain key registry.

Why Not Reject Scope Combinations at Write Time?

The Keystore contract is a single immutable CREATE2 deployment, so it cannot know which grants or combinations future forks will define; rejecting combinations at write time would freeze today’s rules into unupgradeable code. AuthorizeActor therefore stores scope verbatim and validates only timeless structure (admin signer, reserved-bytes-zero, well-formed policyData). Combination semantics are checked at the point of use by whichever context reads the scope — protocol validation for the transaction paths, and account-level ERC-1271 signing (operational) for the signing path (see Signature Verification) — so an unsatisfiable combo is simply inert.

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 a short-lived validity window (valid_before) and node-level deduplication by the fee- and signature-invariant Replay Identifier. This is useful for operations where nonce ordering coordination is undesirable. Reserving NONCE_KEY_MAX as the sentinel permanently removes one channel from the 2^256-wide nonce space, which is immaterial in practice; NONCE_KEY_MAX is always nonce-free and is never a sequenced channel, even for an actor holding NONCE scope.

Why Account Lock?

Locked accounts have a frozen actor set, so the primary state that can invalidate a validated transaction is nonce consumption. This can enable nodes to cache actor state and apply higher mempool rate limits (see Mempool Acceptance). A locked payer running a canonical account implementation that restricts ETH movement while locked further bounds balance changes to gas fees, letting nodes raise payer rate limits, useful for high-throughput payer/sponsor services.

Why CREATE2 for Account Creation?

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

1. Deterministic addresses: Same user_salt + code + initial_actors 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_actors in the salt prevents attackers from deploying with different actors (see Create Entry)

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 senders authenticated via the native secp256k1 path (EOA path or K1_AUTHENTICATOR) with actorId == bytes32(uint256(uint160(sender))), so that code delegation remains portable across non-8130 chains via standard EIP-7702 transactions (a non-secp256k1 self authenticator does not qualify, even if it returns the self-actorId). Eventually this can be expanded to all authenticator types, not just K1 EOAs.

External Account Factories

Account creation, import, signed actor changes, and locking are ordinary EVM entry points on the Keystore contract, so external factories can compose them to mint accounts into a desired end state. This is always possible in EVM but is not available on the 8130 transaction path.

Non-normative future work: once EIP-7819 is adopted, the protocol could be extended with a single canonical external factory. The create entry would emit an EIP-7702 delegation prefix and deploy the account from that factory, which uses Keystore contract state to check the signature and upgrade, extending the delegation account change to all authenticator types rather than the native secp256k1 EOA only as today.

Why a Metadata Field?

Attribution and annotation data (builder/app codes, payment references, off-chain commitments) traditionally ride as a trailing “data suffix” on tx.input. The structured calls array has no such trailing location, so a dedicated optional metadata field gives this data a first-class, signed home without overloading a call. Binding it into both signature payloads makes it tamper-evident.

Why No Value in Calls?

The protocol dispatches each call directly to the specified to address with msg.sender = sender. Since every account has wallet bytecode (via 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 a Transaction Context Precompile?

Transaction context (sender, payer, calls, gas_limit) is immutable transaction metadata; it never changes during execution, and actorId is set after validation and available during execution only. A precompile is the natural fit: it reads directly from the client’s in-memory transaction struct (no journaling or rollback tracking), consumers pull only what they need (policies read actorId for per-actor limits, accounts inspect payer, a sponsoring payer authenticator reads calls and gas_limit at validation time to decide onchain whether to pay), and new context fields are added as new functions without changing IAuthenticator or existing authenticators. Exposing calls and gas_limit from validation is what lets sponsorship be an onchain decision rather than an off-chain co-signing step.

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 actors. 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

The actor_config layout (authenticator ‖ expiry ‖ scope ‖ reserved, with the scope-bit assignment and the reserved bytes acting as a version gate) and the address-derivation commitment are defined by this specification; the full contract ABI surface (typehashes, events, and function signatures such as importAccount/applySignedAccountChanges) is defined in the canonical repository (src/Keystore.sol). Because 8130 has no prior deployment, there is no live actor state written under an earlier format to migrate; the formats here are authoritative from first deployment.

Reference Implementation

IKeystore

The Keystore contract is the canonical ABI surface. Its full source — exact storage packing, typehashes, event ABIs, and function bodies — lives in the canonical contracts repository (the base organization’s EIP-8130 repository on GitHub, src/Keystore.sol) and is authoritative. The sketch below mirrors only the protocol-relevant shape; consult the repository for the complete interface.

interface IKeystore {
    // Packed account state (see Account Lock). The signed local word is localEpoch(high 32) || localSequence(low 32).
    struct ChangeSequences {
        uint64 multichain;    // chain_id 0 channel; a plain monotonic counter
        uint32 localEpoch;    // local channel epoch; IncrementLocalEpoch bumps it and resets localSequence to 0
        uint32 localSequence; // local channel counter; low half of the signed local word
    }

    struct ActorConfig {
        address authenticator;
        uint48 expiry;        // Unix seconds; 0 = no expiry. Actor invalid once block.timestamp > expiry
        uint16 scope;         // grants bitmask; 0x0000 = unrestricted (admin). See Actor Scope
    }

    // Actor used for account creation and import. expiry is NOT expressible here (initial actors are always
    // non-expiring; add expiry post-deployment via a config change). policyData: empty unless POLICY, then manager[20] || commitment[32].
    struct InitialActor {
        bytes32 actorId;
        address authenticator;
        uint16 scope;
        bytes policyData;
    }

    enum AccountChangeChannel { Local, Multichain }
    enum ChangeType { AuthorizeActor, RevokeActor, IncrementLocalEpoch, Lock, Unlock }
    // Leading byte of a signature envelope: Local (0x01) binds block.chainid, Multichain (0x02) binds chainId 0.
    enum SignatureType { Invalid, Local, Multichain }

    struct AccountChange {
        ChangeType changeType;
        bytes payload;        // AuthorizeActor: abi.encode(bytes32 actorId, ActorConfig, bytes policyData);
                              // RevokeActor: abi.encode(bytes32 actorId); Lock: abi.encode(uint16 unlockDelay); others empty
    }

    struct SignedAccountChanges {
        AccountChangeChannel channel;
        uint64 sequence;      // Local: localEpoch || localSequence; Multichain: monotonic counter
        AccountChange[] changes;
        bytes signature;      // admin (scope == 0x00): authenticator || data
    }

    uint32 constant UNSEQUENCED = type(uint32).max; // JIT sentinel for the local low half

    event ActorAuthorized(address indexed account, bytes32 indexed actorId, bytes actorData);
    event ActorRevoked(address indexed account, bytes32 indexed actorId);
    event AccountCreated(address indexed account, bytes32 userSalt, bytes32 codeHash);
    event AccountImported(address indexed account);
    event LocalEpochIncremented(address indexed account, uint32 localEpoch);
    // Protocol-injected receipt log for successful EIP-8130 delegation updates (not emitted in EVM).
    event DelegationApplied(address indexed account, address target);
    event AccountLocked(address indexed account, uint16 unlockDelay);
    event AccountUnlockInitiated(address indexed account, uint48 unlocksAt);

    // Account creation (factory) and counterfactual address preview.
    function createAccount(bytes32 userSalt, bytes calldata bytecode, InitialActor[] calldata initialActors) external returns (address);
    function computeAddress(bytes32 userSalt, bytes calldata bytecode, InitialActor[] calldata initialActors) external view returns (address);

    // Import an existing account (ERC-1271). chainId: 0 = multichain; else MUST equal block.chainid.
    function importAccount(address account, uint256 chainId, InitialActor[] calldata initialActors, bytes calldata signature) external;

    // Single signed entry point for all account changes (authorize/revoke actor, increment epoch, lock/unlock).
    function applySignedAccountChanges(address account, SignedAccountChanges calldata changes) external;

    // Typed-envelope message signing (see Signature Verification). Returns the verified signer and its authority
    // — the "who signed" + granular authority that plain ERC-1271 lacks. auth = sigType(1) || authenticator(20) || data.
    // 8130 accounts implement ERC-1271 isValidSignature on top of this, gating on operational scope.
    function validateSignature(address account, bytes32 hash, bytes calldata auth) external view returns (bytes32 actorId, uint16 scope);
    // Envelope digest a signer signs: keccak256(SIGNED_MESSAGE_TYPEHASH, account, chainId, hash). chainId 0 = all chains.
    function replaySafeHash(address account, uint256 chainId, bytes32 hash) external pure returns (bytes32);
    function envelopeDigest(SignatureType sigType, address account, bytes32 hash) external view returns (bytes32);
    // Lower-level: authenticate an actor over a raw digest (no envelope). Used by off-8130 (e.g. ERC-4337) consumers.
    function authenticateActor(address account, bytes32 hash, bytes calldata auth) external view returns (bytes32 actorId, uint16 scope);

    // Storage views (see the canonical repository for the complete set).
    function getActorConfig(address account, bytes32 actorId) external view returns (ActorConfig memory);
    function getActor(address account, bytes32 actorId) external view returns (ActorConfig memory config, address policyManager, bytes32 policyCommitment);
    function getChangeSequences(address account) external view returns (ChangeSequences memory);
    function getLockStatus(address account) external view returns (bool locked, bool hasInitiatedUnlock, uint48 unlocksAt, uint16 unlockDelay);
    function isContractEstablished(address account) external view returns (bool); // keystore-established, not a proven address key
}

IAuthenticator

interface IAuthenticator {
    function authenticate(
        bytes32 hash,
        bytes calldata data
    ) external view returns (bytes32 actorId);
}

ITransactionContext (Precompile)

interface ITransactionContext {
    struct Call {
        address to;
        bytes data;
    }

    function getTransactionSender() external view returns (address);
    function getTransactionPayer() external view returns (address);
    function getTransactionCalls() external view returns (Call[][] memory);
    function getTransactionGasLimit() external view returns (uint256);
    function getTransactionSenderActorId() external view returns (bytes32);
}

Read-only. Gas is charged as a base cost plus 3 gas per 32 bytes of returned data. getTransactionSender, getTransactionPayer, getTransactionCalls, and getTransactionGasLimit read static sender-signed fields and are available during both authentication and call execution; getTransactionSenderActorId is available during execution only (the actor is resolved after authentication).

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. Gas is charged as a base cost plus a cold SLOAD (2,100 gas) for the first read of a given (account, nonceKey) pair in the transaction, or a warm SLOAD (100 gas) for subsequent reads of the same slot, consistent with EIP-2929 access rules.

Security Considerations

Validation Surface: For canonical authenticators, invalidators are actor_config changes and nonce consumption. Canonical authenticators are pure functions of (hash, data) and the resolved actor_config, so a validated transaction is invalidated only by those two events, keeping the mempool invalidator set small and enumerable (this is why a canonical-only acceptance policy suits high-throughput chains).

A permissive acceptance policy (see Adoption Profiles) deliberately widens this surface: accepting non-canonical authenticators on the transaction path means accepting authenticators that may read mutable state, so an accepted transaction can be invalidated by state beyond actor_config and the nonce, and a node MUST run additional mempool-validation machinery to bound that (for example, tracking the state an authenticator touches and re-validating on change). A base layer typically wants this larger surface; the execution cost is already bounded per call by MAX_AUTHENTICATION_GAS and each authentication is a single STATICCALL returning an actorId, so the extra machinery is about invalidation tracking, not unbounded execution. 8130 makes this an opt-in, allow-only-what-you-need extension rather than an all-or-nothing choice: the declared-authenticator model lets a chain enshrine the pure canonical set and admit specific, focused stateful authenticators only where a use case needs them (and a chain that needs none runs no such machinery at all), instead of having to admit arbitrary wallet-defined validation code wholesale.

Replay Protection: Transactions include chain_id, 2D nonce (nonce_key, nonce_sequence), and a validity window (valid_after, valid_before). For standard and 2D transactions (nonce_key != NONCE_KEY_MAX), replay protection and deduplication are provided by the nonce sequence: inclusion increments (sender, nonce_key), so a given (sender, nonce_key, nonce_sequence) can be included at most once. replay_id does not apply to these transactions. For NONCE_KEY_MAX (nonce-free mode), there is no nonce slot, so replay protection relies on the short-lived valid_before bound and deduplication by the fee- and signature-invariant Replay Identifier (replay_id); the chain enforces a tight window (NONCE_FREE_EXPIRY_WINDOW) to bound it, and block builders MUST NOT include two transactions with the same (sender, replay_id) (see Mempool Replacement).

The full transaction hash MUST NOT be used for nonce-free deduplication or mempool replacement. The transaction hash commits to fee fields (max_fee_per_gas, max_priority_fee_per_gas, gas_limit) and to sender_auth and payer_auth (the authorization blobs), all of which replay_id excludes. Keying on the transaction hash would allow trivial duplication of a single logical transaction, or would treat an intentional fee bump as an unrelated transaction:

• Fee bumps: a legitimate replacement raising max_priority_fee_per_gas (or max_fee_per_gas) changes the transaction hash while leaving the effects, calls, metadata, validity window (valid_after, valid_before), and payer identical. replay_id is unaffected, so the bump is recognized as a replacement of the same logical transaction rather than a distinct one; the bumped transaction still requires a fresh payer_auth when sponsored, since payer_auth commits to the fee fields.
• Re-signed payer_auth: the sender signs over the payer address but not the payer’s signature bytes, so a sponsor can produce a different payer_auth for the same sender body, yielding a different transaction hash for the same logical transaction.
• sender_auth non-determinism: ECDSA signing is randomized (a fresh nonce k produces a different valid (r, s) for the same message and key) and signatures are additionally malleable, so the same key can produce multiple distinct-but-valid sender_auth values for one transaction body. Each recovers the same sender yet yields a different transaction hash.

All three cases resolve to the same replay_id (fee bumps included, since replay_id excludes the fee fields), so deduplicating and replacing on it collapses them to a single mempool slot and, ultimately, a single includable transaction. The validity window cannot be extended via a fee-bump replacement: valid_after and valid_before are part of replay_id, so changing either produces a different replay_id and a new logical transaction, not a replacement of the old one which must independently satisfy nonce/sequence and mempool acceptance rules.

Actor Scope and Policy: Scope grants are protocol-enforced after authenticator execution during validation (fail closed). The policy gate is protocol-enforced during execution (ActorPolicyViolation). See Actor Scope and Actor Policies.

Policy Target as Trust Anchor: For a policy-bearing actor, the resolved target is fully trusted to enforce the committed limits; the key can only reach that target, which decides what happens next. A buggy or malicious manager can do anything its own authority over the account allows. Accounts SHOULD point restricted keys only at audited managers and treat installing one with the same care as granting that contract authority over the account. A manager (and any policy it enforces) SHOULD be non-upgradeable: an upgradeable manager lets whoever controls the upgrade rewrite enforcement, which is equivalent to granting that party root access over everything the manager can do for the account. The committed parameters and any target-held state are the target’s own authorization surface; checking that keccak256(params) matches the stored commitment is the target’s responsibility, not the protocol’s. How the target obtains authority to act for the account is out of scope for this specification.

Policy State on Revocation: revokeActor clears actor_config, policy_commitment, and policy_manager (all keyed by (account, actorId)), which immediately stops the key from reaching its target; there are no per-target protocol entries to enumerate or resurrect, and storage is fully reclaimed. Any parameters a target keeps in its own storage are not protocol state and are not auto-cleared; wallets uninstall them through the target when retiring a key, and an expiry bounds the window during which a not-yet-uninstalled key could otherwise be used.

Actor Management: Config change authorization requires the authorizing actor be admin (scope == 0x00). The EOA actor is implicitly authorized with unrestricted (admin) scope; revocable via portable config change. All actor modification paths are blocked when the account is locked.

Actor Expiry: Prefer non-expiring admins and apply expiry only to restricted keys; a sole expiring admin bricks the account and breaks cross-chain reconstruction (see Actor Expiry).

Local Epoch and Outstanding Signatures: IncrementLocalEpoch cancels every unlanded local signature at the prior epoch (StaleEpoch), including unsequenced/JIT batches; it does not revoke live actors or affect the multichain channel (see Epoch System). Because an unsequenced (JIT) batch is replayable within its epoch, wallets MUST treat epoch increment — not mere non-inclusion — as the durable retirement of a JIT authorization, batching the reducing RevokeActor/AuthorizeActor with IncrementLocalEpoch. Since the epoch does not walk authorizer lineage, an actor added by a landed batch survives later epoch bumps and must be removed with an explicit RevokeActor.

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 K1_AUTHENTICATOR, and the account’s DEFAULT_EOA_REVOKED flag is unset. Generic authenticator contracts MUST NOT satisfy the implicit branch even if they return bytes32(uint256(uint160(sender))), otherwise an arbitrary authenticator could authenticate as any EOA whose implicit actor slot has never been written.

actorId Binding: The protocol checks that the authenticator’s returned actorId maps back to that authenticator in actor_config, preventing a malicious authenticator from claiming control of another authenticator’s actors.

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-scoped actors cannot be used as sender_auth, and vice versa; self-pay requires SELF_PAYER while sponsorship requires SPONSOR_PAYER, so a self-paying session key cannot be repurposed as an unbounded sponsor. 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 authenticator, is validated under SPONSOR_PAYER scope, and is metered separately so the payer’s authenticator choice cannot reduce gas available to calls or otherwise affect execution behavior.

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-actor path is unaffected because sender is non-empty by definition.

Account Creation Security: initial_actors (actorId, authenticator, scope, and policyData; expiry is not expressible at create, per Address Derivation) are salt-committed, preventing front-running of actor assignment. Wallet bytecode should be inert when uninitialized as it can be permissionlessly deployed. The create entry applies only to addresses that satisfy CREATE2 freshness. Without the nonce check, a create entry could be replayed against an EOA that has transaction history at the counterfactual address.

Copyright

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Citation

Please cite this document as:

Chris Hunter (@chunter-cb) <chris.hunter@coinbase.com>, "EIP-8130: Account Abstraction by Account Configuration [DRAFT]," Ethereum Improvement Proposals, no. 8130, October 2025. Available: https://eips.ethereum.org/EIPS/eip-8130.