> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sophon.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Native Account Abstraction (Legacy Chain)

> Account abstraction in the Sophon v1 chain

<Warning>
  This page describes account abstraction in the legacy Sophon v1 chain. The chain
  is being wound down; see the [migration guide](/migration) for current actions.
</Warning>

Sophon v1 inherited native account abstraction from the ZK Stack. Unlike an
ERC-4337 overlay, the ZK Stack transaction model treated programmable accounts and
paymasters as protocol-level capabilities.

The legacy design supported:

* custom signature and authorization logic;
* multisignature and recovery patterns;
* application-specific transaction restrictions;
* paymasters that could sponsor gas or accept alternative fee tokens;
* a unified transaction flow for externally owned and smart-contract accounts.

This page is an architectural summary, not current deployment guidance. The separate
[Sophon Account](/sophon-account/intro) section documents the account SDK and
connectors that remain in this repository.