---
eip: 2970
title: IS_STATIC opcode
author: Vitalik Buterin (@vbuterin)
discussions-to: https://ethereum-magicians.org/t/is-static-opcode-useful-for-aa/4609
status: Stagnant
type: Standards Track
category: Core
created: 2020-09-13
---

## Simple Summary

Add a `IS_STATIC (0x4A)` opcode that pushes `1` if the current context is static (ie. the execution is in a `STATICCALL` or a descendant thereof, so state-changing operations are not possible), and `0` if it is not.

## Abstract

## Motivation

The main intended use case is to allow account abstraction (EIP 2938) to be extended so that accounts can allow static calls from the outside (which are harmless to AA's security model) but not state-changing calls.

## Specification

Add a `IS_STATIC (0x4A)` opcode that pushes `1` if the current context is static (ie. the execution is in a `STATICCALL` or a descendant thereof, so state-changing operations are not possible), and `0` if it is not.

## Rationale

Determining staticness is already possibly using the following hacky technique: make a `CALL` with limited gas, and inside that `CALL` issue one `LOG` and exit. If the context is static, the `CALL` would fail and leave a 0 on the stack; if the context is non-static, the `CALL` would succeed. However, this technique is fragile against changes to gas costs, and is needlessly wasteful. Hence, the status quo neither allows a reasonably effective way of determining whether or not the context is static, nor provides any kind of invariant that executions that do not fail outright will execute the same way in a static and non-static context. This EIP provides a cleaner way of determining staticness.

## Backwards Compatibility

TBD

## Security Considerations

TBD

## Copyright
Copyright and related rights waived via [CC0](../LICENSE.md).