> For the complete documentation index, see [llms.txt](https://docs.phase.cash/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.phase.cash/proxies/overview.md).

# Overview

The blockchain is immutable, and once a contract is deployed, you cannot change its code. This works fine for many applications that can deploy a new contract for every new version they create. Sadly, this isn't adequate for Phase's needs as a lot of info is stored in the contract itself and cannot be moved from contract to contract.\
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We use proxies for almost everything in Phase to get around this issue. A proxy allows us to run any target contract code in the current contract's storage. This means we can deploy a contract once and upgrade its code in the future.\
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This does have its downside, though, as all the code is upgradable, We have to safeguard and secure the protocol to a point so that a bad actor cannot change code instantly. One contract owned by a timelock will control all the proxies inside Phase. With this, every upgrade and code change has to go through a period where everyone can see them and act accordingly.\
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Phase uses the following proxy patterns in its systems:

* [Admin Upgradeable Proxy](/proxies/admin-upgradeable-proxy.md)
* [Storage Upgradeable Proxy](/proxies/storage-upgradeable-proxy.md)
* [Diamonds](/proxies/diamonds.md)