# Reading foreign state

This example demonstrates the verification of the **total supply of USDC on Optimism** from **Gnosis Chain** using a storage proof. The proof will be fetched via HashiAPI and fed to a contract deployed on **Gnosis Chain**. The contract will use **HashiProver** to validate the proof against the last Optimism reported block header stored in Hashi.

<figure><img src="/files/oUOWCVH6w8pFLaUb8rxk" alt=""><figcaption></figcaption></figure>


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://crosschain-alliance.gitbook.io/hashi/getting-started/quick-start/reading-foreign-state.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.