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

# FAQ

> Frequently asked questions about NEAR Playground

## General

<AccordionGroup>
  <Accordion title="Is NEAR Playground free?">
    Yes! NEAR Playground is completely free. Testnet deployments cost nothing - we fund the accounts for you.

    Mainnet deployments require your own NEAR tokens.
  </Accordion>

  <Accordion title="Do I need to install anything?">
    No. NEAR Playground runs entirely in your browser. Just visit [nearplay.app](https://nearplay.app) and start coding.
  </Accordion>

  <Accordion title="Is my code saved?">
    Yes. Your code auto-saves as you type and is stored in your account. You can close the browser and come back later.
  </Accordion>

  <Accordion title="Can I share my projects?">
    Yes. Each project has a shareable link. Others can view your code and deployed contracts.
  </Accordion>
</AccordionGroup>

## Compilation

<AccordionGroup>
  <Accordion title="Why is compilation slow?">
    First compilation takes longer because dependencies need to be downloaded and cached. Subsequent compilations are faster.
  </Accordion>

  <Accordion title="What Rust version is used?">
    We use the latest stable Rust with `cargo-near` for NEAR-optimized builds.
  </Accordion>

  <Accordion title="Can I use external crates?">
    Currently, NEAR Playground supports single-file contracts with `near-sdk`. For complex projects with multiple dependencies, use a local development environment.
  </Accordion>

  <Accordion title="My contract won't compile">
    Common issues:

    * Missing semicolons or brackets
    * Wrong `near-sdk` macro usage
    * Type mismatches

    Check the error messages in the output panel - they show the exact line and issue.
  </Accordion>
</AccordionGroup>

## Deployment

<AccordionGroup>
  <Accordion title="What's the difference between Playground and Wallet mode?">
    **Playground mode**: Free testnet deployment. We create and fund the account for you.

    **Wallet mode**: Mainnet deployment with your own wallet (Meteor). Uses real NEAR tokens.
  </Accordion>

  <Accordion title="Can I deploy to testnet with my wallet?">
    No. Meteor wallet only supports mainnet. For testnet, use Playground mode - it's free and has the same functionality.
  </Accordion>

  <Accordion title="How much does mainnet deployment cost?">
    Roughly 0.1 NEAR per 10KB of contract size, plus \~0.01 NEAR for gas. A typical 150KB contract costs about 1.5 NEAR.
  </Accordion>

  <Accordion title="Can I redeploy to the same address?">
    In Playground mode, each deployment creates a new address. In Wallet mode, you deploy to your own account and can update it.
  </Accordion>
</AccordionGroup>

## Contract Interface

<AccordionGroup>
  <Accordion title="Why do view methods show 'undefined'?">
    The method might be returning `()` (unit type) instead of a value. Make sure your view method has a return type.
  </Accordion>

  <Accordion title="My call method isn't changing state">
    Make sure your method takes `&mut self` instead of `&self`. Only mutable methods can change state.
  </Accordion>

  <Accordion title="How do I pass complex arguments?">
    For structs or vectors, use JSON format in the input field:

    ```json theme={null}
    {"name": "Alice", "age": 25}
    ```
  </Accordion>
</AccordionGroup>

## Troubleshooting

<AccordionGroup>
  <Accordion title="The page is blank or not loading">
    * Clear your browser cache
    * Try a different browser (Chrome or Firefox recommended)
    * Disable browser extensions
  </Accordion>

  <Accordion title="My wallet won't connect">
    * Make sure your wallet is unlocked
    * Try refreshing the page
    * Check if popup blockers are preventing the wallet window
  </Accordion>

  <Accordion title="Deployment is stuck">
    Deployments usually complete in 5-10 seconds. If stuck:

    * Check your internet connection
    * Try refreshing and deploying again
  </Accordion>
</AccordionGroup>