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

# Error Handling

> Typed errors for clean exception handling

`near-kit` converts cryptic RPC JSON errors into typed JavaScript Error classes. You can `catch` these errors and handle them logically.

## The Error Hierarchy

All errors extend `NearError`. You can check for specific types using `instanceof`.

```typescript theme={null}
import {
  FunctionCallError,
  AccountDoesNotExistError,
  NetworkError,
} from "near-kit"

try {
  await near.call("contract.near", "method", {})
} catch (e) {
  if (e instanceof FunctionCallError) {
    // The contract logic failed
    console.log("Panic:", e.panic)
    console.log("Logs:", e.logs)
  } else if (e instanceof AccountDoesNotExistError) {
    // The account isn't real
    console.log(`Account ${e.accountId} not found`)
  } else if (e instanceof NetworkError) {
    // RPC is down
    if (e.retryable) {
      // You might want to try again
    }
  }
}
```

## Error Types

<AccordionGroup>
  <Accordion title="FunctionCallError" icon="code">
    Thrown when a smart contract call fails (panics or runs out of gas).

    **Properties:**

    * `panic`: The panic message from the contract
    * `logs`: Any logs emitted before the failure

    ```typescript theme={null}
    if (e instanceof FunctionCallError) {
      console.log("Contract panicked:", e.panic)
    }
    ```
  </Accordion>

  <Accordion title="AccountDoesNotExistError" icon="user-slash">
    Thrown when trying to interact with an account that doesn't exist.

    **Properties:**

    * `accountId`: The account that wasn't found

    ```typescript theme={null}
    if (e instanceof AccountDoesNotExistError) {
      console.log(`Account ${e.accountId} not found`)
    }
    ```
  </Accordion>

  <Accordion title="NetworkError" icon="wifi-slash">
    Thrown when there's a network or RPC issue.

    **Properties:**

    * `retryable`: Whether it's safe to retry
    * `statusCode`: HTTP status code (if applicable)

    ```typescript theme={null}
    if (e instanceof NetworkError && e.retryable) {
      // Wait and try again
    }
    ```
  </Accordion>

  <Accordion title="InsufficientBalanceError" icon="wallet">
    Thrown when an account doesn't have enough NEAR for the operation.

    **Properties:**

    * `accountId`: The account with insufficient balance
    * `required`: Amount needed
    * `available`: Amount available
  </Accordion>

  <Accordion title="InvalidNonceError" icon="rotate">
    Thrown when a transaction's nonce is stale (usually from concurrent transactions).

    <Tip>
      Use `RotatingKeyStore` to avoid nonce issues in high-concurrency scenarios.
    </Tip>
  </Accordion>
</AccordionGroup>

## Panic Messages

When a contract fails, the most important info is the **Panic Message**. `near-kit` extracts this from the deep RPC response and puts it right on `error.panic`.

Common panics include:

* `ERR_NOT_ENOUGH_FUNDS`
* `ERR_INVALID_ARGUMENT`
* `Smart contract panicked: ...`

Use this string to debug or show user-friendly error messages in your UI.