# Optimism Error Codes

> Breakdown of error codes on Optimism and how to handle them

> For the complete documentation index, see [llms.txt](/docs/llms.txt).

## `429` Errors

| Error Code | Error Message                                                                                                                                                                                                                                                                                  | Solution                                                                                                                                                                                                                                                                                                                                                   |
| ---------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `429`      | `Your app has exceeded its compute units per second capacity. If you have retries enabled, you can safely ignore this message. If not, check out <https://alchemy.com/docs/reference/throughput>`                                                                                              | We recommend [implementing retries](/docs/how-to-implement-retries) if you have not already. If you still experience issues you can increase your throughput limit by [upgrading your account](https://dashboard.alchemy.com/settings/billing).                                                                                                            |
| `429`      | `Your app has exceeded its concurrent requests capacity. If you have retries enabled, you can safely ignore this message. If not, check out <https://alchemy.com/docs/reference/throughput>. Reach out to us if you'd like to increase your limits: <https://alchemy.com/support>` | We recommend [implementing retries](/docs/how-to-implement-retries) if you have not already. If you still experience issues you can increase your throughput limit by [upgrading your account](https://dashboard.alchemy.com/settings/billing).                                                                                                            |
| `429`      | `Optimism sequencer sender global transaction limit exceeded. This limit is set at the chain level. To ensure your request goes through, we recommend implementing retries <https://alchemy.com/docs/how-to-implement-retries>`                                                           | This limit is set by Optimism at the sequencer level, see [Optimism API FAQ](/docs/reference/optimism-api-faq). We recommend [implementing retries](/docs/how-to-implement-retries) if you have not already. If you still experience issues you can increase your throughput limit by [upgrading your account](https://dashboard.alchemy.com/settings/billing). |
| `429`      | `Optimism sequencer global transaction limit exceeded This limit is set at the chain level. To ensure your request goes through, we recommend implementing retries <https://alchemy.com/docs/how-to-implement-retries>`                                                                   | This limit is set by Optimism at the sequencer level, see [Optimism API FAQ](/docs/reference/optimism-api-faq). We recommend [implementing retries](/docs/how-to-implement-retries) if you have not already. If you still experience issues you can increase your throughput limit by [upgrading your account](https://dashboard.alchemy.com/settings/billing). |
| `429`      | `eth_sendRawTransaction is a method with custom rate limits that you have exceeded. If you have retries enabled, you can safely ignore this message. If not, check out <https://alchemy.com/docs/reference/throughput>`                                                                        | We recommend [implementing retries](/docs/how-to-implement-retries) if you have not already. If you still experience issues you can increase your throughput limit by [upgrading your account](https://dashboard.alchemy.com/settings/billing).                                                                                                            |