> ## Documentation Index > Fetch the complete documentation index at: https://docs.blockops.network/llms.txt > Use this file to discover all available pages before exploring further. # Rate limits & error codes > Requests-per-second limits for public and private endpoints, and the error codes the API returns. ### Blockchain API Rate Limiting **What is Rate Limiting?** Rate limiting is a mechanism that controls the number of API requests your application can make to the Blockops RPC nodes within a specific time frame (usually measured in Requests Per Second, or RPS). ### Request limits The Blockchain API has a limit on the number of requests that can be made to each API endpoint. The limit depends on whether you are using the public rpc endpoint or an API key. The number of requests you can make before reaching the limit or being rate-limited will vary based on your chosen method of access. * Public API endpoint - 50 requests/second * Private API endpoint - 1000 requests/second Typically only aggressive use should experience rate limiting. Customers running into rate limits are encouraged to [contact us](/get-started/support). We'll work with you to determine how best to avoid rate limits. *(Note: You can monitor your real-time request volume and remaining limits directly from your Project Dashboard.).* **API Error Codes** The following error codes are frequently returned by our Blockchain API. However, it's important to note that this list doesn't include errors related to network-specific business logic. | Code | Message | Explanation | | ---- | --------------------- | ------------------------------------------------------------------------ | | 401 | Unauthorized Access | Invalid API key or no API key found in request | | 404 | No route matched | This indicates the specific page you are trying to visit is non-existent | | 429 | Too Many Requests | You have exceeded your request limit. | | 500 | Internal Server Error | Something went wrong inside our servers. Contact support. |