Chainlink Functions Service Limits
| Item | Description | Limits |
|---|---|---|
| Supported languages | Supported language of the Source code that is submitted in the Chainlink Functions request | JavaScript compatible with Deno runtime and module imports |
| Maximum requests in flight | The maximum number of simultaneous Chainlink Functions requests that are not fulfilled yet by the DON | Limited by the effective balance |
| Maximum callback gas limit | The maximum amount of gas that you can set for Chainlink Functions to fulfill your callback function | 300,000 |
| Maximum subscriptions | Maximum subscriptions that you can create | unbounded |
| Maximum consumer contracts per subscription | The maximum number of consumer contracts that you can add to a subscription | 100 |
| Maximum duration of a request (Request fulfillment timeout) | The maximum duration of a request is the time allowed for processing a Chainlink Functions request from start to finish, covering all steps such as reading from the chain, executing code, and posting back on chain. If processing takes longer, the request times out, and no charges are applied to your subscription for that request. In such cases, the initially locked estimated request costs must be manually requested to be returned to your subscription balance | 5 minutes |
| Maximum request size | The maximum size of a Chainlink Request. This includes the source code, arguments, and secrets | 30 kilobytes |
| Maximum returned value size | The maximum size of the value that your Function can return | 256 bytes |
| Maximum source code execution time | The maximum amount of time that a source code can run | 10 seconds |
| Maximum memory allocated to the source code | The maximum amount of memory allocated to your source code during execution | 128 megabytes |
| HTTP - Maximum queries | The maximum number of HTTP requests that your source code can make | 5 |
| HTTP - query timeout | The maximum duration of an HTTP request before it times out | 9 seconds |
| HTTP - Maximum URL length | Length of the HTTP URL | 2048 characters |
| HTTP - Maximum request length | The maximum size of an HTTP request, including the request body and HTTP headers | 30 kilobytes |
| HTTP - Maximum response length | The maximum size of an HTTP response | 2 megabytes |
| Max size of request payload CBOR | The maximum size of an encoded request | 30 kilobytes |
| Don-hosted secrets - Maximum Time to live (TTL) | The maximum duration for which a secret hosted on a DON remains valid before it gets deleted |
|
| External module imports - Maximum size | The maximum size in MB that each imported module can be | 10 MB |
| External module imports - Number of imports | The maximum number of external module imports allowed in each request | 100 imports |