# Specs and Limits

Specs and limits to keep in mind while developing with UbiFunctions.

| Item                  | Description                                                                                                                                                                                                                     | Value                                                                |
| --------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------- |
| Supported libraries   | Libraries included in UbiFunctions' Python and NodeJS runtimes.                                                                                                                                                                 | [Supported libraries](https://dev.ubidots.com/ubifunctions/runtimes) |
| Code size             | The maximum code size for an UbiFunction.                                                                                                                                                                                       | 48 MB                                                                |
| Concurrent executions | The max number of activations of a single UbiFunction, that are either executing or queued for execution. This limit is fixed but can be increased upon request.                                                                | 1,000 concurrent executions                                          |
| Logs                  | The max size of an UbiFunction's log.                                                                                                                                                                                           | 10 MB                                                                |
| Memory                | The equivalent RAM memory of the computing resources used by the UbiFunction. Can be increased upon request.                                                                                                                    | 128 MB                                                               |
| Rate limit            | The max amount of activations that can be submitted per UbiFunction per minute. An API call exceeding this limit will receive an HTTP error code 429: TOO MANY REQUESTS. This limit is fixed but can be increased upon request. | 1,800 activations per minute                                         |
| Parameters size       | The maximum size of the body or payload that can be attached to a request. This limit is fixed and cannot be changed.                                                                                                           | 1 MB                                                                 |
| Response size         | The maximum output size of an UbiFunction's response. This limit is fixed and cannot be changed.                                                                                                                                | 5 MB                                                                 |
| Time out              | The maximum duration of an UbiFunction execution. Can be increased upon request, but should never exceed 60,000 ms.                                                                                                             | 40,000 ms                                                            |
| Request headers       | The maximum size of an UbiFunction's request headers.                                                                                                                                                                           | 8 KB                                                                 |
| Response headers      | The maximum size of an UbiFunction's response headers.                                                                                                                                                                          | 4 KB                                                                 |