> ## Documentation Index
> Fetch the complete documentation index at: https://base-a060aa97-docs-add-b20-spec.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# IActivationRegistry reference

> Generated B20 reference for IActivationRegistry functions, events, and errors.

## Functions

| Function                                                                                                                       | Selector     | Summary                                                                              |
| ------------------------------------------------------------------------------------------------------------------------------ | ------------ | ------------------------------------------------------------------------------------ |
| [`isActivated`](/base-chain/specs/upgrades/beryl/b20/specification/reference/interfaces/IActivationRegistry/isActivated)       | `0xba87af80` | Whether `feature` is currently activated. Never reverts.                             |
| [`checkActivated`](/base-chain/specs/upgrades/beryl/b20/specification/reference/interfaces/IActivationRegistry/checkActivated) | `0xde5bfd9b` | Reverts with `FeatureNotActivated(feature)` if `feature` is not currently activated. |
| [`admin`](/base-chain/specs/upgrades/beryl/b20/specification/reference/interfaces/IActivationRegistry/admin)                   | `0xf851a440` | The address authorized to call `activate` and `deactivate`.                          |
| [`activate`](/base-chain/specs/upgrades/beryl/b20/specification/reference/interfaces/IActivationRegistry/activate)             | `0x59db6e85` | Activates `feature`. Emits `FeatureActivated`.                                       |
| [`deactivate`](/base-chain/specs/upgrades/beryl/b20/specification/reference/interfaces/IActivationRegistry/deactivate)         | `0x22eee84c` | Deactivates `feature`. Emits `FeatureDeactivated`.                                   |

## Events

| Event                | Topic0                                                               | Summary                                |
| -------------------- | -------------------------------------------------------------------- | -------------------------------------- |
| `FeatureActivated`   | `0x8c7a0ecdbb8d96e867e43ec1aef80027976ee493c18bef399fa799ed19752451` | Emitted when `feature` is activated.   |
| `FeatureDeactivated` | `0x15bf65a782c3258c63268ba9d7aed710cf9f9315d3687d9a4632ccdad7926c84` | Emitted when `feature` is deactivated. |

## Errors

| Error                    | Selector     | Summary                                                             |
| ------------------------ | ------------ | ------------------------------------------------------------------- |
| `Unauthorized`           | `0x8e4a23d6` | Caller is not the activation admin.                                 |
| `AlreadyActivated`       | `0x866b0041` | Feature is already activated.                                       |
| `FeatureNotActivated`    | `0xb9b2a425` | Feature is not activated.                                           |
| `DelegateCallNotAllowed` | `0x0d89438e` | The precompile was invoked via `DELEGATECALL` or `CALLCODE`.        |
| `StaticCallNotAllowed`   | `0xbeaba5b7` | A state-mutating entry point was invoked from a `STATICCALL` frame. |

<CardGroup cols={2}>
  <Card title="Errors & events index" href="/base-chain/specs/upgrades/beryl/b20/specification/reference/errors-and-events-index" />

  <Card title="Constants & addresses" href="/base-chain/specs/upgrades/beryl/b20/specification/reference/constants-and-addresses" />
</CardGroup>