# IRPCVaultExtensionMethods.IsExtensionMethodAvailable

Location: [gRPC API](https://developer.m-files.com/APIs/gRPC-API/index.md) > [Vault API](https://developer.m-files.com/APIs/gRPC-API/vault/index.md) > [Vault extension methods](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCVaultExtensionMethods/index.md)

HTML version: https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCVaultExtensionMethods/IsExtensionMethodAvailable/

Badges: `Vault API / standard` `read` `session` `idempotent` `returns metadata structure version`

Tells whether an event handler method with the given name exists and is active.

- **Service:** [Vault extension methods](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCVaultExtensionMethods/index.md) `MFiles.IRPCVaultExtensionMethods`
- **gRPC method:** `/MFiles.IRPCVaultExtensionMethods/IsExtensionMethodAvailable`
- **HTTP (mf-http-grpc):** `POST /grpc/v1/is-extension-method-available`
- **Request:** [`IsExtensionMethodAvailableRequest`](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCVaultExtensionMethods/IsExtensionMethodAvailable/index.md#request)
- **Response:** [`IsExtensionMethodAvailableResponse`](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCVaultExtensionMethods/IsExtensionMethodAvailable/index.md#response)
- **Book and level:** Vault API, standard
- **Kind:** read
- **Session:** Required: the session ID from LogIn in the mfiles-session-id-bin metadata.
- **Idempotent:** yes
- **Returns metadata structure version:** yes (in the mfiles-metadata-version-bin trailer)
- **Streaming:** none (unary)

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## Remarks

- Checks only the VaultExtensionMethod event handlers of the vault. Application extension
  methods and the server's built-in methods are not reported.
- A name that does not exist returns `exists` false; the call does not fail.

<a id="request"></a>

## Request: IsExtensionMethodAvailableRequest

> Nested message fields are expanded to depth 3; follow a type link for deeper levels and for the type's own page.

| Field | Type | Description |
|---|---|---|
| `method_identifier` | `string` | The name of the VaultExtensionMethod event handler. |

<a id="response"></a>

## Response: IsExtensionMethodAvailableResponse

> Nested message fields are expanded to depth 3; follow a type link for deeper levels and for the type's own page.

| Field | Type | Description |
|---|---|---|
| `exists` | `bool` | True if an event handler with the name exists. |
| `is_active` | `bool` | True if that event handler is active. |