Authentication

The authentication helpers centralize how the library obtains Google API credentials and builds service clients.

`AuthStrategy` Protocol

Protocol defining a single method:

get_credentials() -> google.auth.credentials.Credentials

Implementations provide refreshed Google credentials.

AuthMethod selects how credentials are acquired. Currently only:

USER_OAUTH – interactive OAuth flow for end users. If you'd like to learn how to use this authentication method, please refer to the Google sheets OAuth documentation.

Pydantic model configuring authentication.

Field	Type	Description
`method`	`AuthMethod`	Strategy used to obtain credentials.
`scopes`	`Sequence[str]`	OAuth scopes requested. Defaults to Sheets and Drive access.
`client_secrets_file`	`str` or `None`	Path to OAuth client JSON when using user OAuth.
`token_cache_file`	`str`	Location to store the refreshable token.
`local_server_port`	`int`	Port used by the OAuth local server. `0` picks a free port.

Resolve credentials using the configured method. For USER_OAUTH it launches the local web server flow and caches the resulting token.

Return an authenticated googleapiclient.discovery.Resource for the Sheets API.

Return an authenticated googleapiclient.discovery.Resource for the Drive API.

Dataclass used by the user OAuth strategy.

Field	Type	Description
`client_secrets_file`	`str`	OAuth client secret file.
`token_cache_file`	`str`	Where to cache the token.
`scopes`	`Sequence[str]`	Scopes requested.
`local_server_port`	`int`	Port for the local callback server.

Strategy implementing the interactive OAuth flow.

Reads cached credentials if present, otherwise acquires a new token and persists the resulting token for reuse.