# Connections and OAuth

> The lifecycle of a mailer connection — creation, updates, deletion, health checks, encrypted credentials — and the OAuth flows that keep API-mode connections authorized.

| Hook | Kind | Tier | Since | Summary |
| --- | --- | --- | --- | --- |
| [`boolean_smtp_aws_enable_imds_role_source`](/hooks/boolean_smtp_aws_enable_imds_role_source/) | filter | B | 1.0.0 | Filters whether BooleanSMTP probes the EC2 IMDSv2 endpoint for an IAM role. |
| [`boolean_smtp_before_connection_delete`](/hooks/boolean_smtp_before_connection_delete/) | action | A | 1.0.0 | Fires immediately before a connection is deleted. |
| [`boolean_smtp_connection_created`](/hooks/boolean_smtp_connection_created/) | action | A | 1.0.0 | Fires after a connection has been created through the REST API. |
| [`boolean_smtp_connection_data`](/hooks/boolean_smtp_connection_data/) | filter | A | 1.0.0 | Filters a connection's data before it is created through the REST API. |
| [`boolean_smtp_connection_deleted`](/hooks/boolean_smtp_connection_deleted/) | action | A | 1.0.0 | Fires after a connection has been deleted. |
| [`boolean_smtp_connection_saved`](/hooks/boolean_smtp_connection_saved/) | action | A | 1.0.0 | Fires after a connection has been written to the database, wherever the write came from. |
| [`boolean_smtp_connection_updated`](/hooks/boolean_smtp_connection_updated/) | action | A | 1.0.0 | Fires after a connection has been updated through the REST API. |
| [`boolean_smtp_google_oauth_redirect_uri`](/hooks/boolean_smtp_google_oauth_redirect_uri/) | filter | A | 1.0.0 | Filters the redirect URI used for the Google OAuth2 connection flow. |
| [`boolean_smtp_health_check`](/hooks/boolean_smtp_health_check/) | action | B | 1.0.0 | Fires on the health-check interval; each run probes every active connection. |
| [`boolean_smtp_health_check_result`](/hooks/boolean_smtp_health_check_result/) | action | A | 1.0.0 | Fires after the scheduled health check has probed one connection and recorded the outcome on it. |
| [`boolean_smtp_microsoft_authorize_url`](/hooks/boolean_smtp_microsoft_authorize_url/) | filter | B | 1.0.0 | Filters the Microsoft identity platform authorize URL used for delegated OAuth. |
| [`boolean_smtp_microsoft_oauth_redirect_uri`](/hooks/boolean_smtp_microsoft_oauth_redirect_uri/) | filter | A | 1.0.0 | Filters the redirect URI used for the Microsoft OAuth2 connection flow. |
| [`boolean_smtp_microsoft_token_url`](/hooks/boolean_smtp_microsoft_token_url/) | filter | B | 1.0.0 | Filters the Microsoft identity platform token endpoint used to exchange or refresh delegated and application tokens. |
| [`boolean_smtp_oauth_providers_register`](/hooks/boolean_smtp_oauth_providers_register/) | action | A | 1.0.0 | Fires after the built-in OAuth providers have been registered. |
| [`boolean_smtp_oauth_refresh`](/hooks/boolean_smtp_oauth_refresh/) | action | B | 1.0.0 | Fires on the OAuth refresh interval; each run renews the access tokens that are about to expire. |
| [`boolean_smtp_oauth_refresh_failed`](/hooks/boolean_smtp_oauth_refresh_failed/) | action | A | 1.0.0 | Fires after an OAuth token refresh fails, once retries are exhausted. |
| [`boolean_smtp_oauth_refresh_success`](/hooks/boolean_smtp_oauth_refresh_success/) | action | A | 1.0.0 | Fires after an OAuth token refresh succeeds. |
| [`boolean_smtp_sensitive_keys`](/hooks/boolean_smtp_sensitive_keys/) | filter | A | 1.0.0 | Filters the exact settings-key names whose values are encrypted at rest, masked in REST responses and redacted from logs. |
| [`boolean_smtp_ses_iam_credentials`](/hooks/boolean_smtp_ses_iam_credentials/) | filter | B | 1.0.0 | Filters the predefined IAM credentials available for SES connections to select from. |
| [`boolean_smtp_ses_iam_selector`](/hooks/boolean_smtp_ses_iam_selector/) | filter | B | 1.0.0 | Filters the list of predefined IAM credentials offered in the SES connection form. |
| [`boolean_smtp_zoho_oauth_redirect_uri`](/hooks/boolean_smtp_zoho_oauth_redirect_uri/) | filter | A | 1.0.0 | Filters the redirect URI used for the Zoho OAuth2 connection flow. |