Add message retention related data types

conversation.go

@@ -595,6 +595,47 @@ func (api *Client) GetConversationInfoContext(ctx context.Context, input *GetCon
 	return &response.Channel, response.Err()
 }
 
+// ConversationRetention represents a conversation's message retention policy.
+// Type uses 1 = never delete, 2 = delete after Duration days (Slack's preset
+// "keep for N days" options), 3 = custom timeline (also delete after Duration),
+// 0 = inherit the workspace default. Duration is in days.
+type ConversationRetention struct {
+	Type     int `json:"retention_type"`
+	Duration int `json:"retention_duration"`
+}
+
+type getConversationRetentionResponse struct {
+	SlackResponse
+	Retention ConversationRetention `json:"retention"`
+}
+
+// GetConversationRetention retrieves a conversation's message retention policy.
+// For more details, see GetConversationRetentionContext documentation.
+func (api *Client) GetConversationRetention(channelID string) (*ConversationRetention, error) {
+	return api.GetConversationRetentionContext(context.Background(), channelID)
+}
+
+// GetConversationRetentionContext retrieves a conversation's message retention
+// policy with a custom context. This uses the undocumented conversations.getRetention
+// method that the Slack web client calls; unlike admin.conversations.getCustomRetention
+// it works with a regular user token. It returns the "not_paid" error on workspaces
+// without the custom-retention feature.
+func (api *Client) GetConversationRetentionContext(ctx context.Context, channelID string) (*ConversationRetention, error) {
+	values := url.Values{
+		"token":   {api.token},
+		"channel": {channelID},
+	}
+	response := &getConversationRetentionResponse{}
+	err := api.postMethod(ctx, "conversations.getRetention", values, response)
+	if err != nil {
+		return nil, err
+	}
+	if err := response.Err(); err != nil {
+		return nil, err
+	}
+	return &response.Retention, nil
+}
+
 // LeaveConversation leaves a conversation.
 // For more details, see LeaveConversationContext documentation.
 func (api *Client) LeaveConversation(channelID string) (bool, error) {

users.go

@@ -186,6 +186,17 @@ type ClientUserBootSubteams struct {
 type TeamPrefs struct {
 	MsgEditWindowMins    *int  `json:"msg_edit_window_mins,omitempty"`
 	AllowMessageDeletion *bool `json:"allow_message_deletion,omitempty"`
+
+	// Message retention defaults. The *_type fields use 1 = retain all messages,
+	// 2 = delete after the matching *_duration (in days); other values mean no
+	// automatic deletion. Public channels use RetentionType/RetentionDuration,
+	// private channels use the Group* fields and DMs/MPIMs use the DM* fields.
+	RetentionType          int `json:"retention_type,omitempty"`
+	RetentionDuration      int `json:"retention_duration,omitempty"`
+	GroupRetentionType     int `json:"group_retention_type,omitempty"`
+	GroupRetentionDuration int `json:"group_retention_duration,omitempty"`
+	DMRetentionType        int `json:"dm_retention_type,omitempty"`
+	DMRetentionDuration    int `json:"dm_retention_duration,omitempty"`
 }
 
 type BootTeam struct {