Attachments, Shares & Events

Attachments & Drive Shares
Real-time Events & User Account

Attachments & Drive Shares

Attachments

Attachment upload and download via /mail/v4/attachments.

Upload

attachment, err := c.UploadAttachment(ctx, addrKR, proton.CreateAttachmentReq{
    MessageID:  "message-id",
    Filename:   "document.pdf",
    MIMEType:   "application/pdf",
    Disposition: proton.AttachmentDisposition,
    Body:       fileBytes,
})

Upload is encrypted with the address keyring and signed (detached) before upload. The server stores the encrypted KeyPacket, DataPacket, and Signature separately.

Download

// Download as bytes
data, err := c.GetAttachment(ctx, attachmentID)

// Stream into io.ReaderFrom
err := c.GetAttachmentInto(ctx, attachmentID, reader)

Key Types

Type	Description
`Attachment`	ID, name, size, MIME type, disposition (inline/attachment), headers, key packets, signature
`CreateAttachmentReq`	MessageID, filename, MIME type, disposition, content ID, body bytes
`Disposition`	InlineDisposition, AttachmentDisposition

Drive Shares

Proton Drive share management via /drive/shares.

Operations

// List shares
shares, err := c.ListShares(ctx, all)

// Get a single share with full key material
share, err := c.GetShare(ctx, shareID)

Key Derivation

Shares use a two-step PGP decryption + passphrase unlock process:

// Decrypt passphrase with address keyring, verify signature, unlock share key
keyRing, err := share.GetKeyRing(addrKR)
// Returns *crypto.KeyRing for Drive access

Key Types

Type	Description
`ShareMetadata`	ShareID, linkID, volumeID, type, state, creation/modify times, creator email
`Share`	Extends metadata with addressID, addressKeyID, encrypted key, passphrase, passphrase signature
`ShareType`	Main (1), Standard (2), Device (3)
`ShareState`	Active (1), Deleted (2)

Real-time Events & User Account

Real-time Events

Event polling and streaming for real-time notifications via /core/v4/events.

Event Streaming

// Get the latest event ID
fromEventID, err := c.GetLatestEventID(context.Background())

// Create a new event streamer
for event := range c.NewEventStream(ctx, 20*time.Second, 20*time.Second, fromEventID) {
    fmt.Println(event.EventID)
    // Process event.User, event.Messages, event.Labels, etc.
}

The event stream uses a custom NewTicker with random jitter to avoid thundering herd.

Event Polling

// Fetch events starting after eventID
events, more, err := c.GetEvent(ctx, eventID)
// Returns up to 50 events per call with more indicating continuation

Event Types

The Event struct contains typed sub-events:

event.User          // User changes
event.UserSettings  // User settings changes
event.MailSettings  // Mail settings changes
event.Messages      // Message changes ([]MessageEvent)
event.Labels        // Label changes ([]LabelEvent)
event.Addresses     // Address changes ([]AddressEvent)
event.Notifications // Notifications ([]NotificationEvent)
event.UsedSpace     // Storage usage changes

Key Types

Type	Description
`Event`	Contains eventID, refresh flags, and typed sub-events
`RefreshFlag`	RefreshMail (1), RefreshAll (255)
`EventAction`	Delete, Create, Update, UpdateFlags
`MessageEvent`	EventItem (ID + Action) with full Message entity
`LabelEvent`	EventItem (ID + Action) with full Label entity
`AddressEvent`	EventItem (ID + Action) with full Address entity

User Account

User account operations via /core/v4/users.

Operations

// Fetch current user info
user, err := c.GetUser(ctx)

// With human verification token
user, err := c.GetUserWithHV(ctx, hvToken)

// Delete account (requires SRP proof re-authentication)
err := c.DeleteUser(ctx, password, proton.DeleteUserReq{
    Reason:  "no longer needed",
    Feedback: "test account",
})

Key Types

Type	Description
`User`	ID, name, display name, email, keys, used/max/upload space limits, credit, currency
`ProductUsedSpace`	Space breakdown by calendar, contact, drive, mail, pass (password manager)
`DeleteUserReq`	Reason, feedback, email confirmation

Feature Flags

Fetch feature flag/toggle results from the Proton API:

features, err := c.GetFeatures(ctx, "sticky-key-uuid")
// Returns FeatureFlagResult for a given UUID sticky key