Events - WhatsApp Rust

The Events feature creates WhatsApp event messages — the scheduled-event bubble with a date, location, and join link. It also sends RSVPs. Like polls, an event carries a per-message message_secret. Responders derive their RSVP encryption key from that secret. Keep the secret so you can send and decrypt responses later.

Access

Access event operations through the client:

let events = client.events();

Methods

create

Create and send an event message.

pub async fn create(
    &self,
    to: &Jid,
    params: EventCreationParams,
) -> Result<(SendResult, Vec<u8>)>

&Jid

required

Recipient JID — a direct message or group chat.

params

EventCreationParams

required

Event details. Only name is required; everything else is optional. See EventCreationParams.

(send_result, message_secret)

(SendResult, Vec<u8>)

A SendResult and the event’s 32-byte message_secret. Store the secret — it is required to decrypt the RSVPs that come back. A fresh secret is generated per event and attached as messageContextInfo.messageSecret; WhatsApp Web rejects an event without one.

Example:

use whatsapp_rust::features::EventCreationParams;

let chat: Jid = "120363012345678@g.us".parse()?;

let (sent, secret) = client.events().create(&chat, EventCreationParams {
    name: "Team offsite".to_string(),
    description: Some("Bring a laptop".to_string()),
    start_time: Some(1_760_000_000),     // unix seconds
    end_time: Some(1_760_010_000),
    location: None,
    extra_guests_allowed: Some(true),
    ..Default::default()
}).await?;

// Persist `secret` keyed by `sent.message_id` so you can decrypt RSVPs later.
println!("Event sent: {}", sent.message_id);

respond

RSVP to an event. The RSVP is end-to-end encrypted against the event’s message_secret.

pub async fn respond(
    &self,
    chat_jid: &Jid,
    event_msg_id: &str,
    event_creator_jid: &Jid,
    message_secret: &[u8],
    response: EventResponseType,
    extra_guest_count: Option<i32>,
) -> Result<SendResult>

chat_jid

&Jid

required

Chat JID where the event was sent.

event_msg_id

&str

required

Message ID of the event creation message.

event_creator_jid

&Jid

required

JID of the user who created the event. It keys the RSVP’s encryption derivation and AAD, so it must match the creator exactly.

message_secret

&[u8]

required

The 32-byte secret from the event creation message.

response

EventResponseType

required

Going, NotGoing, or Maybe. See EventResponseType.

extra_guest_count

Option<i32>

Number of additional guests you’re bringing, when the event allows extra guests.

SendResult

Result of the RSVP send. See SendResult.

Example:

use whatsapp_rust::features::EventResponseType;

let creator: Jid = "15551234567@s.whatsapp.net".parse()?;

client.events()
    .respond(
        &chat,
        &event_msg_id,
        &creator,
        &message_secret,
        EventResponseType::Going,
        Some(2), // bringing two guests
    )
    .await?;

The responder (self) JID also keys the derivation, so it must use the creator’s namespace: your own LID for a LID-addressed event, your PN otherwise (falling back to PN when your LID isn’t known). The library resolves this for you, mirroring the poll-vote path.

Decrypting inbound RSVPs

When you receive an EncEventResponseMessage, decrypt it with the event’s secret using the helpers in wacore::event:

use wacore::event::decrypt_event_response_with_secret;

let response = decrypt_event_response_with_secret(
    &enc_payload,
    &iv,
    &message_secret,       // the secret you stored at create() time
    &event_msg_id,
    &event_creator_jid,    // creator (non-AD form)
    &responder_jid,        // who sent the RSVP (non-AD form)
)?;

println!("RSVP: {:?}", response.response);            // Going / NotGoing / Maybe
println!("Extra guests: {:?}", response.extra_guest_count);

Function	Description
`encrypt_event_response_with_secret(response, secret, stanza_id, creator, responder) -> (Vec<u8>, [u8; 12])`	Encrypt an `EventResponseMessage` against the event secret. Returns `(payload_with_tag, iv)`.
`decrypt_event_response_with_secret(payload, iv, secret, stanza_id, creator, responder) -> EventResponseMessage`	Decrypt an inbound RSVP. The creator + responder JIDs must match what the responder used, or decryption fails (rather than silently mis-decrypting).

Both are thin wrappers over the shared secret_enc_addon machinery specialized for the "Event Response" use-case, matching WhatsApp Web’s WAWebAddonEncryption.

Types

EventCreationParams

#[derive(Debug, Clone, Default)]
pub struct EventCreationParams {
    pub name: String,
    pub description: Option<String>,
    pub start_time: Option<i64>,
    pub end_time: Option<i64>,
    pub join_link: Option<String>,
    pub location: Option<wa::message::LocationMessage>,
    pub is_scheduled_call: Option<bool>,
    pub extra_guests_allowed: Option<bool>,
}

Field	Type	Description
`name`	`String`	Event title (required; must not be empty).
`description`	`Option<String>`	Free-text description.
`start_time`	`Option<i64>`	Start time in unix seconds.
`end_time`	`Option<i64>`	End time in unix seconds.
`join_link`	`Option<String>`	Call/join link.
`location`	`Option<LocationMessage>`	Event location.
`is_scheduled_call`	`Option<bool>`	Mark the event as a scheduled call.
`extra_guests_allowed`	`Option<bool>`	Allow responders to bring extra guests.

EventResponseType

whatsapp_rust re-exports this enum from the generated proto.

pub enum EventResponseType {
    Unknown,   // 0
    Going,     // 1
    NotGoing,  // 2
    Maybe,     // 3
}

Error handling

All methods return Result<T, anyhow::Error>. Common errors:

Empty event name when calling create.
Not logged in — the responder’s own JID can’t be determined.
message_secret not 32 bytes — encryption/decryption rejects the wrong size.
GCM tag verification failed — wrong secret, wrong creator/responder JID, or a tampered payload.

​Access

​Methods

​create

​respond

​Decrypting inbound RSVPs

​Types

​EventCreationParams

​EventResponseType

​Error handling

​See also

Access

Methods

create

respond

Decrypting inbound RSVPs

Types

EventCreationParams

EventResponseType

Error handling

See also