Struct Signal 

pub struct Signal {
    pub received_at: DateTime<Utc>,
    pub app_id: String,
    pub client_user: String,
    pub session_id: String,
    pub signal_type: String,
    pub payload: Vec<String>,
    pub is_test_mode: String,
    pub float_value: Option<f64>,
}

An instance of an outgoing telemetry signal

This struct represents a single telemetry event that will be sent to TelemetryDeck. Signals are automatically created by TelemetryDeck::send and TelemetryDeck::send_sync methods - you typically don’t need to construct these manually.

Serialization

This struct serializes to JSON in camelCase format as expected by the TelemetryDeck API:

{
  "receivedAt": "2025-01-15T10:30:00Z",
  "appID": "xxx-xxx-xxx",
  "clientUser": "hashed-user-id",
  "sessionID": "session-uuid",
  "type": "signalType",
  "payload": ["key1:value1", "key2:value2"],
  "isTestMode": "false",
  "floatValue": 42.5
}

Privacy

• client_user is always SHA-256 hashed before being set
• session_id is a UUID v4 generated per client instance
• is_test_mode is serialized as a string (“true” or “false”)
• float_value is omitted from JSON when None

Fields

received_at: DateTime<Utc>

Timestamp when this signal was generated (UTC)

app_id: String

The TelemetryDeck App ID this signal belongs to

client_user: String

SHA-256 hashed user identifier

This value is automatically hashed by the client before transmission. The server will hash it again with its own salt for privacy.

session_id: String

Session identifier (UUID v4)

Persists for the lifetime of a TelemetryDeck instance. Can be reset using TelemetryDeck::reset_session.

signal_type: String

The type/name of this signal (e.g., “userLogin”, “buttonClick”)

payload: Vec<String>

Custom parameters encoded as “key:value” strings

Created from the HashMap passed to send() or send_sync(). Keys containing colons are sanitized (: → _).

is_test_mode: String

Whether this is a test signal (serialized as string “true” or “false”)

Test signals are shown separately in the TelemetryDeck UI.

float_value: Option<f64>

Optional floating-point value associated with this signal

Useful for tracking numeric metrics like revenue, duration, score, etc. Omitted from JSON when None.

Trait Implementations

impl Debug for Signal

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Signal

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Signal

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.