Struct Invocation 

pub struct Invocation {
    pub id: String,
    pub session_id: Option<String>,
    pub tool_name: String,
    pub input: Value,
    pub output: Option<Value>,
    pub pipe_name: Option<String>,
    pub latency_ms: Option<i64>,
    pub success: bool,
    pub error: Option<String>,
    pub created_at: DateTime<Utc>,
    pub fallback_used: bool,
    pub fallback_type: Option<String>,
}

Invocation log entry for debugging and tracing.

Fields

id: String

Unique invocation identifier.

session_id: Option<String>

Optional parent session ID.

tool_name: String

Name of the MCP tool invoked.

input: Value

Input parameters as JSON.

output: Option<Value>

Output result as JSON (if successful).

pipe_name: Option<String>

Name of the Langbase pipe called.

latency_ms: Option<i64>

Latency in milliseconds.

success: bool

Whether the invocation succeeded.

error: Option<String>

Error message (if failed).

created_at: DateTime<Utc>

When the invocation occurred.

fallback_used: bool

Whether a fallback was used for this invocation.

fallback_type: Option<String>

Type of fallback if used (parse_error, api_unavailable, local_calculation).

Implementations

impl Invocation

pub fn new(tool_name: impl Into<String>, input: Value) -> Self

Create a new invocation log entry

pub fn with_session(self, session_id: impl Into<String>) -> Self

Set the session ID

pub fn with_pipe(self, pipe_name: impl Into<String>) -> Self

Set the pipe name

pub fn success(self, output: Value, latency_ms: i64) -> Self

Mark as successful with output

pub fn failure(self, error: impl Into<String>, latency_ms: i64) -> Self

Mark as failed with error

pub fn with_latency(self, latency_ms: i64) -> Self

Set latency separately

pub fn mark_success(self) -> Self

Mark as successful (simple version without output)

pub fn mark_failed(self, error: impl Into<String>) -> Self

Mark as failed (simple version)

pub fn with_fallback(self, fallback_type: impl Into<String>) -> Self

Mark that a fallback was used

pub fn with_parse_error_fallback(self) -> Self

Mark fallback with specific type constants

pub fn with_api_unavailable_fallback(self) -> Self

Mark fallback due to API unavailability

pub fn with_local_calculation_fallback(self) -> Self

Mark fallback due to local calculation

Trait Implementations

impl Clone for Invocation

fn clone(&self) -> Invocation

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Invocation

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Invocation

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Invocation

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

where __S: Serializer,

Serialize this value into the given Serde serializer.