Enum ObserverEvent 

pub enum ObserverEvent {
    AgentStart {
        model_provider: String,
        model: String,
    },
    LlmRequest {
        model_provider: String,
        model: String,
        messages_count: usize,
    },
    LlmResponse {
        model_provider: String,
        model: String,
        duration: Duration,
        success: bool,
        error_message: Option<String>,
        input_tokens: Option<u64>,
        output_tokens: Option<u64>,
    },
    AgentEnd {
        model_provider: String,
        model: String,
        duration: Duration,
        tokens_used: Option<u64>,
        cost_usd: Option<f64>,
    },
    ToolCallStart {
        tool: String,
        tool_call_id: Option<String>,
        arguments: Option<String>,
    },
    ToolCall {
        tool: String,
        tool_call_id: Option<String>,
        duration: Duration,
        success: bool,
        arguments: Option<String>,
        result: Option<String>,
    },
    TurnComplete,
    ChannelMessage {
        channel: String,
        direction: String,
    },
    HeartbeatTick,
    CacheHit {
        cache_type: String,
        tokens_saved: u64,
    },
    CacheMiss {
        cache_type: String,
    },
    Error {
        component: String,
        message: String,
    },
    DeploymentStarted {
        deploy_id: String,
    },
    DeploymentCompleted {
        deploy_id: String,
        commit_sha: String,
    },
    DeploymentFailed {
        deploy_id: String,
        reason: String,
    },
    RecoveryCompleted {
        deploy_id: String,
    },
}

Discrete events emitted by the agent runtime for observability.

Each variant represents a lifecycle event that observers can record, aggregate, or forward to external monitoring systems. Events carry just enough context for tracing and diagnostics without exposing sensitive prompt or response content.

Variants

AgentStart

The agent orchestration loop has started a new session.

Fields

model_provider: String

model: String

LlmRequest

A request is about to be sent to an LLM model_provider.

This is emitted immediately before a model_provider call so observers can print user-facing progress without leaking prompt contents.

Fields

model_provider: String

model: String

messages_count: usize

LlmResponse

Result of a single LLM model_provider call.

Fields

model_provider: String

model: String

duration: Duration

success: bool

error_message: Option<String>

input_tokens: Option<u64>

output_tokens: Option<u64>

AgentEnd

The agent session has finished.

Carries aggregate usage data (tokens, cost) when the model_provider reports it.

Fields

model_provider: String

model: String

duration: Duration

tokens_used: Option<u64>

cost_usd: Option<f64>

ToolCallStart

A tool call is about to be executed.

Fields

tool: String

tool_call_id: Option<String>

Provider-assigned tool call identifier, when the underlying tool call originated from a native structured tool call block (e.g. OpenAI tool_calls[].id, Anthropic tool_use.id). None for text-parsed (XML/markdown) tool calls.

Observers can correlate ToolCallStart → ToolCall → the emitting LLM response via this id.

arguments: Option<String>

Full JSON arguments the agent passed to the tool. None when arguments are unavailable at the call site.

ToolCall

A tool call has completed with a success/failure outcome.

Fields

tool: String

tool_call_id: Option<String>

Provider-assigned tool call identifier, when present. See ObserverEvent::ToolCallStart::tool_call_id.

duration: Duration

success: bool

arguments: Option<String>

Full JSON arguments the agent passed to the tool.

Carried here (in addition to ToolCallStart) so observers that build a single completed span per tool call — e.g. the OTel exporter — can attach arguments at span-end time without holding per-call state.

result: Option<String>

Scrubbed tool output or error reason. Populated for both success and failure outcomes so backends can show the actual tool result in trace viewers. Credentials are scrubbed before this field is emitted.

TurnComplete

The agent produced a final answer for the current user message.

ChannelMessage

A message was sent or received through a channel.

Fields

channel: String

Channel name (e.g., "telegram", "discord").

direction: String

"inbound" or "outbound".

HeartbeatTick

Periodic heartbeat tick from the runtime keep-alive loop.

CacheHit

Response cache hit — an LLM call was avoided.

Fields

cache_type: String

"hot" (in-memory) or "warm" (SQLite).

tokens_saved: u64

Estimated tokens saved by this cache hit.

CacheMiss

Response cache miss — the prompt was not found in cache.

Fields

cache_type: String

"response" cache layer that was checked.

Error

An error occurred in a named component.

Fields

component: String

Subsystem where the error originated (e.g., "model_provider", "gateway").

message: String

Human-readable error description. Must not contain secrets or tokens.

DeploymentStarted

A deployment has started.

Fields

deploy_id: String

Identifier for the deployment (e.g., commit SHA or release tag).

DeploymentCompleted

A deployment has completed successfully.

Fields

deploy_id: String

commit_sha: String

Commit SHA that was deployed.

DeploymentFailed

A deployment has failed.

Fields

deploy_id: String

reason: String

Human-readable failure reason.

RecoveryCompleted

Recovery from a failed deployment has completed.

Fields

deploy_id: String

Trait Implementations

impl Clone for ObserverEvent

fn clone(&self) -> ObserverEvent

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ObserverEvent

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

Formats the value using the given formatter.