Module telemetry 

Telemetry Module (Core)

Provides centralized observability primitives for the A3S Code agent:

• Span name and attribute key constants
• LLM cost tracking (model, tokens, cost per call)
• Tool execution metrics (duration, success/failure)
• Span helper functions using tracing (no OTel dependency)

For OpenTelemetry initialization (OTLP exporter, subscriber setup), see the telemetry_init module in the a3s-code server crate.

Span Hierarchy

a3s.agent.execute
  +-- a3s.agent.context_resolve
  +-- a3s.agent.turn (repeated)
  |   +-- a3s.llm.completion
  |   +-- a3s.tool.execute (repeated)
  +-- a3s.agent.turn_notify

Structs

CostSummary

Aggregated cost summary

DayCostBreakdown

Cost breakdown by day

LlmCostRecord

Cost record for a single LLM call

ModelCostBreakdown

Cost breakdown by model

ModelPricing

Pricing table for LLM models (cost per 1M tokens)

TimedSpan

A guard that measures elapsed time and records it when dropped

ToolMetrics

Per-session tool execution metrics collector

ToolStats

Statistics for a single tool

Constants

ATTR_CONTEXT_ITEMS

ATTR_CONTEXT_PROVIDERS

ATTR_CONTEXT_TOKENS

ATTR_LLM_COMPLETION_TOKENS

ATTR_LLM_MODEL

ATTR_LLM_PROMPT_TOKENS

ATTR_LLM_PROVIDER

ATTR_LLM_STOP_REASON

ATTR_LLM_STREAMING

ATTR_LLM_TOTAL_TOKENS

ATTR_MAX_TURNS

ATTR_SESSION_ID

ATTR_TOOL_CALLS_COUNT

ATTR_TOOL_DURATION_MS

ATTR_TOOL_EXIT_CODE

ATTR_TOOL_ID

ATTR_TOOL_NAME

ATTR_TOOL_PERMISSION

ATTR_TOOL_SUCCESS

ATTR_TURN_NUMBER

SERVICE_NAME

Service name for telemetry

SPAN_AGENT_EXECUTE

SPAN_AGENT_TURN

SPAN_CONTEXT_RESOLVE

SPAN_LLM_COMPLETION

SPAN_TOOL_EXECUTE

Functions

aggregate_cost_records

Aggregate cost records with optional filters

default_model_pricing

Registry of known model pricing

record_llm_metrics

Record LLM metrics via tracing events.

record_llm_usage

Record LLM token usage on the current span

record_tool_result

Record tool execution result on the current span