Prometheus Metrics

Export agent metrics in Prometheus text exposition format. The synaptic-metrics crate wraps MetricsCallback and serves a /metrics HTTP endpoint for scraping.

Setup

[dependencies]
synaptic = { version = "0.4", features = ["metrics", "callbacks"] }

Quick Start

use std::sync::Arc;
use synaptic::callbacks::MetricsCallback;
use synaptic::metrics::PrometheusExporter;

// Create a MetricsCallback (attach to your agent/model)
let metrics = Arc::new(MetricsCallback::new());

// Create exporter and serve
let exporter = PrometheusExporter::new(metrics.clone());
let handle = exporter.serve("0.0.0.0:9090").await?;

println!("Prometheus metrics at http://{}/metrics", handle.addr());

// ... run your agent ...

// Stop the server when done
handle.stop().await;

Rendered Metrics

The exporter renders these metrics (prefix defaults to synaptic):

Metric	Type	Labels	Description
`synaptic_model_calls_total`	counter	--	Total LLM API calls
`synaptic_model_latency_seconds`	gauge	--	Average model call latency
`synaptic_model_errors_total`	counter	--	Total model call errors
`synaptic_tokens_input_total`	counter	--	Total input tokens consumed
`synaptic_tokens_output_total`	counter	--	Total output tokens consumed
`synaptic_tool_calls_total`	counter	`tool`	Per-tool call count
`synaptic_tool_latency_seconds`	gauge	`tool`	Per-tool average latency
`synaptic_tool_errors_total`	counter	`tool`	Per-tool error count

Custom Prefix

let exporter = PrometheusExporter::new(metrics.clone())
    .with_prefix("myapp");
// Metrics will be named: myapp_model_calls_total, etc.

Rendering Without a Server

If you prefer to integrate with an existing HTTP framework, call render() directly:

let exporter = PrometheusExporter::new(metrics.clone());
let text = exporter.render().await;
// text is Prometheus text exposition format, e.g.:
// # HELP synaptic_model_calls_total Total model calls
// # TYPE synaptic_model_calls_total counter
// synaptic_model_calls_total 42

Prometheus scrape_config Example

scrape_configs:
  - job_name: 'synaptic-agent'
    static_configs:
      - targets: ['localhost:9090']
    scrape_interval: 15s

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