feat(agents): native Prometheus metrics for agent chat runs (#10689)

Operators need a scrape-friendly signal for agent-turn health (completing,
erroring, cancelled, duration) — log-derived counters proved brittle (ANSI/
timezone parsing, restart gaps). Adds localai_agent_runs_total{agent,outcome}
and localai_agent_run_seconds histogram, recorded at the Chat() response
handoff (single choke point of the local execution path). Lazy meter init,
same pattern as the PII events counter (#10641).

Signed-off-by: Stefan Walcz <stefan.walcz@walcz.de>

core/services/agentpool/agent_pool.go

@@ -426,7 +426,15 @@ func (s *AgentPoolService) Chat(name, message string) (string, error) {
 
 	// Process asynchronously
 	go func() {
+		started := time.Now()
 		response := ag.Ask(coreTypes.WithText(message))
+		outcome := "completed"
+		if response == nil {
+			outcome = "cancelled"
+		} else if response.Error != nil {
+			outcome = "error"
+		}
+		recordAgentRun(name, outcome, time.Since(started).Seconds())
 
 		if response == nil {
 			errMsg, _ := json.Marshal(map[string]any{

core/services/agentpool/metrics.go

@@ -0,0 +1,54 @@
+package agentpool
+
+import (
+	"context"
+	"sync"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric"
+)
+
+// Prometheus metrics for agent chat runs. Operators need a scrape-friendly
+// signal for "are agent turns completing, erroring or getting cancelled,
+// and how long do they take" — log-derived counters proved brittle
+// (ANSI/timezone parsing, container-restart gaps). Chat() is the single
+// choke point of the local execution path, so instrumenting the response
+// handoff covers UI chats, API chats and connector-triggered asks alike.
+//
+// Lazily initialised on first record so the package works no matter when
+// (or whether) the Prometheus-backed global MeterProvider is installed —
+// same pattern as core/services/routing/pii.
+var (
+	agentMetricsOnce sync.Once
+	runsCounter      metric.Int64Counter
+	runSeconds       metric.Float64Histogram
+)
+
+func recordAgentRun(agent, outcome string, seconds float64) {
+	agentMetricsOnce.Do(func() {
+		meter := otel.Meter("github.com/mudler/LocalAI")
+		if c, err := meter.Int64Counter(
+			"localai_agent_runs_total",
+			metric.WithDescription("Agent chat runs, labeled by agent and outcome (completed|error|cancelled)"),
+		); err == nil {
+			runsCounter = c
+		}
+		if h, err := meter.Float64Histogram(
+			"localai_agent_run_seconds",
+			metric.WithDescription("Wall-clock duration of agent chat runs in seconds"),
+		); err == nil {
+			runSeconds = h
+		}
+	})
+	attrs := metric.WithAttributes(
+		attribute.String("agent", agent),
+		attribute.String("outcome", outcome),
+	)
+	if runsCounter != nil {
+		runsCounter.Add(context.Background(), 1, attrs)
+	}
+	if runSeconds != nil {
+		runSeconds.Record(context.Background(), seconds, attrs)
+	}
+}