fix(agent): implement OnRetry logging with structured retry fields (#2700)

iceymoss · web-flow · commit 549f717263b3 · 2026-04-24T09:40:08.000-03:00
diff --git a/internal/agent/agent.go b/internal/agent/agent.go
@@ -378,7 +378,7 @@ func (a *sessionAgent) Run(ctx context.Context, call SessionAgentCall) (*fantasy
 			return a.messages.Update(ctx, *currentAssistant)
 		},
 		OnRetry: func(err *fantasy.ProviderError, delay time.Duration) {
-			// TODO: implement
+			slog.Warn("Provider request failed, retrying", providerRetryLogFields(err, delay)...)
 		},
 		OnToolCall: func(tc fantasy.ToolCallContent) error {
 			toolCall := message.ToolCall{
@@ -1318,3 +1318,20 @@ func buildSummaryPrompt(todos []session.Todo) string {
 	}
 	return sb.String()
 }
+
+func providerRetryLogFields(err *fantasy.ProviderError, delay time.Duration) []any {
+	fields := []any{
+		"retry_delay", delay.String(),
+	}
+	if err == nil {
+		return fields
+	}
+	fields = append(fields, "status_code", err.StatusCode)
+	if err.Title != "" {
+		fields = append(fields, "title", err.Title)
+	}
+	if err.Message != "" {
+		fields = append(fields, "message", err.Message)
+	}
+	return fields
+}
diff --git a/internal/agent/agent_test.go b/internal/agent/agent_test.go
@@ -8,6 +8,7 @@ import (
 	"runtime"
 	"strings"
 	"testing"
+	"time"
 
 	"charm.land/fantasy"
 	"charm.land/x/vcr"
@@ -793,3 +794,34 @@ func TestPreparePrompt_OrphanedToolUseMixed(t *testing.T) {
 	}
 	require.Equal(t, 1, syntheticCount, "expected exactly one synthetic result for the orphaned call")
 }
+
+func TestProviderRetryLogFields(t *testing.T) {
+	t.Run("nil provider error", func(t *testing.T) {
+		fields := providerRetryLogFields(nil, 2*time.Second)
+		require.Equal(t, []any{"retry_delay", "2s"}, fields)
+	})
+
+	t.Run("provider error with title and message", func(t *testing.T) {
+		fields := providerRetryLogFields(&fantasy.ProviderError{
+			StatusCode: 429,
+			Title:      "rate limit",
+			Message:    "too many requests",
+		}, 1500*time.Millisecond)
+		require.Equal(t, []any{
+			"retry_delay", "1.5s",
+			"status_code", 429,
+			"title", "rate limit",
+			"message", "too many requests",
+		}, fields)
+	})
+
+	t.Run("provider error without optional strings", func(t *testing.T) {
+		fields := providerRetryLogFields(&fantasy.ProviderError{
+			StatusCode: 503,
+		}, time.Second)
+		require.Equal(t, []any{
+			"retry_delay", "1s",
+			"status_code", 503,
+		}, fields)
+	})
+}
