diff --git a/llm/llm.go b/llm/llm.go
index 2aea24e..9718954 100644
--- a/llm/llm.go
+++ b/llm/llm.go
@@ -6,6 +6,8 @@
 	"encoding/json"
 	"fmt"
 	"log/slog"
+	"net/http"
+	"strconv"
 	"strings"
 	"time"
 )
@@ -194,6 +196,19 @@
 	}
 }
 
+func CostUSDFromResponse(headers http.Header) float64 {
+	h := headers.Get("Skaband-Cost-Microcents")
+	if h == "" {
+		return 0
+	}
+	uc, err := strconv.ParseUint(h, 10, 64)
+	if err != nil {
+		slog.Warn("failed to parse cost header", "header", h)
+		return 0
+	}
+	return float64(uc) / 100_000_000
+}
+
 // Usage represents the billing and rate-limit usage.
 // Most LLM structs do not have JSON tags, to avoid accidental direct use in specific providers.
 // However, the front-end uses this struct, and it relies on its JSON serialization.