diff --git a/internal/runtime/executor/claude_executor.go b/internal/runtime/executor/claude_executor.go
index c7470954..6af08608 100644
--- a/internal/runtime/executor/claude_executor.go
+++ b/internal/runtime/executor/claude_executor.go
@@ -450,59 +450,15 @@ func extractAndRemoveBetas(body []byte) ([]string, []byte) {
 	return betas, body
 }
 
-// injectThinkingConfig adds thinking configuration based on metadata or legacy suffixes.
+// injectThinkingConfig adds thinking configuration based on metadata using the unified flow.
+// It uses util.ResolveClaudeThinkingConfig which internally calls ResolveThinkingConfigFromMetadata
+// and NormalizeThinkingBudget, ensuring consistency with other executors like Gemini.
 func (e *ClaudeExecutor) injectThinkingConfig(modelName string, metadata map[string]any, body []byte) []byte {
-	// Only inject if thinking config is not already present
-	if gjson.GetBytes(body, "thinking").Exists() {
+	budget, ok := util.ResolveClaudeThinkingConfig(modelName, metadata)
+	if !ok {
 		return body
 	}
-
-	budgetTokens, ok := resolveClaudeThinkingBudget(modelName, metadata)
-	if !ok || budgetTokens <= 0 {
-		return body
-	}
-
-	body, _ = sjson.SetBytes(body, "thinking.type", "enabled")
-	body, _ = sjson.SetBytes(body, "thinking.budget_tokens", budgetTokens)
-	return body
-}
-
-func resolveClaudeThinkingBudget(modelName string, metadata map[string]any) (int, bool) {
-	budget, include, effort, matched := util.ThinkingFromMetadata(metadata)
-	if matched {
-		if include != nil && !*include {
-			return 0, false
-		}
-		if budget != nil {
-			normalized := util.NormalizeThinkingBudget(modelName, *budget)
-			if normalized > 0 {
-				return normalized, true
-			}
-			return 0, false
-		}
-		if effort != nil {
-			if derived, ok := util.ThinkingEffortToBudget(modelName, *effort); ok && derived > 0 {
-				return derived, true
-			}
-		}
-	}
-	return claudeBudgetFromSuffix(modelName)
-}
-
-func claudeBudgetFromSuffix(modelName string) (int, bool) {
-	lower := strings.ToLower(strings.TrimSpace(modelName))
-	switch {
-	case strings.HasSuffix(lower, "-thinking-low"):
-		return 1024, true
-	case strings.HasSuffix(lower, "-thinking-medium"):
-		return 8192, true
-	case strings.HasSuffix(lower, "-thinking-high"):
-		return 24576, true
-	case strings.HasSuffix(lower, "-thinking"):
-		return 8192, true
-	default:
-		return 0, false
-	}
+	return util.ApplyClaudeThinkingConfig(body, budget)
 }
 
 // ensureMaxTokensForThinking ensures max_tokens > thinking.budget_tokens when thinking is enabled.
diff --git a/internal/util/claude_thinking.go b/internal/util/claude_thinking.go
new file mode 100644
index 00000000..b0c5a0a2
--- /dev/null
+++ b/internal/util/claude_thinking.go
@@ -0,0 +1,46 @@
+package util
+
+import (
+	"github.com/tidwall/gjson"
+	"github.com/tidwall/sjson"
+)
+
+// ApplyClaudeThinkingConfig applies thinking configuration to a Claude API request payload.
+// It sets the thinking.type to "enabled" and thinking.budget_tokens to the specified budget.
+// If budget is nil or the payload already has thinking config, it returns the payload unchanged.
+func ApplyClaudeThinkingConfig(body []byte, budget *int) []byte {
+	if budget == nil {
+		return body
+	}
+	if gjson.GetBytes(body, "thinking").Exists() {
+		return body
+	}
+	if *budget <= 0 {
+		return body
+	}
+	updated := body
+	updated, _ = sjson.SetBytes(updated, "thinking.type", "enabled")
+	updated, _ = sjson.SetBytes(updated, "thinking.budget_tokens", *budget)
+	return updated
+}
+
+// ResolveClaudeThinkingConfig resolves thinking configuration from metadata for Claude models.
+// It uses the unified ResolveThinkingConfigFromMetadata and normalizes the budget.
+// Returns the normalized budget (nil if thinking should not be enabled) and whether it matched.
+func ResolveClaudeThinkingConfig(modelName string, metadata map[string]any) (*int, bool) {
+	budget, include, matched := ResolveThinkingConfigFromMetadata(modelName, metadata)
+	if !matched {
+		return nil, false
+	}
+	if include != nil && !*include {
+		return nil, true
+	}
+	if budget == nil {
+		return nil, true
+	}
+	normalized := NormalizeThinkingBudget(modelName, *budget)
+	if normalized <= 0 {
+		return nil, true
+	}
+	return &normalized, true
+}