From c80ab8bf0d22a5fe0117fcecf3416aa46832bc6a Mon Sep 17 00:00:00 2001
From: hkfires <10558748+hkfires@users.noreply.github.com>
Date: Tue, 3 Mar 2026 19:05:15 +0800
Subject: [PATCH] feat(thinking): improve provider family checks and clamp
 unsupported levels

---
 internal/thinking/validate.go    | 24 +++++++++++++++++++--
 test/thinking_conversion_test.go | 36 ++++++++++++++++++--------------
 2 files changed, 42 insertions(+), 18 deletions(-)

diff --git a/internal/thinking/validate.go b/internal/thinking/validate.go
index 7f5c57c5..d1f784c5 100644
--- a/internal/thinking/validate.go
+++ b/internal/thinking/validate.go
@@ -53,7 +53,17 @@ func ValidateConfig(config ThinkingConfig, modelInfo *registry.ModelInfo, fromFo
 		return &config, nil
 	}
 
-	allowClampUnsupported := isBudgetBasedProvider(fromFormat) && isLevelBasedProvider(toFormat)
+	// allowClampUnsupported determines whether to clamp unsupported levels instead of returning an error.
+	// This applies when crossing provider families (e.g., openai→gemini, claude→gemini) and the target
+	// model supports discrete levels. Same-family conversions require strict validation.
+	toCapability := detectModelCapability(modelInfo)
+	toHasLevelSupport := toCapability == CapabilityLevelOnly || toCapability == CapabilityHybrid
+	allowClampUnsupported := toHasLevelSupport && !isSameProviderFamily(fromFormat, toFormat)
+
+	// strictBudget determines whether to enforce strict budget range validation.
+	// This applies when: (1) config comes from request body (not suffix), (2) source format is known,
+	// and (3) source and target are in the same provider family. Cross-family or suffix-based configs
+	// are clamped instead of rejected to improve interoperability.
 	strictBudget := !fromSuffix && fromFormat != "" && isSameProviderFamily(fromFormat, toFormat)
 	budgetDerivedFromLevel := false
 
@@ -352,11 +362,21 @@ func isGeminiFamily(provider string) bool {
 	}
 }
 
+func isOpenAIFamily(provider string) bool {
+	switch provider {
+	case "openai", "openai-response", "codex":
+		return true
+	default:
+		return false
+	}
+}
+
 func isSameProviderFamily(from, to string) bool {
 	if from == to {
 		return true
 	}
-	return isGeminiFamily(from) && isGeminiFamily(to)
+	return (isGeminiFamily(from) && isGeminiFamily(to)) ||
+		(isOpenAIFamily(from) && isOpenAIFamily(to))
 }
 
 func abs(x int) int {
diff --git a/test/thinking_conversion_test.go b/test/thinking_conversion_test.go
index 271cc7e5..7d9b7b86 100644
--- a/test/thinking_conversion_test.go
+++ b/test/thinking_conversion_test.go
@@ -386,15 +386,17 @@ func TestThinkingE2EMatrix_Suffix(t *testing.T) {
 			includeThoughts: "true",
 			expectErr:       false,
 		},
-		// Case 30: Effort xhigh → not in low/high → error
+		// Case 30: Effort xhigh → clamped to high
 		{
-			name:        "30",
-			from:        "openai",
-			to:          "gemini",
-			model:       "gemini-mixed-model(xhigh)",
-			inputJSON:   `{"model":"gemini-mixed-model(xhigh)","messages":[{"role":"user","content":"hi"}]}`,
-			expectField: "",
-			expectErr:   true,
+			name:            "30",
+			from:            "openai",
+			to:              "gemini",
+			model:           "gemini-mixed-model(xhigh)",
+			inputJSON:       `{"model":"gemini-mixed-model(xhigh)","messages":[{"role":"user","content":"hi"}]}`,
+			expectField:     "generationConfig.thinkingConfig.thinkingLevel",
+			expectValue:     "high",
+			includeThoughts: "true",
+			expectErr:       false,
 		},
 		// Case 31: Effort none → clamped to low (min supported) → includeThoughts=false
 		{
@@ -1668,15 +1670,17 @@ func TestThinkingE2EMatrix_Body(t *testing.T) {
 			includeThoughts: "true",
 			expectErr:       false,
 		},
-		// Case 30: reasoning_effort=xhigh → error (not in low/high)
+		// Case 30: reasoning_effort=xhigh → clamped to high
 		{
-			name:        "30",
-			from:        "openai",
-			to:          "gemini",
-			model:       "gemini-mixed-model",
-			inputJSON:   `{"model":"gemini-mixed-model","messages":[{"role":"user","content":"hi"}],"reasoning_effort":"xhigh"}`,
-			expectField: "",
-			expectErr:   true,
+			name:            "30",
+			from:            "openai",
+			to:              "gemini",
+			model:           "gemini-mixed-model",
+			inputJSON:       `{"model":"gemini-mixed-model","messages":[{"role":"user","content":"hi"}],"reasoning_effort":"xhigh"}`,
+			expectField:     "generationConfig.thinkingConfig.thinkingLevel",
+			expectValue:     "high",
+			includeThoughts: "true",
+			expectErr:       false,
 		},
 		// Case 31: reasoning_effort=none → clamped to low → includeThoughts=false
 		{