fix: remove non-standard thinking/reasoning_max_tokens from Claude-to… (#3667)

plugins/wasm-go/extensions/ai-proxy/provider/provider.go

@@ -168,6 +168,8 @@ const (
 	finishReasonLength   = "length"
 	finishReasonToolCall = "tool_calls"
 
+	ctxKeyClaudeBudgetTokens     = "claudeBudgetTokens"
+	ctxKeyClaudeThinkingType     = "claudeThinkingType"
 	ctxKeyIncrementalStreaming   = "incrementalStreaming"
 	ctxKeyApiKey                 = "apiKey"
 	CtxKeyApiName                = "apiName"
@@ -1155,6 +1157,21 @@ func (c *ProviderConfig) handleRequestBody(
 	// If main.go detected a Claude request that needs conversion, convert the body
 	needClaudeConversion, _ := ctx.GetContext("needClaudeResponseConversion").(bool)
 	if needClaudeConversion {
+		// Extract thinking config from original Claude body before conversion,
+		// so downstream providers (OpenRouter, ZhipuAI) can access it.
+		thinkingType := gjson.GetBytes(body, "thinking.type").String()
+		if thinkingType == "" {
+			// Claude request had no thinking field at all - treat as disabled
+			thinkingType = "disabled"
+		}
+		ctx.SetContext(ctxKeyClaudeThinkingType, thinkingType)
+		// Only extract budget_tokens when thinking is explicitly enabled
+		if thinkingType == "enabled" {
+			if budgetTokens := gjson.GetBytes(body, "thinking.budget_tokens").Int(); budgetTokens > 0 {
+				ctx.SetContext(ctxKeyClaudeBudgetTokens, int(budgetTokens))
+			}
+		}
+
 		// Convert Claude protocol to OpenAI protocol
 		converter := &ClaudeToOpenAIConverter{}
 		body, err = converter.ConvertClaudeRequestToOpenAI(body)