fix: improve GLM model detection patterns for LM Studio and OpenAI-compatible endpoints

Addresses Issue #11071 where GLM4.5 models via LM Studio get stuck
repeating file reads due to undetected model names.

Changes:
- Add isGlmModel() utility that uses a flexible regex pattern to detect
  GLM models anywhere in the model ID (case-insensitive)
- Handle model name formats like:
  - mlx-community/GLM-4.5-4bit
  - GLM-4.5-UD-Q8_K_XL-00001-of-00008.gguf
  - glm-4.5 (standard format)
  - chatglm variants
- Update LmStudioHandler to apply GLM-specific optimizations when detected
- Update BaseOpenAiCompatibleProvider similarly
- Add comprehensive tests for GLM model detection

When GLM model is detected:
- mergeToolResultText: true (prevents conversation flow disruption)
- parallel_tool_calls: false (GLM may not support this parameter)

src/api/providers/base-openai-compatible-provider.ts

@@ -14,6 +14,7 @@ import { BaseProvider } from "./base-provider"
 import { handleOpenAIError } from "./utils/openai-error-handler"
 import { calculateApiCostOpenAI } from "../../shared/cost"
 import { getApiRequestTimeout } from "./utils/timeout-config"
+import { getGlmModelOptions } from "./utils/glm-model-detection"
 
 type BaseOpenAiCompatibleProviderOptions<ModelName extends string> = ApiHandlerOptions & {
 	providerName: string
@@ -75,6 +76,9 @@ export abstract class BaseOpenAiCompatibleProvider<ModelName extends string>
 	) {
 		const { id: model, info } = this.getModel()
 
+		// Check if this is a GLM model and get recommended options
+		const glmOptions = getGlmModelOptions(model)
+
 		// Centralized cap: clamp to 20% of the context window (unless provider-specific exceptions apply)
 		const max_tokens =
 			getModelMaxOutputTokens({
@@ -86,16 +90,24 @@ export abstract class BaseOpenAiCompatibleProvider<ModelName extends string>
 
 		const temperature = this.options.modelTemperature ?? info.defaultTemperature ?? this.defaultTemperature
 
+		// For GLM models, disable parallel_tool_calls as they may not support it
+		const parallelToolCalls = glmOptions?.disableParallelToolCalls ? false : (metadata?.parallelToolCalls ?? true)
+
 		const params: OpenAI.Chat.Completions.ChatCompletionCreateParamsStreaming = {
 			model,
 			max_tokens,
 			temperature,
-			messages: [{ role: "system", content: systemPrompt }, ...convertToOpenAiMessages(messages)],
+			messages: [
+				{ role: "system", content: systemPrompt },
+				...convertToOpenAiMessages(messages, {
+					mergeToolResultText: glmOptions?.mergeToolResultText ?? false,
+				}),
+			],
 			stream: true,
 			stream_options: { include_usage: true },
 			tools: this.convertToolsForOpenAI(metadata?.tools),
 			tool_choice: metadata?.tool_choice,
-			parallel_tool_calls: metadata?.parallelToolCalls ?? true,
+			parallel_tool_calls: parallelToolCalls,
 		}
 
 		// Add thinking parameter if reasoning is enabled and model supports it

src/api/providers/lm-studio.ts

@@ -17,6 +17,7 @@ import type { SingleCompletionHandler, ApiHandlerCreateMessageMetadata } from ".
 import { getModelsFromCache } from "./fetchers/modelCache"
 import { getApiRequestTimeout } from "./utils/timeout-config"
 import { handleOpenAIError } from "./utils/openai-error-handler"
+import { getGlmModelOptions } from "./utils/glm-model-detection"
 
 export class LmStudioHandler extends BaseProvider implements SingleCompletionHandler {
 	protected options: ApiHandlerOptions
@@ -42,9 +43,16 @@ export class LmStudioHandler extends BaseProvider implements SingleCompletionHan
 		messages: Anthropic.Messages.MessageParam[],
 		metadata?: ApiHandlerCreateMessageMetadata,
 	): ApiStream {
+		const modelId = this.getModel().id
+
+		// Check if this is a GLM model and get recommended options
+		const glmOptions = getGlmModelOptions(modelId)
+
 		const openAiMessages: OpenAI.Chat.ChatCompletionMessageParam[] = [
 			{ role: "system", content: systemPrompt },
-			...convertToOpenAiMessages(messages),
+			...convertToOpenAiMessages(messages, {
+				mergeToolResultText: glmOptions?.mergeToolResultText ?? false,
+			}),
 		]
 
 		// -------------------------
@@ -83,14 +91,19 @@ export class LmStudioHandler extends BaseProvider implements SingleCompletionHan
 		let assistantText = ""
 
 		try {
+			// For GLM models, disable parallel_tool_calls as they may not support it
+			const parallelToolCalls = glmOptions?.disableParallelToolCalls
+				? false
+				: (metadata?.parallelToolCalls ?? true)
+
 			const params: OpenAI.Chat.ChatCompletionCreateParamsStreaming & { draft_model?: string } = {
-				model: this.getModel().id,
+				model: modelId,
 				messages: openAiMessages,
 				temperature: this.options.modelTemperature ?? LMSTUDIO_DEFAULT_TEMPERATURE,
 				stream: true,
 				tools: this.convertToolsForOpenAI(metadata?.tools),
 				tool_choice: metadata?.tool_choice,
-				parallel_tool_calls: metadata?.parallelToolCalls ?? true,
+				parallel_tool_calls: parallelToolCalls,
 			}
 
 			if (this.options.lmStudioSpeculativeDecodingEnabled && this.options.lmStudioDraftModelId) {

src/api/providers/utils/__tests__/glm-model-detection.spec.ts

@@ -0,0 +1,115 @@
+import { isGlmModel, getGlmModelOptions } from "../glm-model-detection"
+
+describe("GLM Model Detection", () => {
+	describe("isGlmModel", () => {
+		describe("should detect GLM models", () => {
+			const validGlmModels = [
+				// Standard Z.ai format
+				"glm-4.5",
+				"glm-4.6",
+				"glm-4.7",
+				"glm-4.5-air",
+				"glm-4.5v",
+				// MLX format (from user's report)
+				"mlx-community/GLM-4.5-4bit",
+				"mlx-community/GLM-4.5-8bit",
+				// GGUF format (from user's report)
+				"GLM-4.5-UD-Q8_K_XL-00001-of-00008.gguf",
+				"GLM-4.5-UD-Q4_K_M.gguf",
+				// HuggingFace format
+				"THUDM/glm-4-9b-chat",
+				"THUDM/glm-4v-9b",
+				// ChatGLM variants
+				"chatglm-6b",
+				"chatglm2-6b",
+				"chatglm3-6b",
+				"ChatGLM-6B",
+				// Without hyphen
+				"glm4",
+				"GLM4",
+				// Mixed case
+				"GLM-4.5",
+				"Glm-4.5",
+			]
+
+			test.each(validGlmModels)('should detect "%s" as a GLM model', (modelId) => {
+				expect(isGlmModel(modelId)).toBe(true)
+			})
+		})
+
+		describe("should NOT detect non-GLM models", () => {
+			const nonGlmModels = [
+				// OpenAI models
+				"gpt-4",
+				"gpt-4-turbo",
+				"gpt-3.5-turbo",
+				"o1-preview",
+				// Anthropic models
+				"claude-3-opus",
+				"claude-3.5-sonnet",
+				// Llama models
+				"llama-3.1-70b",
+				"meta-llama/Llama-3.1-8B-Instruct",
+				// Mistral models
+				"mistral-7b",
+				"mixtral-8x7b",
+				// DeepSeek models
+				"deepseek-coder",
+				"deepseek-reasoner",
+				// Qwen models
+				"qwen-2.5-72b",
+				"qwen-coder",
+				// Empty/undefined
+				"",
+			]
+
+			test.each(nonGlmModels)('should NOT detect "%s" as a GLM model', (modelId) => {
+				expect(isGlmModel(modelId)).toBe(false)
+			})
+		})
+
+		it("should return false for undefined modelId", () => {
+			expect(isGlmModel(undefined)).toBe(false)
+		})
+	})
+
+	describe("getGlmModelOptions", () => {
+		it("should return options for GLM models", () => {
+			const options = getGlmModelOptions("glm-4.5")
+			expect(options).toEqual({
+				mergeToolResultText: true,
+				disableParallelToolCalls: true,
+			})
+		})
+
+		it("should return options for MLX GLM models", () => {
+			const options = getGlmModelOptions("mlx-community/GLM-4.5-4bit")
+			expect(options).toEqual({
+				mergeToolResultText: true,
+				disableParallelToolCalls: true,
+			})
+		})
+
+		it("should return options for GGUF GLM models", () => {
+			const options = getGlmModelOptions("GLM-4.5-UD-Q8_K_XL-00001-of-00008.gguf")
+			expect(options).toEqual({
+				mergeToolResultText: true,
+				disableParallelToolCalls: true,
+			})
+		})
+
+		it("should return undefined for non-GLM models", () => {
+			expect(getGlmModelOptions("gpt-4")).toBeUndefined()
+			expect(getGlmModelOptions("llama-3.1")).toBeUndefined()
+			expect(getGlmModelOptions("claude-3")).toBeUndefined()
+		})
+
+		it("should return undefined for undefined modelId", () => {
+			expect(getGlmModelOptions(undefined)).toBeUndefined()
+		})
+
+		it("should return undefined for empty string", () => {
+			expect(getGlmModelOptions("")).toBeUndefined()
+		})
+	})
+})

src/api/providers/utils/glm-model-detection.ts

@@ -0,0 +1,80 @@
+/**
+ * Utility functions for detecting GLM (General Language Model) models.
+ *
+ * GLM models from Z.ai/THUDM may require special handling:
+ * - mergeToolResultText: true - prevents conversation flow disruption
+ * - parallel_tool_calls: false - some GLM models do not support this parameter
+ */
+
+/**
+ * Pattern to detect GLM models in model IDs.
+ *
+ * This regex matches "glm" anywhere in the model ID (case-insensitive),
+ * including common variations like:
+ * - "glm-4.5" (standard Z.ai format)
+ * - "glm4" (without hyphen)
+ * - "chatglm" (ChatGLM variants)
+ * - "mlx-community/GLM-4.5-4bit" (MLX format with prefix)
+ * - "GLM-4.5-UD-Q8_K_XL-00001-of-00008.gguf" (GGUF format)
+ * - "THUDM/glm-4-9b-chat" (HuggingFace format)
+ */
+const GLM_MODEL_PATTERN = /glm/i
+
+/**
+ * Detects if a model ID represents a GLM (General Language Model) model.
+ *
+ * @param modelId - The model ID to check (e.g., "glm-4.5", "mlx-community/GLM-4.5-4bit")
+ * @returns true if the model ID indicates a GLM model, false otherwise
+ *
+ * @example
+ * ```typescript
+ * isGlmModel("glm-4.5") // true
+ * isGlmModel("mlx-community/GLM-4.5-4bit") // true
+ * isGlmModel("GLM-4.5-UD-Q8_K_XL.gguf") // true
+ * isGlmModel("chatglm-6b") // true
+ * isGlmModel("gpt-4") // false
+ * isGlmModel("llama-3.1") // false
+ * ```
+ */
+export function isGlmModel(modelId: string | undefined): boolean {
+	if (!modelId) {
+		return false
+	}
+	return GLM_MODEL_PATTERN.test(modelId)
+}
+
+/**
+ * Configuration options for GLM models when used via LM Studio
+ * or OpenAI-compatible endpoints.
+ */
+export interface GlmModelOptions {
+	/**
+	 * If true, merge text content after tool_results into the last tool message
+	 * instead of creating a separate user message. This prevents GLM models from
+	 * losing context or reasoning_content after tool results.
+	 */
+	mergeToolResultText: boolean
+
+	/**
+	 * If true, disable parallel_tool_calls parameter for GLM models
+	 * since they may not support it.
+	 */
+	disableParallelToolCalls: boolean
+}
+
+/**
+ * Returns the recommended configuration options for a GLM model.
+ *
+ * @param modelId - The model ID to check
+ * @returns GlmModelOptions if GLM model detected, undefined otherwise
+ */
+export function getGlmModelOptions(modelId: string | undefined): GlmModelOptions | undefined {
+	if (!isGlmModel(modelId)) {
+		return undefined
+	}
+
+	return {
+		mergeToolResultText: true,
+		disableParallelToolCalls: true,
+	}
+}