fix: 修复 OpenAI provider （gpt-5.4/gpt-5.3-codex等模型）下 内建mcp__plugin_weixin_weixin__reply 微信工具不可见的问题 (#359)

* fix: 修复 OpenAI provider 下 MCP 工具不可见

* docs: 补充 OpenAI MCP 工具列表注释

* fix: 修正 OpenAI Langfuse 输入记录

* refactor: 使用类型守卫收窄 Langfuse role

* fix: 保留 Langfuse OpenAI 数组消息角色

* fix: 合并 Langfuse OpenAI tool_calls

* fix: 修复 OpenAI Langfuse 类型检查

src/services/api/openai/index.ts

@@ -5,6 +5,7 @@ import type {
   StreamEvent,
   SystemAPIErrorMessage,
   AssistantMessage,
+  UserMessage,
 } from '../../../types/message.js'
 import type { AgentId } from '../../../types/ids.js'
 import type { Tools } from '../../../Tool.js'
@@ -32,18 +33,58 @@ import type { Options } from '../claude.js'
 import { randomUUID } from 'crypto'
 import {
   createAssistantAPIErrorMessage,
+  createUserMessage,
   normalizeContentFromAPI,
 } from '../../../utils/messages.js'
 import type { SDKAssistantMessageError } from '../../../entrypoints/agentSdkTypes.js'
 import {
   isToolSearchEnabled,
   extractDiscoveredToolNames,
+  isDeferredToolsDeltaEnabled,
 } from '../../../utils/toolSearch.js'
 import {
+  formatDeferredToolLine,
   isDeferredTool,
   TOOL_SEARCH_TOOL_NAME,
 } from '@claude-code-best/builtin-tools/tools/ToolSearchTool/prompt.js'
 
+/**
+ * Mirrors the Anthropic request path's deferred-tool announcement for OpenAI.
+ *
+ * OpenAI-compatible endpoints cannot consume Anthropic's `defer_loading` or
+ * `tool_reference` beta payloads directly, so the model needs the same textual
+ * list of deferred MCP tool names that Anthropic receives before it can ask
+ * ToolSearchTool to load their full schemas.
+ */
+function prependDeferredToolListIfNeeded(
+  messages: (AssistantMessage | UserMessage)[],
+  tools: Tools,
+  deferredToolNames: Set<string>,
+  useToolSearch: boolean,
+): (AssistantMessage | UserMessage)[] {
+  if (!useToolSearch || isDeferredToolsDeltaEnabled()) return messages
+
+  const deferredToolList = tools
+    .filter(tool => deferredToolNames.has(tool.name))
+    .map(formatDeferredToolLine)
+    .sort()
+    .join('\n')
+
+  if (!deferredToolList) return messages
+
+  return [
+    createUserMessage({
+      content: `<available-deferred-tools>\n${deferredToolList}\n</available-deferred-tools>`,
+      isMeta: true,
+    }),
+    ...messages,
+  ]
+}
+
+function isOpenAIConvertibleMessage(msg: Message): msg is AssistantMessage | UserMessage {
+  return msg.type === 'assistant' || msg.type === 'user'
+}
+
 /**
  * Assemble the final AssistantMessage (and optional max_tokens error) from
  * accumulated stream state. Extracted to avoid duplication between the
@@ -176,9 +217,18 @@ export async function* queryModelOpenAI(
 
     // 8. Convert messages and tools to OpenAI format
     const enableThinking = isOpenAIThinkingEnabled(openaiModel)
-    const openaiMessages = anthropicMessagesToOpenAI(messagesForAPI, systemPrompt, {
-      enableThinking,
-    })
+    const openAIConvertibleMessages = messagesForAPI.filter(isOpenAIConvertibleMessage)
+    const messagesWithDeferredToolList = prependDeferredToolListIfNeeded(
+      openAIConvertibleMessages,
+      tools,
+      deferredToolNames,
+      useToolSearch,
+    )
+    const openaiMessages = anthropicMessagesToOpenAI(
+      messagesWithDeferredToolList,
+      systemPrompt,
+      { enableThinking },
+    )
     const openaiTools = anthropicToolsToOpenAI(standardTools)
     const openaiToolChoice = anthropicToolChoiceToOpenAI(options.toolChoice)
 
@@ -356,7 +406,7 @@ export async function* queryModelOpenAI(
     recordLLMObservation(options.langfuseTrace ?? null, {
       model: openaiModel,
       provider: 'openai',
-      input: convertMessagesToLangfuse(messagesForAPI, systemPrompt),
+      input: convertMessagesToLangfuse(openaiMessages),
       output: convertOutputToLangfuse(collectedMessages),
       usage: {
         input_tokens: usage.input_tokens,