diff --git a/astrbot/core/config/default.py b/astrbot/core/config/default.py
index 5bf7de7a45..e672680b80 100644
--- a/astrbot/core/config/default.py
+++ b/astrbot/core/config/default.py
@@ -1360,7 +1360,7 @@
                         "api_base": "https://api.kimi.com/coding",
                         "timeout": 120,
                         "proxy": "",
-                        "custom_headers": {"User-Agent": "claude-code/0.1.0"},
+                        "custom_headers": {},
                         "anth_thinking_config": {"type": "", "budget": 0, "effort": ""},
                     },
                     "Moonshot": {
@@ -1397,7 +1397,7 @@
                         "api_base": "https://api.minimaxi.com/anthropic",
                         "timeout": 120,
                         "proxy": "",
-                        "custom_headers": {"User-Agent": "claude-code/0.1.0"},
+                        "custom_headers": {},
                         "anth_thinking_config": {"type": "", "budget": 0, "effort": ""},
                     },
                     "Xiaomi": {
@@ -1422,7 +1422,7 @@
                         "api_base": "https://token-plan-cn.xiaomimimo.com/anthropic",
                         "timeout": 120,
                         "proxy": "",
-                        "custom_headers": {"User-Agent": "claude-code/0.1.0"},
+                        "custom_headers": {},
                         "anth_thinking_config": {"type": "", "budget": 0, "effort": ""},
                     },
                     "xAI": {
diff --git a/astrbot/core/provider/headers.py b/astrbot/core/provider/headers.py
new file mode 100644
index 0000000000..b40d3f94ba
--- /dev/null
+++ b/astrbot/core/provider/headers.py
@@ -0,0 +1,24 @@
+from astrbot import __version__
+
+DEFAULT_USER_AGENT = f"astrbot/{__version__}"
+
+
+def build_provider_headers(custom_headers: object = None) -> dict[str, str]:
+    """Build provider headers with an overridable AstrBot user agent.
+
+    Args:
+        custom_headers: Optional header mapping from provider configuration.
+
+    Returns:
+        A new header dictionary with string values and one User-Agent header.
+    """
+    headers = {"User-Agent": DEFAULT_USER_AGENT}
+    if isinstance(custom_headers, dict):
+        for name, value in custom_headers.items():
+            name, value = str(name), str(value)
+            if name.lower() == "user-agent":
+                if value.strip():
+                    headers["User-Agent"] = value
+            else:
+                headers[name] = value
+    return headers
diff --git a/astrbot/core/provider/provider.py b/astrbot/core/provider/provider.py
index 891bfdea9e..5e1274c24c 100644
--- a/astrbot/core/provider/provider.py
+++ b/astrbot/core/provider/provider.py
@@ -12,6 +12,7 @@
     RerankResult,
     ToolCallsResult,
 )
+from astrbot.core.provider.headers import build_provider_headers
 from astrbot.core.provider.register import provider_cls_map
 from astrbot.core.utils.astrbot_path import get_astrbot_path
 
@@ -31,6 +32,9 @@ def __init__(self, provider_config: dict) -> None:
         super().__init__()
         self.model_name = ""
         self.provider_config = provider_config
+        self.request_headers = build_provider_headers(
+            provider_config.get("custom_headers")
+        )
 
     def set_model(self, model_name: str) -> None:
         """Set the current model name"""
diff --git a/astrbot/core/provider/sources/anthropic_source.py b/astrbot/core/provider/sources/anthropic_source.py
index c861ded6ba..5a21737b44 100644
--- a/astrbot/core/provider/sources/anthropic_source.py
+++ b/astrbot/core/provider/sources/anthropic_source.py
@@ -26,6 +26,7 @@
     log_connection_failure,
 )
 
+from ..headers import build_provider_headers
 from ..register import register_provider_adapter
 from .request_retry import retry_provider_request, retry_provider_request_context
 
@@ -71,12 +72,14 @@ def _resolve_custom_headers(
         *,
         required_headers: dict[str, str] | None = None,
     ) -> dict[str, str] | None:
-        merged_headers = cls._normalize_custom_headers(provider_config) or {}
+        merged_headers = build_provider_headers(
+            cls._normalize_custom_headers(provider_config)
+        )
         if required_headers:
             for header_name, header_value in required_headers.items():
                 if not merged_headers.get(header_name, "").strip():
                     merged_headers[header_name] = header_value
-        return merged_headers or None
+        return merged_headers
 
     def __init__(
         self,
diff --git a/astrbot/core/provider/sources/azure_tts_source.py b/astrbot/core/provider/sources/azure_tts_source.py
index 34d8116cf5..6c039122d8 100644
--- a/astrbot/core/provider/sources/azure_tts_source.py
+++ b/astrbot/core/provider/sources/azure_tts_source.py
@@ -10,7 +10,7 @@
 from httpx import AsyncClient, Timeout
 
 from astrbot import logger
-from astrbot.core.config.default import VERSION
+from astrbot.core.provider.headers import build_provider_headers
 from astrbot.core.utils.astrbot_path import get_astrbot_temp_path
 from astrbot.core.utils.datetime_utils import generate_timestamp_id
 
@@ -25,6 +25,7 @@
 
 class OTTSProvider:
     def __init__(self, config: dict) -> None:
+        self.request_headers = build_provider_headers(config.get("custom_headers"))
         self.skey = config["OTTS_SKEY"]
         self.api_url = config["OTTS_URL"]
         self.auth_time_url = config["OTTS_AUTH_TIME"]
@@ -47,7 +48,9 @@ def client(self) -> AsyncClient:
 
     async def __aenter__(self):
         self._client = AsyncClient(
-            timeout=self.timeout, proxy=self.proxy if self.proxy else None
+            headers=self.request_headers,
+            timeout=self.timeout,
+            proxy=self.proxy if self.proxy else None,
         )
         return self
 
@@ -93,7 +96,7 @@ async def get_audio(self, text: str, voice_params: dict) -> str:
                         "volume": voice_params["volume"],
                     },
                     headers={
-                        "User-Agent": f"AstrBot/{VERSION}",
+                        **self.request_headers,
                         "UAK": "AstrBot/AzureTTS",
                     },
                 )
@@ -148,7 +151,7 @@ def client(self) -> AsyncClient:
     async def __aenter__(self):
         self._client = AsyncClient(
             headers={
-                "User-Agent": f"AstrBot/{VERSION}",
+                **self.request_headers,
                 "Content-Type": "application/ssml+xml",
                 "X-Microsoft-OutputFormat": "riff-48khz-16bit-mono-pcm",
             },
@@ -194,7 +197,7 @@ async def get_audio(self, text: str) -> str:
             content=ssml,
             headers={
                 "Authorization": f"Bearer {self.token}",
-                "User-Agent": f"AstrBot/{VERSION}",
+                **self.request_headers,
             },
         )
         response.raise_for_status()
@@ -223,6 +226,7 @@ def _parse_provider(
                     raise ValueError("无效的other[...]格式，应形如 other[{...}]")
                 json_str = match.group(1).strip()
                 otts_config = json.loads(json_str)
+                otts_config.setdefault("custom_headers", config.get("custom_headers"))
                 required = {"OTTS_SKEY", "OTTS_URL", "OTTS_AUTH_TIME"}
                 if missing := required - otts_config.keys():
                     raise ValueError(f"缺少OTTS参数: {', '.join(missing)}")
diff --git a/astrbot/core/provider/sources/bailian_rerank_source.py b/astrbot/core/provider/sources/bailian_rerank_source.py
index 030f59dd57..11c8334aac 100644
--- a/astrbot/core/provider/sources/bailian_rerank_source.py
+++ b/astrbot/core/provider/sources/bailian_rerank_source.py
@@ -70,7 +70,8 @@ def __init__(self, provider_config: dict, provider_settings: dict) -> None:
         }
 
         self.client = aiohttp.ClientSession(
-            headers=headers, timeout=aiohttp.ClientTimeout(total=self.timeout)
+            headers={**self.request_headers, **headers},
+            timeout=aiohttp.ClientTimeout(total=self.timeout),
         )
 
         # 设置模型名称
diff --git a/astrbot/core/provider/sources/dashscope_embedding_source.py b/astrbot/core/provider/sources/dashscope_embedding_source.py
index 5502016697..56fd14fb38 100644
--- a/astrbot/core/provider/sources/dashscope_embedding_source.py
+++ b/astrbot/core/provider/sources/dashscope_embedding_source.py
@@ -69,7 +69,10 @@ async def get_embeddings(self, text: list[str]) -> list[list[float]]:
             or self.model.startswith("tongyi-embedding-vision")
         )
 
-        kwargs: dict = {"base_address": self.base_url}
+        kwargs: dict = {
+            "base_address": self.base_url,
+            "headers": self.request_headers.copy(),
+        }
         if "embedding_dimensions" in self.provider_config:
             try:
                 dimensions = int(self.provider_config["embedding_dimensions"])
diff --git a/astrbot/core/provider/sources/dashscope_tts.py b/astrbot/core/provider/sources/dashscope_tts.py
index 6019ad0932..00c082b6b8 100644
--- a/astrbot/core/provider/sources/dashscope_tts.py
+++ b/astrbot/core/provider/sources/dashscope_tts.py
@@ -71,6 +71,7 @@ def _call_qwen_tts(self, model: str, text: str):
 
         kwargs = {
             "model": model,
+            "headers": self.request_headers.copy(),
             "messages": None,
             "api_key": self.chosen_api_key,
             "voice": self.voice or "Cherry",
@@ -122,7 +123,9 @@ async def _download_audio_from_url(self, url: str) -> bytes | None:
         timeout = max(self.timeout_ms / 1000, 1) if self.timeout_ms else 20
         try:
             async with (
-                aiohttp.ClientSession() as session,
+                aiohttp.ClientSession(
+                    headers={"User-Agent": self.request_headers["User-Agent"]}
+                ) as session,
                 session.get(
                     url,
                     timeout=aiohttp.ClientTimeout(total=timeout),
@@ -139,6 +142,9 @@ async def _synthesize_with_cosyvoice(
         text: str,
     ) -> tuple[bytes | None, str]:
         synthesizer = SpeechSynthesizer(
+            headers={
+                name.lower(): value for name, value in self.request_headers.items()
+            },
             model=model,
             voice=self.voice,
             format=AudioFormat.WAV_24000HZ_MONO_16BIT,
diff --git a/astrbot/core/provider/sources/edge_tts_source.py b/astrbot/core/provider/sources/edge_tts_source.py
index f4604be6a3..3cf39883ec 100644
--- a/astrbot/core/provider/sources/edge_tts_source.py
+++ b/astrbot/core/provider/sources/edge_tts_source.py
@@ -3,8 +3,10 @@
 import subprocess
 
 import edge_tts
+from edge_tts.constants import WSS_HEADERS
 
 from astrbot.core import logger
+from astrbot.core.provider.headers import DEFAULT_USER_AGENT
 from astrbot.core.utils.astrbot_path import get_astrbot_temp_path
 from astrbot.core.utils.datetime_utils import generate_timestamp_id
 
@@ -12,6 +14,9 @@
 from ..provider import TTSProvider
 from ..register import register_provider_adapter
 
+# Edge TTS exposes synthesis headers as a shared SDK default, not a client option.
+WSS_HEADERS["User-Agent"] = DEFAULT_USER_AGENT
+
 """
 edge_tts 方式，能够免费、快速生成语音，使用需要先安装edge-tts库
 ```
diff --git a/astrbot/core/provider/sources/elevenlabs_tts_source.py b/astrbot/core/provider/sources/elevenlabs_tts_source.py
index f6977e8b21..3cfa36c313 100644
--- a/astrbot/core/provider/sources/elevenlabs_tts_source.py
+++ b/astrbot/core/provider/sources/elevenlabs_tts_source.py
@@ -119,6 +119,7 @@ def __init__(
         if proxy:
             logger.info(f"[ElevenLabs TTS] 使用代理: {proxy}")
         self.client = httpx.AsyncClient(
+            headers=self.request_headers,
             timeout=timeout,
             proxy=proxy or None,
             trust_env=False,
diff --git a/astrbot/core/provider/sources/fishaudio_tts_api_source.py b/astrbot/core/provider/sources/fishaudio_tts_api_source.py
index 2330f52128..7fe3aa2e9c 100644
--- a/astrbot/core/provider/sources/fishaudio_tts_api_source.py
+++ b/astrbot/core/provider/sources/fishaudio_tts_api_source.py
@@ -65,6 +65,7 @@ def __init__(
         if self.proxy:
             logger.info(f"[FishAudio TTS] 使用代理: {self.proxy}")
         self.headers = {
+            **self.request_headers,
             "Authorization": f"Bearer {self.chosen_api_key}",
         }
         # FishAudio API 要求 model 作为 HTTP header 发送，而非请求体字段
diff --git a/astrbot/core/provider/sources/gemini_embedding_source.py b/astrbot/core/provider/sources/gemini_embedding_source.py
index 71e9dadc9d..0723d55f4c 100644
--- a/astrbot/core/provider/sources/gemini_embedding_source.py
+++ b/astrbot/core/provider/sources/gemini_embedding_source.py
@@ -24,7 +24,9 @@ def __init__(self, provider_config: dict, provider_settings: dict) -> None:
         api_base: str = provider_config["embedding_api_base"]
         timeout: int = int(provider_config.get("timeout", 20))
 
-        http_options = types.HttpOptions(timeout=timeout * 1000)
+        http_options = types.HttpOptions(
+            timeout=timeout * 1000, headers=self.request_headers
+        )
         if api_base:
             api_base = api_base.removesuffix("/")
             http_options.base_url = api_base
@@ -34,6 +36,8 @@ def __init__(self, provider_config: dict, provider_settings: dict) -> None:
             logger.info(f"[Gemini Embedding] 使用代理: {proxy}")
 
         self.client = genai.Client(api_key=api_key, http_options=http_options).aio
+        # The SDK adds its own lower-case UA alongside our explicit header.
+        self.client._api_client._http_options.headers.pop("user-agent", None)
 
         self.model = provider_config.get(
             "embedding_model",
diff --git a/astrbot/core/provider/sources/gemini_source.py b/astrbot/core/provider/sources/gemini_source.py
index b6b7a97fb2..00268b2c0b 100644
--- a/astrbot/core/provider/sources/gemini_source.py
+++ b/astrbot/core/provider/sources/gemini_source.py
@@ -85,6 +85,7 @@ def _init_client(self) -> None:
         """初始化Gemini客户端"""
         proxy = self.provider_config.get("proxy", "")
         http_options = types.HttpOptions(
+            headers=self.request_headers,
             base_url=self.api_base,
             timeout=self.timeout * 1000,  # 毫秒
         )
@@ -114,6 +115,8 @@ def _init_client(self) -> None:
             api_key=self.chosen_api_key,
             http_options=http_options,
         ).aio
+        # The SDK adds its own lower-case UA alongside our explicit header.
+        self.client._api_client._http_options.headers.pop("user-agent", None)
 
     def _init_safety_settings(self) -> None:
         """初始化安全设置"""
diff --git a/astrbot/core/provider/sources/gemini_tts_source.py b/astrbot/core/provider/sources/gemini_tts_source.py
index 03b5405b82..136916aa1d 100644
--- a/astrbot/core/provider/sources/gemini_tts_source.py
+++ b/astrbot/core/provider/sources/gemini_tts_source.py
@@ -28,7 +28,9 @@ def __init__(
         api_key: str = provider_config.get("gemini_tts_api_key", "")
         api_base: str | None = provider_config.get("gemini_tts_api_base")
         timeout: int = int(provider_config.get("gemini_tts_timeout", 20))
-        http_options = types.HttpOptions(timeout=timeout * 1000)
+        http_options = types.HttpOptions(
+            timeout=timeout * 1000, headers=self.request_headers
+        )
 
         if api_base:
             api_base = api_base.removesuffix("/")
@@ -39,6 +41,8 @@ def __init__(
             logger.info(f"[Gemini TTS] 使用代理: {proxy}")
 
         self.client = genai.Client(api_key=api_key, http_options=http_options).aio
+        # The SDK adds its own lower-case UA alongside our explicit header.
+        self.client._api_client._http_options.headers.pop("user-agent", None)
         self.model: str = provider_config.get(
             "gemini_tts_model",
             "gemini-2.5-flash-preview-tts",
diff --git a/astrbot/core/provider/sources/gsv_selfhosted_source.py b/astrbot/core/provider/sources/gsv_selfhosted_source.py
index f9c9076688..f4cac0ce1e 100644
--- a/astrbot/core/provider/sources/gsv_selfhosted_source.py
+++ b/astrbot/core/provider/sources/gsv_selfhosted_source.py
@@ -42,6 +42,7 @@ def __init__(
     async def initialize(self) -> None:
         """异步初始化：在 ProviderManager 中被调用"""
         self._session = aiohttp.ClientSession(
+            headers=self.request_headers,
             timeout=aiohttp.ClientTimeout(total=self.timeout),
         )
         try:
diff --git a/astrbot/core/provider/sources/gsvi_tts_source.py b/astrbot/core/provider/sources/gsvi_tts_source.py
index f875ecb4b2..d8ae84aa8f 100644
--- a/astrbot/core/provider/sources/gsvi_tts_source.py
+++ b/astrbot/core/provider/sources/gsvi_tts_source.py
@@ -50,7 +50,7 @@ async def get_audio(self, text: str) -> str:
             "text_lang": self.text_lang,
         }
 
-        async with aiohttp.ClientSession() as session:
+        async with aiohttp.ClientSession(headers=self.request_headers) as session:
             async with session.post(url, json=data, headers=headers) as response:
                 if response.status == 200:
                     resp_json = await response.json()
diff --git a/astrbot/core/provider/sources/kimi_code_source.py b/astrbot/core/provider/sources/kimi_code_source.py
index 02c200271f..bac18ce190 100644
--- a/astrbot/core/provider/sources/kimi_code_source.py
+++ b/astrbot/core/provider/sources/kimi_code_source.py
@@ -1,9 +1,10 @@
+from ..headers import DEFAULT_USER_AGENT
 from ..register import register_provider_adapter
 from .anthropic_source import ProviderAnthropic
 
 KIMI_CODE_API_BASE = "https://api.kimi.com/coding"
 KIMI_CODE_DEFAULT_MODEL = "kimi-for-coding"
-KIMI_CODE_USER_AGENT = "claude-code/0.1.0"
+KIMI_CODE_USER_AGENT = DEFAULT_USER_AGENT
 
 
 @register_provider_adapter(
diff --git a/astrbot/core/provider/sources/mimo_stt_api_source.py b/astrbot/core/provider/sources/mimo_stt_api_source.py
index 8417e7a988..75117a6be8 100644
--- a/astrbot/core/provider/sources/mimo_stt_api_source.py
+++ b/astrbot/core/provider/sources/mimo_stt_api_source.py
@@ -84,7 +84,7 @@ async def get_text(self, audio_url: str) -> str:
         try:
             response = await self.client.post(
                 build_api_url(self.api_base),
-                headers=build_headers(self.chosen_api_key),
+                headers={**build_headers(self.chosen_api_key), **self.request_headers},
                 json=payload,
             )
             try:
diff --git a/astrbot/core/provider/sources/mimo_tts_api_source.py b/astrbot/core/provider/sources/mimo_tts_api_source.py
index a9ccaae340..0182615740 100644
--- a/astrbot/core/provider/sources/mimo_tts_api_source.py
+++ b/astrbot/core/provider/sources/mimo_tts_api_source.py
@@ -103,7 +103,7 @@ def _build_payload(self, text: str) -> dict:
     async def get_audio(self, text: str) -> str:
         response = await self.client.post(
             build_api_url(self.api_base),
-            headers=build_headers(self.chosen_api_key),
+            headers={**build_headers(self.chosen_api_key), **self.request_headers},
             json=self._build_payload(text),
         )
 
diff --git a/astrbot/core/provider/sources/minimax_token_plan_source.py b/astrbot/core/provider/sources/minimax_token_plan_source.py
index 8d86c77b73..b16c7e4dc2 100644
--- a/astrbot/core/provider/sources/minimax_token_plan_source.py
+++ b/astrbot/core/provider/sources/minimax_token_plan_source.py
@@ -47,7 +47,7 @@ async def get_models(self) -> list[str]:
             logger.warning("No API key configured for MiniMax Token Plan.")
             return []
         try:
-            async with httpx.AsyncClient() as client:
+            async with httpx.AsyncClient(headers=self.request_headers) as client:
                 resp = await client.get(
                     "https://api.minimaxi.com/v1/models",
                     headers={"Authorization": f"Bearer {key}"},
diff --git a/astrbot/core/provider/sources/minimax_tts_api_source.py b/astrbot/core/provider/sources/minimax_tts_api_source.py
index f86e70b3c6..d815a48f80 100644
--- a/astrbot/core/provider/sources/minimax_tts_api_source.py
+++ b/astrbot/core/provider/sources/minimax_tts_api_source.py
@@ -103,7 +103,7 @@ async def _call_tts_stream(self, text: str) -> AsyncIterator[str]:
         """进行流式请求"""
         try:
             async with (
-                aiohttp.ClientSession() as session,
+                aiohttp.ClientSession(headers=self.request_headers) as session,
                 session.post(
                     self.concat_base_url,
                     headers=self.headers,
diff --git a/astrbot/core/provider/sources/nvidia_embedding_source.py b/astrbot/core/provider/sources/nvidia_embedding_source.py
index 475fadeecc..d650c68b4a 100644
--- a/astrbot/core/provider/sources/nvidia_embedding_source.py
+++ b/astrbot/core/provider/sources/nvidia_embedding_source.py
@@ -49,7 +49,7 @@ async def _get_client(self):
             }
             timeout = aiohttp.ClientTimeout(total=self.timeout)
             self.client = aiohttp.ClientSession(
-                headers=headers,
+                headers={**self.request_headers, **headers},
                 timeout=timeout,
             )
         return self.client
diff --git a/astrbot/core/provider/sources/nvidia_rerank_source.py b/astrbot/core/provider/sources/nvidia_rerank_source.py
index 6f3f92c1cd..4d241a6545 100644
--- a/astrbot/core/provider/sources/nvidia_rerank_source.py
+++ b/astrbot/core/provider/sources/nvidia_rerank_source.py
@@ -37,7 +37,8 @@ async def _get_client(self):
                 "Accept": "application/json",
             }
             self.client = aiohttp.ClientSession(
-                headers=headers, timeout=aiohttp.ClientTimeout(total=self.timeout)
+                headers={**self.request_headers, **headers},
+                timeout=aiohttp.ClientTimeout(total=self.timeout),
             )
         return self.client
 
diff --git a/astrbot/core/provider/sources/ollama_embedding_source.py b/astrbot/core/provider/sources/ollama_embedding_source.py
index 8982fc51de..411310304f 100644
--- a/astrbot/core/provider/sources/ollama_embedding_source.py
+++ b/astrbot/core/provider/sources/ollama_embedding_source.py
@@ -42,7 +42,7 @@ async def _get_client(self):
             }
             timeout = aiohttp.ClientTimeout(total=self.timeout)
             self.client = aiohttp.ClientSession(
-                headers=headers,
+                headers={**self.request_headers, **headers},
                 timeout=timeout,
             )
         return self.client
diff --git a/astrbot/core/provider/sources/openai_embedding_source.py b/astrbot/core/provider/sources/openai_embedding_source.py
index f1e5bc880e..8f29017f4e 100644
--- a/astrbot/core/provider/sources/openai_embedding_source.py
+++ b/astrbot/core/provider/sources/openai_embedding_source.py
@@ -39,6 +39,7 @@ def __init__(self, provider_config: dict, provider_settings: dict) -> None:
         )
         logger.info(f"[OpenAI Embedding] {provider_id} Using API Base: {api_base}")
         self.client = AsyncOpenAI(
+            default_headers=self.request_headers,
             api_key=provider_config.get("embedding_api_key"),
             base_url=api_base,
             timeout=int(provider_config.get("timeout", 20)),
diff --git a/astrbot/core/provider/sources/openai_source.py b/astrbot/core/provider/sources/openai_source.py
index f7870b7137..0bff46406e 100644
--- a/astrbot/core/provider/sources/openai_source.py
+++ b/astrbot/core/provider/sources/openai_source.py
@@ -359,16 +359,10 @@ def __init__(self, provider_config, provider_settings) -> None:
         self.api_keys: list = super().get_keys()
         self.chosen_api_key = self.api_keys[0] if len(self.api_keys) > 0 else None
         self.timeout = provider_config.get("timeout", 120)
-        self.custom_headers = provider_config.get("custom_headers", {})
+        self.custom_headers = self.request_headers
         if isinstance(self.timeout, str):
             self.timeout = int(self.timeout)
 
-        if not isinstance(self.custom_headers, dict) or not self.custom_headers:
-            self.custom_headers = None
-        else:
-            for key in self.custom_headers:
-                self.custom_headers[key] = str(self.custom_headers[key])
-
         if "api_version" in provider_config:
             # Using Azure OpenAI API
             self.client = AsyncAzureOpenAI(
diff --git a/astrbot/core/provider/sources/openai_tts_api_source.py b/astrbot/core/provider/sources/openai_tts_api_source.py
index 27485765fd..6ea2bfba8f 100644
--- a/astrbot/core/provider/sources/openai_tts_api_source.py
+++ b/astrbot/core/provider/sources/openai_tts_api_source.py
@@ -37,6 +37,7 @@ def __init__(
             logger.info(f"[OpenAI TTS] 使用代理: {proxy}")
             http_client = httpx.AsyncClient(proxy=proxy)
         self.client = AsyncOpenAI(
+            default_headers=self.request_headers,
             api_key=self.chosen_api_key,
             base_url=provider_config.get("api_base"),
             timeout=timeout,
diff --git a/astrbot/core/provider/sources/tei_rerank_source.py b/astrbot/core/provider/sources/tei_rerank_source.py
index 9a5d58aaf7..a455c11e34 100644
--- a/astrbot/core/provider/sources/tei_rerank_source.py
+++ b/astrbot/core/provider/sources/tei_rerank_source.py
@@ -31,7 +31,7 @@ def __init__(self, provider_config: dict, provider_settings: dict) -> None:
         self.raw_scores = provider_config.get("tei_rerank_raw_scores", False)
         self.return_text = provider_config.get("tei_rerank_return_text", False)
 
-        h = {}
+        h = self.request_headers.copy()
         if self.api_key:
             h["Authorization"] = f"Bearer {self.api_key}"
         self.client = aiohttp.ClientSession(
diff --git a/astrbot/core/provider/sources/vllm_rerank_source.py b/astrbot/core/provider/sources/vllm_rerank_source.py
index 6fd44bc589..104fb62858 100644
--- a/astrbot/core/provider/sources/vllm_rerank_source.py
+++ b/astrbot/core/provider/sources/vllm_rerank_source.py
@@ -26,7 +26,7 @@ def __init__(self, provider_config: dict, provider_settings: dict) -> None:
         self.timeout = provider_config.get("timeout", 20)
         self.model = provider_config.get("rerank_model", "BAAI/bge-reranker-base")
 
-        h = {}
+        h = self.request_headers.copy()
         if self.auth_key:
             h["Authorization"] = f"Bearer {self.auth_key}"
         self.client = aiohttp.ClientSession(
diff --git a/astrbot/core/provider/sources/volcengine_tts.py b/astrbot/core/provider/sources/volcengine_tts.py
index 9e1453df6a..24c4f45be1 100644
--- a/astrbot/core/provider/sources/volcengine_tts.py
+++ b/astrbot/core/provider/sources/volcengine_tts.py
@@ -75,7 +75,7 @@ async def get_audio(self, text: str) -> str:
 
         try:
             async with (
-                aiohttp.ClientSession() as session,
+                aiohttp.ClientSession(headers=self.request_headers) as session,
                 session.post(
                     self.api_base,
                     data=json.dumps(payload),
diff --git a/astrbot/core/provider/sources/whisper_api_source.py b/astrbot/core/provider/sources/whisper_api_source.py
index 60aee070b7..cbb06fc9c0 100644
--- a/astrbot/core/provider/sources/whisper_api_source.py
+++ b/astrbot/core/provider/sources/whisper_api_source.py
@@ -22,6 +22,7 @@ def __init__(
         self.chosen_api_key = provider_config.get("api_key", "")
 
         self.client = AsyncOpenAI(
+            default_headers=self.request_headers,
             api_key=self.chosen_api_key,
             base_url=provider_config.get("api_base"),
             timeout=provider_config.get("timeout", NOT_GIVEN),
diff --git a/astrbot/core/provider/sources/xinference_rerank_source.py b/astrbot/core/provider/sources/xinference_rerank_source.py
index 9c3a77c158..88e9fc8522 100644
--- a/astrbot/core/provider/sources/xinference_rerank_source.py
+++ b/astrbot/core/provider/sources/xinference_rerank_source.py
@@ -44,6 +44,7 @@ async def initialize(self) -> None:
         else:
             logger.info("Xinference Rerank: No API key provided.")
             self.client = Client(self.base_url)
+        self.client._headers.update(self.request_headers)
 
         try:
             running_models = await self.client.list_models()
diff --git a/astrbot/core/provider/sources/xinference_stt_provider.py b/astrbot/core/provider/sources/xinference_stt_provider.py
index f0e905e6d8..20729cb4ec 100644
--- a/astrbot/core/provider/sources/xinference_stt_provider.py
+++ b/astrbot/core/provider/sources/xinference_stt_provider.py
@@ -40,6 +40,7 @@ async def initialize(self) -> None:
         else:
             logger.info("Xinference STT: No API key provided.")
             self.client = Client(self.base_url)
+        self.client._headers.update(self.request_headers)
 
         try:
             running_models = await self.client.list_models()
diff --git a/tests/test_provider_user_agent.py b/tests/test_provider_user_agent.py
new file mode 100644
index 0000000000..792bd009a8
--- /dev/null
+++ b/tests/test_provider_user_agent.py
@@ -0,0 +1,223 @@
+import copy
+
+import pytest
+import pytest_asyncio
+from aiohttp import web
+
+from astrbot import __version__
+from astrbot.core.provider.headers import DEFAULT_USER_AGENT, build_provider_headers
+from astrbot.core.provider.sources.anthropic_source import ProviderAnthropic
+from astrbot.core.provider.sources.bailian_rerank_source import BailianRerankProvider
+from astrbot.core.provider.sources.dashscope_embedding_source import (
+    DashScopeEmbeddingProvider,
+)
+from astrbot.core.provider.sources.gemini_embedding_source import (
+    GeminiEmbeddingProvider,
+)
+from astrbot.core.provider.sources.gemini_source import ProviderGoogleGenAI
+from astrbot.core.provider.sources.gemini_tts_source import ProviderGeminiTTSAPI
+from astrbot.core.provider.sources.kimi_code_source import ProviderKimiCode
+from astrbot.core.provider.sources.nvidia_embedding_source import (
+    NvidiaEmbeddingProvider,
+)
+from astrbot.core.provider.sources.nvidia_rerank_source import NvidiaRerankProvider
+from astrbot.core.provider.sources.ollama_embedding_source import (
+    OllamaEmbeddingProvider,
+)
+from astrbot.core.provider.sources.openai_embedding_source import (
+    OpenAIEmbeddingProvider,
+)
+from astrbot.core.provider.sources.openai_responses_source import (
+    ProviderOpenAIResponses,
+)
+from astrbot.core.provider.sources.openai_source import ProviderOpenAIOfficial
+from astrbot.core.provider.sources.openai_tts_api_source import ProviderOpenAITTSAPI
+from astrbot.core.provider.sources.tei_rerank_source import TEIRerankProvider
+from astrbot.core.provider.sources.vllm_rerank_source import VLLMRerankProvider
+from astrbot.core.provider.sources.whisper_api_source import ProviderOpenAIWhisperAPI
+
+
+@pytest.mark.parametrize(
+    "custom_headers", [None, {}, [], "invalid", {"User-Agent": " "}]
+)
+def test_provider_headers_default_to_current_version(custom_headers):
+    assert build_provider_headers(custom_headers) == {
+        "User-Agent": f"astrbot/{__version__}"
+    }
+
+
+@pytest.mark.parametrize("name", ["User-Agent", "user-agent", "USER-AGENT"])
+def test_provider_headers_preserve_custom_values_without_mutation(name):
+    custom = {name: "custom/1.0", "X-Trace-Id": 123}
+    original = copy.deepcopy(custom)
+    assert build_provider_headers(custom) == {
+        "User-Agent": "custom/1.0",
+        "X-Trace-Id": "123",
+    }
+    assert custom == original
+
+
+@pytest_asyncio.fixture
+async def provider_http_server(unused_tcp_port, monkeypatch):
+    """Capture actual SDK requests without contacting external providers."""
+    requests = []
+    monkeypatch.setenv("NO_PROXY", "127.0.0.1")
+    monkeypatch.setenv("no_proxy", "127.0.0.1")
+
+    async def handle(request):
+        requests.append(request.headers)
+        return web.json_response(
+            {
+                "object": "list",
+                "data": [],
+                "models": [],
+                "output": {"embeddings": [{"embedding": [0.1], "text_index": 0}]},
+            }
+        )
+
+    app = web.Application()
+    app.router.add_route("*", "/{path:.*}", handle)
+    runner = web.AppRunner(app)
+    await runner.setup()
+    try:
+        await web.TCPSite(runner, "127.0.0.1", unused_tcp_port).start()
+        yield f"http://127.0.0.1:{unused_tcp_port}", requests
+    finally:
+        await runner.cleanup()
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "provider_cls",
+    [
+        ProviderOpenAIOfficial,
+        ProviderOpenAIResponses,
+        OpenAIEmbeddingProvider,
+        ProviderOpenAITTSAPI,
+        ProviderOpenAIWhisperAPI,
+        ProviderAnthropic,
+        ProviderKimiCode,
+        ProviderGoogleGenAI,
+        GeminiEmbeddingProvider,
+        ProviderGeminiTTSAPI,
+    ],
+)
+@pytest.mark.parametrize("custom_headers", [{}, {"user-agent": "custom/1.0"}])
+async def test_provider_sdk_sends_exactly_one_user_agent(
+    provider_cls, custom_headers, provider_http_server
+):
+    base_url, requests = provider_http_server
+    config = {
+        "id": "test-provider",
+        "model": "test-model",
+        "key": ["test-key"],
+        "api_key": "test-key",
+        "api_base": base_url,
+        "embedding_api_key": "test-key",
+        "embedding_api_base": base_url,
+        "gemini_tts_api_key": "test-key",
+        "gemini_tts_api_base": base_url,
+        "custom_headers": custom_headers,
+    }
+    original = copy.deepcopy(config)
+    provider = provider_cls(config, {})
+    try:
+        await provider.client.models.list()
+        assert len(requests) == 1
+        assert requests[0].getall("User-Agent") == [
+            custom_headers.get("user-agent", DEFAULT_USER_AGENT)
+        ]
+        assert config == original
+    finally:
+        await provider.terminate()
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "provider_cls",
+    [
+        BailianRerankProvider,
+        TEIRerankProvider,
+        VLLMRerankProvider,
+        NvidiaEmbeddingProvider,
+        NvidiaRerankProvider,
+        OllamaEmbeddingProvider,
+    ],
+)
+@pytest.mark.parametrize("custom_headers", [{}, {"USER-AGENT": "custom/1.0"}])
+async def test_aiohttp_provider_sends_user_agent(
+    provider_cls, custom_headers, provider_http_server
+):
+    base_url, requests = provider_http_server
+    provider = provider_cls(
+        {
+            "embedding_api_key": "test-key",
+            "embedding_api_base": base_url,
+            "rerank_api_key": "test-key",
+            "rerank_api_base": base_url,
+            "custom_headers": custom_headers,
+        },
+        {},
+    )
+    try:
+        client = provider.client or await provider._get_client()
+        async with client.get(base_url) as response:
+            assert response.status == 200
+        assert requests[0].getall("User-Agent") == [
+            custom_headers.get("USER-AGENT", DEFAULT_USER_AGENT)
+        ]
+    finally:
+        await provider.terminate()
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("model", ["text-embedding-v4", "qwen3-vl-embedding"])
+@pytest.mark.parametrize("custom_headers", [{}, {"User-Agent": "custom/1.0"}])
+async def test_dashscope_sends_user_agent(model, custom_headers, provider_http_server):
+    base_url, requests = provider_http_server
+    provider = DashScopeEmbeddingProvider(
+        {
+            "embedding_api_key": "test-key",
+            "embedding_api_base": base_url,
+            "embedding_model": model,
+            "custom_headers": custom_headers,
+        },
+        {},
+    )
+    assert await provider.get_embeddings(["hello"]) == [[0.1]]
+    assert requests[0].getall("User-Agent") == [
+        custom_headers.get("User-Agent", DEFAULT_USER_AGENT)
+    ]
+
+
+@pytest.mark.asyncio
+async def test_edge_tts_synthesis_uses_astrbot_user_agent(monkeypatch, unused_tcp_port):
+    edge_tts = pytest.importorskip("edge_tts")
+    from astrbot.core.provider.sources import edge_tts_source  # noqa: F401
+
+    requests = []
+
+    async def handle(request):
+        requests.append(request.headers)
+        websocket = web.WebSocketResponse()
+        await websocket.prepare(request)
+        await websocket.receive()
+        await websocket.receive()
+        await websocket.close()
+        return websocket
+
+    app = web.Application()
+    app.router.add_get("/", handle)
+    runner = web.AppRunner(app)
+    await runner.setup()
+    monkeypatch.setattr(
+        edge_tts.communicate, "WSS_URL", f"ws://127.0.0.1:{unused_tcp_port}/?test=1"
+    )
+    try:
+        await web.TCPSite(runner, "127.0.0.1", unused_tcp_port).start()
+        with pytest.raises(edge_tts.exceptions.NoAudioReceived):
+            async for _ in edge_tts.Communicate("hello", "en-US-AriaNeural").stream():
+                pass
+        assert requests[0].getall("User-Agent") == [DEFAULT_USER_AGENT]
+    finally:
+        await runner.cleanup()