feat(codex): 引入 upstream_headers hook 机制，为 Codex 注入 session/conversation/account headers

- 新增 upstream_headers.py：可注册 provider+endpoint 维度的 extra headers 构建 hook
- Codex openai:cli 注入 session_id + conversation_id（由 prompt_cache_key sha256 派生）
- Codex openai:compact 注入 chatgpt-account-id（来自 auth_config）+ session_id，不注入 conversation_id
- 修复 prompt_cache：compact 格式现统一为 codex 策略，不再跳过注入
- chat_handler_base / cli_request_mixin 均在 extra_headers 阶段调用 build_upstream_extra_headers

src/api/handlers/base/chat_handler_base.py

@@ -91,6 +91,7 @@ from src.services.provider.stream_policy import (
 from src.services.provider.transport import (
     build_provider_url,
 )
+from src.services.provider.upstream_headers import build_upstream_extra_headers
 from src.services.scheduling.aware_scheduler import ProviderCandidate
 from src.services.system.config import SystemConfigService
 from src.services.task.request_state import MutableRequestBodyState
@@ -836,6 +837,16 @@ class ChatHandlerBase(BaseMessageHandler, ABC):
         if envelope:
             extra_headers.update(envelope.extra_headers() or {})
 
+        hook_headers = build_upstream_extra_headers(
+            provider_type=provider_type,
+            endpoint_sig=str(provider_api_format) if provider_api_format else None,
+            request_body=request_body,
+            original_headers=original_headers,
+            decrypted_auth_config=auth_info.decrypted_auth_config if auth_info else None,
+        )
+        if hook_headers:
+            extra_headers.update(hook_headers)
+
         return ProviderRequestResult(
             request_body=request_body,
             url_model=url_model,

src/api/handlers/base/cli_request_mixin.py

@@ -20,6 +20,7 @@ from src.services.provider.stream_policy import (
     resolve_upstream_is_stream,
 )
 from src.services.provider.transport import build_provider_url
+from src.services.provider.upstream_headers import build_upstream_extra_headers
 
 if TYPE_CHECKING:
     from src.api.handlers.base.cli_protocol import CliHandlerProtocol
@@ -302,6 +303,16 @@ class CliRequestMixin:
         if envelope:
             extra_headers.update(envelope.extra_headers() or {})
 
+        hook_headers = build_upstream_extra_headers(
+            provider_type=provider_type,
+            endpoint_sig=provider_api_format,
+            request_body=request_body,
+            original_headers=original_headers,
+            decrypted_auth_config=auth_info.decrypted_auth_config if auth_info else None,
+        )
+        if hook_headers:
+            extra_headers.update(hook_headers)
+
         provider_payload, provider_headers = self._request_builder.build(
             request_body,
             original_headers,

src/services/provider/adapters/codex/plugin.py

@@ -11,6 +11,8 @@
 
 from __future__ import annotations
 
+import hashlib
+from collections.abc import Mapping
 from typing import Any
 from urllib.parse import urlencode
 
@@ -31,6 +33,85 @@ fetch_models_codex = create_preset_models_fetcher("codex")
 # ---------------------------------------------------------------------------
 
 
+def _get_header_value(headers: Mapping[str, Any] | None, header_name: str) -> str | None:
+    if not isinstance(headers, Mapping):
+        return None
+
+    target = str(header_name or "").strip().lower()
+    if not target:
+        return None
+
+    for name, value in headers.items():
+        if str(name or "").strip().lower() != target:
+            continue
+        normalized = str(value or "").strip()
+        return normalized or None
+    return None
+
+
+def _build_short_header_id(seed: str) -> str:
+    return hashlib.sha256(seed.encode()).hexdigest()[:16]
+
+
+def _build_codex_headers(
+    request_body: Any,
+    original_headers: Mapping[str, Any] | None,
+    *,
+    include_conversation_id: bool,
+    decrypted_auth_config: dict[str, Any] | None = None,
+) -> dict[str, str]:
+    """Codex upstream: chatgpt-account-id + session_id + conversation_id."""
+    headers: dict[str, str] = {}
+
+    if decrypted_auth_config:
+        account_id = str(decrypted_auth_config.get("account_id") or "").strip()
+        if account_id:
+            headers["chatgpt-account-id"] = account_id
+
+    if isinstance(request_body, dict):
+        cache_key = str(request_body.get("prompt_cache_key") or "").strip()
+        if cache_key:
+            short_id = _build_short_header_id(cache_key)
+            if not _get_header_value(original_headers, "session_id"):
+                headers["session_id"] = short_id
+            if include_conversation_id and not _get_header_value(
+                original_headers, "conversation_id"
+            ):
+                headers["conversation_id"] = short_id
+
+    return headers
+
+
+def build_codex_cli_headers(
+    request_body: Any,
+    original_headers: Mapping[str, Any] | None,
+    *,
+    decrypted_auth_config: dict[str, Any] | None = None,
+) -> dict[str, str]:
+    from src.services.provider.adapters.codex.context import is_codex_compact_request
+
+    return _build_codex_headers(
+        request_body,
+        original_headers,
+        include_conversation_id=not is_codex_compact_request(endpoint_sig="openai:cli"),
+        decrypted_auth_config=decrypted_auth_config,
+    )
+
+
+def build_codex_compact_headers(
+    request_body: Any,
+    original_headers: Mapping[str, Any] | None,
+    *,
+    decrypted_auth_config: dict[str, Any] | None = None,
+) -> dict[str, str]:
+    return _build_codex_headers(
+        request_body,
+        original_headers,
+        include_conversation_id=False,
+        decrypted_auth_config=decrypted_auth_config,
+    )
+
+
 def build_codex_url(
     endpoint: Any,
     *,
@@ -165,10 +246,13 @@ def register_all() -> None:
     from src.core.provider_oauth_utils import register_auth_enricher
     from src.services.model.upstream_fetcher import UpstreamModelsFetcherRegistry
     from src.services.provider.transport import register_transport_hook
+    from src.services.provider.upstream_headers import register_upstream_headers_hook
 
     # Transport
     register_transport_hook("codex", "openai:cli", build_codex_url)
     register_transport_hook("codex", "openai:compact", build_codex_url)
+    register_upstream_headers_hook("codex", "openai:cli", build_codex_cli_headers)
+    register_upstream_headers_hook("codex", "openai:compact", build_codex_compact_headers)
 
     # Auth
     register_auth_enricher("codex", enrich_codex)

src/services/provider/prompt_cache.py

@@ -8,7 +8,6 @@ from collections.abc import Mapping
 from typing import Any
 
 from src.core.provider_types import ProviderType, normalize_provider_type
-from src.services.provider.adapters.codex.context import is_codex_compact_request
 from src.utils.url_utils import is_official_openai_api_url
 
 _OFFICIAL_OPENAI_PROMPT_CACHE_FORMATS: frozenset[str] = frozenset({"openai:chat", "openai:cli"})
@@ -112,15 +111,13 @@ def resolve_prompt_cache_key_scope(
 ) -> str | None:
     """Resolve which prompt cache strategy should be used for this request."""
     fmt = str(provider_api_format or "").strip().lower()
+    pt = normalize_provider_type(provider_type)
+    if pt == ProviderType.CODEX.value and fmt in {"openai:cli", "openai:compact"}:
+        return "codex"
+
     if fmt == "openai:compact":
         return None
 
-    pt = normalize_provider_type(provider_type)
-    if pt == ProviderType.CODEX.value and fmt == "openai:cli":
-        if is_codex_compact_request(endpoint_sig=fmt):
-            return None
-        return "codex"
-
     if fmt in _OFFICIAL_OPENAI_PROMPT_CACHE_FORMATS and is_official_openai_api_url(base_url):
         return "openai"
 

src/services/provider/upstream_headers.py

@@ -0,0 +1,59 @@
+"""Provider-specific upstream request header hooks."""
+
+from __future__ import annotations
+
+from collections.abc import Mapping
+from typing import Any, Callable
+
+from src.core.provider_types import normalize_provider_type
+from src.services.provider.envelope import ensure_providers_bootstrapped
+
+UpstreamHeadersHookFn = Callable[..., dict[str, str]]
+
+_hooks: dict[tuple[str, str], UpstreamHeadersHookFn] = {}
+
+
+def register_upstream_headers_hook(
+    provider_type: str,
+    endpoint_sig: str,
+    hook: UpstreamHeadersHookFn,
+) -> None:
+    """Register a provider-specific extra upstream headers builder."""
+    pt = normalize_provider_type(provider_type)
+    sig = str(endpoint_sig or "").strip().lower()
+    if not pt or not sig:
+        return
+    _hooks[(pt, sig)] = hook
+
+
+def build_upstream_extra_headers(
+    *,
+    provider_type: str | None,
+    endpoint_sig: str | None,
+    request_body: Any,
+    original_headers: Mapping[str, Any] | None,
+    decrypted_auth_config: dict[str, Any] | None,
+) -> dict[str, str]:
+    """Build provider-specific extra upstream headers for the current request."""
+    pt = normalize_provider_type(provider_type)
+    sig = str(endpoint_sig or "").strip().lower()
+    if not pt or not sig:
+        return {}
+
+    ensure_providers_bootstrapped(provider_types=[pt])
+    hook = _hooks.get((pt, sig))
+    if hook is None:
+        return {}
+
+    return hook(
+        request_body,
+        original_headers,
+        decrypted_auth_config=decrypted_auth_config,
+    )
+
+
+__all__ = [
+    "UpstreamHeadersHookFn",
+    "build_upstream_extra_headers",
+    "register_upstream_headers_hook",
+]