diff --git a/cacholote/config.py b/cacholote/config.py
index e667242..25f6a18 100644
--- a/cacholote/config.py
+++ b/cacholote/config.py
@@ -15,6 +15,7 @@
 # limitations under the License.
 from __future__ import annotations
 
+import abc
 import datetime
 import logging
 import pathlib
@@ -41,6 +42,14 @@
 )
 
 
+class Context(abc.ABC):
+    @abc.abstractmethod
+    def __init__(self, *args: Any, **kwargs: Any) -> None: ...
+
+    @abc.abstractmethod
+    def upload_log(self, *args: Any, **kwargs: Any) -> None: ...
+
+
 class Settings(pydantic_settings.BaseSettings):
     use_cache: bool = True
     cache_db_urlpath: Optional[str] = _DEFAULT_CACHE_DB_URLPATH
@@ -61,6 +70,7 @@ class Settings(pydantic_settings.BaseSettings):
         _DEFAULT_LOGGER
     )
     lock_timeout: Optional[float] = None
+    context: Optional[Context] = None
 
     @pydantic.field_validator("create_engine_kwargs")
     def validate_create_engine_kwargs(
@@ -151,8 +161,10 @@ class set:
         Note that existing tags are overwritten.
     return_cache_entry: bool, default: False
         Whether to return the cache database entry rather than decoded results.
-    lock_timeout: fload, optional, default: None
+    lock_timeout: float, optional, default: None
         Time to wait before raising an error if a cache file is locked.
+    context: Context, optional, default: None
+        CADS context for internal use.
     """
 
     def __init__(self, **kwargs: Any):
diff --git a/cacholote/extra_encoders.py b/cacholote/extra_encoders.py
index 8a4a47d..5b321e2 100644
--- a/cacholote/extra_encoders.py
+++ b/cacholote/extra_encoders.py
@@ -111,15 +111,26 @@ def _filesystem_is_local(fs: fsspec.AbstractFileSystem) -> bool:
     return isinstance(fs, fsspec.get_filesystem_class("file"))
 
 
+def _kwargs_to_str(**kwargs: Any) -> str:
+    return " ".join([f"{k}={v}" for k, v in kwargs.items()])
+
+
 @contextlib.contextmanager
 def _logging_timer(event: str, **kwargs: Any) -> Generator[float, None, None]:
     logger = config.get().logger
+    context = config.get().context
     logger.info(f"start {event}", **kwargs)
+    if event == "upload" and context is not None:
+        context.upload_log(f"start {event}. {_kwargs_to_str(**kwargs)}")
+
     tic = time.perf_counter()
     yield tic
     toc = time.perf_counter()
+
     kwargs["_".join(event.split() + ["time"])] = toc - tic  # elapsed time
     logger.info(f"end {event}", **kwargs)
+    if event == "upload" and context is not None:
+        context.upload_log(f"end {event}. {_kwargs_to_str(**kwargs)}")
 
 
 class FileInfoModel(pydantic.BaseModel):