In some implementations, a user device can maintain a multi-device context store. For example, the user device can receive device and/or user context information from multiple devices and store the context information in a local data store. The user device can collect local device and/or user context information and store the context information in the local context store. The user device can receive user/device context queries from client processes and send the client processes user/device context information from multiple devices in response to the queries.