Every legacy callback call from callbacks-legacy now goes through one typed
Python shim, litellm.rust_bridge.legacy_callbacks, the only Python module
the crate reaches. Before, the crate called Logging methods, litellm.utils
hooks, the logging worker, the executor and several litellm globals
directly, and its tests retyped those signatures by hand, so an outdated
fake could accept a call the real code rejects. python_contract.json lists
each shim function's parameters: a Python test pins it to the real
signatures and a Rust test pins it to the Rust enum.
The lifecycle contract changes to match the Python @client wrapper:
- the driver emits CallEvent::Started before begin, so every host sees one
start time
- RequestContext carries the route-resolved api_key, so legacy pre_call and
post_call receive it, and post_call's additional_args match the Python OCR
path
- Passthrough and its re-aliasing are gone
- async deployment hooks always run, and the "no callbacks" shortcut that
skipped the logging payload is removed, as in the Python path
The OCR api_key is a SecretValue from the wire request onward, so Debug
output upstream of the callback contract cannot leak it.
host-python's RouteHost now classifies native failures once through
classify, and host ops return HostOpError. The OCR route host keeps main's
public errors by sending both through the existing Python map_failure.