vllm-omni/docs/design/module/engine_orchestration.md

title, kind, status, owners, primary_code_paths, related_code_paths, depends_on, validation_paths, upstream_refs, last_reviewed

title	kind	status	owners	primary_code_paths	related_code_paths	depends_on	validation_paths	upstream_refs	last_reviewed
Engine Orchestration	module	draft	@tzhouam @yinpeiqi @fake0fan @Sy0307	vllm_omni/engine/**	vllm_omni/distributed/omni_coordinator/** vllm_omni/distributed/ray_utils/**	vllm_omni_config.md input_output_modality_contracts.md omni_connector.md	tests/engine/** tests/distributed/omni_coordinator/**	vllm.v1.engine	2026-07-16

Engine orchestration

Engine orchestration coordinates configured AR and diffusion stages while keeping public clients independent from stage processes and transports.

Candidate invariants

ORCH-INV-001: The orchestrator owns cross-stage routing

Rule: Entrypoints and stage clients MUST NOT independently forward a request to a downstream stage.

ORCH-INV-002: Stage clients do not own routing policy

Rule: Stage clients MUST implement communication and lifecycle operations without selecting the next logical stage.

ORCH-INV-003: Terminal state is monotonic

Rule: Once a request reaches a terminal state, orchestration MUST NOT forward new work for that request.

Safe-change guide

Test routing, output ordering, cancellation, failure propagation, shutdown, and representative multi-stage execution.