neuron-tai/.scratch/distributed-gguf-runtime/issues/033-build-a-standalone-fake-c-grpc-shard-worker.md

DGR-033: Build a standalone fake C++ gRPC Shard worker

• Status / triage: specification only; ready-for-agent; passes: false
• Execution mode: AFK
• Milestone: M1
• Dependencies: DGR-022, DGR-024, DGR-032
• Blocks (derived): DGR-036, DGR-040
• Labels: area:worker, area:grpc, type:vertical-slice, priority:p0, ready-for-agent
• Evidence class: fixture
• Hardware: none
• Model: fake
• Upstream: no

Objective / description

Fresh Ralph session: read .scratch/distributed-gguf-runtime/RALPH-CONTEXT.md, source issue .scratch/distributed-gguf-runtime/issues/033-build-a-standalone-fake-c-grpc-shard-worker.md, and evidence READMEs for dependencies (DGR-022, DGR-024, DGR-032) before changing code. Inspect live source/tests rather than trusting legacy pass states. Objective: Prove the standalone worker process, stream, lifecycle, and supervision shape before llama.cpp integration.

Acceptance criteria

• A standalone C++ executable serves the complete lifecycle and stream RPC contract using the fake engine.
• Python integration tests cover startup, health, capability, fragmented prefill, decode, release, cancellation, and graceful shutdown.
• Bounded messages, deadlines, flow control, and independent session cancellation are enforced.
• The worker exposes neither llama.cpp RPC nor arbitrary graph execution.
• Applicable shared quality gates in prd.json pass, and the evidence handoff records exact commands/results, changed files, limitations, and dependency handoff.

Shared quality gates

• Targeted deterministic tests pass; Python changes also pass python -m compileall packages tests.
• git diff --check passes.
• Default tests are model-download-free, API-credit-free, and GPU-free.
• Evidence README records exact changed files, commands/results, limitations, and dependency handoff; no fabricated evidence or inherited completion credit.
• Native changes pass focused out-of-tree CMake build and CTest; patch changes verify clean apply/check/reverse against the exact llama.cpp pin.
• Runs are opt-in and record exact artifact/split hashes, runtime/upstream pin, backend/driver, hardware, network, commands, and raw metrics. Model artifacts use configured mounted-drive storage and never /home.
• Preserve existing Transformers behavior and backend-agnostic Tracker routing/load balancing/billing/relay semantics unless an explicit versioned contract says otherwise. One scoped story commit is expected during execution, but this specification-materialization change is not committed.

Evidence handoff

Write and verify .scratch/distributed-gguf-runtime/evidence/DGR-033/README.md. Until every criterion and applicable gate has real evidence, this story remains passes: false. Legacy evidence is provenance only, not completion credit.