neuron-tai/.scratch/distributed-gguf-runtime/issues/037-bind-llama-cpp-to-the-standalone-worker.md

DGR-037: Bind llama.cpp to the standalone worker

• Status / triage: specification only; ready-for-agent; passes: false
• Execution mode: AFK
• Milestone: M2
• Dependencies: DGR-022, DGR-023, DGR-031, DGR-034, DGR-035
• Blocks (derived): DGR-038, DGR-039, DGR-040, DGR-051
• Labels: area:worker, area:llama, type:vertical-slice, priority:p0, ready-for-agent
• Evidence class: real-model
• Hardware: optional
• Model: dense-llama
• Upstream: yes

Objective / description

Fresh Ralph session: read .scratch/distributed-gguf-runtime/RALPH-CONTEXT.md, source issue .scratch/distributed-gguf-runtime/issues/037-bind-llama-cpp-to-the-standalone-worker.md, and evidence READMEs for dependencies (DGR-022, DGR-023, DGR-031, DGR-034, DGR-035) before changing code. Inspect live source/tests rather than trusting legacy pass states. Objective: Replace the fake engine with the pinned llama.cpp ShardEngine implementation without changing the public worker contract.

Acceptance criteria

• Worker loads exactly one artifact/recipe/range identity and rejects mismatched stream requests.
• All execution passes through ShardEngine; llama.cpp implementation types remain private.
• Health and metrics expose loaded identity, authoritative ownership, memory, and execution state.
• Graceful shutdown releases model/session resources; injected process death is observable and bounded.
• 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-037/README.md. Until every criterion and applicable gate has real evidence, this story remains passes: false. Legacy evidence is provenance only, not completion credit.