neuron-tai/.scratch/distributed-gguf-runtime/issues/021-define-the-versioned-named-tensor-stream-envelope.md

DGR-021: Define the versioned named-tensor stream envelope

• Status / triage: specification only; ready-for-agent; passes: false
• Execution mode: AFK
• Milestone: M1
• Dependencies: DGR-018
• Blocks (derived): DGR-022, DGR-023, DGR-025, DGR-031, DGR-035, DGR-046
• Labels: area:protocol, type:infrastructure, priority:p0, ready-for-agent
• Evidence class: model-free
• Hardware: none
• Model: generic
• Upstream: no

Objective / description

Fresh Ralph session: read .scratch/distributed-gguf-runtime/RALPH-CONTEXT.md, source issue .scratch/distributed-gguf-runtime/issues/021-define-the-versioned-named-tensor-stream-envelope.md, and evidence READMEs for dependencies (DGR-018) before changing code. Inspect live source/tests rather than trusting legacy pass states. Objective: Establish the backend-neutral protobuf envelope used by direct and relayed Shard activation traffic.

Acceptance criteria

• Define schema version, request/work ID, route session/epoch, shard range/effective start, phase, position, and idempotency step.
• Define named tensors with shape, dtype, byte order, bounded fragments, compression identity, and checksum.
• Reserve extensible fields for token-ID sidebands, architecture state, recurrent state, and MTP without claiming implementations.
• Add deterministic serialization, fragmentation, checksum, unknown-field, and size-limit tests.
• 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-021/README.md. Until every criterion and applicable gate has real evidence, this story remains passes: false. Legacy evidence is provenance only, not completion credit.