club-3090/AGENTS.md

AGENTS.md

Guidance for AI coding agents (Claude Code, Cursor, Copilot, Continue, etc.) working in this repo. Focused — only conventions an agent wouldn't infer from the code itself.

Read first

Before making non-trivial changes:

• README.md — what the repo is, two-routes framing, repo layout
• docs/SINGLE_CARD.md / docs/DUAL_CARD.md — pick-by-workload guidance + the cliffs they reference
• docs/UPSTREAM.md — every upstream issue / PR we depend on or have filed (see "Upstream issues" section below for why this matters)
• models/qwen3.6-27b/INTERNALS.md — DFlash forensics, AutoRound rationale, Marlin pad fork, MTP head
• CONTRIBUTING.md — what kinds of PRs land cleanly + benchmark + verify protocol

Hardware truths

• 2× RTX 3090 Ampere SM 8.6, PCIe-only, no NVLink (and we won't add it).
• Custom all-reduce must be disabled in vLLM/SGLang configs (PCIe topology breaks NVLink-assumed paths).
• No native FP8 compute; FP8 KV is a storage optimization only.
• Speculative decoding using EAGLE / DFlash is blocked on Qwen3-Next family (DeltaNet rollback). MTP works. See docs/UPSTREAM.md — vllm#39931.

Upstream issues — single source of truth

docs/UPSTREAM.md tracks every upstream issue / PR we depend on, have filed, or use as context. Before filing a new upstream issue or referencing an existing one in code/docs, check this file. When status changes (issue closed, PR merged, pin bumped), update the row.

This rule exists because we previously had upstream links scattered across CHANGELOG, INTERNALS, FAQ, and per-compose comment headers — and they drifted. The tracker file is the canonical place; cross-link to it from anywhere else.

When filing a fresh upstream issue from this work:

1. Add the row to docs/UPSTREAM.md first
2. Link the issue back to noonghunna/club-3090 in the body (helps maintainers see affected user surface)
3. If the upstream eventually merges + propagates, update the row to ✅ Resolved and bump the relevant pin (Genesis commit, vLLM nightly, etc.) in the same commit / PR

Conventions on this repo

Bench protocol

3 warm + 5 measured runs. Canonical prompts: 800-word essay (narrative, max_tokens=1000) + quicksort code (max_tokens=800). temperature=0.6, top_p=0.95, top_k=20. Capture both wall-time TPS and engine-internal gen throughput from logs. Always capture per-card peak VRAM alongside TPS.

Genesis opt-in env vars

Genesis ships ~50 env-gated patches. Some are targeted bugfixes (P64 streaming, PN8 memory savings, P3/P5/P6 KV); others are behavioral mitigations that silently rewrite the request (P68 = tool_choice → required, P69 = inject "must use tool" reminder). Behavioral mitigations need a streaming + large-prompt repro before shipping default-on. We learned this the hard way on 2026-04-29 — see docs/UPSTREAM.md → Genesis #9 row + the club-3090 #2 thread.

If you're considering enabling a new Genesis env var by default in a shipped compose:

1. Read the patch's header docstring in vllm/_genesis/wiring/. Does it modify request.tool_choice, request.messages, or rewrite output?
2. If yes (behavioral): run a streaming repro with prompt > the patch's threshold + a casual user message ("hi") + tool_choice: auto. If finish_reason=stop with empty content, don't ship default-on.
3. Pure bugfixes (no behavioral override) are fine to ship default-on once they pass verify-full.sh.

CHANGELOG

• CHANGELOG.md (cross-cutting) and models/<name>/CHANGELOG.md (per-model) are append-only history. Don't rewrite past entries even when a finding is superseded — add a new entry. The historical trail is load-bearing for "why did we do X."
• Old entries can reference files / patches that no longer exist. That's fine — leave them.

Compose variants

• Each variant ships with a header table comparing it against sibling composes in the same directory. Update both directions when adding/removing variants.
• Keep the variant set lean. Three composes that overlap badly (similar TPS + similar context + same KV) is worse than two with a clean differentiation. Removed fast-chat.yml 2026-04-29 for exactly this reason.

Compose filename convention — <topology>-<feature>.yml

The model is implied by the parent directory (models/<model>/vllm/compose/); don't repeat it in the filename. Topology is the first segment, feature suffixes follow.

Position	Examples	Notes
Topology prefix	single · dual · multi3 · multi4 · multi8	single and dual have no count ambiguity (always 1 / always 2 GPUs). multi<N> requires the count because N varies (3 / 4 / 5 / 6 / 8). Aligns with docs/SINGLE_CARD.md / DUAL_CARD.md / MULTI_CARD.md framing.
Feature suffix(es)	-nvlink · -mtp · -dflash · -turbo (TQ3 KV) · -int8 (INT8 PTH) · -awq · -noviz	Stacked in conventional order: interconnect → drafter → KV → vision modifier. Example: dual-nvlink-dflash-noviz.yml reads as "TP=2, NVLink, DFlash drafter, no vision."
Default-recommended	Drop implicit suffix	Qwen's dual.yml is MTP+fp8. Only add explicit suffix when there's another drafter/KV variant in the same directory (e.g. Gemma has dual.yml + dual-dflash.yml, so the default doesn't need -mtp).

Examples (post-2026-05-09):

• models/qwen3.6-27b/vllm/compose/dual.yml (Qwen dual default — fp8 + MTP)
• models/qwen3.6-27b/vllm/compose/dual-turbo.yml (Qwen dual + TQ3)
• models/gemma-4-31b/vllm/compose/dual.yml (Gemma dual default — bf16 + MTP — different config from Qwen's dual.yml, disambiguated by directory)
• models/gemma-4-31b/vllm/compose/dual-int8.yml (Gemma dual + INT8 PTH KV)
• models/gemma-4-31b/vllm/compose/single.yml (Gemma single-card variant)

Filename collisions across model directories are fine — the path itself disambiguates. Registry tags in scripts/switch.sh decouple from filenames; rename only the file path in the VARIANTS map and keep tags backward-compatible.

Profile schema header (every compose, every time)

Every compose starts with a Profile (at-a-glance) block declaring the (Model, Topology, Drafter, KV, Vision, Max-ctx, Genesis) tuple in structured form. Free-form description follows below the schema, not in place of it.

# ===========================================================================
# Profile (at-a-glance):
#   Model:     <name + quant — e.g. "Qwen3.6-27B (Lorbus AutoRound INT4)">
#   Topology:  <e.g. "Dual 3090 PCIe (TP=2, no NVLink)">
#   Drafter:   <none | MTP n=N | DFlash n=N | ngram K=N>
#   KV:        <fp8_e5m2 | bf16 | int8_per_token_head | turboquant_3bit_nc>
#   Vision:    <yes | no>
#   Max ctx:   <e.g. 262K>
#   Genesis:   <none | v7.72.2 | N/A — Genesis is Qwen3-Next-specific>
#   Status:    <optional — only if not production: ⚠️ PREVIEW / BOOT-OOM / etc.>
#   Best for:  <one short phrase — what workload this serves; ⭐ for canonical>
# ---------------------------------------------------------------------------
# (existing free-form description continues below)

This rule applies to shipped composes AND local-only test composes — apply the convention even before deciding whether to ship; it avoids a rename later if the experiment graduates.

When testing a new model, write filenames in <topology>-<feature>.yml form from the start (not <model>-<feature>.yml). When the model isn't Qwen3-Next, write Genesis: N/A — Genesis is Qwen3-Next-specific so readers don't expect Genesis-style perf folds where they don't apply.

Where do experimental / unvalidated composes live?

Same directory as shipped composes, but kept untracked until validation passes. Don't create a separate experimental/ subdirectory — the relative paths to ../patches/... and ../cache/... are calibrated to the compose dir, and promoting an experiment from a sub-folder would require re-pathing every mount.

Workflow:

1. Author the compose in models/<model>/vllm/compose/<topology>-<feature>.yml with the standard profile schema header. Mark Status: ⚠️ EXPERIMENTAL (or ⚠️ PREVIEW if quality issues are known) so readers know it's not validated.
2. Don't git add until validation passes. The file shows up in git status as ?? — that's the signal. git ls-tree -r HEAD lists only shipped composes; the gap between that and ls compose/*.yml tells you what's pending validation.
3. Validation gates before promoting: verify-full.sh 8/8, verify-stress.sh 7/7 (or documented failures with rationale), bench.sh (numbers added to BENCHMARKS.md), soak-test.sh SOAK_MODE=continuous (catches Cliff 2b).
4. Promote: drop the Status: ⚠️ EXPERIMENTAL line from the profile schema, git add, commit. Cross-rig validation can come later via the numbers-from-your-rig issue template.

For entirely new models under validation (e.g. "let's try MiniMax-M2.7"): keep the whole models/<new-model>/ directory untracked until at least one compose validates. Avoid pushing models/<new-model>/README.md etc. before there's a working compose to back it up — empty model directories on master signal capability we don't actually have.

References (orphan composes / patches sitting in this state as of 2026-05-09):

• models/gemma-4-31b/vllm/compose/dual-awq.yml — local-only AWQ-4bit weights variant, Status: ⚠️ EXPERIMENTAL
• models/gemma-4-31b/vllm/compose/dual-dflash-int8.yml — Status: ⚠️ EXPERIMENTAL (boots only with vLLM PR #42102 vendored mounts)
• models/qwen3.6-27b/vllm/compose/qwopus-bf16mtp.yml — Status: ⚠️ PREVIEW (41× line repetition + NIAH drop, not production)

Documentation

• Don't create new docs proactively. Most non-obvious things belong in INTERNALS.md, FAQ.md, SINGLE_CARD.md, or DUAL_CARD.md. New top-level files only when there's a recurring search miss.
• Charts: source .svg + exported .png at retina resolution (≥1500px wide). Markdown embeds use .png (clicking opens a viewable image; SVG opens raw XML). Re-generate with python3 tools/charts/gen-perf.py and gen-vram.py after editing data.
• For any change that adds a footnote to "this depends on upstream X" — the answer is to link the row in docs/UPSTREAM.md, not to inline-cite the upstream URL.

Tests

• verify-full.sh — fast functional smoke (~1–2 min). Runs on every compose change.
• verify-stress.sh — boundary cases (longctx ladder + tool-prefill OOM ~5–10 min). Runs on cliff-related changes.
• bench.sh — canonical TPS bench. Run when you change anything that could move TPS (compose flags, Genesis env vars, vLLM pin).

Commits

• New commit per logical change. Don't amend published commits.
• Commit messages: subject ≤72 chars, imperative ("Disable P68/P69..." not "Disabled..."), optional body for "why."
• Don't push without local verify-full + verify-stress passing for the affected compose.

Hooks / verification

• Pre-flight checks live in scripts/preflight.sh and run from setup.sh + launch.sh. They check docker / GPU / disk before any heavy work. If a check fails, print an actionable Fix: hint, never a cryptic mid-run crash.

Things to NOT do

• Don't add NVLink suggestions. The user has explicitly declined.
• Don't recommend EAGLE / DFlash spec-decode on Qwen3-Next single-card. It's blocked by DeltaNet rollback (see docs/UPSTREAM.md → vllm#39931). MTP works.
• Don't enable Genesis behavioral patches (P68/P69 class) by default. They override user intent. If a user wants them, they can flip the env var.
• Don't claim a TPS number you didn't measure. "Should be ~80" labeled as estimate is fine; "is 80" needs a bench.
• Don't compress historical CHANGELOG entries. Append-only.
• Don't scatter upstream issue links across multiple docs. Link to the row in docs/UPSTREAM.md instead.