hao-ai-lab-FastVideo/STACK.md

PR Stack — will/ltx2_sr_port Split Tracker

Status: TEMPORARY — delete after the full stack lands on main. Last updated: 2026-05-04 Canonical source: will/ltx2_sr_port — the unified branch holding all 41 commits in dependency order.

This file tracks the 10-PR split of will/ltx2_sr_port. Each PR is a slice of the canonical branch, stacked on its predecessor.

For per-PR design rationale see .agents/memory/dreamverse-integration/pr-roadmap.md. For decisions log see .agents/memory/dreamverse-integration/decisions-log.md. For co-author attribution see CO-AUTHORS.md.

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Stack diagram

origin/main
  └─ will/api_7.6        [open PR #1257]    GPU pool + worker subprocess (7 commits)
     └─ will/api_7.7     [open PR #1258]    Prompt enhancer + LLMProvider (3 commits)
        └─ will/api_7.8                     Streaming auxiliaries (2 commits)
           └─ will/api_7.9                  Router upstream (3 commits)
              └─ will/api_7.10              generate_async + Dynamo (3 commits)
                 └─ will/api_8              Server contract docs (3 commits)
                    └─ will/ltx2_sr_runtime         LTX-2 SR + i2v + harness (9 commits)
                       └─ will/ltx2_nvfp4           NVFP4 + per-component compile (6 commits)
                          └─ will/ltx2_post_fixes   Post-handoff parity fixes (2 commits)
                             └─ will/agents_cleanup .agents/ cleanup + STACK.md (3 commits)

Total: 41 commits across 10 PRs (mean 4.1 per PR — reviewable size).

Branch table

#	PR branch	Open PR	Slice	Tip SHA	Commits	Concern
1	will/api_7.6	#1257	1–7	SEE NOTES	7	GPU pool + worker subprocess + test coverage + 4 review-fixup commits
2	will/api_7.7	#1258	8–10	SEE NOTES	3	Prompt enhancer + LLMProvider abstraction (cerebras, groq)
3	will/api_7.8	(not yet)	11–12	SEE NOTES	2	Streaming auxiliaries (safety, rewrite, logger, mock)
4	will/api_7.9	(not yet)	13–15	SEE NOTES	3	Router upstream + fastvideo router-serve CLI + test coverage
5	will/api_7.10	(not yet)	16–18	SEE NOTES	3	VideoEvent hierarchy + VideoGenerator.generate_async + Dynamo health helper
6	will/api_8	(not yet)	19–21	SEE NOTES	3	Server contract docs (OpenAI HTTP + Dynamo) + Dreamverse/Dynamo shape contract tests
7	will/ltx2_sr_runtime	(not yet)	22–30	SEE NOTES	9	LTX-2 SR runtime port + i2v conditioning + alignment harness against FastVideo-internal
8	will/ltx2_nvfp4	(not yet)	31–36	SEE NOTES	6	NVFP4 wire-up + per-component compile + typed transformer_quant flow
9	will/ltx2_post_fixes	(not yet)	37–38	SEE NOTES	2	Post-handoff parity fixes (Gemma to() round-trip, list-of-generators)
10	will/agents_cleanup	(not yet)	39–41	SEE NOTES	3	.agents/ Phase 1 cleanup + dreamverse-integration memory + STACK/CO-AUTHORS docs

Tip SHAs: see git log --oneline --reverse origin/main..will/ltx2_sr_port for the authoritative sequence. SHAs change whenever will/ltx2_sr_port is rebased or amended (e.g. when injecting new Co-authored-by trailers). Rather than hardcode them here (which goes stale), use the live re-slicing commands below.

Re-slice commands (run when will/ltx2_sr_port SHAs change)

After any rebase or trailer injection on will/ltx2_sr_port, recompute the boundary SHAs and reset all split branches:

# Show the 41 commits with their slice numbers
git log --oneline --reverse origin/main..will/ltx2_sr_port | nl -ba

# Capture boundary tips by index
SHA_7_6=$(git log --oneline --reverse origin/main..will/ltx2_sr_port | sed -n '7p'  | awk '{print $1}')
SHA_7_7=$(git log --oneline --reverse origin/main..will/ltx2_sr_port | sed -n '10p' | awk '{print $1}')
SHA_7_8=$(git log --oneline --reverse origin/main..will/ltx2_sr_port | sed -n '12p' | awk '{print $1}')
SHA_7_9=$(git log --oneline --reverse origin/main..will/ltx2_sr_port | sed -n '15p' | awk '{print $1}')
SHA_7_10=$(git log --oneline --reverse origin/main..will/ltx2_sr_port | sed -n '18p' | awk '{print $1}')
SHA_8=$(git log --oneline --reverse origin/main..will/ltx2_sr_port | sed -n '21p' | awk '{print $1}')
SHA_LTX2_SR=$(git log --oneline --reverse origin/main..will/ltx2_sr_port | sed -n '30p' | awk '{print $1}')
SHA_LTX2_NVFP4=$(git log --oneline --reverse origin/main..will/ltx2_sr_port | sed -n '36p' | awk '{print $1}')
SHA_LTX2_POST=$(git log --oneline --reverse origin/main..will/ltx2_sr_port | sed -n '38p' | awk '{print $1}')
SHA_AGENTS=$(git log --oneline --reverse origin/main..will/ltx2_sr_port | sed -n '41p' | awk '{print $1}')

# Reset all 10 branches to the new boundary tips
git branch -f will/api_7.6           "$SHA_7_6"
git branch -f will/api_7.7           "$SHA_7_7"
git branch -f will/api_7.8           "$SHA_7_8"
git branch -f will/api_7.9           "$SHA_7_9"
git branch -f will/api_7.10          "$SHA_7_10"
git branch -f will/api_8             "$SHA_8"
git branch -f will/ltx2_sr_runtime   "$SHA_LTX2_SR"
git branch -f will/ltx2_nvfp4        "$SHA_LTX2_NVFP4"
git branch -f will/ltx2_post_fixes   "$SHA_LTX2_POST"
git branch -f will/agents_cleanup    "$SHA_AGENTS"

After resetting, force-push the branches whose PRs are open:

git push --force-with-lease origin will/api_7.6
git push --force-with-lease origin will/api_7.7
git push --force-with-lease origin will/ltx2_sr_port

Independence map

PR	Hard-depends on	Could rebase to land independently?
7.6	origin/main only	✅ already independent
7.7	7.6 (uses GpuPool from 7.6)	❌
7.8	7.7 (auxiliaries plug into prompt enhancer)	❌
7.9	origin/main (router is orthogonal to streaming)	✅ — could rebase onto 7.6 directly if 7.7/7.8 stall
7.10	7.6 (GpuPool) + on-main ContinuationState (PR 7)	✅ — only needs 7.6, can fast-track over the 7.7/7.8 stack
8	7.10 (consumes generate_async + VideoEvent)	❌
ltx2_sr_runtime	origin/main + (independent of 7.x streaming work)	✅ — purely LTX-2-specific
ltx2_nvfp4	ltx2_sr_runtime + per-component compile (which is on ltx2_sr_runtime)	❌
ltx2_post_fixes	ltx2_nvfp4	❌
agents_cleanup	NOTHING — pure infra	✅ — fully independent of every other PR

Landing strategy

The default landing path is bottom-up through the stack: 7.6 → 7.7 → 7.8 → 7.9 → 7.10 → 8 → ltx2_sr_runtime → ltx2_nvfp4 → ltx2_post_fixes → agents_cleanup.

After a PR merges, the canonical branch and remaining splits should be rebased onto the new origin/main (which now contains the just-merged PR), then re-sliced via the commands above.

If review on a mid-stack PR stalls, fast-track candidates are:

• will/agents_cleanup (no dependency)
• will/ltx2_sr_runtime (no dependency on 7.x streaming work)
• will/api_7.9 (router is orthogonal — rebase to land directly on 7.6)
• will/api_7.10 (only needs 7.6 — rebase to land directly on 7.6)

Verification per PR

For each PR's branch, verify the slice content with:

# Show commits + verify count
git log --oneline <PARENT>..<BRANCH> | wc -l   # expect the count from the table

# Confirm tree state at the tip matches the canonical branch's slice tip
git diff <slice-tip-SHA-on-canonical> <BRANCH>  # expect empty

When to delete this file

When all 10 PRs have merged to main. Until then, keep this file fresh: re-run the re-slice commands and update any commit-count cells whose sequence shifts.