---
name: kev-verify
description: Verify a Kev change has no regression and ship it as a reviewed PR. Use when refactoring, editing kev/*.py, scripts, the Space or the playground, and when opening or merging Kev pull requests (stacked branches, squash merges).
title: kev-verify
canonical_url: https://skilld.dev/gh/jaredpalmer/kev/kev-verify
last_updated: 2026-10-04T16:32:20.000Z
---

> Index of every page on this site: [llms.txt](https://skilld.dev/llms.txt)

> **Skill from skilld.dev.** Follow the user's requested action.
> If the user asked to fork this Skill, follow the fork workflow below. Do not execute the Skill instructions while copying it.
> Otherwise, follow the instructions below for this session. You do not need to install anything.
>
> If the user asked to install this Skill, run `npx skilld install jaredpalmer/kev/kev-verify`. Install writes the Skill files into the project, so every session loads them.
>
> ## Fork workflow
>
> A fork creates an editable local Skill with its original author and licence. The request authorizes copying and local installation.
> 1. Check `./skills/kev-verify`, the project lockfile, and selected Agent targets together. If the local directory or installed Skill exists, stop. Never overwrite an existing directory or Agent target.
> 2. Read [source metadata](https://skilld.dev/api/v1/skills/jaredpalmer/kev/kev-verify) once. Use sourceUrl, sourceCommit, skillPath, sourceGone, and license. If the source is gone or its path is missing, stop. If license is null, read licence files at the source commit.
> 3. Fetch only the source commit into a temporary Git repository. Do not clone full history. Derive repository_url from sourceUrl, including repository renames. If sourceCommit is absent, resolve the sourceUrl ref once. Set source_commit to that actual commit. Run these commands in one shell call:
>
> ```sh
> git init --quiet "$temporary_dir"
> git -C "$temporary_dir" fetch --quiet --depth=1 "$repository_url" "$source_commit"
> git -C "$temporary_dir" checkout --quiet --detach FETCH_HEAD
> ```
>
> Read applicable licence declarations and notices at that commit. If copying is not permitted, report the restriction and stop.
> 4. Inspect source entries together, then copy the directory containing skillPath into `./skills/kev-verify`. Use the user's path if selected. Keep the original SKILL.md, relative links, scripts, binary assets, and executable modes. Exclude .git metadata. Reject symlinks and paths outside the Skill directory. After checking entries, use cp -a where available. A regular source directory needs no custom copy script. Do not save this page wrapper as SKILL.md.
> Preserve author credit, notices, and applicable licence files from repository or parent directories. Add PROVENANCE.md with the Skill page, source URL, actual commit, original path, and licence. Retain any existing PROVENANCE.md and record new provenance separately. Batch source inspection, copying, and provenance work where practical.
> 5. In the project root, run `skilld install ./skills/kev-verify --mode copy --plain`. If skilld is unavailable, use `npx skilld install ./skills/kev-verify --mode copy --plain`. This known command needs no help lookup. Install does not support --json. Use detected Agent targets, or add --agent for the targets the user selected. Install the local path, never the upstream selector. If installation fails, preserve the local copy and report the exact failure.
> 6. Confirm the local lockfile source and installed Agent copies once. Report the local path, actual commit, and Agent targets. After edits, reinstall the same local path. Upstream updates must not replace it. Do not publish or push unless the user asks.

# Verify and ship a Kev change

Behaviour is defined by numbers: probabilities, saved weights, frozen-suite bytes. A refactor is done when the numbers
are bit-identical to `main`, not when the tests are green. Work bottom-up: unit suites, then weight-backed parity, then
the harness below for anything that touches the model, the loader, the trainer, the data converters or the metrics.

## 1. Fast suites (also CI)

```bash
uv run --extra serve python -m pytest tests/test_unit.py tests/test_research.py tests/test_generators.py tests/test_conventions.py tests/test_documents_tools.py tests/test_hard_v1.py tests/test_devtools_v1.py tests/test_breadth_v1.py tests/test_rounds.py tests/test_skill_scripts.py -q
```

`test_rounds.py` recomputes the committed read-outs of rounds 5-18 and their verdicts from saved rows and compares every
number exactly; main carries only the rows of round 5's read-out and round 15's locked verdict (the rest are on the tag
`research-archive-2026-09-24` or gitignored), so after touching `kev/rounds.py`, `kev/metrics.py` or a round spec also run
it against a checkout that holds them:
`KEV_ROUNDS_ROOT=/path/to/kev uv run --extra serve python -m pytest tests/test_rounds.py -q` (0 skips, 0 differences).

`test_conventions.py` fails when a rule that has a canonical home is re-derived elsewhere (head.pt access, KEV_* env
reads, option keys, the context literal, device selection). Do not add an allowlist entry to make it pass; call the
helper. Add a row when a new helper becomes canonical.

## 2. Weight-backed parity (local, ~3 min)

```bash
uv run --extra serve python -m pytest tests/test_model.py -q     # needs runs/smoke-hl/00-trial-0/checkpoint
```

Merged vs unmerged LoRA, prefix cache vs full pass, shape-bucket padding, row form vs packed mask, hybrid isolation on
Qwen3.5-0.8B-Base, `--init_from` end to end. The Qwen2.5 checkpoint in `runs/smoke-hl` is only there for the packed mask,
which the hybrid Qwen3.5 bases never use. Run it for any change under `kev/model.py`, `kev/checkpoint.py`, `kev/serve.py`, `kev/train.py`.

## 3. Serving

```bash
uv run --extra serve python -m kev.serve --run runs/smoke-hl/00-trial-0/checkpoint --port 8009 &
KEV_BASE_URL=http://127.0.0.1:8009 uv run --extra serve python -m pytest tests/test_api.py -q
```

Space changes: `python3 -m py_compile space/app.py`; the Space vendors `kev/{model,api,checkpoint}.py` via
`scripts/publish_space.sh`, so any change to those needs a republish. Playground: `cd playground && npm run lint && npx tsc --noEmit -p .`.

### Browser end-to-end checks

- If there is no local checkpoint, `--run jaredpalmer/kev-0.6b` provides a small public CPU fallback.
  This verifies serving integration, not parity with the released Qwen3.5 family.
- Start the playground with `cd playground && npm run dev -- -p 3001`; it proxies `/kev/*` to :8009.
  Wait for the server's Uvicorn ready log before loading the page, since model metadata is fetched once on mount.
- At `/`, click **Support triage**, then **Run**: expect six answer cards covering Choice, Noul, and Score.
  The header displays the base and checkpoint run, not the API model alias. Inspect `/v1/models` separately
  when testing the model-card contract.
- The Questions textarea is `#questions`; it accepts JSON directly, so API edge cases can be tested through
  the real UI without changing TypeScript types or mocking requests. Capture the POST response as well as pixels.
- At `/chess`, use **Model vs model**, **New game**, then **Step** for a bounded one-move test.
  Expect a legal move, populated move/evaluation panels, and Black to move. Avoid **Play** for a one-request test.
- `KEV_API_KEY` is read at server startup. Restart with a throwaway local key to verify rejection without a bearer
  header and acceptance with the correct header. The playground has no key input and will show 401 in this mode.
  Restore the open server afterward. `/openapi.json` remains accessible without a key.
- If desktop tools cannot connect to a display, use real headless Chromium via an isolated Playwright environment
  when approved; save full-page screenshots and network responses. Do not substitute mocked frontend responses.
  A full-page capture can include a sticky footer over a card; also capture a scrolled viewport when needed.

#### Devin Secrets Needed

None for local testing with public checkpoints and a throwaway local API key. Private checkpoints require
`HF_TOKEN`; hosted protected endpoints require their configured API key rather than the local test value.

## 4. Parity harness against main

Run the *old* code from a worktree and the new code from the checkout on the same inputs, then compare bytes. Both halves
run on **Qwen3.5**, the architecture the family ships: the benchmark scores the released Kev-0.8B (hybrid Gated DeltaNet,
row form, prefix cache) and the trainer fine-tunes Qwen3.5-0.8B-Base. CPU with fixed seeds is deterministic on these too
(checked 2026-09-22: max |Δ| = 0.0 on the benchmark rows and on all 372 adapter tensors).

```bash
git worktree add /tmp/kev-main origin/main
OLD="env PYTHONPATH=/tmp/kev-main $PWD/.venv/bin/python"          # `import kev` resolves to the worktree; kev is not installed in the venv
SUITE="$PWD/evals/smoke-v1"                                        # absolute: the worktree process must read this checkout's files
# benchmark rows/report (model, loader, metrics, api, data), ~15 s per tree on an M-series CPU
(cd /tmp/kev-main && $OLD -m kev.benchmark --run jaredpalmer/kev-0.8b --suite "$SUITE" --out /tmp/bench-main)
uv run python -m kev.benchmark --run jaredpalmer/kev-0.8b --suite "$SUITE" --out /tmp/bench-new
# -> rows.json must be identical; report.json identical on every numeric field
# training (trainer, losses, augmentation), ~5 min per tree (reference DeltaNet kernels on CPU): same args, then compare
# head.pt["head"] tensors and adapter_model.safetensors
ARGS="--n_per_source 4 --epochs 1 --accum 2 --batch 2 --device cpu --base Qwen/Qwen3.5-0.8B-Base --lr 1e-4 --perm_kl 0.2 --perm_frac 1 --p_none_pair 0.5 --ord_w 0.3"
(cd /tmp/kev-main && OMP_NUM_THREADS=4 $OLD -m kev.train $ARGS --out /tmp/train-main); OMP_NUM_THREADS=4 uv run python -m kev.train $ARGS --out /tmp/train-new
# data converters: json.dumps(build(3, "test", 0, only=[...])) from both trees must be equal
```

Everything the worktree process opens must be an absolute path into this checkout. "max |Δ| = 0.0" is the bar; a nonzero
difference is a behaviour change to explain in the PR or fix. The packed block-causal mask exists only on attention-only
bases, so a change to that path also needs the Qwen2.5 checkpoint in `runs/smoke-hl` (`tests/test_model.py` covers it);
nothing else should be verified on Qwen2.5. Anything that depends on CUDA kernels, bf16 or the 4B / 9B sizes is verified on
Modal with the real base (`kev-modal-study`), not here.

## 5. Ship

- One branch per concern, stacked on the previous branch while it is under review. Write the body with the
  `kev-pr-description` skill (problem, mechanism, uncertainty, scope); the parity evidence from this skill goes in its
  `Test plan` as re-runnable commands and numbers, not "tests pass".
- Review every PR with the `thermonuclear-code-review` skill (a read-only subagent works well) and apply the findings
  before merging; the reviewer has caught real bugs (a dropped import, a double-applied temperature).
- Merge with `gh pr merge <n> --squash`. Because of the squash, rebase the next stacked branch with
  `git rebase --onto origin/main <merged-branch> <next-branch>` (a plain rebase replays the already-merged commits and conflicts).
- Never commit regenerated `runs/leaderboard.*` or frozen `evals/` files as part of a refactor.