## Outcome

- Writer #2 becomes `pi-qwen3-coder-next-openrouter` (model `openrouter/qwen/qwen3-coder-next`, vendor alibaba, harness pi, permission edit, effort medium). Alias `qwen-openrouter-pi` moves to the new route.
- Why this candidate: it is the direct successor to the retired coder route, the cheapest in the packet (0.12 / 0.80), Qwen is explicitly allowed through OpenRouter, and its 262144 context has no long-context premium tier to misquote. `qwen3.7-plus` is rejected for the 256000-token price step and higher base price; `qwen3-coder-flash` is the fallback if coder-next fails the tool-support check (see Open questions).
- `pi-qwen3-coder-plus-openrouter` is retired, not deleted: off the admitted list and roster, price row kept, inventory and routes carry a retired comment.
- Writer #1 and routes 3–6 unchanged, same order.

## Files

- New model file, `kxm.model.v2`, for `pi-qwen3-coder-next-openrouter` (same directory as the existing `pi-qwen3-coder-plus-openrouter` model file).
- Inventory: add the new id; mark the old id `retired` with a dated comment (404 on 2026-10-17).
- Routes / admitted list: remove old id, add new id with permission edit; retired comment on the old entry.
- Writer roster, effort medium: replace position 2 only.
- `.kxm/prices.yaml`: keep `qwen/qwen3-coder-plus` row at last list price with a retired note; add `qwen/qwen3-coder-next` 0.12 / 0.80, context 262144; bump date to 2026-10-17 and recompute sha256 in the same change.
- `plans/evidence/` new note: OpenRouter 404 for the old slug, candidate table, price source date, selection rationale, tool-support verification result.
- `plans/implementation-plan.md` Tracking → Decided: record the writer #2 swap and the brake reasoning.
- Docs: harness-routing, config reference, CLI reference, assignment runner, glossary (only if it names the route), changelog.
- `dist/`: regenerate only if a test or grep shows the old route id or slug embedded in a bundle.

## Tests

- Roster-policy tests: writer #2 expectations switch to the new id; assert the old id is absent from admitted and roster but present in inventory as retired.
- Prices loader test: fixture with the new date/hash passes; a mismatched sha256 is refused.
- Inventory-before-admit test: admitting an id not in inventory fails closed.
- Brake test: `openrouter/moonshotai/...` as a writer is refused with the native-harness reason; a meta slug is refused as unadmitted.
- Model-file schema test for the new file (v2, harness pi, vendor alibaba, edit present).
- Docs brake / lint:docs: no doc still names `qwen3-coder-plus` as a live writer.
- `npm run verify` after `npm ci`.

## Docs

- harness-routing: roster table row 2, retired-route note, pricing tier note (none for coder-next).
- Config reference: prices.yaml example rows and the date/sha pin rule.
- CLI reference: any example output showing writer #2.
- Assignment runner: default writer rotation example.
- Glossary: alias `qwen-openrouter-pi` target, if listed.
- Changelog: "writer #2 replaced; old route retired, price history kept."

## Risks and guards

- Tool support unverified from this packet. Guard: the writer must run a real `pi auth check --provider openrouter` and a one-shot edit smoke on the new model before admitting; if the model cannot call tools, do not admit, fall back to `qwen3-coder-flash` under the same check.
- Moonshot via OpenRouter is refused: kimi has a native harness, so this is the native-vendor-through-Pi case the brake exists for. Not selected.
- Meta via OpenRouter is an admission question, not in scope; not selected.
- prices.yaml hash drift: date and sha256 updated in the same commit; loader refuses mismatch, so verify runs it.
- Ordering: inventory edit lands before routes admit, in the same change, so no intermediate state admits an unknown id.
- History: no deletion of the old price row or inventory entry.
- Refuse: editing writer #1, planner, reviewer-cli, reviewer-arch; reordering Argon/Flash; adding a harness preferences overlay; inventing supported_parameters or prices.

## Sequence

1. Evidence note under `plans/evidence/` with the 404 and candidate table.
2. New model file; inventory add + retire old.
3. prices.yaml rows, date, sha256.
4. Routes/admitted + roster swap; alias move.
5. Tests (roster, loader, brake, inventory, schema).
6. Docs and changelog; Tracking entry.
7. Tool-support smoke on the new route; fail closed if it cannot edit.
8. `npm ci && npm run verify`; regenerate `dist` only if embedded strings changed.
9. One commit per logical change (evidence/model, prices, routes+tests, docs).

## Non-goals

- No change to writer #1, critics, or Gemini positions.
- No Meta or Moonshot admission.
- No catalog feed, price refresh tooling, or routing report changes.
- No alias compatibility shim for the old route id; it brakes.

## Open questions

- Does `qwen/qwen3-coder-next` advertise tool calling on OpenRouter (`supported_parameters` absent from packet)? Assumption labeled: yes; blocking if false.
- Exact directory names for model files, inventory, routes, and roster-policy tests in this repo.
- Does `dist` embed the roster or route ids?
- Should the alias `qwen-openrouter-pi` follow the new route or be retired with the old one? Assumed: follows.