DashScope dropped cosyvoice-v1 from its REST-supported model list. v2
(and v3+) speak a different shape: voice / format / sample_rate live
under `input`, not `parameters`; non-streaming responses return
`output.audio.url` (signed OSS URL) instead of inline `output.audio.data`
base64. The previous adapter sent v1-shaped bodies to a bare
`https://dashscope-intl.aliyuncs.com/api/v1` baseURL and parsed
`audio.data`, which 404'd before the migration and would 200-with-no-
audio after — both invisible regressions for the gateway.
Adapter changes:
- Rewrite request body to v2 schema (voice/format under input).
- Add follow-up GET against `output.audio.url`; stream into ArrayBuffer
with a 25 MB hard cap and explicit drain-tracking finally, so a
misbehaving URL cannot exhaust memory and a half-read body cannot
hang a connection.
- Re-document baseURL contract: adapters do NOT append path; ops must
configure the FULL endpoint URL (root cause of the original 404
storm). DEFAULT_COSYVOICE_MODEL bumped to `cosyvoice-v2`, default
voice to `longxiaochun_v2`.
Voice catalog: regenerated with 19 representative cosyvoice-v2 voices
(assistant / customer-service / child / en-US / en-GB / ja-JP / ko-KR)
so the frontend voice picker is no longer a 2-entry stub. Full catalog
(100+) remains on the Alibaba docs page — we'll sync on demand rather
than scrape.
Seed script: `--dashscope-region intl|cn` (default `intl`),
`--dashscope-upstream-model cosyvoice-v2`, baseURL now resolves to
`https://<host>/api/v1/services/audio/tts/SpeechSynthesizer` so a
mis-typed region or path cannot reintroduce the 404.
Tests: new dashscope-cosyvoice.test.ts covers v2 body shape (asserts
`parameters` absent — regression), audio.url follow-up fetch, 401
propagation with `.status`, empty-envelope falling back into the
router's recoverable-error path, and catalog freshness (no leftover v1
ids). Verified locally against the staging DashScope key: 200 +
playable mp3 end to end.
End-state of the multi-step KTD-5 / KTD-6 / U8 work. The knoway sidecar
is no longer reachable from server code; the router is required at boot
and now owns chat completions, TTS synthesis, and voice catalog listing.
Highlights:
- LLM_ROUTER_MASTER_KEY becomes required; app.ts drops the graceful-
skip branch and the chat fallback fetch path is gone.
- /audio/speech and /audio/voices route through new routeTts /
listTtsVoices entries that reuse the chat key-rotator + per-attempt
timeout + abort propagation.
- DEFAULT_CHAT_MODEL / DEFAULT_TTS_MODEL move from env to configKV so
default-model swaps are hot-reloadable via Pub/Sub.
- GATEWAY_BASE_URL removed from env schema, .env, .env.local, smoke,
verification harness. Redis upstream-voices cache deleted — catalogs
come from in-process adapter JSON.
- routeTts splits adapter error contract by ApiError statusCode:
4xx propagates without fallback; 5xx folds into the network-failure
fallback path. handleTTS wraps billing + span attribute in try/finally
to plug a span leak when ttsMeter.accumulate() throws.
- seed-router-config.ts rewritten with --merge (default) / --reset /
--dry-run modes and env-var key handoff (OPENROUTER_KEY / AZURE_KEY /
DASHSCOPE_KEY) so prod seed flows never put plaintext on the CLI.
Adds DashScope CosyVoice seeding.
Docs (CLAUDE.md, architecture-overview.md, transport-and-routes.md)
reflect the new boundary. verifications/llm-router.md replaces the
overstated "U1-U9 shipped" line with an evidence-vs-pending table.
Tests: full 40-file / 343-case server suite green. New regressions pin
ApiError 4xx → no-fallback, ApiError 5xx → fallback, TTS billing
failure → span closed and error propagated.