v0.12.18 — dependable joins and truthful operator failures

v0.12.18 tightens the paths that decide whether a meeting bot really joined,
is still alive, and failed for a reason an operator can act on. It also makes
the MCP front door stream correctly, fixes Lite startup, and removes several
false-success states from bot creation and deployment.

Meeting reliability

• Google Meet lobby bots are no longer reaped at five minutes while still
  legitimately waiting for admission (#862).
• Meet host denial wins over ambient reCAPTCHA and terminates with a typed,
  non-retryable reason (#840).
• The browser locale is deterministic (en-US by default), with its resolved
  language recorded for diagnosis (#856). The English lobby path was walked
  live; arbitrary non-English joining is not claimed.
• Teams no longer treats generic alert UI as evidence that the bot was
  removed; the staged bot stayed active for 207 seconds under the live removal
  monitor (#600).
• Mixed-lane turns without a resolved participant name now use the stable
  Speaker label instead of leaking the internal seg_N cluster identifier
  (#890). Human name binding remains a later attribution-quality step.
• Teams authentication redirects and non-admitted bot deaths now preserve
  their real causes instead of degrading into admission timeouts or
  reason: None (#915, #926). These external failure shapes are
  machine-proven; neither recurred during the release witness.
• Stop during pre-admission now reaches the phase-aware withdraw path and
  cleans up the workload (#889). Meet's host-side knock can still persist;
  that distinct visible withdrawal gap remains
  #839.

Truthful APIs and operator behavior

• A bot workload that never starts no longer yields false 201; POST /bots
  returns 502 with the cause and marks the meeting failed immediately (#718).
• Invalid native meeting IDs containing URL/query characters fail at intake
  with 422; callers should use meeting_url and passcode (#892).
• Meeting API remains available for durable reads during Redis loss and
  reports Redis degradation on /health; Redis-dependent Stop fails narrowly
  and retryably (#809).
• Redis keyspace reconciliation is no longer on the ten-second collector hot
  loop, removing the known /health saturation amplifier (#893).
• The webhook introspection capture is bounded, removing its unbounded
  in-process retention source (#803).

MCP, webhooks, and identity

• MCP streamable HTTP is available through the authenticated gateway /mcp
  front door. Sessioned GET /mcp opens and keeps its SSE stream instead of
  being buffered into a timeout (#795, #921).
• Admin token mint honors JSON scopes, keeps query compatibility, and refuses
  unsupported body fields loudly (#922).
• Core now records recent webhook delivery outcomes in a per-user,
  secret-safe ledger exposed at GET /user/webhook/deliveries (#841 core
  half). The dashboard does not display that ledger yet; the consumer remains
  open in v0.12.20.

Deployment

• Helm migrations use the same pinned image tag as the deployed release
  (#900).
• Admin API retries transient database DNS/connect races with bounded backoff
  (#901).
• Vexa Lite pins all service environments to Python 3.12, restoring reliable
  admin API startup and first-run key provisioning (#927).
• The no-STT contract is documented truthfully: transcription is required by
  default and missing configuration fails loudly; capture-only is an explicit
  transcribe_enabled=false choice (#532).

Upgrading

From any v0.12.x release, pin IMAGE_TAG=v0.12.18. The guarded :v012
pointer moves only after the published image set, value gate, and release
witness are green. There is no database schema migration in this batch.

Behavior refinements to note:

• token JSON bodies reject unknown fields with 422;
• native meeting IDs carrying URL characters reject with 422;
• bot workload start failure now returns 502, not 201;
• /mcp and /user/webhook/deliveries are new gateway surfaces.

Artifact identity

The stable tags are same-byte aliases of frozen release candidates; they were
not rebuilt after validation. Production revision 103 and meetings 24740/24741
witnessed the stage2 Bot at
sha256:9442a44558fd48950208cbef40673cc7a0b2feb41f380964fc74a0e25bf18fae.
The public Bot below is the packet3 replacement: its runtime inputs are
tree-identical to the tagged source and its image/Compose validation passed,
but it was not deployed or human-witnessed on hosted stage or production.

Hosted production directly held the listed admin API, runtime, meeting API,
and gateway bytes. It held the stage2 Bot digest recorded above, not the
packet3 public Bot digest. Agent worker, agent API, MCP, Terminal, packet3 Bot,
and Lite are proven by published-candidate validation; they are not claimed as
hosted production workloads.

Known boundaries

• Host-visible graceful lobby withdrawal remains #839.
• Dashboard webhook Delivery History remains #841.
• Teams auth-redirect and Zoom non-admission reason fixes have exact-head
  machine evidence but no live recurrence in the witness window.
• Jitsi hosted meeting detail remains #937.
• Real audio→words is witnessed live; the standalone machine wav→words oracle
  remains deferred.
• Hosted transcription currently has a functional Cloudflare fallback, while
  primary health remains false and direct BBB was not exercised.
• Hosted Account/API-key management currently has a webapp-to-Admin-API
  compatibility incident (#942,
  platform carry vexa-platform#127).
  It is not delivered or closed by this OSS release.

Credits

Contributors: Joseph Yaksich, Felix-Ayush, and Dmitry Grankin.

Reporter credit: Valerie Phoenix (#927).

Community PR validator: Dmitry Grankin.

Release witness: Dmitry Grankin, corroborated by dashboard, bot, meeting API,
Redis, Postgres, and Kubernetes evidence.

Delivery guarantees