v0.1.10 — metadata backend + a slimmer install

v0.1.10 — metadata backend + a slimmer install

Released: 2026-07-21

Headline: tycoon gets dramatically smaller and more focused. The
ingestion rewrite's first milestone lands — a typed MetadataBackend
protocol behind all run history — and the FastAPI web UI, Dagster
orchestration, and Nao/ask AI agent are removed outright, dropping
the lockfile from 174 to 109 packages. The cycle plan is in
docs/proposals/v0.1.10-scope.md; the
rewrite's map is the new
ingestion architecture doc.

Landed

• MetadataBackend protocol + DuckDB file backend (#82, PRs #136/#137)
  — run history now flows through typed RunStarted / RunCompleted /
  RunFailed events and a structural Protocol instead of raw SQL against
  hardcoded table names. Every dlt dispatch emits lifecycle events
  (best-effort — a metadata write never blocks a run), and
  data history / data status read through the backend. Alternative
  backends (MotherDuck, Postgres, in-memory for tests) become an
  implementation of the Protocol, not a fork of the capture path.
• Server / Dagster / ask extras removed (#139, PR #147) — ~15 modules
  deleted. tycoon ask and tycoon register llm are gone (typer's
  standard "no such command" error, no stubs). The init wizard is now
  4 steps: ingestion → warehouse → dbt → rill. tycoon start/stop
  manage exactly two servers: Rill dashboards (:9009) and the Quack
  live warehouse (:9494).
• Ingestion architecture doc (PR #149) — the plain-English map of
  where ingestion is going: Runtime / Destination / MetadataBackend
  protocols, the dlt tier model, and the milestone sequence for #81.

Upgrading from 0.1.9

• If you used tycoon ask: the AI-agent surface is removed. Existing
  ask: blocks and stack.orchestrator* keys in tycoon.yml are
  ignored harmlessly — no migration needed, no file edits required.
  An AI-assisted surface will be rethought as part of the rewrite (#78).
• If you used the Dagster integration: tycoon run <tool> still
  forwards to any CLI in your environment, so a self-managed Dagster
  (or Airflow, or cron via tycoon schedule) keeps working — tycoon
  just no longer manages it.
• If you installed extras: pip install 'database-tycoon[server]',
  [dagster], and [ask] no longer exist. A plain
  pip install database-tycoon carries everything the CLI does.

Behind the scenes

• Real test coverage rose from ~65% to ~73% with the deletion of the
  largely-untested server/orchestration code; the coverage floor moved
  to 68% with the same drift headroom as before.
• pandas is now an explicit, pinned core dependency — nothing in
  tycoon imports it, but dlt's on-demand filesystem source needs it for
  CSV reading (optional-extra treatment tracked in #148).
• All user-facing hints, docs pages, and wizard copy that referenced the
  removed surface were swept, and the CLI-surface stale-string sentinel
  now guards tycoon ask / register llm / Nao references so this
  class of drift fails tests.

What's next

The ingestion rewrite continues milestone by milestone — source catalog
manifest, Runtime protocol implementations, and the dlt tier model. See
the ingestion architecture doc and #81
for the sequence.