What's new

vgi-go is at v0.22.0, speaking wire protocol 1.3.0 — the same protocol the Python and TypeScript SDKs speak, driven by the same DuckDB extension. This page groups what landed by theme.

Versions are per SDK

vgi-go versions on its own line and does not track vgi-python’s numbers. Protocol version is what they share: a v0.22.0 Go worker and a 0.28.x Python worker both speak 1.3.0 and are interchangeable behind the same extension.

Breaking changes

v0.18.0 — functions resolve by (catalog, schema, name)

A function name was never a unique key. Dispatch was a flat name lookup, so the same name registered in two schemas collided as overloads. Resolution is now keyed on the full path, and the unary RPCs that re-resolve a function by name carry the schema too — without that, a call bound correctly and then ran the other schema’s implementation, returning a wrong-but-plausible answer.

Protocol 1.0.0 → 1.2.0.

v0.15.0 — required_field_filter_paths → required_filters

Renamed, and the shape changed from a flat list to conjunctive normal form: an AND of OR-groups. See Requiring a filter.

Result caching

A worker can advertise that its result is reusable by attaching vgi.cache.* metadata to its first data batch. The vocabulary is HTTP’s — a freshness lifetime, a reuse scope, validators for conditional revalidation, and stale-serving grace windows.

Release	What landed
v0.15.0	CacheControl and the vgi.cache.* keys for table functions.
v0.16.0	Cache control from a buffered finalize; conditional-revalidation validators surfaced as params.IfNoneMatch / IfModifiedSince.
v0.16.0	Opt-in for scalar functions.
v0.17.0	PartitionScope for per-partition caching.
v0.18.0	PerValue — per-VALUE memoization for exchange-mode maps.

→ Cache results on the client

Function shapes

• Blended table-in-out (v0.16.0) — set FunctionMetadata.InputFromArgs; positional args are the per-row input columns, so one registration serves a literal call, a column call, and a correlated LATERAL. v0.16.0 also added per-output-row provenance so batched correlated LATERAL stays correct.
• Parallel finalize / substream_id (v0.16.0) for table-in-out functions.
• Const-argument constraints enforced at bind — scalars in v0.10.0, aggregates in v0.11.0. A ge=/le=/choices= you declared is actually binding.

→ Function patterns

Catalogs

Release	What landed
v0.19.0	Global functions — publish selected functions into DuckDB’s system.main so they are callable unqualified. Protocol 1.2.0 → 1.3.0.
v0.21.0	Per-catalog attach options.
v0.15.0	RequiredFilters in CNF — refuse an unbounded scan.

→ Expose a catalog

v0.22.0 — three failures moved to where they are caused

Each of these used to register cleanly and fail somewhere unrelated.

Fix	What used to happen
type= rejects unknown Arrow type names	Was: vgi:“type=bigint” silently became VARCHAR, then failed to bind against an integer literal with an error naming the call site. Now: rejected at registration, with the right Arrow name suggested.
RegisterAggregate gob-registers its state	Was: you had to call gob.Register(&MyState) yourself, or the first GROUP BY failed. Now: registered from NewState; your own call is a harmless no-op.
COPY format name collisions are rejected	Was: a reader and a writer sharing a format name silently lost one of them. Now: rejected at registration, with one handler serving both directions merged to direction=“both”.

Upgrading from ≤ v0.21.0 can stop a worker that used to start

A worker carrying an unrecognised type= will now refuse to start rather than registering a wrong signature. That is the point of the change, but it is a behaviour change and not merely a better message — check your struct tags before upgrading. The error names the value and suggests the correct Arrow name.

Performance

• Data plane (v0.17.0) — per-row and per-batch allocation and CPU cut in the hot paths.

Next steps

• Start building → Function patterns.
• The full API → Package overview.
• Upstream history → Query-farm/vgi-go releases.