GSD SDK query migration (summary blurb)

Copy-paste friendly for Discord and GitHub comments.

@gsd-build/sdk replaces the untyped, monolithic gsd-tools.cjs subprocess with a typed, tested, registry-based query system and gsd-sdk query, giving GSD structured results, classified errors (GSDError with ErrorClassification), and golden-verified parity with the old CLI. That gives the framework one stable contract instead of a fragile, very large CLI that every workflow had to spawn and parse by hand.

What users can expect

Same GSD commands and workflows they already use.
Snappier runs (less Node startup on chained tool calls).
Fewer mysterious mid-workflow failures and safer upgrades, because behavior is covered by tests and a single stable contract.
Stronger predictability: outputs and failure modes are consistent and explicit.

Cost and tokens

The SDK does not automatically reduce LLM tokens per model call. Savings show up indirectly: fewer ambiguous tool results and fewer retry or recovery loops, which often lowers real-world session cost and wall time.

Agents then vs now

Agents always followed workflow instructions. What improved is the surface those steps run on. Before, workflows effectively said to shell out to gsd-tools.cjs and interpret stdout or JSON with brittle assumptions. Now they point at gsd-sdk query and typed handlers that return the shapes prompts expect, with clearer error reasons when something must stop or be fixed, so instruction following holds end to end with less thrash from bad parses or silent output drift.