Why: Generative UI proposal U2 needs the host side of the contract:
owner-isolated surface storage with revision CAS, an execution-level
enable/disable ledger (default-off, epoch bumped on every transition so
in-flight submits after a disable are rejected), a single-choke-point
service that validates specs (strict decode + catalog rules) before
saving, event publish with pending recovery, the optional SurfaceHost
extension capability, and direct API endpoints that share the same
guard (no bypass by entrance).
Evidence: go build/vet clean; full go test ./... passes (SQLite);
surface store tests also pass under AGENT_PG_TEST_DSN (PostgreSQL);
surface.txt regenerated via the AST snapshot test.
Impact: Additive migration v22 (new tables only); existing endpoints and
plugin_grants semantics untouched; old consumers unaffected. U3+ (data
binding, actions, frontend) deliberately out of scope.
Refs: Documents proposal 2026-10-10-generative-ui-plugin.md (r2 U2);
Core PR #25; Dev task feature/generative-ui-u2
Why: Downstream products must extend the base through a public package and host API instead of editing internal code.
Evidence: go test ./... passed, including plugin v2 assets, sidecar startup, migration v13, pending confirms, HITL timeout, hash embedder, command pairs, and the extension surface snapshot.
Impact: apiVersion 2.0-experimental rejects empty network allowlists for declarative HTTP. Hash embeddings stay opt-in via models.embedding.provider=hash. Plugin secrets resolve per owner at execution time.
Refs: docs/proposals/2026-10-01-plugin-contract-v2.md
Co-authored-by: Cursor <cursoragent@cursor.com>
weichen
