# RFC: API extractor reports

Status: proposed

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> Split out from the original "Doc-sync and API reports" RFC (2026-06-11). Parts 1-2 (doc-block typechecking, event-taxonomy verification) shipped — see [doc-sync enforcement](../../implemented/process/2026-06-11-doc-sync-enforcement.md). This is the deferred part 3, kept as a standalone proposal.

## Problem

Public API changes are invisible — nothing makes "this commit changed the public surface" an explicit, reviewable fact. A reviewer reading a diff can miss that an exported type gained a field or a method signature shifted.

## Proposal

api-extractor (or `tsc --emitDeclarationOnly` + a normalized public-surface dump) producing a checked-in `etc/<pkg>.api.md` per package; CI fails if regeneration differs. Every public-API change becomes a diff line a reviewer (or review agent) must see.

## Status / why deferred

Deferred when doc-sync landed: low value for an internal monorepo where reviewers already see the source diff, and a heavy, finicky dependency. Revisit if the packages are ever published externally — at that point a stable, diffable public surface earns its keep.