[breaking-change] Undocumented breaking changes detected (2026-09-18)

Recent commits introduced a breaking API change that appears undocumented as a breaking change.

Breaking Changes

1. Public libbeat/statestore API was changed incompatibly in a bug-fix PR

Commit(s):

• eda1030a14290b0160027dae8a6480af3480fe25

PR:

• https://github.com/elastic/beats/pull/53178

What broke: libbeat/statestore changed exported method signatures and removed exported methods:

• statestore.States.StoreKey() string -> StoreKey(typ, id string) string
• statestore.States.StoreFor(typ string) (*Store, error) -> StoreFor(typ, id string) (*Store, error)
• (*statestore.Store).SetID(id string) removed
• backend.Store.SetID(id string) removed

This is source-incompatible for downstream code implementing these interfaces or calling these methods.

Evidence:

• libbeat/statestore/store.go:33 now defines StoreKey(typ, id string) string.
• libbeat/statestore/store.go:39 now defines StoreFor(typ, id string) (*Store, error).
• libbeat/statestore/store.go removed func (s *Store) SetID(id string) (shown in commit diff hunk @@ -81,10 +80,6 @@).
• libbeat/statestore/backend/backend.go removed SetID(id string) from type Store interface (diff hunk @@ -68,10 +68,6 @@).

Pre-change signatures/methods (from eda1030a14^):

• libbeat/statestore/store.go:33 had StoreKey() string.
• libbeat/statestore/store.go:40 had StoreFor(typ string) (*Store, error).
• libbeat/statestore/store.go:84-86 had func (s *Store) SetID(id string) { s.shared.backend.SetID(id) }.
• libbeat/statestore/backend/backend.go:72-74 had SetID(id string) in type Store interface.

Why undocumented:

• The same commit adds changelog/fragments/1788817407-es-cursor-store-input-index.yaml as kind: bug-fix describing cursor index scoping/re-ingest behavior, but it does not mention API incompatibility or migration guidance.
• In this commit set there were no README/DEVELOPING/RELEASE/CHANGELOG docs updates describing this as a breaking API change.
• PR metadata lookup from this environment returned HTTP 403, so PR body/discussion could not be independently verified here.

Suggested fix: Document this as a breaking API change (or restore compatibility shims), and add migration guidance for external implementers/callers of libbeat/statestore interfaces.

Suggested Actions

• Document each breaking change in release notes/changelog as breaking-change when applicable
• Add migration guidance for libbeat/statestore API consumers

---

What is this? | From workflow: Breaking Change Detect

Give us feedback! React with if perfect, if helpful, if not.

• expires on Sep 25, 2026, 1:15 PM UTC