setHeaders typed headers as Record<string, string>, so there was no
type-safe way to clear a header (e.g. Authorization on logout) — passing
an empty string left the header present with a blank value.
Widen the signature to Record<string, string | null | undefined> and drop
any entry whose value is null/undefined. setHeaders remains a full overwrite,
so clearing one header while keeping the rest is the spread pattern:
setHeaders({ ...copilotkit.headers, Authorization: null }). A shared
normalizeHeaders helper enforces the same string-only invariant at both
write paths (constructor and setHeaders).
Update the react-core AuthTokenSync skill example to show the logout/clear
path and warn that a header must not be managed via both the headers prop and
imperative setHeaders (the provider re-applies prop-derived headers as a full
overwrite when its inputs change). Also update the setHeaders reference
signature docs. Tests cover null/undefined stripping, empty-string
preservation, overwrite-not-merge semantics, single-header clear via spread,
subscriber notification, and propagation to local and remote
(ProxiedCopilotRuntimeAgent) agents.
Fixes#5535
Austin Merrick
4c71ea1138