TokenValidatorInterface

The auth seam the MCP HTTP/SSE transport needs from its host: turn a bearer token into an authenticated {@see Principal}, or null if it doesn't authenticate. One method, not a split "is this token valid" / "who does it belong to" pair — the transport never validates a token without immediately needing the principal it resolves to, and never resolves a principal from anything but a token, so a second seam would only add indirection. Implement this once per host token/identity store (a database-backed API token table, a JWT verifier, a static token list for local dev, …) and hand the instance to your transport adapter (e.g. the controller that terminates the MCP HTTP endpoint).

abstract public function validate(string $token, ?string $ip = null): ?Milpa\McpServer\Auth\Principal

Validate a raw bearer token and resolve the {@see Principal} behind it. Implementations are expected to also apply their own liveness rules (expiry, revocation, owner still active, …) and MAY record usage (e.g. last-used-at/ip) as a side effect of a successful validation. Return null for anything that is not currently a valid token: unknown, expired, revoked, or belonging to an inactive principal.

Parameters