Function buildClient

mcp/src/http-server.ts:271–293

* Construct the per-request E2AClient for an already-resolved principal. * * Why the agent-email default lives here and not in the SDK: the SDK is a thin * contract shared by CLI, browser, server, and Python users — auto-resolving an * agent on construction would be too magical for those callers

(
  opts: HttpServerOptions,
  bearer: string,
  principal: ResolvedPrincipal,
)

 * user) to pass `email` explicitly.
 */
function buildClient(
  opts: HttpServerOptions,
  bearer: string,
  principal: ResolvedPrincipal,
): McpClient {
  const { agentEmail, scope } = principal;
  if (opts.clientFactory) {
    // Preserve the no-arg-factory shape for callers (and tests) that don't
    // care about the resolved email/scope. Pass them through only when set.
    return agentEmail || scope
      ? opts.clientFactory(bearer, { ...(agentEmail ? { agentEmail } : {}), ...(scope ? { scope } : {}) })
      : opts.clientFactory(bearer);
  }
  return new McpClient(
    new E2AClient({ apiKey: bearer, baseUrl: opts.baseUrl }),
    agentEmail ?? "",
    // Fail CLOSED if scope is ever absent: "agent" is the least-privilege tier
    // (account = full admin surface). principal.scope is always set today, so
    // this only guards a future refactor — but a fail-open default here would
    // silently expose the admin surface.
    scope ?? "agent",
  );
}

/**
 * Resolve a bearer's scope + bound agent from whoami (GET /account), which the