/**
 * Runtime JSON-RPC stdio session.
 *
 * `runStdioSession({ input, output, admission, registry, engine, feed, ... })`
 * drives the `weft rpc-stdio` CLI subcommand. It implements the stable
 * JSON-RPC stdio transport: reading newline-delimited JSON frames from
 * `input`, running each through the JSON-RPC dispatcher, and writing
 * responses to `output`.
 *
 * Admission is mandatory:
 *   - `{ kind: 'startup-token', token }` — the first frame must be a
 *     `weft.authenticate` call whose `params.token` matches. On match,
 *     the session principal is `stdio-local` with admin scopes. On
 *     mismatch, the session returns `exit 2` without starting.
 *   - `{ kind: 'allow-unauthenticated-local-admin' }` — session starts
 *     immediately with a `stdio-local` principal. The CLI flag that
 *     enables this reads "grants full engine access to any local
 *     process that can spawn this binary" in both the help text and
 *     the startup log.
 *   - `{ kind: 'require-one' }` — neither flag supplied → exit 2.
 *
 * The session is a thin wrapper over the WS session: the only real
 * difference is the transport (newline-delimited stdin/stdout instead
 * of a socket) and the admission gate. Subscribe / unsubscribe and all
 * the JSON-RPC semantics come from the shared session.
 */
import type { OperationRegistry } from './operation-catalog.ts';
import type { WorkflowEventFeed } from './workflow-event-feed.ts';
export type StdioAdmission = {
    readonly kind: 'require-one';
} | {
    readonly kind: 'startup-token';
    readonly token: string;
} | {
    readonly kind: 'allow-unauthenticated-local-admin';
};
export type StdioSessionOptions = {
    readonly input: ReadableStream<Uint8Array>;
    readonly output: WritableStream<Uint8Array>;
    readonly admission: StdioAdmission;
    readonly registry: OperationRegistry;
    readonly engine: unknown;
    readonly feed: WorkflowEventFeed;
    readonly maxFrameBytes?: number;
    readonly maxSubscriptions?: number;
};
export type StdioSessionResult = {
    readonly exitCode: number;
    readonly reason?: string;
};
export declare function runStdioSession(options: StdioSessionOptions): Promise<StdioSessionResult>;