/** Legacy marker some models emit after a serialized JSON tool request. */
export declare const END_TOOL_REQUEST = "[END_TOOL_REQUEST]";
/** Harmony stream marker that introduces the target channel before a tool call. */
export declare const HARMONY_CHANNEL_MARKER = "<|channel|>";
/** Harmony stream marker that may separate the header from the JSON payload. */
export declare const HARMONY_MESSAGE_MARKER = "<|message|>";
/** Harmony stream marker that may close a serialized tool-call payload. */
export declare const HARMONY_CALL_MARKER = "<|call|>";
/**
 * Harmony marker real gpt-oss emits in place of the reference grammar's literal `code` token —
 * e.g. `<|constrain|>json` declares the tool-call payload format. (EXT-43.)
 */
export declare const HARMONY_CONSTRAIN_MARKER = "<|constrain|>";
/** Tool names in bracket/plain-text repairs intentionally match provider-safe ids only. */
export declare function isPlainTextToolNameChar(char: string | undefined): boolean;
/**
 * Harmony tool names may be NAMESPACED with dots (real gpt-oss emits `to=functions.get_weather`),
 * so the Harmony header scanner accepts `.` on top of the provider-safe id chars. This is a
 * Harmony-only widening (EXT-43): the bracket/XML-ish dialects keep {@link isPlainTextToolNameChar}
 * unchanged so their prose-safety is untouched. The final dot-segment is the tool name matched
 * against the allow-list (see {@link finalDotSegment}).
 */
export declare function isHarmonyToolNameChar(char: string | undefined): boolean;
/**
 * The tool name for a (possibly namespaced) Harmony target: the final dot-segment.
 * `functions.get_weather` → `get_weather`; `functions.tools.get_weather` → `get_weather`; a dotless
 * `get_weather` → itself. Returns `''` for a trailing-dot / empty final segment (rejected upstream).
 */
export declare function finalDotSegment(name: string): string;
/** Skips spaces and tabs only, preserving line boundaries for grammar decisions. */
export declare function skipHorizontalWhitespace(text: string, start: number): number;
/** Skips all JavaScript whitespace when line structure is no longer meaningful. */
export declare function skipWhitespace(text: string, start: number): number;
/** Consumes either Unix or Windows line endings and returns the first offset after them. */
export declare function consumeLineBreak(text: string, start: number): number | null;
/**
 * Finds the exclusive end offset of a balanced JSON object starting at `start`. Returns null if
 * the object never closes, or (when `maxPayloadBytes` is set) as soon as the scan runs past the
 * cap — the payload-size gate that keeps a runaway blob from being treated as a tool call.
 */
export declare function findJsonObjectEnd(text: string, start: number, maxPayloadBytes?: number): number | null;