/**
 * RoiLedger — per-(repo, tool) net token history, persisted across sessions.
 *
 * `SavingsLedger` already tracks saved/spent totals, but only by *source* (cache,
 * contextSqueeze, ...) and only in `~/.lemma-cache/ledger.json` — one file, no notion of
 * which repo or which specific tool earned its keep. That is not enough to answer "does
 * `affected_tests` pay for its schema in THIS repo", which is what `tool-profiles.ts` needs
 * to auto-tune the advertised surface instead of relying purely on the hand-curated
 * `CORE_TOOL_NAMES` list.
 *
 * Scope: one small JSON file per repo, keyed by a hash of the repo path, holding cumulative
 * (calls, tokensSaved, tokensSpent) per tool name. Fail-open throughout — a lookup or write
 * that errors must never break the caller; it just means no history this time.
 *
 * Hard rule inherited from `tool-profiles.ts`: the tool surface resolves once at startup and
 * never mutates mid-session. This ledger is written continuously, but only ever *read* by
 * `resolveToolSurface` once, at process start — so a promotion always reflects PRIOR
 * sessions, never the one currently running.
 */
export interface ToolRoiStats {
    calls: number;
    tokensSaved: number;
    tokensSpent: number;
}
export declare function recordRoiSaved(repoRoot: string, tool: string, tokensSaved: number): void;
export declare function recordRoiSpent(repoRoot: string, tool: string, tokensSpent: number): void;
/** All per-tool history for this repo, or an empty map if none exists yet or the read fails. */
export declare function getRoiStats(repoRoot: string): Record<string, ToolRoiStats>;
/** Test seam only — production code should never need to wipe another repo's history. */
export declare function resetRoiLedger(repoRoot: string): void;
//# sourceMappingURL=RoiLedger.d.ts.map