/**
 * Decision limits — the one place a provider's `decisionLimits` are read and
 * a state's size is estimated against them.
 *
 * `SystemOneDecisionProvider` refuses an over-limit request through these
 * functions, and `NeuroLink.decisionLimits()` / `estimateDecisionStateTokens`
 * expose the same functions to hosts, so what a host measures before the call
 * is exactly what the pre-flight check measures inside it. Two estimators that
 * drift apart would let a host size a state as fitting and then watch it be
 * refused.
 *
 * @module utils/decisionLimits
 */
import type { DecisionLimits, DecisionLimitsReading, DecisionState, ProviderDescriptor } from "../types/index.js";
/**
 * Estimate how many tokens a decision model will read from `state`.
 *
 * `estimateTokens` assumes ~4 characters per token. That holds for English
 * and is several times too generous for other scripts on an English
 * tokenizer, so when the limits declare a `nonAsciiTokensPerChar` rate,
 * non-ASCII characters are counted at it instead. Digits, ASCII punctuation
 * and astral characters (emoji) are each counted separately only when the
 * limits declare a rate for that class — a tokenizer that reads each digit,
 * and most punctuation, on its own makes a number-heavy or JSON-heavy state
 * several times longer than the ~4-characters-per-token estimate suggests. A
 * non-string state is serialized first, as it is on the wire.
 *
 * This is the estimator the pre-flight refusal uses: a state this reports at
 * or under `maxStateTokens` is sent, one over it is refused before any
 * network call.
 */
export declare function estimateDecisionStateTokens(state: DecisionState, limits?: Pick<DecisionLimits, "nonAsciiTokensPerChar" | "digitTokensPerChar" | "symbolTokensPerChar" | "astralTokensPerChar">): number;
/**
 * Flatten a descriptor's `decisionLimits` for one model: the per-model entry
 * overrides the base, field by field, and `advisory` becomes
 * `enforcedLocally: false`. Returns null for a descriptor that declares no
 * limits.
 */
export declare function resolveDecisionLimitsReading(descriptor: Pick<ProviderDescriptor, "name" | "decisionLimits">, model: string): DecisionLimitsReading | null;