import type { EventEnvelope } from "./wireTypes.js";
/** Thin accessor layer over the wire format. Every place that reads
 *  `ev.data.foo` directly is a leak of the wire format into consumer
 *  code; if the runtime renames `usage.inputTokens` → `usage.promptTokens`
 *  tomorrow (provider libraries do this constantly), we don't want to
 *  chase the rename through every helper. Confine wire-format
 *  knowledge to this one module.
 *
 *  Rule for `lib/eval/`: no helper reads `ev.data.foo` directly — add
 *  an accessor here first, then use it. Enforce in code review. */
/** Group events by their `data.type`. One pass; produces a plain
 *  object (per AGENTS.md: prefer objects over Maps). */
export declare function groupByType(events: EventEnvelope[]): Record<string, EventEnvelope[]>;
/** Convenience: filter to one event type. Prefer `groupByType` when
 *  you need multiple types in one pass. */
export declare function byType(events: EventEnvelope[], type: string): EventEnvelope[];
/** Epoch milliseconds for an event's timestamp. */
export declare function timestampMs(ev: EventEnvelope): number;
/** Thread id stamped on a promptCompletion / toolCall / toolCallStart
 *  by Task 0. Null for legacy traces (pre-prereq). */
export declare function threadIdOf(ev: EventEnvelope): string | null;
/** Tool name on a toolCall / toolCallStart. */
export declare function toolNameOf(ev: EventEnvelope): string;
/** Input-token count from a promptCompletion's `data.usage`. Returns
 *  0 if absent. The key name is locked here — if the runtime starts
 *  using a different shape (`prompt_tokens`, `input_tokens`, …),
 *  update this one site rather than chasing every consumer. */
export declare function tokensIn(ev: EventEnvelope): number;
export declare function tokensOut(ev: EventEnvelope): number;
/** USD cost on a promptCompletion. Reads `cost.totalCost` (TokenCost
 *  shape from lib/statelogClient.ts). */
export declare function cost(ev: EventEnvelope): number;
/** Model name on a promptCompletion. Strips wrapping quotes — call
 *  sites in `lib/runtime/prompt.ts` pass `JSON.stringify(modelName)`,
 *  which surrounds the string with quotes. */
export declare function modelOf(ev: EventEnvelope): string;
/** Tools array advertised to the LLM on a promptCompletion. */
export declare function toolsOf(ev: EventEnvelope): string[];
/** Last user-role message content from a promptCompletion's
 *  `data.messages` array. Returns null if no user message exists.
 *  The "user message" is appended to the message thread after any
 *  system prompt(s), so the LAST user-role entry in the first-turn
 *  messages is the prompt the user just typed. */
export declare function userMessageOf(promptCompletion: EventEnvelope): string | null;
/** Assistant's reply text on a promptCompletion. Returns null when
 *  the completion is empty or absent. */
export declare function completionOf(promptCompletion: EventEnvelope): string | null;