import type { Format } from 'logform';
export declare const LEVEL_TO_SEVERITY: Record<string, string>;
/**
 * Round-trip the record through safe-stable-stringify so circular references
 * (HTTP client/response cycles, request/response objects, framework execution
 * contexts) become "[Circular]" instead of crashing the log emit, and bigints
 * serialize as strings (JSON.stringify can't, and the bare safe-stringify output
 * wouldn't round-trip through JSON.parse). Symbol keys winston relies on are
 * untouched (JSON ignores them), so Object.assign only rewrites string fields.
 */
export declare function bigIntSafeFormat(): Format;
/**
 * Inject every logged HeaderRegistry key present in the active RequestContext frame
 * into the record under its `name` (→ top-level jsonPayload.<name> in GCP, filterable
 * as jsonPayload.requestId, jsonPayload.tenantId, …). Values are read DIRECTLY from
 * RequestContext, secured keys masked via {@link ContextKey.maskForLogs} — no
 * ContextReader. Caller-supplied fields on the record win on conflict. Runs on EVERY
 * winston call, including winston's own handleExceptions/handleRejections lines that
 * bypass the WinstonLogger wrapper.
 *
 * This mirrors the (duplicated, on purpose) inline logic in BunyanLogger: it must run
 * ONLY when a winston backend is installed, never for the plain ConsoleLogger. A log
 * line with no active RequestContext just injects nothing (startup and background-job
 * lines are legitimately out of context).
 */
export declare function injectContextFormat(): Format;
/**
 * Map the winston level onto a top-level `severity` field that the Cloud Logging
 * agent lifts onto the LogEntry.
 */
export declare function severityFormat(): Format;
/**
 * Local-only human format:
 * `[LEVEL][time][Controller.method][loggerName][ctx tags]: message { …extra }` + Error Details block.
 * Level FIRST, then time (the ordering the production-tested format was tuned for). `controller`/`method` render
 * as a compact bracket, `loggerName` as its own bracket, every other registered context key as a
 * `key:value` tag, and anything else the caller attached as trailing JSON. Byte-identical to the bunyan
 * backend for the same record + `fields`.
 *
 * `fields`, when given, is the app-chosen ordered ALLOW-LIST of context keys to render as tags (hides
 * local noise like `requestPath`); when omitted, the registered logged keys render in registry order.
 * The time value comes from the `format.timestamp({format:'HH:mm:ss.SSS'})` layer in WinstonConsoleFactory.
 */
export declare function localPrettyFormat(fields?: string[]): Format;