/**
 * @fileoverview Change-journal writer — single-writer, fsync'd, hash-chained
 *               append (SMI-5456 Wave 1 Step 3 / SMI-5470).
 * @module @skillsmith/core/journal/writer
 *
 * P-5 single-writer invariant (docs/internal/implementation/smi-5456-skillsmith-agent-wave1.md
 * "Shared-State / Coordination Audit"): the journal file is written by the
 * apply-family MCP tools ONLY, and every writer in this process funnels
 * through `appendJournalRecord`, which serializes behind ONE module-scoped
 * promise queue. That queue — not any per-caller locking — is what makes
 * concurrent `apply_namespace_rename` / `apply_recommended_edit` / `undo_apply`
 * calls in the same server process produce well-formed, correctly-chained
 * lines instead of interleaved/torn writes.
 *
 * Durability: each append opens the file, writes the line, calls
 * `FileHandle.sync()` (fsync), then closes — so a record that returns
 * successfully is durable on disk before the caller's apply/undo response
 * goes out, matching the "fsync'd appends" requirement in the plan's P-5
 * table.
 */
import type { JournalRecord, JournalRecordInput } from './types.js';
/**
 * Recompute a record's `record_hash` from its other fields. Exported so the
 * reader can independently verify each line without duplicating the
 * canonicalization logic (drift between writer and reader would silently
 * break every chain-verification call).
 */
export declare function computeRecordHash(record: Omit<JournalRecord, 'record_hash'>): string;
/**
 * Error thrown when the journal's last line cannot be parsed as a valid
 * record — the writer cannot safely determine the chain head to append
 * after. This is distinct from the reader's "corrupt tail = report, never
 * throw" contract: a reader is producing evidence about the past and must
 * degrade gracefully; a writer is about to create NEW evidence and silently
 * starting a fresh chain over a corrupt/tampered tail would hide exactly
 * the tamper signal the chain exists to surface.
 */
export interface JournalCorruptTailError extends Error {
    kind: 'journal.write.corrupt_tail';
}
export declare function isCorruptTailError(err: unknown): err is JournalCorruptTailError;
/**
 * Append a record to the journal. Serialized behind the module-scoped
 * write queue and fsync'd before the returned promise resolves.
 *
 * Callers (the apply-family tools) should treat a rejection as fail-soft —
 * the journal is an evidence trail, not a gate on the user's mutation —
 * and log rather than propagate. See `tools/apply-journal.helpers.ts` in
 * `@skillsmith/mcp-server` for the call-site convention.
 */
export declare function appendJournalRecord(input: JournalRecordInput): Promise<JournalRecord>;
//# sourceMappingURL=writer.d.ts.map