/**
 * Default (real-filesystem) `ProviderSessionReaders` for the identity resolver
 * (DEC-116). Every reader is **best-effort + total**: any missing file, format
 * drift, or parse error yields `undefined`, so the resolver degrades to
 * `{ source: "none" }` and the caller mints a keypair-anchored id (never throws,
 * never blocks connect). The transcript layouts were live-verified 2026-05-30
 * (gemini's path layout drifts across versions — we match on `.project_root`).
 */
import type { ProviderSessionReaders } from "./resolver.js";
export declare const defaultProviderSessionReaders: ProviderSessionReaders;
/**
 * How much of the tail of a Claude transcript to scan for the current title.
 *
 * A transcript is append-only, and `customTitle` is carried by dedicated
 * **rename-event records** (`type: "custom-title"`) — NOT by ordinary records.
 * Measured 2026-07-25 over all 8078 local transcripts: title-bearing records are
 * 0.06% of tail records (5.1% within the one heavily-renamed transcript that
 * motivated this fix). The newest such record is therefore near the END, and a
 * 64 KiB window reaches it: of the 45 transcripts that carry a title at all,
 * **all 45** are resolved from this window — 0 missed, 0 wrong values.
 *
 * Bounded rather than whole-file because this now runs on the heartbeat and live
 * transcripts reach hundreds of MB (largest local: 233 MB; cost 0.30 ms/call).
 */
export declare const CLAUDE_TITLE_TAIL_BYTES: number;
/**
 * How much of the TAIL of `~/.codex/session_index.jsonl` to read. Codex resolves
 * last-match-wins, so the tail is what matters; the file grows monotonically and
 * this also runs on the heartbeat (48 KiB today, so today's whole file fits).
 * A session whose entry has aged out of the window simply yields `undefined`,
 * which the caller treats as "keep the name you have".
 */
export declare const CODEX_INDEX_TAIL_BYTES: number;
/**
 * Upper bound on a display name written into presence. A host title is
 * user-controlled and unbounded; `isH2ASession` only checks `typeof`, so an
 * absurd title would otherwise land in every peer's presence read. Truncated
 * rather than rejected so the name stays findable by the substring match that
 * `discover_sessions(name:)` performs.
 */
export declare const MAX_DISPLAY_NAME_CHARS = 200;
/** Initial re-scan delay after a transcript lookup MISSES (negative cache). */
export declare const TRANSCRIPT_MISS_BACKOFF_MS = 60000;
/** Ceiling for the negative-cache backoff. */
export declare const TRANSCRIPT_MISS_BACKOFF_MAX_MS = 300000;
/**
 * Injectable FS readers for `readHostSessionName` (test-friendly).
 * Only reading is required; real-FS defaults are `defaultHostNameReaders`.
 */
export interface HostNameReaders {
    /**
     * Read the LAST `maxBytes` of a file as newline-delimited lines, dropping a
     * leading partial record when the file was truncated. Returns [] on any error.
     *
     * Deliberately not `readLines(path, maxLines)` (the pre-fix head reader): a
     * head read of an append-only transcript returns the title as of session
     * START and can never observe a later rename. An external implementor of this
     * interface gets a compile error rather than silently-stale names.
     */
    readTailLines(path: string, maxBytes: number): string[];
    /**
     * List newline-delimited JSONL entries from the TAIL of
     * `~/.codex/session_index.jsonl` (see `CODEX_INDEX_TAIL_BYTES`).
     */
    readCodexSessionIndex(): string[];
    /** Whether the home dir root is known (for path construction). */
    homedir(): string;
    /**
     * Locate the transcript file for a Claude session id. Optional: defaults to
     * scanning `~/.claude/projects`. Injectable so a test can COUNT the scans and
     * pin the negative-cache behaviour — that walk is 87 directories / 14345 files
     * and it sits on a 5-second timer, so a repeated miss must not re-walk.
     */
    findClaudeTranscript?(cwd: string, sessionId: string, home: string): string | undefined;
}
export declare const defaultHostNameReaders: HostNameReaders;
/**
 * Read the host-native session name for the given session.
 *
 * - **claude**: reads the transcript JSONL (located via the CLAUDE_CODE_SESSION_ID
 *   resolver); scans the TAIL for the LAST `customTitle` (the current user
 *   rename — the transcript is append-only), then falls back to the first
 *   `agentName` seen. Never returns `aiTitle`.
 * - **codex**: reads `~/.codex/session_index.jsonl`; returns `thread_name` for
 *   the entry whose `id === sessionId` (last-match wins).
 * - Other hosts: returns undefined.
 *
 * Always best-effort (returns undefined on any parse/IO error).
 */
export declare function readHostSessionName(opts: {
    host: string;
    cwd: string;
    sessionId?: string;
    readers?: HostNameReaders;
}): string | undefined;
/**
 * Build a re-callable resolver for this session's host-native display name, for
 * the heartbeat refresh path (spec 2026-07-25-h2a-lane-addressing §D1b).
 *
 * `readHostSessionName` is a one-shot: it re-scans every project directory to
 * locate the transcript. This factory memoizes the transcript path (the session
 * id is fixed for the life of the server process) so a steady-state heartbeat
 * costs one bounded tail read.
 *
 * **Negative caching (required, not an optimization).** A session whose
 * transcript never appears is a real, observed state — it is the RC-3 case in the
 * spec, where `CLAUDE_CODE_SESSION_ID` names a session with no transcript at all.
 * Memoizing only on success meant that session re-walked
 * `~/.claude/projects` — 87 directories, 14345 files, 8.73 ms — on EVERY
 * heartbeat, i.e. every 5 seconds, forever. So a miss is cached too, with
 * exponential backoff from `TRANSCRIPT_MISS_BACKOFF_MS` to
 * `TRANSCRIPT_MISS_BACKOFF_MAX_MS`. A transcript that appears later is still
 * picked up, just not instantly — bounded by the current backoff.
 *
 * Returns `undefined` whenever the title cannot be read — the caller must treat
 * that as "keep the name you have", never as "fall back to the cwd basename".
 */
export declare function createHostSessionNameRefresher(opts: {
    host: string;
    cwd: string;
    sessionId?: string;
    readers?: HostNameReaders;
    /** Injectable clock, for testing the negative cache without real waiting. */
    now?: () => number;
}): () => string | undefined;
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