diff --git a/README.md b/README.md
index a74291e..d37444d 100644
--- a/README.md
+++ b/README.md
@@ -32,7 +32,8 @@ ComfyUI's native caching often breaks with external API nodes (dynamic timestamp
 - **Device-Portable Caching:** All tensors are saved to CPU and loaded with `map_location="cpu"`, so cache files work regardless of GPU configuration.
 - **Atomic Writes:** Cache files are written to a temp file first, then atomically replaced — preventing corruption from interrupted writes.
 - **Concurrent-Safe:** File locking on every cache read/write operation.
-- **Sidecar Metadata (v1.3.0):** Every saved entry gets a `{hash_key}.json` sidecar with human-readable `label`, `created_at`, `last_accessed_at`, and payload summary. Image outputs also get a `{hash_key}.thumb.png` 256px preview. Sidecar data is decoupled from the hash, so editing a `label` never invalidates cache. This is what the upcoming Hash Vault Browser indexes.
+- **Sidecar Metadata (v1.3.0):** Every saved entry gets a `{hash_key}.json` sidecar with human-readable `label`, `created_at`, `last_accessed_at`, and payload summary. Image outputs also get a `{hash_key}.thumb.png` 256px preview. Sidecar data is decoupled from the hash, so editing a `label` never invalidates cache. This is what the Hash Vault Browser indexes.
+- **Hash Vault Browser (v1.4.0):** A modal gallery over the entire vault. Open from `Extensions → AKURATE → Hash Vault Browser` in the ComfyUI menu. Shows every cached entry as a card with thumbnail, label, relative age, and `.pt` size. Live substring filter on label + hash. Click a card to copy its hash to clipboard. Sorted by last-accessed desc. No load-into-workflow action in v0.1 — that's v1.5+.
 
 ### Sidecar Label Input
 
diff --git a/__init__.py b/__init__.py
index eb1fd92..2d8990b 100644
--- a/__init__.py
+++ b/__init__.py
@@ -1,5 +1,8 @@
 from .api_optimizer_nodes import NODE_CLASS_MAPPINGS, NODE_DISPLAY_NAME_MAPPINGS
+from . import hash_vault_browser  # registers the /akurate/hash_vault/list route
 
-__all__ =['NODE_CLASS_MAPPINGS', 'NODE_DISPLAY_NAME_MAPPINGS']
+WEB_DIRECTORY = "./web"
 
-print("\033[34m[ComfyUI-API-Optimizer] \033[92mLoaded Cost Tracker & Deterministic Hash Vault\033[0m")
\ No newline at end of file
+__all__ = ['NODE_CLASS_MAPPINGS', 'NODE_DISPLAY_NAME_MAPPINGS', 'WEB_DIRECTORY']
+
+print("\033[34m[ComfyUI-API-Optimizer] \033[92mLoaded Cost Tracker, Hash Vault, and Browser\033[0m")
\ No newline at end of file
diff --git a/hash_vault_browser.py b/hash_vault_browser.py
new file mode 100644
index 0000000..1ec508a
--- /dev/null
+++ b/hash_vault_browser.py
@@ -0,0 +1,77 @@
+"""Hash Vault Browser backend route.
+
+Registers GET /akurate/hash_vault/list which walks output/hash_vault/, reads
+every {hash}.json sidecar, and returns a JSON array sorted by last_accessed_at
+desc. Thumbnails are served by ComfyUI's built-in /view route using
+type=output&subfolder=hash_vault&filename={hash}.thumb.png — no extra route
+needed on our side.
+
+The .pt files themselves are never read here; they are opaque + expensive to
+load, and the sidecar already carries everything the browser UI needs.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+from typing import Any
+
+try:
+    import folder_paths
+except ImportError:
+    folder_paths = None
+
+try:
+    from server import PromptServer
+    from aiohttp import web
+except ImportError:
+    PromptServer = None
+    web = None
+
+
+def _vault_dir() -> str | None:
+    if folder_paths is None:
+        return None
+    return os.path.join(folder_paths.get_output_directory(), "hash_vault")
+
+
+def _list_entries() -> list[dict[str, Any]]:
+    """Walk hash_vault/, read sidecars, return enriched entries sorted by last_accessed_at desc."""
+    vault = _vault_dir()
+    if not vault or not os.path.isdir(vault):
+        return []
+
+    entries: list[dict[str, Any]] = []
+    for name in os.listdir(vault):
+        if not name.endswith(".json"):
+            continue
+        sidecar_path = os.path.join(vault, name)
+        hash_key = name[:-5]  # strip .json
+
+        try:
+            with open(sidecar_path, "r", encoding="utf-8") as f:
+                sidecar = json.load(f)
+        except (OSError, json.JSONDecodeError):
+            continue
+
+        pt_path = os.path.join(vault, f"{hash_key}.pt")
+        pt_size = os.path.getsize(pt_path) if os.path.exists(pt_path) else 0
+
+        sidecar["pt_size"] = pt_size
+        sidecar["pt_exists"] = pt_size > 0
+        entries.append(sidecar)
+
+    entries.sort(key=lambda e: e.get("last_accessed_at", ""), reverse=True)
+    return entries
+
+
+if PromptServer is not None and web is not None:
+    routes = PromptServer.instance.routes
+
+    @routes.get("/akurate/hash_vault/list")
+    async def hash_vault_list(request):
+        try:
+            data = _list_entries()
+            return web.json_response({"entries": data, "count": len(data)})
+        except Exception as e:
+            return web.json_response({"error": str(e)}, status=500)
diff --git a/pyproject.toml b/pyproject.toml
index 19be3cf..d1f4388 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [project]
 name = "comfyui-api-optimizer"
 description = "API cost tracking, deterministic hash caching, and lazy execution bypass for cloud API workflows"
-version = "1.3.0"
+version = "1.4.0"
 license = { file = "LICENSE" }
 
 [project.urls]
diff --git a/web/hash_vault_browser.js b/web/hash_vault_browser.js
new file mode 100644
index 0000000..8c670df
--- /dev/null
+++ b/web/hash_vault_browser.js
@@ -0,0 +1,269 @@
+import { app } from "../../scripts/app.js";
+
+const LIST_URL = "/akurate/hash_vault/list";
+const THUMB_URL = (hash, name) =>
+    `/view?filename=${encodeURIComponent(name)}&type=output&subfolder=hash_vault&rand=${hash.slice(0, 8)}`;
+
+const STYLE = `
+.akurate-hv-backdrop {
+    position: fixed; inset: 0; background: rgba(0,0,0,0.82);
+    z-index: 10000; display: flex; align-items: center; justify-content: center;
+    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
+}
+.akurate-hv-modal {
+    background: #1a1a1a; color: #eee; border: 1px solid #333; border-radius: 8px;
+    width: 92vw; height: 90vh; display: flex; flex-direction: column;
+    box-shadow: 0 20px 60px rgba(0,0,0,0.6);
+}
+.akurate-hv-header {
+    padding: 14px 20px; border-bottom: 1px solid #333;
+    display: flex; align-items: center; gap: 16px;
+}
+.akurate-hv-header h2 { margin: 0; font-size: 16px; font-weight: 500; }
+.akurate-hv-count { color: #888; font-size: 13px; }
+.akurate-hv-search {
+    flex: 1; background: #0f0f0f; color: #eee; border: 1px solid #333;
+    border-radius: 4px; padding: 6px 10px; font-size: 13px;
+    font-family: inherit; outline: none;
+}
+.akurate-hv-search:focus { border-color: #4a90e2; }
+.akurate-hv-close {
+    background: transparent; color: #aaa; border: 1px solid #333;
+    border-radius: 4px; padding: 4px 10px; cursor: pointer; font-size: 14px;
+}
+.akurate-hv-close:hover { background: #333; color: #fff; }
+.akurate-hv-body {
+    flex: 1; overflow-y: auto; padding: 16px 20px;
+}
+.akurate-hv-grid {
+    display: grid; gap: 14px;
+    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
+}
+.akurate-hv-card {
+    background: #111; border: 1px solid #2a2a2a; border-radius: 6px;
+    overflow: hidden; cursor: pointer; transition: border-color 0.12s, transform 0.12s;
+    display: flex; flex-direction: column;
+}
+.akurate-hv-card:hover { border-color: #4a90e2; transform: translateY(-1px); }
+.akurate-hv-thumb {
+    width: 100%; aspect-ratio: 1 / 1; background: #0a0a0a;
+    display: flex; align-items: center; justify-content: center;
+    color: #555; font-size: 36px;
+}
+.akurate-hv-thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
+.akurate-hv-meta {
+    padding: 8px 10px; font-size: 12px; line-height: 1.35;
+    display: flex; flex-direction: column; gap: 2px; min-height: 54px;
+}
+.akurate-hv-label { color: #eee; font-weight: 500; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+.akurate-hv-label.empty { color: #666; font-style: italic; font-weight: 400; }
+.akurate-hv-sub { color: #888; font-size: 11px; }
+.akurate-hv-empty {
+    text-align: center; color: #666; padding: 60px 20px; font-size: 14px;
+}
+.akurate-hv-toast {
+    position: fixed; bottom: 30px; left: 50%; transform: translateX(-50%);
+    background: #2a2a2a; color: #eee; border: 1px solid #4a90e2;
+    padding: 10px 18px; border-radius: 6px; font-size: 13px;
+    z-index: 10001; opacity: 0; transition: opacity 0.2s;
+    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
+}
+.akurate-hv-toast.show { opacity: 1; }
+`;
+
+function injectStyle() {
+    if (document.getElementById("akurate-hv-style")) return;
+    const el = document.createElement("style");
+    el.id = "akurate-hv-style";
+    el.textContent = STYLE;
+    document.head.appendChild(el);
+}
+
+function formatBytes(n) {
+    if (!n) return "—";
+    if (n < 1024) return `${n} B`;
+    if (n < 1024 ** 2) return `${(n / 1024).toFixed(1)} KB`;
+    if (n < 1024 ** 3) return `${(n / 1024 ** 2).toFixed(1)} MB`;
+    return `${(n / 1024 ** 3).toFixed(2)} GB`;
+}
+
+function relativeAge(isoString) {
+    if (!isoString) return "unknown";
+    const then = new Date(isoString).getTime();
+    const now = Date.now();
+    const secs = Math.max(0, (now - then) / 1000);
+    if (secs < 60) return "just now";
+    if (secs < 3600) return `${Math.round(secs / 60)}m ago`;
+    if (secs < 86400) return `${Math.round(secs / 3600)}h ago`;
+    if (secs < 86400 * 30) return `${Math.round(secs / 86400)}d ago`;
+    if (secs < 86400 * 365) return `${Math.round(secs / (86400 * 30))}mo ago`;
+    return `${Math.round(secs / (86400 * 365))}y ago`;
+}
+
+function showToast(text) {
+    const toast = document.createElement("div");
+    toast.className = "akurate-hv-toast";
+    toast.textContent = text;
+    document.body.appendChild(toast);
+    requestAnimationFrame(() => toast.classList.add("show"));
+    setTimeout(() => {
+        toast.classList.remove("show");
+        setTimeout(() => toast.remove(), 250);
+    }, 1600);
+}
+
+function buildCard(entry) {
+    const card = document.createElement("div");
+    card.className = "akurate-hv-card";
+
+    const thumb = document.createElement("div");
+    thumb.className = "akurate-hv-thumb";
+    if (entry.thumbnail) {
+        const img = document.createElement("img");
+        img.src = THUMB_URL(entry.hash_key, entry.thumbnail);
+        img.loading = "lazy";
+        img.onerror = () => {
+            thumb.innerHTML = "";
+            thumb.textContent = "⋄";
+        };
+        thumb.appendChild(img);
+    } else {
+        const kind = entry.payload?.kind || "?";
+        thumb.textContent = kind === "dict" ? "{…}" : kind === "tensor" ? "⊞" : "⋄";
+    }
+    card.appendChild(thumb);
+
+    const meta = document.createElement("div");
+    meta.className = "akurate-hv-meta";
+
+    const label = document.createElement("div");
+    label.className = "akurate-hv-label";
+    if (entry.label) {
+        label.textContent = entry.label;
+    } else {
+        label.classList.add("empty");
+        label.textContent = entry.hash_key.slice(0, 12);
+    }
+
+    const sub = document.createElement("div");
+    sub.className = "akurate-hv-sub";
+    sub.textContent = `${relativeAge(entry.last_accessed_at)} · ${formatBytes(entry.pt_size)}`;
+
+    meta.appendChild(label);
+    meta.appendChild(sub);
+    card.appendChild(meta);
+
+    card.addEventListener("click", () => {
+        navigator.clipboard.writeText(entry.hash_key).then(
+            () => showToast(`Hash copied: ${entry.hash_key.slice(0, 12)}…`),
+            () => showToast("Copy failed — selection blocked"),
+        );
+    });
+
+    return card;
+}
+
+function buildModal(entries) {
+    const backdrop = document.createElement("div");
+    backdrop.className = "akurate-hv-backdrop";
+
+    const modal = document.createElement("div");
+    modal.className = "akurate-hv-modal";
+
+    const header = document.createElement("div");
+    header.className = "akurate-hv-header";
+    const title = document.createElement("h2");
+    title.textContent = "Hash Vault Browser";
+    const count = document.createElement("span");
+    count.className = "akurate-hv-count";
+    const search = document.createElement("input");
+    search.className = "akurate-hv-search";
+    search.placeholder = "Filter by label…";
+    search.type = "text";
+    const close = document.createElement("button");
+    close.className = "akurate-hv-close";
+    close.textContent = "Close";
+    header.append(title, count, search, close);
+
+    const body = document.createElement("div");
+    body.className = "akurate-hv-body";
+    const grid = document.createElement("div");
+    grid.className = "akurate-hv-grid";
+    body.appendChild(grid);
+
+    modal.append(header, body);
+    backdrop.appendChild(modal);
+
+    function render(filter) {
+        const needle = (filter || "").trim().toLowerCase();
+        grid.innerHTML = "";
+        let shown = 0;
+        for (const entry of entries) {
+            if (needle) {
+                const hay = (entry.label || "").toLowerCase() + " " + entry.hash_key.toLowerCase();
+                if (!hay.includes(needle)) continue;
+            }
+            grid.appendChild(buildCard(entry));
+            shown++;
+        }
+        if (shown === 0) {
+            const empty = document.createElement("div");
+            empty.className = "akurate-hv-empty";
+            empty.textContent = entries.length === 0
+                ? "Vault is empty — save something via Hash Vault (Save API Result) first."
+                : "No entries match the filter.";
+            grid.appendChild(empty);
+        }
+        count.textContent = needle ? `${shown} of ${entries.length}` : `${entries.length} entries`;
+    }
+
+    function dismiss() {
+        backdrop.remove();
+        document.removeEventListener("keydown", onKey);
+    }
+    function onKey(e) {
+        if (e.key === "Escape") dismiss();
+    }
+
+    close.addEventListener("click", dismiss);
+    backdrop.addEventListener("click", (e) => { if (e.target === backdrop) dismiss(); });
+    document.addEventListener("keydown", onKey);
+    search.addEventListener("input", () => render(search.value));
+
+    document.body.appendChild(backdrop);
+    search.focus();
+    render("");
+}
+
+async function openBrowser() {
+    injectStyle();
+    try {
+        const resp = await fetch(LIST_URL);
+        if (!resp.ok) {
+            showToast(`Vault list failed: HTTP ${resp.status}`);
+            return;
+        }
+        const data = await resp.json();
+        buildModal(data.entries || []);
+    } catch (e) {
+        showToast(`Vault list failed: ${e.message}`);
+    }
+}
+
+app.registerExtension({
+    name: "akurate.HashVaultBrowser",
+    commands: [
+        {
+            id: "akurate.HashVaultBrowser.open",
+            label: "AKURATE: Hash Vault Browser",
+            icon: "pi pi-database",
+            function: openBrowser,
+        },
+    ],
+    menuCommands: [
+        {
+            path: ["Extensions"],
+            commands: ["akurate.HashVaultBrowser.open"],
+        },
+    ],
+});