diff --git a/bindings/napi/BeaconStateView.zig b/bindings/napi/BeaconStateView.zig
index b6a758333..2cdd4748e 100644
--- a/bindings/napi/BeaconStateView.zig
+++ b/bindings/napi/BeaconStateView.zig
@@ -72,7 +72,7 @@ pub const js_meta = js.class(.{ .properties = .{
 } });
 
 cached_state: ?*CachedBeaconState = null,
-pool_rc: ?*pool.PoolRc = null,
+pool_rc: @TypeOf(pool.state.pool_rc) = null,
 const BeaconStateView = @This();
 
 pub fn init() BeaconStateView {
diff --git a/bindings/napi/blst.zig b/bindings/napi/blst.zig
index c48298e78..780f70d2f 100644
--- a/bindings/napi/blst.zig
+++ b/bindings/napi/blst.zig
@@ -39,25 +39,31 @@ const BATCH_VERIFY_SIZE = 32;
 /// Initialized lazily on first use, torn down via `deinitThreadPool`.
 var thread_pool: ?*ThreadPool = null;
 
-pub fn initThreadPool(n_workers: u16) !void {
-    if (thread_pool != null) return error.PoolExists;
-    thread_pool = try ThreadPool.init(std.heap.page_allocator, napi_io.get(), .{ .n_workers = n_workers });
-}
+/// Native-only thread pool lifecycle, reached from `root.zig` through the
+/// pub `lifecycle` var so it is not part of the JS module surface.
+const Lifecycle = struct {
+    pub fn initThreadPool(_: *Lifecycle, n_workers: u16) !void {
+        if (thread_pool != null) return error.PoolExists;
+        thread_pool = try ThreadPool.init(std.heap.page_allocator, napi_io.get(), .{ .n_workers = n_workers });
+    }
 
-/// Closes the `ThreadPool` used for blst operations.
-///
-/// Note: this can invalidate any inflight verification requests. Consumer is responsible
-/// for the lifecycle of their program and should only call this when all work is done.
-///
-/// This note is however application dependent. For the use case of lodestar,
-/// it's likely that this would not be called at all.
-/// Same goes for any other long-lived processes.
-pub fn deinitThreadPool() void {
-    if (thread_pool) |p| {
-        p.deinit(napi_io.get());
-        thread_pool = null;
+    /// Closes the `ThreadPool` used for blst operations.
+    ///
+    /// Note: this can invalidate any inflight verification requests. Consumer is responsible
+    /// for the lifecycle of their program and should only call this when all work is done.
+    ///
+    /// This note is however application dependent. For the use case of lodestar,
+    /// it's likely that this would not be called at all.
+    /// Same goes for any other long-lived processes.
+    pub fn deinitThreadPool(_: *Lifecycle) void {
+        if (thread_pool) |p| {
+            p.deinit(napi_io.get());
+            thread_pool = null;
+        }
     }
-}
+};
+
+pub var lifecycle: Lifecycle = .{};
 
 var gpa: std.heap.DebugAllocator(.{}) = .init;
 const allocator = if (builtin.mode == .Debug)
diff --git a/bindings/napi/config.zig b/bindings/napi/config.zig
index 0132bd02f..a59092fe3 100644
--- a/bindings/napi/config.zig
+++ b/bindings/napi/config.zig
@@ -9,7 +9,7 @@ const Preset = @import("preset").Preset;
 
 const max_blob_schedule_entries = 16;
 
-pub const State = struct {
+const State = struct {
     config: BeaconConfig = undefined,
     initialized: bool = false,
     config_name: [64]u8 = undefined,
@@ -71,7 +71,7 @@ pub fn set(object: js.Value, genesis_root: js.Uint8Array) !void {
     state.initialized = true;
 }
 
-pub fn chainConfigFromObject(env: napi.Env, obj: napi.Value) !ChainConfig {
+fn chainConfigFromObject(env: napi.Env, obj: napi.Value) !ChainConfig {
     var chain_config: ChainConfig = undefined;
 
     inline for (std.meta.fields(ChainConfig)) |field| {
diff --git a/bindings/napi/pool.zig b/bindings/napi/pool.zig
index 2e0ec480b..c23dcec40 100644
--- a/bindings/napi/pool.zig
+++ b/bindings/napi/pool.zig
@@ -9,14 +9,14 @@ const allocator = std.heap.page_allocator;
 
 const default_pool_size: u32 = 0;
 
-pub const PoolRc = RefCount(Node.Pool);
+const PoolRc = RefCount(Node.Pool);
 
 /// Pool is wrapped in `RefCount` so binding objects holding pool refs at
 /// process exit keep the pool alive until their JS finalizer runs. NAPI
 /// env cleanup hook fires before module-level JS holders are finalized,
 /// so an unconditional `pool.deinit()` there would free memory that
 /// `pool.unref()` calls in those finalizers still need.
-pub const State = struct {
+const State = struct {
     pool_rc: ?*PoolRc = null,
 
     pub fn init(self: *State) !void {
diff --git a/bindings/napi/pubkeys.zig b/bindings/napi/pubkeys.zig
index 86e611682..79a25f2f4 100644
--- a/bindings/napi/pubkeys.zig
+++ b/bindings/napi/pubkeys.zig
@@ -19,7 +19,7 @@ const max_stack_aggregate_pubkeys = 512;
 /// per epoch at 12s slots), so growth stays proportionate at any network scale.
 const growth_step: u32 = preset.MAX_PENDING_DEPOSITS_PER_EPOCH * ((90 * 24 * 60 * 60) / (12 * preset.SLOTS_PER_EPOCH));
 
-pub const State = struct {
+const State = struct {
     pubkey2index: PubkeyIndexMap = undefined,
     index2pubkey: Index2PubkeyCache = undefined,
     initialized: bool = false,
diff --git a/bindings/napi/root.zig b/bindings/napi/root.zig
index 13abd58f7..d48f59bc0 100644
--- a/bindings/napi/root.zig
+++ b/bindings/napi/root.zig
@@ -32,7 +32,7 @@ fn init(old_ref_count: u32) !void {
         }
 
         const n_workers = @min(cpu_count, @import("bls").ThreadPool.MAX_WORKERS);
-        try blst.initThreadPool(@intCast(n_workers));
+        try blst.lifecycle.initThreadPool(@intCast(n_workers));
         try pool.state.init();
         try pubkeys.state.init();
         config.state.init();
@@ -55,7 +55,7 @@ fn detectCpuCount() !usize {
 fn cleanup(new_ref_count: u32) void {
     if (new_ref_count == 0) {
         // Last environment — tear down shared state.
-        blst.deinitThreadPool();
+        blst.lifecycle.deinitThreadPool();
         config.state.deinit();
         pubkeys.state.deinit();
         pool.state.deinit();
diff --git a/build.zig.zon b/build.zig.zon
index c1c37f6d4..326d2c865 100644
--- a/build.zig.zon
+++ b/build.zig.zon
@@ -40,8 +40,8 @@
             .hash = "zig_yaml-0.1.0-C1161kFWAwDxjKAFmklKwWVDvz2mmq0Q__bDhGGjeyd3",
         },
         .zapi = .{
-            .url = "git+https://github.com/chainsafe/zapi.git?ref=zapi-v2.x.0#92fe4babe4022ceb94a5cb24022a18fe27417d69",
-            .hash = "zapi-2.2.0-rIqzUXBaBADUsvvvB2N5kOBdLEO0rGPhowTqmIXe3qVh",
+            .url = "https://github.com/ChainSafe/zapi/archive/refs/tags/zapi-v3.1.0.tar.gz",
+            .hash = "zapi-3.1.0-rIqzUQJsBADCFUrmxoTZyOhSTkcW6m3t_OgOHc6oxnm9",
         },
         .zbench = .{
             .url = "git+https://github.com/hendriknielaender/zBench#b2b89c475e3ef1bb2bd71255c80478a82d3e0ca8",
diff --git a/package.json b/package.json
index 28e4cd195..b198cba77 100644
--- a/package.json
+++ b/package.json
@@ -57,11 +57,8 @@
     ]
   },
   "dependencies": {
-    "@chainsafe/zapi": "github:ChainSafe/zapi#6649cef91b19bcd9854aa1ffa4d0c1aed7270f55"
+    "@chainsafe/zapi": "3.1.0"
   },
-  "bundleDependencies": [
-    "@chainsafe/zapi"
-  ],
   "devDependencies": {
     "@biomejs/biome": "^2.3.11",
     "@chainsafe/benchmark": "^2.0.1",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index d6611513b..b57408b12 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -9,8 +9,8 @@ importers:
   .:
     dependencies:
       '@chainsafe/zapi':
-        specifier: github:ChainSafe/zapi#6649cef91b19bcd9854aa1ffa4d0c1aed7270f55
-        version: https://codeload.github.com/ChainSafe/zapi/tar.gz/6649cef91b19bcd9854aa1ffa4d0c1aed7270f55
+        specifier: 3.1.0
+        version: 3.1.0
     devDependencies:
       '@biomejs/biome':
         specifier: ^2.3.11
@@ -401,9 +401,8 @@ packages:
     resolution: {integrity: sha512-H8YdEoXXv2Hw17gDWGOJEya4LHlBbpChJP3jDQRfIk9hhwr0c/zbBemBRmjADowZhArL+ymkO+j5hGaYySjdpw==}
     engines: {node: '>= 18'}
 
-  '@chainsafe/zapi@https://codeload.github.com/ChainSafe/zapi/tar.gz/6649cef91b19bcd9854aa1ffa4d0c1aed7270f55':
-    resolution: {tarball: https://codeload.github.com/ChainSafe/zapi/tar.gz/6649cef91b19bcd9854aa1ffa4d0c1aed7270f55}
-    version: 2.2.0
+  '@chainsafe/zapi@3.1.0':
+    resolution: {integrity: sha512-WRamllUXrrmx4G4qzmg0vRvcWQ+/Lgm7TgOFbqeJFPKlNv8CApTyA3BP6tudBaJyQYJSXlOn2RWrdv5e0EFwSw==}
     hasBin: true
 
   '@colors/colors@1.5.0':
@@ -2443,7 +2442,7 @@ snapshots:
       '@chainsafe/swap-or-not-shuffle-win32-arm64-msvc': 1.2.1
       '@chainsafe/swap-or-not-shuffle-win32-x64-msvc': 1.2.1
 
-  '@chainsafe/zapi@https://codeload.github.com/ChainSafe/zapi/tar.gz/6649cef91b19bcd9854aa1ffa4d0c1aed7270f55': {}
+  '@chainsafe/zapi@3.1.0': {}
 
   '@colors/colors@1.5.0':
     optional: true