From 6f6c9c8697f26c5394dc351f04cec08656e905b6 Mon Sep 17 00:00:00 2001
From: Anson Chung <58066418+anscg@users.noreply.github.com>
Date: Wed, 4 Feb 2026 06:24:42 +0800
Subject: [PATCH] Implement MLT (#633)

* Add MLT tile type

* MLT code implementation

* fix build - /app needs to wait for new pmtiles version on npm

* update CHANGELOGs and python, js versions [#596, #633]

---------

Co-authored-by: Michael Barry <msbarry@users.noreply.github.com>
Co-authored-by: Brandon Liu <bdon@users.noreply.github.com>
Co-authored-by: Brandon Liu <bdon@bdon.org>
---
 cpp/pmtiles.hpp                      | 1 +
 js/CHANGELOG.md                      | 3 +++
 js/examples/leaflet.html             | 2 +-
 js/examples/maplibre.html            | 2 +-
 js/examples/maplibre_advanced.html   | 2 +-
 js/examples/maplibre_raster_dem.html | 2 +-
 js/package-lock.json                 | 4 ++--
 js/package.json                      | 2 +-
 js/src/index.ts                      | 2 ++
 js/test/v3.test.ts                   | 1 +
 python/pmtiles/pmtiles/tile.py       | 1 +
 python/pmtiles/setup.py              | 2 +-
 spec/v3/CHANGELOG.md                 | 3 +++
 13 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/cpp/pmtiles.hpp b/cpp/pmtiles.hpp
index 2819f33..b340f58 100644
--- a/cpp/pmtiles.hpp
+++ b/cpp/pmtiles.hpp
@@ -18,6 +18,7 @@ const uint8_t TILETYPE_PNG = 0x2;
 const uint8_t TILETYPE_JPEG = 0x3;
 const uint8_t TILETYPE_WEBP = 0x4;
 const uint8_t TILETYPE_AVIF = 0x5;
+const uint8_t TILETYPE_MLT = 0x6;
 
 const uint8_t COMPRESSION_UNKNOWN = 0x0;
 const uint8_t COMPRESSION_NONE = 0x1;
diff --git a/js/CHANGELOG.md b/js/CHANGELOG.md
index aea7568..1fefe4d 100644
--- a/js/CHANGELOG.md
+++ b/js/CHANGELOG.md
@@ -1,3 +1,6 @@
+4.4.0
+* add [MapLibre Vector Tile](https://github.com/maplibre/maplibre-tile-spec) `.mlt` support by @anscg [#633]
+
 4.3.2
 * fix leafletRasterLayer empty images: set `display: none`
 
diff --git a/js/examples/leaflet.html b/js/examples/leaflet.html
index 1972e75..09015d9 100644
--- a/js/examples/leaflet.html
+++ b/js/examples/leaflet.html
@@ -4,7 +4,7 @@
         <meta charset="utf-8"/>
         <link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.0/dist/leaflet.css" />
         <script src="https://unpkg.com/leaflet@1.9.0/dist/leaflet.js"></script>
-        <script src="https://unpkg.com/pmtiles@4.3.2/dist/pmtiles.js"></script>
+        <script src="https://unpkg.com/pmtiles@4.4.0/dist/pmtiles.js"></script>
         <style>
             body, #map {
                 height:100vh;
diff --git a/js/examples/maplibre.html b/js/examples/maplibre.html
index 8d90ca6..1d0186d 100644
--- a/js/examples/maplibre.html
+++ b/js/examples/maplibre.html
@@ -4,7 +4,7 @@
         <meta charset="utf-8"/>
         <link rel="stylesheet" href="https://unpkg.com/maplibre-gl@5.13.0/dist/maplibre-gl.css" crossorigin="anonymous">
         <script src="https://unpkg.com/maplibre-gl@5.13.0/dist/maplibre-gl.js" crossorigin="anonymous"></script>
-        <script src="https://unpkg.com/pmtiles@4.3.2/dist/pmtiles.js"></script>
+        <script src="https://unpkg.com/pmtiles@4.4.0/dist/pmtiles.js"></script>
         <style>
             body {
                 margin: 0;
diff --git a/js/examples/maplibre_advanced.html b/js/examples/maplibre_advanced.html
index ec7c68e..8b1b5ff 100644
--- a/js/examples/maplibre_advanced.html
+++ b/js/examples/maplibre_advanced.html
@@ -4,7 +4,7 @@
         <meta charset="utf-8"/>
         <link rel="stylesheet" href="https://unpkg.com/maplibre-gl@5.13.0/dist/maplibre-gl.css" crossorigin="anonymous">
         <script src="https://unpkg.com/maplibre-gl@5.13.0/dist/maplibre-gl.js" crossorigin="anonymous"></script>
-        <script src="https://unpkg.com/pmtiles@4.3.2/dist/pmtiles.js"></script>
+        <script src="https://unpkg.com/pmtiles@4.4.0/dist/pmtiles.js"></script>
         <style>
             body {
                 margin: 0;
diff --git a/js/examples/maplibre_raster_dem.html b/js/examples/maplibre_raster_dem.html
index 6833ff0..b913b4f 100644
--- a/js/examples/maplibre_raster_dem.html
+++ b/js/examples/maplibre_raster_dem.html
@@ -4,7 +4,7 @@
         <meta charset="utf-8"/>
         <link rel="stylesheet" href="https://unpkg.com/maplibre-gl@5.13.0/dist/maplibre-gl.css" crossorigin="anonymous">
         <script src="https://unpkg.com/maplibre-gl@5.13.0/dist/maplibre-gl.js" crossorigin="anonymous"></script>
-        <script src="https://unpkg.com/pmtiles@4.3.2/dist/pmtiles.js"></script>
+        <script src="https://unpkg.com/pmtiles@4.4.0/dist/pmtiles.js"></script>
         <style>
             body {
                 margin: 0;
diff --git a/js/package-lock.json b/js/package-lock.json
index ba3efd0..3e035c8 100644
--- a/js/package-lock.json
+++ b/js/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "pmtiles",
-  "version": "4.3.2",
+  "version": "4.4.0",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "pmtiles",
-      "version": "4.3.2",
+      "version": "4.4.0",
       "license": "BSD-3-Clause",
       "dependencies": {
         "fflate": "^0.8.2"
diff --git a/js/package.json b/js/package.json
index c42c9f2..3fd691e 100644
--- a/js/package.json
+++ b/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "pmtiles",
-  "version": "4.3.2",
+  "version": "4.4.0",
   "description": "PMTiles archive decoder for browsers",
   "type": "module",
   "main": "dist/cjs/index.cjs",
diff --git a/js/src/index.ts b/js/src/index.ts
index 31a7db9..4981b52 100644
--- a/js/src/index.ts
+++ b/js/src/index.ts
@@ -205,6 +205,7 @@ export enum TileType {
   Jpeg = 3,
   Webp = 4,
   Avif = 5,
+  Mlt = 6,
 }
 
 export function tileTypeExt(t: TileType): string {
@@ -213,6 +214,7 @@ export function tileTypeExt(t: TileType): string {
   if (t === TileType.Jpeg) return ".jpg";
   if (t === TileType.Webp) return ".webp";
   if (t === TileType.Avif) return ".avif";
+  if (t === TileType.Mlt) return ".mlt";
   return "";
 }
 
diff --git a/js/test/v3.test.ts b/js/test/v3.test.ts
index 02e1d1e..7ad0c02 100644
--- a/js/test/v3.test.ts
+++ b/js/test/v3.test.ts
@@ -350,6 +350,7 @@ describe("pmtiles v3", () => {
     assert.equal(".jpg", tileTypeExt(TileType.Jpeg));
     assert.equal(".webp", tileTypeExt(TileType.Webp));
     assert.equal(".avif", tileTypeExt(TileType.Avif));
+    assert.equal(".mlt", tileTypeExt(TileType.Mlt));
   });
 
   interface TileJsonLike {
diff --git a/python/pmtiles/pmtiles/tile.py b/python/pmtiles/pmtiles/tile.py
index 66682c3..d175c10 100644
--- a/python/pmtiles/pmtiles/tile.py
+++ b/python/pmtiles/pmtiles/tile.py
@@ -126,6 +126,7 @@ class TileType(Enum):
     JPEG = 3
     WEBP = 4
     AVIF = 5
+    MLT = 6
 
 
 def deserialize_directory(buf):
diff --git a/python/pmtiles/setup.py b/python/pmtiles/setup.py
index d4455b5..6e07905 100644
--- a/python/pmtiles/setup.py
+++ b/python/pmtiles/setup.py
@@ -5,7 +5,7 @@ with open("README.md", "r") as fh:
 
 setuptools.setup(
     name="pmtiles",
-    version="3.5.0",
+    version="3.6.0",
     author="Brandon Liu",
     author_email="brandon@protomaps.com",
     description="Library and utilities to write and read PMTiles archives - cloud-optimized archives of map tiles.",
diff --git a/spec/v3/CHANGELOG.md b/spec/v3/CHANGELOG.md
index 520c8c6..1022c35 100644
--- a/spec/v3/CHANGELOG.md
+++ b/spec/v3/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+## Version 3.5
+- add [MapLibre Vector Tile](https://github.com/maplibre/maplibre-tile-spec) `.mlt` enum by @msbarry [#596]
+
 ## Version 3.4
 - Clarify that entry lengths must be > 0.
 - Add details about ordering of leaf directories.