diff --git a/Justfile b/Justfile
index 53a5941..ea1194f 100644
--- a/Justfile
+++ b/Justfile
@@ -215,7 +215,7 @@ repl:
     @just trapos --cli
 
 # Local CI entry point used by Git hooks. Pass args through to `test`.
-ci *args: check-craftos check
+ci *args: check-craftos check check-packages
     @just test {{args}}
     @just test-timeout
 
@@ -368,6 +368,93 @@ check: check-luacheck check-lychee
     luacheck --quiet .
     @just lint-markdown
 
+# Validate package descriptors and require version bumps for changed package files.
+check-packages: check-jq
+    #!/usr/bin/env bash
+    set -euo pipefail
+    repo='{{justfile_directory()}}'
+    cd "$repo"
+
+    semver_gt() {
+        local a_major a_minor a_patch b_major b_minor b_patch
+        IFS=. read -r a_major a_minor a_patch <<<"$1"
+        IFS=. read -r b_major b_minor b_patch <<<"$2"
+        if [ "${a_major:-0}" -gt "${b_major:-0}" ]; then return 0; fi
+        if [ "${a_major:-0}" -lt "${b_major:-0}" ]; then return 1; fi
+        if [ "${a_minor:-0}" -gt "${b_minor:-0}" ]; then return 0; fi
+        if [ "${a_minor:-0}" -lt "${b_minor:-0}" ]; then return 1; fi
+        [ "${a_patch:-0}" -gt "${b_patch:-0}" ]
+    }
+
+    fail=0
+    packages=()
+    while IFS= read -r name; do packages+=("$name"); done < <(jq -r '.packages | keys[]' packages/index.json | sort)
+
+    for name in "${packages[@]}"; do
+        desc="packages/$name/ccpm.json"
+        if [ ! -f "$desc" ]; then
+            printf '%s\n' "FAIL: packages/index.json lists missing descriptor $desc" >&2
+            fail=1
+            continue
+        fi
+
+        desc_name="$(jq -r '.name // empty' "$desc")"
+        desc_version="$(jq -r '.version // empty' "$desc")"
+        index_version="$(jq -r --arg name "$name" '.packages[$name] // empty' packages/index.json)"
+        if [ "$desc_name" != "$name" ]; then
+            printf '%s\n' "FAIL: $desc has name '$desc_name', expected '$name'" >&2
+            fail=1
+        fi
+        if [ "$desc_version" != "$index_version" ]; then
+            printf '%s\n' "FAIL: $name version differs between descriptor ($desc_version) and packages/index.json ($index_version)" >&2
+            fail=1
+        fi
+
+        last_desc_commit="$(git log -n 1 --format=%H -- "$desc" || true)"
+        if [ -z "$last_desc_commit" ]; then
+            continue
+        fi
+        old_version="$(git show "$last_desc_commit:$desc" | jq -r '.version // empty')"
+
+        files=()
+        while IFS= read -r file; do files+=("$file"); done < <(jq -r '.files[]?' "$desc")
+        if [ "${#files[@]}" -gt 0 ] && ! git diff --quiet "$last_desc_commit" -- "${files[@]}"; then
+            if ! semver_gt "$desc_version" "$old_version"; then
+                printf '%s\n' "FAIL: $name package files changed since $desc was last bumped ($old_version); bump $desc and packages/index.json" >&2
+                git diff --name-only "$last_desc_commit" -- "${files[@]}" >&2
+                fail=1
+            fi
+        fi
+    done
+
+    for desc in packages/*/ccpm.json; do
+        [ -e "$desc" ] || continue
+        name="$(jq -r '.name // empty' "$desc")"
+        if ! jq -e --arg name "$name" '.packages[$name] != null' packages/index.json >/dev/null; then
+            printf '%s\n' "FAIL: descriptor $desc is missing from packages/index.json" >&2
+            fail=1
+        fi
+    done
+
+    trapos_desc='packages/trapos/ccpm.json'
+    trapos_commit="$(git log -n 1 --format=%H -- "$trapos_desc" || true)"
+    if [ -n "$trapos_commit" ]; then
+        trapos_version="$(jq -r '.version // empty' "$trapos_desc")"
+        old_trapos_version="$(git show "$trapos_commit:$trapos_desc" | jq -r '.version // empty')"
+        deps=()
+        while IFS= read -r dep; do deps+=("packages/$dep/ccpm.json"); done < <(jq -r '.dependencies[]?' "$trapos_desc")
+        if [ "${#deps[@]}" -gt 0 ] && ! git diff --quiet "$trapos_commit" -- "${deps[@]}"; then
+            if ! semver_gt "$trapos_version" "$old_trapos_version"; then
+                printf '%s\n' "FAIL: trapos dependencies changed since trapos was last bumped ($old_trapos_version); bump $trapos_desc and packages/index.json" >&2
+                git diff --name-only "$trapos_commit" -- "${deps[@]}" >&2
+                fail=1
+            fi
+        fi
+    fi
+
+    if [ "$fail" -ne 0 ]; then exit 1; fi
+    printf '%s\n' 'OK: package versions aligned'
+
 # Validate local markdown links and heading anchors with lychee.
 lint-markdown: check-lychee
     lychee --config lychee.toml .
diff --git a/manifest.json b/manifest.json
index 662cc13..74bfeec 100644
--- a/manifest.json
+++ b/manifest.json
@@ -1,6 +1,6 @@
 {
   "name": "TrapOS",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "branch": "next",
   "packages": [
     "trapos"
diff --git a/packages/index.json b/packages/index.json
index f2ba10a..68e3e56 100644
--- a/packages/index.json
+++ b/packages/index.json
@@ -1,11 +1,11 @@
 {
   "packages": {
-    "tos-core": "0.2.0",
-    "tos-test": "0.1.0",
-    "tos-boot": "0.1.0",
-    "tos-net": "0.1.0",
-    "tos-ui": "0.1.0",
-    "tos-ai": "0.1.0",
-    "trapos": "0.4.0"
+    "tos-core": "0.3.0",
+    "tos-test": "0.2.0",
+    "tos-boot": "0.2.0",
+    "tos-net": "0.2.0",
+    "tos-ui": "0.2.0",
+    "tos-ai": "0.2.0",
+    "trapos": "0.5.0"
   }
 }
diff --git a/packages/tos-ai/ccpm.json b/packages/tos-ai/ccpm.json
index 4520f11..b23cc35 100644
--- a/packages/tos-ai/ccpm.json
+++ b/packages/tos-ai/ccpm.json
@@ -1,6 +1,6 @@
 {
   "name": "tos-ai",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "TrapOS AI hello-world client (opencode proxy)",
   "dependencies": ["tos-core"],
   "files": [
diff --git a/packages/tos-boot/ccpm.json b/packages/tos-boot/ccpm.json
index 8d113e4..c5d5243 100644
--- a/packages/tos-boot/ccpm.json
+++ b/packages/tos-boot/ccpm.json
@@ -1,6 +1,6 @@
 {
   "name": "tos-boot",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "TrapOS boot: startup MOTD and autostart server launcher",
   "dependencies": ["tos-core"],
   "files": [
diff --git a/packages/tos-core/ccpm.json b/packages/tos-core/ccpm.json
index 51c7f19..ab6aa66 100644
--- a/packages/tos-core/ccpm.json
+++ b/packages/tos-core/ccpm.json
@@ -1,6 +1,6 @@
 {
   "name": "tos-core",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "description": "TrapOS base: package manager, event loop, upgrade and event tools",
   "dependencies": [],
   "files": [
diff --git a/packages/tos-net/ccpm.json b/packages/tos-net/ccpm.json
index eff2311..a2af338 100644
--- a/packages/tos-net/ccpm.json
+++ b/packages/tos-net/ccpm.json
@@ -1,6 +1,6 @@
 {
   "name": "tos-net",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "TrapOS networking: routed modem messaging, router, ping",
   "dependencies": ["tos-core"],
   "files": [
diff --git a/packages/tos-test/ccpm.json b/packages/tos-test/ccpm.json
index e92df28..db385f2 100644
--- a/packages/tos-test/ccpm.json
+++ b/packages/tos-test/ccpm.json
@@ -1,6 +1,6 @@
 {
   "name": "tos-test",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "TrapOS test framework and CraftOS-PC suite runner",
   "dependencies": ["tos-core"],
   "files": [
diff --git a/packages/tos-ui/ccpm.json b/packages/tos-ui/ccpm.json
index bd1dd5d..179feb4 100644
--- a/packages/tos-ui/ccpm.json
+++ b/packages/tos-ui/ccpm.json
@@ -1,6 +1,6 @@
 {
   "name": "tos-ui",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "TrapOS terminal UI toolkit and demo",
   "dependencies": ["tos-core"],
   "files": [
diff --git a/packages/trapos/ccpm.json b/packages/trapos/ccpm.json
index 0ddbf5c..5c96e63 100644
--- a/packages/trapos/ccpm.json
+++ b/packages/trapos/ccpm.json
@@ -1,6 +1,6 @@
 {
   "name": "trapos",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "description": "TrapOS full install meta-package",
   "dependencies": ["tos-boot", "tos-net", "tos-ui", "tos-test"],
   "files": [],
diff --git a/tests/packages.lua b/tests/packages.lua
new file mode 100644
index 0000000..865a9f6
--- /dev/null
+++ b/tests/packages.lua
@@ -0,0 +1,101 @@
+local createLibTest = require('/apis/libtest');
+
+local testlib = createLibTest({ ... });
+
+local PACKAGES_DIR = '/trapos/packages';
+local INDEX_PATH = PACKAGES_DIR .. '/index.json';
+
+local function readJson(path)
+  local file = fs.open(path, 'r');
+  testlib.assertTrue(file, 'missing JSON file: ' .. path);
+  local body = file.readAll();
+  file.close();
+  local value = textutils.unserializeJSON(body);
+  testlib.assertTrue(value, 'invalid JSON file: ' .. path);
+  return value;
+end
+
+local function sortedKeys(map)
+  local keys = {};
+  for key in pairs(map or {}) do
+    keys[#keys + 1] = key;
+  end
+  table.sort(keys);
+  return keys;
+end
+
+local function descriptorPaths()
+  local paths = {};
+  for _, name in ipairs(fs.list(PACKAGES_DIR)) do
+    local dir = PACKAGES_DIR .. '/' .. name;
+    local path = dir .. '/ccpm.json';
+    if fs.isDir(dir) and fs.exists(path) then
+      paths[#paths + 1] = { name = name, path = path };
+    end
+  end
+  table.sort(paths, function(a, b) return a.name < b.name; end);
+  return paths;
+end
+
+local function packageMap()
+  local packages = {};
+  for _, entry in ipairs(descriptorPaths()) do
+    packages[entry.name] = readJson(entry.path);
+  end
+  return packages;
+end
+
+local function assertSemver(version, label)
+  testlib.assertTrue(type(version) == 'string', label .. ' version must be a string');
+  testlib.assertTrue(string.match(version, '^%d+%.%d+%.%d+$') ~= nil, label .. ' version must be x.y.z');
+end
+
+testlib.test('package index matches descriptors', function()
+  local index = readJson(INDEX_PATH);
+  local packages = packageMap();
+  local indexNames = sortedKeys(index.packages);
+  local descriptorNames = sortedKeys(packages);
+
+  testlib.assertEquals(#indexNames, #descriptorNames, 'index and descriptor counts differ');
+  for i, name in ipairs(descriptorNames) do
+    testlib.assertEquals(indexNames[i], name, 'index package names differ');
+    testlib.assertEquals(index.packages[name], packages[name].version, name .. ' index version differs');
+  end
+end);
+
+testlib.test('package descriptors are internally consistent', function()
+  local packages = packageMap();
+  for name, desc in pairs(packages) do
+    testlib.assertEquals(desc.name, name, name .. ' descriptor name differs from directory');
+    assertSemver(desc.version, name);
+    testlib.assertTrue(type(desc.dependencies) == 'table', name .. ' dependencies must be a table');
+    testlib.assertTrue(type(desc.files) == 'table', name .. ' files must be a table');
+    testlib.assertTrue(type(desc.autostart) == 'table', name .. ' autostart must be a table');
+
+    if name ~= 'trapos' then
+      testlib.assertTrue(#desc.files > 0, name .. ' must ship at least one file');
+    end
+
+    for _, dependency in ipairs(desc.dependencies) do
+      testlib.assertTrue(packages[dependency] ~= nil, name .. ' depends on unknown package ' .. dependency);
+    end
+
+    local files = {};
+    for _, filePath in ipairs(desc.files) do
+      files[filePath] = true;
+      testlib.assertTrue(fs.exists('/trapos/' .. filePath), name .. ' missing shipped file ' .. filePath);
+    end
+
+    for _, autostart in ipairs(desc.autostart) do
+      testlib.assertTrue(files[autostart .. '.lua'], name .. ' autostart not listed in files: ' .. autostart);
+    end
+  end
+end);
+
+testlib.test('root manifest tracks trapos package version', function()
+  local manifest = readJson('/trapos/manifest.json');
+  local trapos = readJson(PACKAGES_DIR .. '/trapos/ccpm.json');
+  testlib.assertEquals(manifest.version, trapos.version);
+end);
+
+testlib.run();