diff --git a/.github/targets_validator.py b/.github/targets_validator.py
new file mode 100644
index 00000000..677082ea
--- /dev/null
+++ b/.github/targets_validator.py
@@ -0,0 +1,187 @@
+import sys
+import json
+import glob
+import argparse
+import configparser
+import re
+from dataclasses import dataclass
+
+DEVICE_TYPES = ['txbp', 'vrx', 'timer', 'aat']
+PLATFORMS = ['esp8285', 'esp32', 'esp32-c3', 'esp32-s3']
+UPLOAD_METHODS = ['uart', 'etx', 'passthru', 'wifi']
+DEVICE_KEYS = ['product_name', 'firmware', 'platform', 'upload_methods', 'validation_ignores']
+
+# PlatformIO board -> targets.json "platform" value
+BOARD_PLATFORMS = {
+    'esp8285': 'esp8285',
+    'esp12e': 'esp8285',
+    'esp32dev': 'esp32',
+    'esp32-c3-devkitm-1': 'esp32-c3',
+    'esp32-s3-devkitc-1': 'esp32-s3',
+}
+
+
+@dataclass
+class Finding:
+    severity: str       # 'error' or 'warning'
+    target: str         # 'vendor.type.device', or the offending vendor/environment
+    code: str | None    # ignorable via the device's "validation_ignores" when set
+    message: str
+
+
+def load_environments():
+    """Parse targets/*.ini and return {env_name: platform} for every [env:...] section,
+    resolving each env's platform through its 'extends' chain down to an
+    env_common_* section with a 'board'."""
+    ini = configparser.RawConfigParser(strict=False)
+    for inifile in sorted(glob.glob('targets/*.ini')):
+        ini.read(inifile)
+
+    def resolve_platform(section, seen=()):
+        if section in seen or not ini.has_section(section):
+            return None
+        if ini.has_option(section, 'board'):
+            return BOARD_PLATFORMS.get(ini.get(section, 'board'))
+        if ini.has_option(section, 'extends'):
+            for parent in re.split(r'[,\s]+', ini.get(section, 'extends')):
+                platform = resolve_platform(parent, seen + (section,))
+                if platform is not None:
+                    return platform
+        return None
+
+    environments = {}
+    for section in ini.sections():
+        if section.startswith('env:'):
+            environments[section[4:]] = resolve_platform(section)
+    return environments
+
+
+class TargetsValidator:
+    def __init__(self, targets, environments):
+        self.targets = targets
+        self.environments = environments
+        self.findings = []
+        self.ignores = {}  # target -> that device's "validation_ignores" set
+
+    def error(self, target, message, code=None):
+        self.findings.append(Finding('error', target, code, message))
+
+    def warn(self, target, message, code=None):
+        self.findings.append(Finding('warning', target, code, message))
+
+    def validate(self):
+        for vendor in self.targets:
+            self.validate_vendor(vendor, self.targets[vendor])
+        self.validate_unreferenced_environments()
+        return self.findings
+
+    def validate_vendor(self, vendor, types):
+        if not re.match(r'^[a-z0-9_-]+$', vendor):
+            self.error(vendor, f'vendor tag "{vendor}" can only include lowercase a-z, 0-9, and underscores and dashes')
+
+        if 'name' not in types or not isinstance(types['name'], str) or not types['name']:
+            self.error(vendor, f'vendor "{vendor}" must have a non-empty "name" child element')
+
+        if not any(type in DEVICE_TYPES for type in types):
+            self.error(vendor, f'vendor "{vendor}" must have at least one device type, one of {DEVICE_TYPES}')
+
+        for type in types:
+            if type not in DEVICE_TYPES + ['name']:
+                self.error(vendor, f'invalid tag "{type}" in "{vendor}"')
+            if type in DEVICE_TYPES:
+                for device in types[type]:
+                    self.validate_device(vendor, type, device, types[type][device])
+
+    def validate_device(self, vendor, type, devname, device):
+        target = f'{vendor}.{type}.{devname}'
+        self.ignores[target] = set(device.get('validation_ignores', []))
+
+        if not re.match(r'^[A-Za-z0-9_-]+$', devname):
+            self.error(target, f'device tag "{devname}" can only include a-z, A-Z, 0-9, and underscores and dashes', 'invalid_device_tag')
+
+        for key in device:
+            if key not in DEVICE_KEYS:
+                self.error(target, f'device "{target}" has an unknown child element "{key}"', 'unknown_device_key')
+
+        if 'product_name' not in device or not isinstance(device['product_name'], str) or not device['product_name']:
+            self.error(target, f'device "{target}" must have a non-empty "product_name" child element', 'missing_product_name')
+
+        if 'upload_methods' not in device or not isinstance(device['upload_methods'], list) or not device['upload_methods']:
+            self.error(target, f'device "{target}" must have a non-empty "upload_methods" list', 'missing_upload_methods')
+        else:
+            methods = device['upload_methods']
+            for method in methods:
+                if method not in UPLOAD_METHODS:
+                    self.error(target, f'invalid upload method "{method}" for target "{target}", must be one of {UPLOAD_METHODS}', 'invalid_upload_method')
+            if len(set(methods)) != len(methods):
+                self.error(target, f'duplicate upload methods for target "{target}"', 'duplicate_upload_method')
+
+        platform = device.get('platform')
+        if platform not in PLATFORMS:
+            self.error(target, f'device "{target}" must have a "platform" child element, one of {PLATFORMS}', 'invalid_platform')
+            platform = None
+
+        if 'firmware' not in device or not isinstance(device['firmware'], str):
+            self.error(target, f'device "{target}" must have a "firmware" child element', 'missing_firmware')
+        else:
+            firmware = device['firmware']
+            env_platform = self.environments.get(firmware + '_via_UART')
+            if firmware + '_via_UART' not in self.environments:
+                self.error(target, f'device "{target}" firmware "{firmware}" has no [env:{firmware}_via_UART] in targets/*.ini', 'invalid_firmware_file')
+            elif env_platform is None:
+                self.error(target, f'could not determine the platform of [env:{firmware}_via_UART] from targets/*.ini', 'unknown_env_platform')
+            elif platform is not None and env_platform != platform:
+                self.error(target, f'device "{target}" "firmware" and "platform" MUST match: firmware "{firmware}" is {env_platform}, not {platform}', 'firmware_platform_mismatch')
+
+    def validate_unreferenced_environments(self):
+        firmwares = set()
+        for vendor in self.targets:
+            for type in self.targets[vendor]:
+                if type in DEVICE_TYPES:
+                    for device in self.targets[vendor][type].values():
+                        if isinstance(device.get('firmware'), str):
+                            firmwares.add(device['firmware'])
+        for env in sorted(self.environments):
+            if not env.endswith('_via_UART'):
+                continue
+            firmware = env[:-len('_via_UART')]
+            if firmware.startswith('DEBUG_'):
+                continue
+            if firmware not in firmwares:
+                self.warn(env, f'[env:{env}] in targets/*.ini is not referenced by any target in hardware/targets.json')
+
+    def report(self, warn_as_error=False):
+        had_error = False
+        for finding in self.findings:
+            if finding.code is not None and finding.code in self.ignores.get(finding.target, ()):
+                continue
+            print(f'{finding.severity.upper()}: {finding.message}')
+            if finding.severity == 'error' or warn_as_error:
+                had_error = True
+        return 1 if had_error else 0
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Validate hardware/targets.json")
+    parser.add_argument("--warn", "-w", action='store_true', default=False, help="Treat warnings as errors")
+    args = parser.parse_args()
+
+    with open('hardware/targets.json') as f:
+        try:
+            targets = json.load(f)
+        except json.JSONDecodeError as e:
+            print(f'ERROR: hardware/targets.json is not valid JSON: {e}')
+            return 1
+
+    environments = load_environments()
+    if not environments:
+        print('ERROR: no [env:...] sections found in targets/*.ini, run from the repository root')
+        return 1
+
+    validator = TargetsValidator(targets, environments)
+    validator.validate()
+    return validator.report(warn_as_error=args.warn)
+
+
+if __name__ == '__main__':
+    sys.exit(main())
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index eea660be..2c869d4d 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -1,7 +1,16 @@
 name: Build ExpressLRS Backpack
 on: [push, pull_request]
 jobs:
+  validate:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v7
+    - name: Validate targets.json
+      run: python3 .github/targets_validator.py
+
   targets:
+    needs: validate
     runs-on: ubuntu-latest
     outputs:
       targets: ${{ steps.set-targets.outputs.targets }}
diff --git a/hardware/targets.json b/hardware/targets.json
index 87b0b60c..a693f1da 100644
--- a/hardware/targets.json
+++ b/hardware/targets.json
@@ -445,7 +445,7 @@
             },
             "v12": {
                 "product_name": "HelloRadioSky V12 TX",
-                "firmware": "ESP_TX_Backpack",
+                "firmware": "ESP32C3_TX_Backpack",
                 "platform": "esp32-c3",
                 "upload_methods": ["etx", "wifi"]
             }
@@ -456,7 +456,7 @@
         "txbp": {
             "max": {
                 "product_name": "DAKEFPV MAX TX",
-                "firmware": "ESP_TX_Backpack",
+                "firmware": "ESP32C3_TX_Backpack",
                 "platform": "esp32-c3",
                 "upload_methods": ["etx", "wifi"]
             }