diff --git a/scriptworker/ed25519.py b/scriptworker/ed25519.py
index f8ab2c13..e7c85028 100644
--- a/scriptworker/ed25519.py
+++ b/scriptworker/ed25519.py
@@ -5,6 +5,7 @@
     log (logging.Logger): the log object for the module
 
 """
+import argparse
 import base64
 from binascii import Error as Base64Error
 from cryptography.exceptions import InvalidSignature, UnsupportedAlgorithm
@@ -12,6 +13,8 @@
 from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey, Ed25519PublicKey
 import functools
 import logging
+import sys
+from scriptworker.constants import DEFAULT_CONFIG
 from scriptworker.exceptions import ScriptWorkerEd25519Error, ScriptWorkerException
 from scriptworker.utils import read_from_file
 
@@ -130,3 +133,51 @@ def verify_ed25519_signature(public_key, contents, signature, message):
         public_key.verify(signature, contents)
     except (UnsupportedAlgorithm, InvalidSignature) as exc:
         raise ScriptWorkerEd25519Error(message % {'exc': str(exc)})
+
+
+# verify_ed25519_signature_cmdln {{{1
+def verify_ed25519_signature_cmdln(args=None, exception=SystemExit):
+    """Verify an ed25519 signature from the command line.
+
+    Args:
+        args (list, optional): the commandline args to parse. If ``None``, use
+            ``sys.argv[1:]``. Defaults to ``None``.
+        exception (Exception, optional): the exception to raise on failure.
+            Defaults to ``SystemExit``.
+
+    """
+    args = args or sys.argv[1:]
+    parser = argparse.ArgumentParser(
+        description="""Verify an ed25519 signature from the command line.
+
+Given a file and its detached signature, verify that it has been signed with
+a valid key. This key can be specified on the command line; otherwise we'll
+default to ``config['ed25519_public_keys']``.""")
+    parser.add_argument('--pubkey', help='path to a base64-encoded ed25519 pubkey, optional')
+    parser.add_argument('file_path')
+    parser.add_argument('sig_path')
+    opts = parser.parse_args(args)
+    log = logging.getLogger('scriptworker')
+    log.setLevel(logging.DEBUG)
+    logging.basicConfig()
+    pubkeys = {}
+    if opts.pubkey:
+        pubkeys['cmdln'] = [read_from_file(opts.pubkey)]
+    pubkeys.update(dict(DEFAULT_CONFIG['ed25519_public_keys']))
+    contents = read_from_file(opts.file_path, file_type='binary')
+    signature = read_from_file(opts.sig_path, file_type='binary')
+    for key_type, seeds in pubkeys.items():
+        for seed in seeds:
+            try:
+                verify_ed25519_signature(
+                    ed25519_public_key_from_string(seed), contents, signature,
+                    "didn't work with {}".format(seed)
+                )
+                log.info("Verified good with {} seed {} !".format(
+                    key_type, seed
+                ))
+                sys.exit(0)
+            except ScriptWorkerEd25519Error:
+                pass
+    else:
+        raise exception("This is not a valid signature!")
diff --git a/scriptworker/test/test_ed25519.py b/scriptworker/test/test_ed25519.py
index 4d95be60..120aa72b 100644
--- a/scriptworker/test/test_ed25519.py
+++ b/scriptworker/test/test_ed25519.py
@@ -68,3 +68,23 @@ def test_verify_ed25519_signature(unsigned_path, signature_path, public_key_path
 def test_bad_ed25519_public_key_from_string():
     with pytest.raises(ScriptWorkerEd25519Error):
         swed25519.ed25519_public_key_from_string('bad_base64_string')
+
+
+@pytest.mark.parametrize('pubkey_path, file_path, sig_path, exception', ((
+    os.path.join(ED25519_DIR, 'scriptworker_public_key'),
+    os.path.join(ED25519_DIR, 'foo.json'),
+    os.path.join(ED25519_DIR, 'foo.json.scriptworker.sig'),
+    SystemExit
+), (
+    None,
+    os.path.join(ED25519_DIR, 'foo.json'),
+    os.path.join(ED25519_DIR, 'foo.json.scriptworker.sig'),
+    ScriptWorkerEd25519Error
+)))
+def test_ed25519_cmdln(pubkey_path, file_path, sig_path, exception):
+    args = []
+    if pubkey_path is not None:
+        args.extend(['--pubkey', pubkey_path])
+    args.extend([file_path, sig_path])
+    with pytest.raises(exception):
+        swed25519.verify_ed25519_signature_cmdln(args=args, exception=ScriptWorkerEd25519Error)
diff --git a/setup.py b/setup.py
index d1e7cce6..3a44c8c4 100644
--- a/setup.py
+++ b/setup.py
@@ -82,6 +82,7 @@ def run_tests(self):
             "scriptworker = scriptworker.worker:main",
             "rebuild_gpg_homedirs = scriptworker.gpg:rebuild_gpg_homedirs",
             "verify_cot = scriptworker.cot.verify:verify_cot_cmdln",
+            "verify_ed25519_signature = scriptworker.ed25519:verify_ed25519_signature_cmdln",
         ],
     },
     zip_safe=False,