diff --git a/src/cmd-buildupload b/src/cmd-buildupload
index f8ce3a2f6c..cbbdb7305d 100755
--- a/src/cmd-buildupload
+++ b/src/cmd-buildupload
@@ -38,6 +38,10 @@ def parse_args():
     group = parser.add_mutually_exclusive_group()
     group.add_argument("--skip-builds-json", help="Don't push builds.json",
                        action='store_true')
+    group.add_argument("--start-build", help="Update builds.json to denote an in-progress build",
+                       action='store_true')
+    group.add_argument("--fail-build", help="Update builds.json to denote the in-progress build failed",
+                       action='store_true')
 
     subparsers = parser.add_subparsers(dest='cmd', title='subcommands')
     subparsers.required = True
@@ -63,18 +67,25 @@ def cmd_upload_s3(args):
     if args.build == 'latest':
         args.build = builds.get_latest()
     print(f"Targeting build: {args.build}")
-    for arch in builds.get_build_arches(args.build):
-        s3_upload_build(args, builds.get_build_dir(args.build, arch),
-                        bucket, f'{prefix}/{args.build}/{arch}')
-    # if there's anything else in the build dir, just upload it too,
-    # e.g. pipelines might inject additional metadata
-    for f in os.listdir(f'builds/{args.build}'):
-        # arches already uploaded higher up
-        if f in builds.get_build_arches(args.build):
-            continue
-        # assume it's metadata
-        s3_copy(f'builds/{args.build}/{f}', bucket, f'{prefix}/{args.build}/{f}',
-                CACHE_MAX_AGE_METADATA, args.acl)
+    if args.start_build:
+        builds.set_build_in_progress(args.build)
+        builds.flush()
+    elif args.fail_build:
+        builds.set_build_failed(args.build)
+        builds.flush()
+    else:
+        for arch in builds.get_build_arches(args.build):
+            s3_upload_build(args, builds.get_build_dir(args.build, arch),
+                            bucket, f'{prefix}/{args.build}/{arch}')
+        # if there's anything else in the build dir, just upload it too,
+        # e.g. pipelines might inject additional metadata
+        for f in os.listdir(f'builds/{args.build}'):
+            # arches already uploaded higher up
+            if f in builds.get_build_arches(args.build):
+                continue
+            # assume it's metadata
+            s3_copy(f'builds/{args.build}/{f}', bucket, f'{prefix}/{args.build}/{f}',
+                    CACHE_MAX_AGE_METADATA, args.acl)
     if not args.skip_builds_json:
         s3_copy(BUILDFILES['list'], bucket, f'{prefix}/builds.json',
                 CACHE_MAX_AGE_METADATA, args.acl, extra_args={}, dry_run=args.dry_run)
diff --git a/src/cosalib/builds.py b/src/cosalib/builds.py
index e6c1be7c69..b8c6a197eb 100644
--- a/src/cosalib/builds.py
+++ b/src/cosalib/builds.py
@@ -134,6 +134,28 @@ def bump_timestamp(self):
         self._data['timestamp'] = rfc3339_time()
         self.flush()
 
+    def set_build_in_progress(self, build_id):
+        data = { 'id': build_id }
+        # Pipelines should set this to some sort of "unique" identifier
+        # for this build.  Something like <HOST>-<JOB>-<BUILDID>-<ARCH>
+        # For the FCOS pipeline, a good identifier would be the
+        # name of the pod that the Jenkins Kubernetes plugin creates.
+        pipeline_instance_data = os.environ.get('COSA_PIPELINE_INSTANCE_ID')
+        if pipeline_instance_data:
+            data['pipeline'] = pipeline_instance_data
+        self._data['build-started'] = data
+
+    def set_build_failed(self, build_id):
+        started = self._data.get('build-started')
+        if started is None:
+            raise Exception("Tried to fail build {build_id},"
+                            " but no build-started key present in builds.json")
+        if started['id'] != build_id:
+            raise Exception("Tried to fail build {build_id},"
+                            " but active build is {started['id']}")
+        self._data['build-failed'] = started
+        del self._data['build-started']
+
     def raw(self):
         return self._data