diff --git a/my/arbtt.py b/my/arbtt.py
new file mode 100644
index 0000000..2ef82a4
--- /dev/null
+++ b/my/arbtt.py
@@ -0,0 +1,93 @@
+'''
+[[https://github.com/nomeata/arbtt#arbtt-the-automatic-rule-based-time-tracker][Arbtt]] time tracking
+'''
+
+REQUIRES = ['ijson', 'cffi']
+
+
+from pathlib import Path
+from typing import Sequence, Iterable, List, Optional
+
+
+def inputs() -> Sequence[Path]:
+    try:
+        from my.config import arbtt as user_config
+    except ImportError:
+        from .core.warnings import low
+        low("Couldn't find 'arbtt' config section, falling back to the default capture.log (usually in HOME dir). Add 'arbtt' section with logfiles = '' to suppress this warning.")
+        return []
+    else:
+        from .core import get_files
+        return get_files(user_config.logfiles)
+
+
+from .core import dataclass, Json, Res, PathIsh, datetime_aware
+from .core.common import isoparse
+
+
+@dataclass
+class Entry:
+    '''
+    For the format reference, see
+    https://github.com/nomeata/arbtt/blob/e120ad20b9b8e753fbeb02041720b7b5b271ab20/src/DumpFormat.hs#L39-L46
+    '''
+
+    json: Json
+    # inactive time -- in ms
+
+    @property
+    def dt(self) -> datetime_aware:
+        # contains utc already
+        ds = self.json['date']
+        elen = 27
+        lds = len(ds)
+        if lds < elen:
+            # ugh. sometimes contains less that 6 decimal points
+            ds = ds[:-1] + '0' * (elen - lds) + 'Z'
+        elif lds > elen:
+            # ahd sometimes more...
+            ds = ds[:elen - 1] + 'Z'
+
+        return isoparse(ds)
+
+    @property
+    def active(self) -> Optional[str]:
+        # NOTE: WIP, might change this in the future...
+        ait = (w for w in self.json['windows'] if w['active'])
+        a = next(ait, None)
+        if a is None:
+            return None
+        a2 = next(ait, None)
+        assert a2 is None, a2 # hopefully only one can be active in a time?
+
+        p = a['program']
+        t = a['title']
+        # todo perhaps best to keep it structured, e.g. for influx
+        return f'{p}: {t}'
+
+
+# todo multiple threads? not sure if would help much... (+ need to find offset somehow?)
+def entries() -> Iterable[Res[Entry]]:
+    inps = list(inputs())
+
+    base: List[PathIsh] = ['arbtt-dump', '--format=json']
+
+    cmds: List[List[PathIsh]]
+    if len(inps) == 0:
+        cmds = [base] # rely on default
+    else:
+        # otherise, 'merge' them
+        cmds = [base + ['--logfile', f] for f in inps]
+
+    import ijson.backends.yajl2_cffi as ijson # type: ignore
+    from subprocess import Popen, PIPE
+    for cmd in cmds:
+        with Popen(cmd, stdout=PIPE) as p:
+            out = p.stdout; assert out is not None
+            for json in ijson.items(out, 'item'):
+                yield Entry(json=json)
+
+
+from .core import stat, Stats
+def stats() -> Stats:
+    return stat(entries)
diff --git a/my/config.py b/my/config.py
index b6f91e6..fb502c3 100644
--- a/my/config.py
+++ b/my/config.py
@@ -69,3 +69,7 @@ class time:
 
 class orgmode:
     paths: Paths
+
+
+class arbtt:
+    logfiles: Paths
diff --git a/my/core/__init__.py b/my/core/__init__.py
index 8567cd7..f680f37 100644
--- a/my/core/__init__.py
+++ b/my/core/__init__.py
@@ -4,6 +4,7 @@ from .common import get_files
 from .common import LazyLogger
 from .common import warn_if_empty
 from .common import stat, Stats
+from .common import datetime_naive, datetime_aware
 
 from .cfg import make_config
 from .util import __NOT_HPI_MODULE__
diff --git a/my/core/common.py b/my/core/common.py
index 0ec8448..b39a10a 100644
--- a/my/core/common.py
+++ b/my/core/common.py
@@ -552,3 +552,7 @@ def to_jsons(it) -> Iterable[Json]:
             yield error_to_json(r)
         else:
             yield asdict(r)
+
+
+datetime_naive = datetime
+datetime_aware = datetime
diff --git a/my/hypothesis.py b/my/hypothesis.py
index 40fbb6c..bd0aedc 100644
--- a/my/hypothesis.py
+++ b/my/hypothesis.py
@@ -67,9 +67,8 @@ def pages() -> List[Res[Page]]:
     return sort_res_by(_dal().pages(), key=key)
 
 
-# todo not public api yet
-def stats():
-    from .core import stat
+from .core import stat, Stats
+def stats() -> Stats:
     return {
         **stat(highlights),
         **stat(pages),
diff --git a/my/location/google.py b/my/location/google.py
index 96bdf5e..c200b06 100644
--- a/my/location/google.py
+++ b/my/location/google.py
@@ -41,6 +41,7 @@ TsLatLon = Tuple[int, int, int]
 
 def _iter_via_ijson(fo) -> Iterable[TsLatLon]:
     # ijson version takes 25 seconds for 1M items (without processing)
+    # todo extract to common?
     try:
         # pip3 install ijson cffi
         import ijson.backends.yajl2_cffi as ijson # type: ignore
diff --git a/tox.ini b/tox.ini
index 270f2ed..9bd8464 100644
--- a/tox.ini
+++ b/tox.ini
@@ -76,6 +76,7 @@ commands =
     hpi module install my.reddit
     hpi module install my.stackexchange.stexport
     hpi module install my.pinboard
+    hpi module install my.arbtt
 
     # todo fuck. -p my.github isn't checking the subpackages?? wtf...
     # guess it wants .pyi file??
@@ -94,6 +95,7 @@ commands =
                     -p my.location.google             \
                     -p my.time.tz.via_location        \
                     -p my.calendar.holidays           \
+                    -p my.arbtt                       \
                     --txt-report  .coverage.mypy-misc \
                     --html-report .coverage.mypy-misc \
                     {posargs}