diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..dc273e8
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,50 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        shell: bash -l {0}
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ['3.11', '3.12', '3.13']
+
+    steps:
+      - name: Cancel previous runs
+        uses: styfle/cancel-workflow-action@0.7.0
+        with:
+          access_token: ${{ github.token }}
+      - name: Checkout source
+        uses: actions/checkout@v2
+
+      - name: Conda setup
+        uses: conda-incubator/setup-miniconda@v2
+        with:
+          channels: conda-forge
+          mamba-version: '*'
+          python-version: ${{ matrix.python-version }}
+          activate-environment: test_env_xwmb
+          auto-activate-base: false
+
+      - name: Set up conda environment
+        run: |
+          mamba env update -n test_env_xwmb -f ci/environment.yml
+          python -m pip install -e .
+      - name: Conda list information
+        run: |
+          conda env list
+          conda list
+      - name: Test with pytest
+        run: |
+          pytest
diff --git a/ci/environment.yml b/ci/environment.yml
index cc3256a..f9b6dd4 100644
--- a/ci/environment.yml
+++ b/ci/environment.yml
@@ -3,7 +3,6 @@ channels:
   - conda-forge
   - nodefaults
 dependencies:
-  - python>=3.12
   - black
   - netcdf4
   - pylint
diff --git a/pyproject.toml b/pyproject.toml
index ffaf2a3..9bf4531 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,7 +18,7 @@ classifiers = [
 ]
 dependencies = [
     "regionate >= 0.5.0",
-    "xwmt >= 0.1.0",
+    "xwmt >= 0.2.0",
 ]
 
 [project.urls]
diff --git a/xwmb/budget.py b/xwmb/budget.py
index 03c6012..a8ceb31 100644
--- a/xwmb/budget.py
+++ b/xwmb/budget.py
@@ -168,6 +168,8 @@ def mass_budget(self, lambda_name, greater_than=False, integrate=True, along_sec
                 raise TypeError(f"Boolean or list of 3 numbers expected, got {type(default_bins).__name__}")
         elif isinstance(bins, np.ndarray):
             self.add_bins_gridcoords(lambda_name, bins)
+        elif isinstance(bins, xr.DataArray):
+            self.add_bins_gridcoords(lambda_name, bins.values)
         elif bins is None:
             pass
         else:
diff --git a/xwmb/tests/test_budget.py b/xwmb/tests/test_budget.py
new file mode 100644
index 0000000..a86ed4c
--- /dev/null
+++ b/xwmb/tests/test_budget.py
@@ -0,0 +1,108 @@
+import xgcm
+import xwmb
+import xarray as xr
+import numpy as np
+
+def synthetic_dataset():
+    x_f = np.array([-0.5, 0.5])
+    x_c = 0.5*(x_f[:-1] + x_f[1:])
+
+    y_f = np.array([0.5, 1.5, 2.5])
+    y_c = 0.5*(y_f[:-1] + y_f[1:])
+
+    lam_f = np.array([0, 1, 2])
+    lam_c = 0.5*(lam_f[:-1] + lam_f[1:])
+
+    t_f = np.array([0, 1])
+    t_c = 0.5*(t_f[:-1] + t_f[1:])
+
+    coords = {
+        "x_c": x_c,
+        "x_f": x_f,
+        "y_c": y_c,
+        "y_f": y_f,
+        "lam_c": lam_c,
+        "lam_f": lam_f,
+        "t_c": t_c,
+        "t_f": t_f
+    }
+    ds = xr.Dataset(coords=coords)
+    ds = ds.assign_coords({
+        "geolon": xr.broadcast(ds.x_c, ds.y_c)[0],
+        "geolat": xr.broadcast(ds.x_c, ds.y_c)[0],
+        "geolon_c": xr.broadcast(ds.x_f, ds.y_f)[0],
+        "geolat_c": xr.broadcast(ds.x_f, ds.y_f)[1],
+    })
+
+    # Grid cell area
+    ds["area"] = xr.ones_like(xr.broadcast(ds.x_c, ds.y_c)[0])
+
+    # Time-averaged size and contours of water mass
+    ds["lam"] = ds.lam_c * xr.ones_like(xr.broadcast(ds.t_c, ds.lam_c, ds.y_c, ds.x_c)[0])
+    ds["thickness"] = xr.ones_like(ds.lam)
+
+    # Bounding snapshots of size and contours of water mass
+    ds["lam_bounds"] = ds.lam_c * xr.ones_like(xr.broadcast(ds.t_f, ds.lam_c, ds.y_c, ds.x_c)[0])
+    ds["thickness_bounds"] = xr.ones_like(ds.lam_bounds)
+
+    # Lateral mass transport
+    ds["umo"] = xr.zeros_like(xr.broadcast(ds.t_c, ds.lam_c, ds.y_c, ds.x_f)[0])
+    ds["vmo"] = xr.where(
+        ds.y_f == 1.5,
+        ds.lam_c - 1.,
+        xr.zeros_like(xr.broadcast(ds.t_c, ds.lam_c, ds.y_f, ds.x_c)[0])
+    )
+
+    # Volume-integrated tendency
+    ds["tend"] = xr.where(
+        ds.y_c == 2.0,
+        1.,
+        xr.zeros_like(xr.broadcast(ds.t_c, ds.lam_c, ds.y_c, ds.x_c)[0])
+    )
+    return ds
+
+def synthetic_grid():
+
+    ds = synthetic_dataset()
+
+    # Placeholder until https://github.com/hdrake/xbudget/issues/21
+    ds = ds.rename({"t_c":"time", "t_f":"time_bounds"})
+
+    coords = {
+        "X": {"center":"x_c", "outer":"x_f"},
+        "Y": {"center":"y_c", "outer":"y_f"},
+        "Z": {"center":"lam_c", "outer":"lam_f"},
+        "T": {"center":"time", "outer":"time_bounds"}
+    }
+    grid = xgcm.Grid(
+        ds,
+        coords = coords,
+        boundary = {"X": "extend", "Y":"extend", "Z":"extend", "T":"extend"},
+        metrics = {("X","Y"): "area"},
+        autoparse_metadata=False
+    )
+
+    return grid
+
+def test_mass_budget():
+    grid = synthetic_grid()
+
+    xbudget_dict = {
+        "mass": {
+            "thickness": "thickness",
+            "rhs": {"sum": {"advection": {"sum": {"lateral": {"sum": {
+                "zonal_convergence": {"product": {"zonal_divergence": {"difference": {"zonal_mass_transport": "umo"}}}},
+                "meridional_convergence": {"product": {"meridional_divergence": {"difference": {"meridional_mass_transport": "vmo"}}}}
+            }}}}}}
+        },
+        "tracer": {"lambda": "lam", "rhs": {"sum": {"tendency": {"var": "tend"}}}}
+    }
+
+    wmb = xwmb.WaterMassBudget(
+        grid,
+        xbudget_dict,
+        rebin=False,
+        rho_ref = 1.
+    )
+
+    wmb.mass_budget("tracer", bins=grid._ds.lam_f).compute()
\ No newline at end of file