diff --git a/docs/api/api.rst b/docs/api/api.rst
index c65c5ce6c..12ef181b2 100644
--- a/docs/api/api.rst
+++ b/docs/api/api.rst
@@ -1,10 +1,17 @@
 API Functions
 =============
 
+Main API functions
+------------------
+
 .. automodule:: junifer.api
    :members:
    :imported-members:
 
+
+Decorators
+----------
+
 .. automodule:: junifer.api.decorators
    :members:
    :imported-members:
diff --git a/docs/contribution.rst b/docs/contribution.rst
index db6dba11e..8a5d369c1 100644
--- a/docs/contribution.rst
+++ b/docs/contribution.rst
@@ -174,10 +174,10 @@ texts.
     # The BIDS datagrabber requires three parameters: the types of data we want,
     # the specific pattern that matches each type, and the variables that will be
     # replaced int he patterns.
-    types = ["T1w", "bold"]
+    types = ["T1w", "BOLD"]
     patterns = {
         "T1w": "{subject}/anat/{subject}_T1w.nii.gz",
-        "bold": "{subject}/func/{subject}_task-rest_bold.nii.gz",
+        "BOLD": "{subject}/func/{subject}_task-rest_bold.nii.gz",
     }
     replacements = ["subject"]
     ###############################################################################
@@ -203,7 +203,7 @@ texts.
     ###############################################################################
     # Another feature of the datagrabber is the ability to get a specific
     # element by its name. In this case, we index `sub-01` and we get the file
-    # paths for the two types of data we want (T1w and bold).
+    # paths for the two types of data we want (T1w and BOLD).
     with PatternDataladDataGrabber(
         rootdir=rootdir,
         types=types,
diff --git a/docs/extending/datagrabber.rst b/docs/extending/datagrabber.rst
new file mode 100644
index 000000000..51e50fc03
--- /dev/null
+++ b/docs/extending/datagrabber.rst
@@ -0,0 +1,271 @@
+.. include:: ../links.inc
+
+.. _extending_datagrabbers:
+
+Creating DataGrabbers
+=====================
+
+DataGrabbers are the first step of the pipeline. It's purpose is to interpret
+the structure of a dataset and provide two specific functionalities:
+
+1) Given an *element*, provide the path to each kind of data available for this
+   element (e.g. the path to the T1 image, the path to the T2 image, etc.)
+2) Provide the list of *elements* available in the dataset.
+
+In this section, we will see how to create a datagrabber for a dataset. Basic
+aspects of datagrabbers are covedered in the 
+:ref:`Understanding DataGrabbers <datagrabber>` section.
+
+.. _extending_datagrabbers_think:
+
+Step 1: Think about the element
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Like with any programming-related task, the first step is to think. When
+creating a DataGrabber, we need to first define what an *element* is.
+The *element* should be the smallest unit of data that can be processed. That
+is, for each element, there should be a set of data that can be processed, but
+only one of each *data type* (see :ref:`data_types`).
+
+For example, if we have a dataset from an fMRI study in which:
+
+a) both T1w and fMRI was acquired 
+b) 20 subjects went through a experiment twice
+c) the experiment included resting-stage fMRI and a task named *stroop*
+
+then the *element* should be composed of 3 items:
+
+*  ``subject``: The subject IDs, e.g. `sub001`, `sub002`, ... `sub020`
+*  ``session``: The sesion number, e.g. `ses1`, `ses2`
+*  ``task``: The task performed, e.g. `rest`, `stroop`
+
+If any of this items were not part of the element, then we will have more than
+one ``T1w`` and/or ``BOLD`` image for each subject, which is not allowed.
+
+Importantly, nothing prevents that one image is part of two different elements.
+For example, it is usually the case that the ``T1w`` image is not acquired for
+each task, but once in the entire session. So in this case, the ``T1w`` image
+for the element (``sub001``, ``ses1``, ``rest``) will be the same as the
+``T1w`` image for the element (``sub001``, ``ses1``, ``stroop``).
+
+We will now continue this section using as an example, a dataset in BIDS format
+in which each 9 subjects (`sub-01` to `sub-09`) were scanned each in 3
+sessions (`ses-01`, `ses-02`, `ses-03`) and each session included a `T1w` and
+a `BOLD` image (resting-state), except for `ses-03` which was only anatomical.
+
+Step 2: Think about the dataset's structure
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Now that we have our element defined, we need to think about the structure of
+the dataset. Mainly, because the structure of the dataset will determine how
+the DataGrabber needs to be implemented.
+
+Junifer provides an abstract class to deal with datasets that can be thought in
+terms of *patterns*. A *pattern* is a string that contains placeholders that are
+replaced by the actual values of the element. In our BIDS example, the path
+to the T1w image of subject `sub-01` and session `ses-01`, relative to the
+dataset location, is ``sub-01/ses-01/anat/sub-01_ses-01_T1w.nii.gz``. By 
+replacing ``sub-01`` with ``sub-02``, we can obtain the T1w image of the first
+session of the second subject. Indeed, the path to the T1w images can be
+expressed as a pattern:
+
+``{subject}/{session}/anat/{subject}_{session}_T1w.nii.gz``
+
+where ``{subject}`` is the replacement for the subject id and ``{session}}``
+is the replacement for the session id.
+
+Since it is a BIDS dataaset, the same happens with the BOLD images. The path to
+the BOLD images can be expressed as a pattern:
+
+``{subject}/{session}/func/{subject}_{session}_task-rest_bold.nii.gz``
+
+
+This will be the norm in most of the datasets. If your dataset can be expressed
+in terms of patterns, then follow :ref:`extending_datagrabbers_pattern`.
+Otherwise, we recommend that you take time to re-think about your dataset
+structure and why it does not have clear *patterns*. Feel free to open a
+discussion in the `junifer Discussions`_ page. Most probably we can help you
+get your dataset in order.
+
+If there is no other way, then you can follow :ref:`extending_datagrabbers_base`
+to create a DataGrabber from scratch.
+
+
+.. _extending_datagrabbers_pattern:
+
+Option A: Extending from PatternDataGrabber
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The :py:class:`~junifer.datagrabber.PatternDataGrabber` class is an
+abstract class that has the functionality of understanding patterns embeded
+in it.
+
+Before creating the datagrabber, we need to define 3 variables:
+
+* ``types``: A list with the available :ref:`data_types` in our dataset 
+* ``patterns``: A dictionary that specifies the pattern for each data type.
+* ``replacements``: A list indicating which of the elements in the patterns
+  should be replaced by the values of the element.
+
+For example, in our BIDS example, the variables will be:
+
+.. code-block:: python
+
+    types = ["T1w", "BOLD"]
+    patterns = {
+       "T1w": "{subject}/{session}/anat/{subject}_{session}_T1w.nii.gz",
+       "BOLD": "{subject}/{session}/func/{subject}_{session}_task-rest_bold.nii.gz",
+    }
+    replacements = ["subject", "session"]
+
+
+An additional fourth variable is the ``datadir``, which should be the path to
+where the dataset is located. For example, if the dataset is located in
+``/data/project/test/data``, then ``datadir`` should be
+``/data/project/test/data``. Or, if we want to allow the user to specify the
+location of the dataset, we can expose the variable in the constructor, as in 
+this example
+
+With this defined, we can now create our datagrabber, we will name it
+``ExampleBIDSDataGrabber``:
+
+
+.. code-block:: python
+
+    from junifer.datagrabber.pattern import PatternDataGrabber
+
+    class ExampleBIDSDataGrabber(PatternDataGrabber):
+
+        def __init__(self, datadir):
+            types = ["T1w", "BOLD"]
+            patterns = {
+               "T1w": "{subject}/{session}/anat/{subject}_{session}_T1w.nii.gz",
+               "BOLD": "{subject}/{session}/func/{subject}_{session}_task-rest_bold.nii.gz",
+            }
+            replacements = ["subject", "session"]
+            super().__init__(
+               datadir=datadir,
+               types=types, 
+               patterns=patterns,
+               replacements=replacements)
+
+
+Our datagrabber is ready to be used by junifer. However, it is still unknown
+to the library. We need to register it in the library. To do so, we need to
+use the :py:func:`~junifer.api.decorators.register_datagrabber` decorator.
+
+
+.. code-block:: python
+
+    from junifer.datagrabber.pattern import PatternDataGrabber
+    from junifer.api.decorators import register_datagrabber
+
+
+    @register_datagrabber
+    class ExampleBIDSDataGrabber(PatternDataGrabber):
+
+        def __init__(self, datadir):
+            types = ["T1w", "BOLD"]
+            patterns = {
+               "T1w": "{subject}/{session}/anat/{subject}_{session}_T1w.nii.gz",
+               "BOLD": "{subject}/{session}/func/{subject}_{session}_task-rest_bold.nii.gz",
+            }
+            replacements = ["subject", "session"]
+            super().__init__(
+               datadir=datadir,
+               types=types, 
+               patterns=patterns,
+               replacements=replacements)
+
+
+Now, we can use our datagrabber in junifer, by setting the ``datagrabber`` kind
+in the yaml file to ``ExampleBIDSDataGrabber``. Remember that we still need to
+set the ``datadir``.
+
+.. code-block:: yaml
+   
+      datagrabber:
+         kind: ExampleBIDSDataGrabber
+         datadir: /data/project/test/data
+
+
+Optional: Using datalad 
+-----------------------
+
+If you are using datalad, you can use the 
+:py:class:`~junifer.datagrabber.PatternDataladDataGrabber` instead of the 
+:py:class:`~junifer.datagrabber.PatternDataGrabber`. This class will also
+interpret patterns, but will also use datalad to `clone` and `get` the data.
+
+The main difference between the two is that the ``datadir`` is not the actual
+location of the dataset, but the location where the dataset will be cloned. It 
+can now be ``None``, which means that the data will be downloaded to a
+temporary directory. To set the location of the dataset, you can use the
+``uri`` argument in the constructor. Additionally, a ``rootdir`` argument can
+be used to specify the path to the root directory of the dataset after doing
+``datalad clone``
+
+In the example, the dataset is hosted in gin 
+(``https://gin.g-node.org/juaml/datalad-example-bids``).
+
+When we clone this dataset, we will see the following structure:
+
+.. code-block::
+
+      .
+      └── example_bids_ses
+         ├── sub-01
+         │   ├── ses-01
+         │   ├── ses-02
+         │   └── ses-03
+         ├── sub-02
+         │   ├── ses-01
+         │   ├── ses-02
+         │   └── ses-03
+         ├── sub-03
+         ...
+
+So the patterns will start after ``example_bids_ses``. This is our ``rootdir``.
+
+Now we have our 2 additional variables:
+
+.. code-block:: python
+
+    uri = "https://gin.g-node.org/juaml/datalad-example-bids"
+    rootdir = "example_bids_ses"
+
+
+And we can create our datagrabber:
+
+
+.. code-block:: python
+
+    from junifer.datagrabber.pattern import PatternDataladDataGrabber
+    from junifer.api.decorators import register_datagrabber
+
+
+    @register_datagrabber
+    class ExampleBIDSDataGrabber(PatternDataladDataGrabber):
+
+        def __init__(self):
+            types = ["T1w", "BOLD"]
+            patterns = {
+               "T1w": "{subject}/{session}/anat/{subject}_{session}_T1w.nii.gz",
+               "BOLD": "{subject}/{session}/func/{subject}_{session}_task-rest_bold.nii.gz",
+            }
+            replacements = ["subject", "session"]
+            uri = "https://gin.g-node.org/juaml/datalad-example-bids"
+            rootdir = "example_bids_ses"
+            super().__init__(
+               datadir=None,
+               uri=uri,
+               rootdir=rootdir,
+               types=types, 
+               patterns=patterns,
+               replacements=replacements)
+
+
+.. _extending_datagrabbers_base:
+
+Option B: Extending from BaseDataGrabber
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
\ No newline at end of file
diff --git a/docs/extending/index.rst b/docs/extending/index.rst
new file mode 100644
index 000000000..3706e914e
--- /dev/null
+++ b/docs/extending/index.rst
@@ -0,0 +1,26 @@
+.. include:: ../links.inc
+
+.. _extending:
+
+Extending junifer
+=================
+
+While we aim to provide as many datasets and markers as possible, we are also
+interested in allowing users to extend the functionality with their own
+datagrabbers, preprocessing, markers, etc.
+
+This does not mean that the new functinality will have to be included in
+junifer before the user can use them. Instead, the user can simply
+create a new python file, code the desired functionality and use it with
+junifer. This is the first step towards including the new functionality in
+the junifer package.
+
+In this section we will show how to extend junifer, by creating new
+datagrabbers, preprocessing and markers, following the *junifer* way.
+
+
+.. toctree::
+   :maxdepth: 1
+   :caption: Contents:
+
+   datagrabber
diff --git a/docs/index.rst b/docs/index.rst
index 5aaa20d88..5d77b0a21 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -25,6 +25,7 @@ enabling others to extend it easily.
    installation
    understanding/index.rst
    builtin
+   extending/index.rst
    auto_examples/index.rst
    api/index.rst
    contribution
diff --git a/docs/links.inc b/docs/links.inc
index 268bae5d8..27f6489c8 100644
--- a/docs/links.inc
+++ b/docs/links.inc
@@ -27,6 +27,7 @@
 
 .. _`Github`: https://github.com/
 .. _`junifer Github`: https://github.com/juaml/junifer
+.. _`junifer Discussions`: https://github.com/juaml/junifer/discussions
 
 .. _`Wikipedia`: https://wikipedia.org
 
diff --git a/docs/understanding/data.rst b/docs/understanding/data.rst
index 97dcb5642..a109d9955 100644
--- a/docs/understanding/data.rst
+++ b/docs/understanding/data.rst
@@ -42,6 +42,9 @@ Data types
    * - ``BOLD``
      - BOLD image (4D)
      - Preprocessed/Denoised BOLD image (fmriprep output)
+   * - ``BOLD_confounds``
+     - BOLD image confounds (CSV/TSV file)
+     - Confounds that can be applied to the BOLD image.
    * - ``VBM_GM``
      - VBM Gray Matter segmentation (3D)
      - CAT output (`m0wp1` images)
diff --git a/docs/understanding/index.rst b/docs/understanding/index.rst
index abc1a6e00..808bf141a 100644
--- a/docs/understanding/index.rst
+++ b/docs/understanding/index.rst
@@ -1,5 +1,7 @@
 .. include:: ../links.inc
 
+.. _understanding:
+
 Understanding junifer
 =====================
 
diff --git a/examples/run_datagrabber_bids_datalad.py b/examples/run_datagrabber_bids_datalad.py
index eb14892a6..727fc5178 100644
--- a/examples/run_datagrabber_bids_datalad.py
+++ b/examples/run_datagrabber_bids_datalad.py
@@ -23,10 +23,10 @@ configure_logging(level="INFO")
 # The BIDS datagrabber requires three parameters: the types of data we want,
 # the specific pattern that matches each type, and the variables that will be
 # replaced int he patterns.
-types = ["T1w", "bold"]
+types = ["T1w", "BOLD"]
 patterns = {
     "T1w": "{subject}/anat/{subject}_T1w.nii.gz",
-    "bold": "{subject}/func/{subject}_task-rest_bold.nii.gz",
+    "BOLD": "{subject}/func/{subject}_task-rest_bold.nii.gz",
 }
 replacements = ["subject"]
 ###############################################################################
@@ -52,7 +52,7 @@ with PatternDataladDataGrabber(
 ###############################################################################
 # Another feature of the datagrabber is the ability to get a specific
 # element by its name. In this case, we index `sub-01` and we get the file
-# paths for the two types of data we want (T1w and bold).
+# paths for the two types of data we want (T1w and BOLD).
 with PatternDataladDataGrabber(
     rootdir=rootdir,
     types=types,
diff --git a/junifer/datagrabber/tests/test_datagrabber_utils.py b/junifer/datagrabber/tests/test_datagrabber_utils.py
index c26e4be97..4b203a718 100644
--- a/junifer/datagrabber/tests/test_datagrabber_utils.py
+++ b/junifer/datagrabber/tests/test_datagrabber_utils.py
@@ -19,7 +19,7 @@ def test_validate_types() -> None:
     with pytest.raises(TypeError, match="must be a list of strings"):
         validate_types([1])  # type: ignore
 
-    validate_types(["T1w", "bold"])
+    validate_types(["T1w", "BOLD"])
 
 
 def test_validate_replacements() -> None:
@@ -31,7 +31,7 @@ def test_validate_replacements() -> None:
 
     patterns = {
         "T1w": "{subject}/anat/{subject}_T1w.nii.gz",
-        "bold": "{subject}/func/{subject}_task-rest_bold.nii.gz",
+        "BOLD": "{subject}/func/{subject}_task-rest_bold.nii.gz",
     }
 
     with pytest.raises(TypeError, match="must be a list of strings"):
@@ -42,7 +42,7 @@ def test_validate_replacements() -> None:
 
     wrong_patterns = {
         "T1w": "{subject}/anat/_T1w.nii.gz",
-        "bold": "{session}/func/_task-rest_bold.nii.gz",
+        "BOLD": "{session}/func/_task-rest_bold.nii.gz",
     }
 
     with pytest.raises(ValueError, match="At least one pattern"):
@@ -53,7 +53,7 @@ def test_validate_replacements() -> None:
 
 def test_validate_patterns() -> None:
     """Test validation of patterns."""
-    types = ["T1w", "bold"]
+    types = ["T1w", "BOLD"]
     with pytest.raises(TypeError, match="must be a dict"):
         validate_patterns(types, "wrong")  # type: ignore
 
@@ -74,12 +74,12 @@ def test_validate_patterns() -> None:
 
     patterns = {
         "T1w": "{subject}/anat/{subject}_T1w.nii.gz",
-        "bold": "{subject}/func/{subject}_task-rest_bold.nii.gz",
+        "BOLD": "{subject}/func/{subject}_task-rest_bold.nii.gz",
     }
 
     wrongpatterns = {
         "T1w": "{subject}/anat/{subject}*.nii",
-        "bold": "{subject}/func/{subject}_task-rest_bold.nii.gz",
+        "BOLD": "{subject}/func/{subject}_task-rest_bold.nii.gz",
     }
 
     with pytest.raises(ValueError, match="following a replacement"):
diff --git a/junifer/datagrabber/tests/test_multiple.py b/junifer/datagrabber/tests/test_multiple.py
index 5e1298d3a..c7113986c 100644
--- a/junifer/datagrabber/tests/test_multiple.py
+++ b/junifer/datagrabber/tests/test_multiple.py
@@ -27,7 +27,7 @@ def test_multiple() -> None:
         "T1w": "{subject}/{session}/anat/{subject}_{session}_T1w.nii.gz",
     }
     pattern2 = {
-        "bold": "{subject}/{session}/func/"
+        "BOLD": "{subject}/{session}/func/"
         "{subject}_{session}_task-rest_bold.nii.gz",
     }
     dg1 = PatternDataladDataGrabber(
@@ -41,7 +41,7 @@ def test_multiple() -> None:
     dg2 = PatternDataladDataGrabber(
         rootdir=rootdir,
         uri=repo_uri,
-        types=["bold"],
+        types=["BOLD"],
         patterns=pattern2,
         replacements=replacements,
     )
@@ -50,7 +50,7 @@ def test_multiple() -> None:
 
     types = dg.get_types()
     assert "T1w" in types
-    assert "bold" in types
+    assert "BOLD" in types
 
     expected_subs = [
         (f"sub-{i:02d}", f"ses-{j:02d}")
@@ -64,7 +64,7 @@ def test_multiple() -> None:
 
         data = dg[("sub-01", "ses-01")]
         assert "T1w" in data
-        assert "bold" in data
+        assert "BOLD" in data
 
     meta = dg.get_meta()
     assert "class" in meta
@@ -85,7 +85,7 @@ def test_multiple_no_intersection() -> None:
         "T1w": "{subject}/{session}/anat/{subject}_{session}_T1w.nii.gz",
     }
     pattern2 = {
-        "bold": "{subject}/{session}/func/"
+        "BOLD": "{subject}/{session}/func/"
         "{subject}_{session}_task-rest_bold.nii.gz",
     }
     dg1 = PatternDataladDataGrabber(
@@ -99,7 +99,7 @@ def test_multiple_no_intersection() -> None:
     dg2 = PatternDataladDataGrabber(
         rootdir=rootdir,
         uri=repo_uri2,
-        types=["bold"],
+        types=["BOLD"],
         patterns=pattern2,
         replacements=replacements,
     )
diff --git a/junifer/datagrabber/tests/test_pattern_datalad.py b/junifer/datagrabber/tests/test_pattern_datalad.py
index 7cacf7b60..3397d9582 100644
--- a/junifer/datagrabber/tests/test_pattern_datalad.py
+++ b/junifer/datagrabber/tests/test_pattern_datalad.py
@@ -45,11 +45,11 @@ def test_bids_PatternDataladDataGrabber(tmp_path: Path) -> None:
 
     """
     # Define types
-    types = ["T1w", "bold"]
+    types = ["T1w", "BOLD"]
     # Define patterns
     patterns = {
         "T1w": "{subject}/anat/{subject}_T1w.nii.gz",
-        "bold": "{subject}/func/{subject}_task-rest_bold.nii.gz",
+        "BOLD": "{subject}/func/{subject}_task-rest_bold.nii.gz",
     }
     # Define replacements
     replacements = ["subject"]
@@ -75,8 +75,8 @@ def test_bids_PatternDataladDataGrabber(tmp_path: Path) -> None:
             assert t_sub["T1w"]["path"] == (
                 dg.datadir / f"{elem}/anat/{elem}_T1w.nii.gz"
             )
-            assert "path" in t_sub["bold"]
-            assert t_sub["bold"]["path"] == (
+            assert "path" in t_sub["BOLD"]
+            assert t_sub["BOLD"]["path"] == (
                 dg.datadir / f"{elem}/func/{elem}_task-rest_bold.nii.gz"
             )
 
@@ -104,11 +104,11 @@ def test_bids_PatternDataladDataGrabber_datadir(tmp_path: Path) -> None:
 
     """
     # Define types
-    types = ["T1w", "bold"]
+    types = ["T1w", "BOLD"]
     # Define patterns
     patterns = {
         "T1w": "{subject}/anat/{subject}_T1w.nii.gz",
-        "bold": "{subject}/func/{subject}_task-rest_bold.nii.gz",
+        "BOLD": "{subject}/func/{subject}_task-rest_bold.nii.gz",
     }
     # Define replacements
     replacements = ["subject"]
@@ -118,7 +118,7 @@ def test_bids_PatternDataladDataGrabber_datadir(tmp_path: Path) -> None:
     datadir = "dataset"  # use string and not absolute path
     patterns = {
         "T1w": "example_bids/{subject}/anat/{subject}_T*w.nii.gz",
-        "bold": "example_bids/{subject}/func/{subject}_task-rest_*.nii.gz",
+        "BOLD": "example_bids/{subject}/func/{subject}_task-rest_*.nii.gz",
     }
     with PatternDataladDataGrabber(
         uri=repo_uri,
@@ -134,18 +134,18 @@ def test_bids_PatternDataladDataGrabber_datadir(tmp_path: Path) -> None:
             assert t_sub["T1w"]["path"] == (
                 dg.datadir / f"{elem}/anat/{elem}_T1w.nii.gz"
             )
-            assert "path" in t_sub["bold"]
-            assert t_sub["bold"]["path"] == (
+            assert "path" in t_sub["BOLD"]
+            assert t_sub["BOLD"]["path"] == (
                 dg.datadir / f"{elem}/func/{elem}_task-rest_bold.nii.gz"
             )
 
 
 def test_bids_PatternDataladDataGrabber_session():
     """Test a subject and session-based BIDS datalad datagrabber."""
-    types = ["T1w", "bold"]
+    types = ["T1w", "BOLD"]
     patterns = {
         "T1w": "{subject}/{session}/anat/{subject}_{session}_T1w.nii.gz",
-        "bold": "{subject}/{session}/func/"
+        "BOLD": "{subject}/{session}/func/"
         "{subject}_{session}_task-rest_bold.nii.gz",
     }
     replacements = ["subject", "session"]
@@ -162,7 +162,7 @@ def test_bids_PatternDataladDataGrabber_session():
     rootdir = "example_bids_ses"
     # repo_commit =  _testing_dataset['example_bids_ses']['id']
 
-    # With T1W and bold, only 2 sessions are available
+    # With T1W and BOLD, only 2 sessions are available
     with PatternDataladDataGrabber(
         rootdir=rootdir,
         uri=repo_uri,
diff --git a/junifer/datareader/tests/test_default_reader.py b/junifer/datareader/tests/test_default_reader.py
index a645844ce..4ebf61b34 100644
--- a/junifer/datareader/tests/test_default_reader.py
+++ b/junifer/datareader/tests/test_default_reader.py
@@ -42,7 +42,7 @@ def test_meta() -> None:
 
     nib_data_path = Path(nib_testing.data_path)
     t_path = nib_data_path / "example4d.nii.gz"
-    input = {"bold": {"path": t_path}}
+    input = {"BOLD": {"path": t_path}}
     output = reader.fit_transform(input)
     assert "meta" in output
     assert "datareader" in output["meta"]
@@ -67,23 +67,23 @@ def test_read_nifti(fname: str) -> None:
 
     t_path = nib_data_path / fname
 
-    input = {"bold": {"path": t_path}}
+    input = {"BOLD": {"path": t_path}}
     output = reader.fit_transform(input)
 
     assert isinstance(output, dict)
-    assert "bold" in output
-    assert isinstance(output["bold"], dict)
-    assert "path" in output["bold"]
-    assert "data" in output["bold"]
+    assert "BOLD" in output
+    assert isinstance(output["BOLD"], dict)
+    assert "path" in output["BOLD"]
+    assert "data" in output["BOLD"]
 
-    read_img = output["bold"]["data"]
+    read_img = output["BOLD"]["data"]
 
     t_read_img = nib.load(t_path)
     assert_array_equal(read_img.get_fdata(), t_read_img.get_fdata())
 
-    input = {"bold": {"path": t_path.as_posix()}}
+    input = {"BOLD": {"path": t_path.as_posix()}}
     output2 = reader.fit_transform(input)
-    assert output["bold"]["path"] == output2["bold"]["path"]
+    assert output["BOLD"]["path"] == output2["BOLD"]["path"]
 
 
 def test_read_unknown() -> None: