diff --git a/.github/workflows/semconvgen.yml b/.github/workflows/semconvgen.yml
index 28a42a8f..16ede1c5 100644
--- a/.github/workflows/semconvgen.yml
+++ b/.github/workflows/semconvgen.yml
@@ -13,7 +13,7 @@ jobs:
   tests:
     runs-on: ubuntu-latest
     defaults:
-      run: 
+      run:
         working-directory: semantic-conventions/
     steps:
     - uses: actions/checkout@v3
@@ -39,7 +39,7 @@ jobs:
       run: pylint *.py src/
     - name: Type checking (mypy)
       run: mypy src/
-      
+
 
   build-and-publish-docker:
     runs-on: ubuntu-latest
@@ -68,3 +68,13 @@ jobs:
         else
           tag_and_push "${GITHUB_REF#"refs/tags/"}"
         fi
+    - name: Push the Dev Docker image
+      if: startsWith(github.ref, 'refs/heads/feature/')
+      run: |
+        echo "${{ secrets.DOCKER_PASSWORD }}" | docker login -u "${{ secrets.DOCKER_USERNAME }}" --password-stdin
+        function tag_and_push {
+          docker tag semconvgen "otel/semconvgen:${1}" && docker push "otel/semconvgen:${1}"
+        }
+        TAG="${GITHUB_REF#"refs/heads/"}"
+        TAG="${TAG/"/"/"-"}"
+        tag_and_push "${TAG}"
diff --git a/semantic-conventions/CHANGELOG.md b/semantic-conventions/CHANGELOG.md
index 153d7587..e608dace 100644
--- a/semantic-conventions/CHANGELOG.md
+++ b/semantic-conventions/CHANGELOG.md
@@ -4,6 +4,11 @@ Please update the changelog as part of any significant pull request.
 
 ## Unreleased
 
+- Added code-generation mode that groups attributes by the root namespace and ability to write each group into individual file.
+  [BREAKING] The `--file-per-group <pattern>` that used to create multiple directories (like `output/<pattern>/file`) now generates
+  multiple files (`output/<pattern>file`) instead.
+  ([#243](https://github.com/open-telemetry/build-tools/pull/243))
+
 ## v0.23.0
 
 - Rephrase and relax sampling-relevant description
@@ -17,7 +22,7 @@ Please update the changelog as part of any significant pull request.
   ([#205](https://github.com/open-telemetry/build-tools/pull/205))
 - Fix referencing template attributes
   ([#206](https://github.com/open-telemetry/build-tools/pull/206))
-  
+
 ## v0.21.0
 
 - Render template-type attributes from yaml files
diff --git a/semantic-conventions/README.md b/semantic-conventions/README.md
index 9d1bc5a7..5ebdba88 100644
--- a/semantic-conventions/README.md
+++ b/semantic-conventions/README.md
@@ -85,8 +85,8 @@ convention that have the tag `network`.
 `<!-- semconv http.server(tag=network, full) -->` will print the constraints and attributes of both `http` and `http.server`
 semantic conventions that have the tag `network`.
 
-`<!-- semconv metric.http.server.active_requests(metric_table) -->` will print a table describing a single metric 
-`http.server.active_requests`. 
+`<!-- semconv metric.http.server.active_requests(metric_table) -->` will print a table describing a single metric
+`http.server.active_requests`.
 
 ## Code Generator
 
@@ -125,12 +125,70 @@ This way, multiple files are generated. The value of `pattern` can be one of the
 - `semconv_id`: The id of the semantic convention.
 - `prefix`: The prefix with which all attributes starts with.
 - `extends`: The id of the parent semantic convention.
+- `root_namespace`: The root namespace of attribute to group by.
 
 Finally, additional value can be passed to the template in form of `key=value` pairs separated by
 comma using the `--parameters [{key=value},]+` or `-D` flag.
 
 ### Customizing Jinja's Whitespace Control
 
-The image also supports customising
+The image also supports customizing
 [Whitespace Control in Jinja templates](https://jinja.palletsprojects.com/en/3.1.x/templates/#whitespace-control)
 via the additional flag `--trim-whitespace`. Providing the flag will enable both `lstrip_blocks` and `trim_blocks`.
+
+### Accessing Semantic Conventions in the template
+
+When template is processed, it has access to a set of variables that depends on the `--file-per-group` value (or lack of it).
+You can access properties of these variables and call Jinja or Python functions defined on them.
+
+#### Single file (no `--file-per-group` pattern is provided)
+
+Processes all parsed semantic conventions
+
+- `semconvs` - the dictionary containing parsed `BaseSemanticConvention` instances with semconv `id` as a key
+- `attributes_and_templates` - the dictionary containing all attributes (including template ones) grouped by their root namespace.
+  Each element in the dictionary is a list of attributes that share the same root namespace. Attributes that don't have a namespace
+  appear under `""` key.
+- `attributes` - the list of all attributes from all parsed semantic conventions. Does not include template attributes.
+- `attribute_templates` - the list of all attribute templates from all parsed semantic conventions.
+
+#### The `root_namespace` pattern
+
+Processes a single namespace and is called for each namespace detected.
+
+- `attributes_and_templates` - the list containing all attributes (including template ones) in the given root namespace.
+- `root_namespace` - the root namespace being processed.
+
+#### Other patterns
+
+Processes a single pattern value and is called for each distinct value.
+
+- `semconv` - the instance of parsed `BaseSemanticConvention` being processed.
+
+### Filtering and mapping
+
+Jinja templates has a notion of [filters](https://jinja.palletsprojects.com/en/2.11.x/templates/#list-of-builtin-filters) allowing to transform objects or filter lists.
+
+Semconvgen supports following additional filters to simplify common operations in templates.
+
+#### `SemanticAttribute` operations
+
+1. `is_definition` - Checks if the attribute is the original definition of the attribute and not a reference.
+2. `is_deprecated` - Checks if the attribute is deprecated. The same check can also be done with `(attribute.stability | string())  == "StabilityLevel.DEPRECATED"`
+3. `is_experimental` - Checks if the attribute is experimental. The same check can also be done with `(attribute.stability | string())  == "StabilityLevel.EXPERIMENTAL"`
+4. `is_stable` - Checks if the attribute is experimental. The same check can also be done with `(attribute.stability | string())  == "StabilityLevel.STABLE"`
+5. `is_template` - Checks if the attribute is a template attribute.
+
+#### String operations
+
+1. `first_up` - Upper-cases the first character in the string. Does not modify anything else
+2. `regex_replace(text, pattern, replace)` - Makes regex-based replace in `text` string using `pattern``
+3. `to_camelcase` - Converts a string to camel case (using `.` and `_` as words delimiter in the original string).
+   The first character of every word is upper-cased, other characters are lower-cased. E.g. `foo.bAR_baz` becomes `fooBarBaz`
+4. `to_const_name` - Converts a string to Python or Java constant name (SNAKE_CASE) replacing `.` or `-` with `_`. E.g.
+   `foo.bAR-baz` becomes `FOO_BAR_BAZ`.
+5. `to_doc_brief` - Trims whitespace and removes dot at the end. E.g. ` Hello world.\t` becomes `Hello world`
+
+#### `BaseSemanticConvention` operations
+
+1. `is_metric` - Checks if semantic convention describes a metric.
diff --git a/semantic-conventions/src/opentelemetry/semconv/main.py b/semantic-conventions/src/opentelemetry/semconv/main.py
index ce144d94..e6331814 100644
--- a/semantic-conventions/src/opentelemetry/semconv/main.py
+++ b/semantic-conventions/src/opentelemetry/semconv/main.py
@@ -129,7 +129,8 @@ def add_code_parser(subparsers):
     parser.add_argument(
         "--output",
         "-o",
-        help="Specify the output file for the code generation.",
+        help="Specify the output file name for the code generation. "
+        "See also `--file-per-group` on how to generate multiple files.",
         type=str,
         required=True,
     )
@@ -143,8 +144,10 @@ def add_code_parser(subparsers):
     parser.add_argument(
         "--file-per-group",
         dest="pattern",
-        help="Each Semantic Convention is processed by the template and store in a different file. PATTERN is expected "
-        "to be the name of a SemanticConvention field and is prepended as a prefix to the output argument",
+        help="Semantic conventions are processed by the template and stored in a different file. "
+        "File names start with a 'pattern' and end with the name specified in the 'output' argument. "
+        "The 'pattern' can either match 'root_namespace' to group attributes by the root namespace or "
+        "match a name of Semantic Convention property which value will be used as a file name prefix.",
         type=str,
     )
     parser.add_argument(
diff --git a/semantic-conventions/src/opentelemetry/semconv/model/semantic_attribute.py b/semantic-conventions/src/opentelemetry/semconv/model/semantic_attribute.py
index f6df923d..f22a9bbd 100644
--- a/semantic-conventions/src/opentelemetry/semconv/model/semantic_attribute.py
+++ b/semantic-conventions/src/opentelemetry/semconv/model/semantic_attribute.py
@@ -60,6 +60,7 @@ class SemanticAttribute:
     sampling_relevant: bool
     note: str
     position: List[int]
+    root_namespace: str
     inherited: bool = False
     imported: bool = False
 
@@ -203,6 +204,10 @@ def parse(
             fqn = fqn.strip()
             parsed_brief = TextWithLinks(brief.strip() if brief else "")
             parsed_note = TextWithLinks(note.strip())
+
+            namespaces = fqn.split(".")
+            root_namespace = namespaces[0] if len(namespaces) > 1 else ""
+
             attr = SemanticAttribute(
                 fqn=fqn,
                 attr_id=attr_id,
@@ -218,6 +223,7 @@ def parse(
                 sampling_relevant=sampling_relevant,
                 note=parsed_note,
                 position=position,
+                root_namespace=root_namespace,
             )
             if attr.fqn in attributes:
                 position = position_data[list(attribute)[0]]
@@ -318,7 +324,6 @@ def parse_stability_deprecated(stability, deprecated, position_data):
 
     @staticmethod
     def check_stability(stability_value, position):
-
         stability_value_map = {
             "deprecated": StabilityLevel.DEPRECATED,
             "experimental": StabilityLevel.EXPERIMENTAL,
diff --git a/semantic-conventions/src/opentelemetry/semconv/model/semantic_convention.py b/semantic-conventions/src/opentelemetry/semconv/model/semantic_convention.py
index 13ade651..9aafb1c8 100644
--- a/semantic-conventions/src/opentelemetry/semconv/model/semantic_convention.py
+++ b/semantic-conventions/src/opentelemetry/semconv/model/semantic_convention.py
@@ -264,6 +264,9 @@ def __init__(self, group):
         self.metric_name = group.get("metric_name")
         self.unit = group.get("unit")
         self.instrument = group.get("instrument")
+
+        namespaces = self.metric_name.split(".")
+        self.root_namespace = namespaces[0] if len(namespaces) > 1 else ""
         self.validate()
 
     def validate(self):
diff --git a/semantic-conventions/src/opentelemetry/semconv/templating/code.py b/semantic-conventions/src/opentelemetry/semconv/templating/code.py
index b84a39fd..1685d967 100644
--- a/semantic-conventions/src/opentelemetry/semconv/templating/code.py
+++ b/semantic-conventions/src/opentelemetry/semconv/templating/code.py
@@ -21,10 +21,17 @@
 from jinja2 import Environment, FileSystemLoader, select_autoescape
 
 from opentelemetry.semconv.model.semantic_attribute import (
+    AttributeType,
     RequirementLevel,
+    SemanticAttribute,
+    StabilityLevel,
     TextWithLinks,
 )
-from opentelemetry.semconv.model.semantic_convention import SemanticConventionSet
+from opentelemetry.semconv.model.semantic_convention import (
+    BaseSemanticConvention,
+    MetricSemanticConvention,
+    SemanticConventionSet,
+)
 from opentelemetry.semconv.model.utils import ID_RE
 
 
@@ -156,6 +163,36 @@ def to_camelcase(name: str, first_upper=False) -> str:
     return first + "".join(word.capitalize() for word in rest)
 
 
+def first_up(name: str) -> str:
+    return name[0].upper() + name[1:]
+
+
+def is_stable(obj: typing.Union[SemanticAttribute, BaseSemanticConvention]) -> bool:
+    return obj.stability == StabilityLevel.STABLE
+
+
+def is_deprecated(obj: typing.Union[SemanticAttribute, BaseSemanticConvention]) -> bool:
+    return obj.stability == StabilityLevel.DEPRECATED
+
+
+def is_experimental(
+    obj: typing.Union[SemanticAttribute, BaseSemanticConvention]
+) -> bool:
+    return obj.stability is None or obj.stability == StabilityLevel.EXPERIMENTAL
+
+
+def is_definition(attribute: SemanticAttribute) -> bool:
+    return attribute.is_local and attribute.ref is None
+
+
+def is_template(attribute: SemanticAttribute) -> bool:
+    return AttributeType.is_template_type(str(attribute.attr_type))
+
+
+def is_metric(semconv: BaseSemanticConvention) -> bool:
+    return isinstance(semconv, MetricSemanticConvention)
+
+
 class CodeRenderer:
     pattern = f"{{{ID_RE.pattern}}}"
 
@@ -188,6 +225,7 @@ def get_data_single_file(
             "semconvs": semconvset.models,
             "attributes": semconvset.attributes(),
             "attribute_templates": semconvset.attribute_templates(),
+            "attributes_and_templates": self._grouped_attribute_definitions(semconvset),
         }
         data.update(self.parameters)
         return data
@@ -206,18 +244,30 @@ def setup_environment(env: Environment, trim_whitespace: bool):
         env.filters["to_const_name"] = to_const_name
         env.filters["merge"] = merge
         env.filters["to_camelcase"] = to_camelcase
+        env.filters["first_up"] = first_up
         env.filters["to_html_links"] = to_html_links
         env.filters["regex_replace"] = regex_replace
         env.filters["render_markdown"] = render_markdown
+        env.filters["is_deprecated"] = is_deprecated
+        env.filters["is_definition"] = is_definition
+        env.filters["is_stable"] = is_stable
+        env.filters["is_experimental"] = is_experimental
+        env.filters["is_template"] = is_template
+        env.filters["is_metric"] = is_metric
+        env.tests["is_stable"] = is_stable
+        env.tests["is_experimental"] = is_experimental
+        env.tests["is_deprecated"] = is_deprecated
+        env.tests["is_definition"] = is_definition
+        env.tests["is_template"] = is_template
+        env.tests["is_metric"] = is_metric
         env.trim_blocks = trim_whitespace
         env.lstrip_blocks = trim_whitespace
 
     @staticmethod
-    def prefix_output_file(file_name, pattern, semconv):
+    def prefix_output_file(file_name, prefix):
         basename = os.path.basename(file_name)
         dirname = os.path.dirname(file_name)
-        value = getattr(semconv, pattern)
-        return os.path.join(dirname, to_camelcase(value, True), basename)
+        return os.path.join(dirname, to_camelcase(prefix, True) + basename)
 
     def render(
         self,
@@ -233,19 +283,97 @@ def render(
             autoescape=select_autoescape([""]),
         )
         self.setup_environment(env, self.trim_whitespace)
-        if pattern:
-            for semconv in semconvset.models.values():
-                output_name = self.prefix_output_file(output_file, pattern, semconv)
-                data = self.get_data_multiple_files(semconv, template_path)
-                template = env.get_template(file_name, globals=data)
-                template.globals["now"] = datetime.datetime.utcnow()
-                template.globals["version"] = os.environ.get("ARTIFACT_VERSION", "dev")
-                template.globals["RequirementLevel"] = RequirementLevel
-                template.stream(data).dump(output_name)
+        if pattern == "root_namespace":
+            self._render_group_by_root_namespace(
+                semconvset, template_path, file_name, output_file, env
+            )
+        elif pattern is not None:
+            self._render_by_pattern(
+                semconvset, template_path, file_name, output_file, pattern, env
+            )
         else:
             data = self.get_data_single_file(semconvset, template_path)
             template = env.get_template(file_name, globals=data)
-            template.globals["now"] = datetime.datetime.utcnow()
-            template.globals["version"] = os.environ.get("ARTIFACT_VERSION", "dev")
-            template.globals["RequirementLevel"] = RequirementLevel
-            template.stream(data).dump(output_file)
+            self._write_template_to_file(template, data, output_file)
+
+    def _render_by_pattern(
+        self,
+        semconvset: SemanticConventionSet,
+        template_path: str,
+        file_name: str,
+        output_file: str,
+        pattern: str,
+        env: Environment,
+    ):
+        for semconv in semconvset.models.values():
+            prefix = getattr(semconv, pattern)
+            output_name = self.prefix_output_file(output_file, prefix)
+            data = self.get_data_multiple_files(semconv, template_path)
+            template = env.get_template(file_name, globals=data)
+            self._write_template_to_file(template, data, output_name)
+
+    def _render_group_by_root_namespace(
+        self,
+        semconvset: SemanticConventionSet,
+        template_path: str,
+        file_name: str,
+        output_file: str,
+        env: Environment,
+    ):
+        attribute_and_templates = self._grouped_attribute_definitions(semconvset)
+        metrics = self._grouped_metric_definitions(semconvset)
+        for ns, attribute_and_templates in attribute_and_templates.items():
+            sanitized_ns = ns if ns != "" else "other"
+            output_name = self.prefix_output_file(output_file, sanitized_ns)
+
+            data = {
+                "template": template_path,
+                "attributes_and_templates": attribute_and_templates,
+                "metrics": metrics.get(ns) or [],
+                "root_namespace": sanitized_ns,
+            }
+            data.update(self.parameters)
+
+            template = env.get_template(file_name, globals=data)
+            self._write_template_to_file(template, data, output_name)
+
+    def _grouped_attribute_definitions(self, semconvset):
+        grouped_attributes = {}
+        for semconv in semconvset.models.values():
+            for attr in semconv.attributes_and_templates:
+                if not is_definition(attr):  # skip references
+                    continue
+                if attr.root_namespace not in grouped_attributes:
+                    grouped_attributes[attr.root_namespace] = []
+                grouped_attributes[attr.root_namespace].append(attr)
+
+        for ns in grouped_attributes:
+            grouped_attributes[ns] = sorted(grouped_attributes[ns], key=lambda a: a.fqn)
+        return grouped_attributes
+
+    def _grouped_metric_definitions(self, semconvset):
+        grouped_metrics = {}
+        for semconv in semconvset.models.values():
+            if not is_metric(semconv):
+                continue
+
+            if semconv.root_namespace not in grouped_metrics:
+                grouped_metrics[semconv.root_namespace] = []
+
+            grouped_metrics[semconv.root_namespace].append(semconv)
+
+        for ns in grouped_metrics:
+            grouped_metrics[ns] = sorted(
+                grouped_metrics[ns], key=lambda a: a.metric_name
+            )
+        return grouped_metrics
+
+    def _write_template_to_file(self, template, data, output_name):
+        template.globals["now"] = datetime.datetime.utcnow()
+        template.globals["version"] = os.environ.get("ARTIFACT_VERSION", "dev")
+        template.globals["RequirementLevel"] = RequirementLevel
+
+        content = template.render(data)
+        if content != "":
+            with open(output_name, "w", encoding="utf-8") as f:
+                f.write(content)
diff --git a/semantic-conventions/src/tests/data/jinja/attribute_templates/template b/semantic-conventions/src/tests/data/jinja/attribute_templates/template
index 486ddce2..d320e990 100644
--- a/semantic-conventions/src/tests/data/jinja/attribute_templates/template
+++ b/semantic-conventions/src/tests/data/jinja/attribute_templates/template
@@ -25,22 +25,13 @@
   {%- elif type == "double" -%}
     doubleKey
   {%- else -%}
-    {{lowerFirst(type)}}Key
+    {{ type | to_camelcase(False)}}Key
   {%- endif -%}
 {%- endmacro %}
-{%- macro print_value(type, value) -%}
-  {{ "\"" if type == "String"}}{{value}}{{ "\"" if type == "String"}}
-{%- endmacro %}
-{%- macro upFirst(text) -%}
-  {{ text[0]|upper}}{{text[1:] }}
-{%- endmacro %}
-{%- macro lowerFirst(text) -%}
-  {{ text[0]|lower}}{{text[1:] }}
-{%- endmacro %}
 package io.opentelemetry.instrumentation.api.attributetemplates;
 
 class AttributesTemplate {
-{%- for attribute_template in attribute_templates if attribute_template.is_local and not attribute_template.ref %}
+{%- for attribute_template in attribute_templates | select("is_definition") %}
 
   /**
   * {{attribute_template.brief | render_markdown(code="{{@code {0}}}", paragraph="{0}")}}
@@ -49,17 +40,17 @@ class AttributesTemplate {
   * <p>Notes:
     <ul> {{attribute_template.note | render_markdown(code="{{@code {0}}}", paragraph="<li>{0}</li>", list="{0}")}} </ul>
     {%- endif %}
-    {%- if (attribute_template.stability | string())  == "StabilityLevel.DEPRECATED" %}
+    {%- if attribute_template | is_deprecated %}
   *
   * @deprecated {{attribute_template.brief | to_doc_brief}}.
     {%- endif %}
   */
-    {%- if (attribute_template.stability | string()) == "StabilityLevel.DEPRECATED"  %}
+    {%- if attribute_template | is_deprecated  %}
   @Deprecated
     {%- endif %}
-  public static final AttributeKey<{{upFirst(to_java_return_type(attribute_template.instantiated_type | string))}}> {{attribute_template.fqn | to_const_name}} = {{to_java_key_type(attribute_template.instantiated_type | string)}}("{{attribute_template.fqn}}");
+  public static final AttributeKey<{{ to_java_return_type(attribute_template.instantiated_type | string) | to_camelcase(True)}}> {{attribute_template.fqn | to_const_name}} = {{to_java_key_type(attribute_template.instantiated_type | string)}}("{{attribute_template.fqn}}");
 {%- endfor %}
-{%- for attribute in attributes if attribute.is_local and not attribute.ref %}
+{%- for attribute in attributes | select("is_definition") %}
 
   /**
   * {{attribute.brief | render_markdown(code="{{@code {0}}}", paragraph="{0}")}}
@@ -68,14 +59,14 @@ class AttributesTemplate {
   * <p>Notes:
     <ul> {{attribute.note | render_markdown(code="{{@code {0}}}", paragraph="<li>{0}</li>", list="{0}")}} </ul>
     {%- endif %}
-    {%- if (attribute.stability | string())  == "StabilityLevel.DEPRECATED" %}
+    {%- if attribute | is_deprecated %}
   *
   * @deprecated {{attribute.brief | to_doc_brief}}.
     {%- endif %}
   */
-    {%- if (attribute.stability | string()) == "StabilityLevel.DEPRECATED"  %}
+    {%- if attribute | is_deprecated  %}
   @Deprecated
     {%- endif %}
-  public static final AttributeKey<{{upFirst(to_java_return_type(attribute.instantiated_type | string))}}> {{attribute.fqn | to_const_name}} = {{to_java_key_type(attribute.instantiated_type | string)}}("{{attribute.fqn}}");
+  public static final AttributeKey<{{ to_java_return_type(attribute.instantiated_type | string) | to_camelcase(True)}}> {{attribute.fqn | to_const_name}} = {{to_java_key_type(attribute.instantiated_type | string)}}("{{attribute.fqn}}");
 {%- endfor %}
 }
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/all/FirstAttributes.java b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/all/FirstAttributes.java
new file mode 100644
index 00000000..9281a5f2
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/all/FirstAttributes.java
@@ -0,0 +1,18 @@
+package io.opentelemetry.instrumentation.api.semconv;
+
+class FirstAttributes {
+  /**
+  * short description of attr_one
+  */
+  public static final AttributeKey<Boolean> FIRST_ATTR_ONE = booleanKey("first.attr_one");
+
+  /**
+  * short description of attr_one_a
+  */
+  public static final AttributeKey<Long> FIRST_ATTR_ONE_A = longKey("first.attr_one_a");
+
+  /**
+  * this is the description of attribute template
+  */
+  public static final AttributeKeyTemplate<String> FIRST_ATTR_TEMPLATE_ONE = stringKey("first.attr_template_one");
+}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/all/SecondAttributes.java b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/all/SecondAttributes.java
new file mode 100644
index 00000000..abc59440
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/all/SecondAttributes.java
@@ -0,0 +1,8 @@
+package io.opentelemetry.instrumentation.api.semconv;
+
+class SecondAttributes {
+  /**
+  * short description of attr_two
+  */
+  public static final AttributeKey<String> SECOND_ATTR_TWO = stringKey("second.attr_two");
+}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/all/ThirdAttributes.java b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/all/ThirdAttributes.java
new file mode 100644
index 00000000..e4a9bca1
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/all/ThirdAttributes.java
@@ -0,0 +1,13 @@
+package io.opentelemetry.instrumentation.api.semconv;
+
+class ThirdAttributes {
+  /**
+  * this is the description of attribute template
+  */
+  public static final AttributeKeyTemplate<String> THIRD_ATTR_TEMPLATE_THREE = stringKey("third.attr_template_three");
+
+  /**
+  * short description of attr_three
+  */
+  public static final AttributeKey<String> THIRD_ATTR_THREE = stringKey("third.attr_three");
+}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes.yml b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes.yml
new file mode 100644
index 00000000..f4a1a6cc
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes.yml
@@ -0,0 +1,56 @@
+groups:
+  - id: first_group_id
+    type: attribute_group
+    brief: first description
+    prefix: first
+    attributes:
+      - id: attr_one
+        type: boolean
+        brief: short description of attr_one
+      - id: attr_template_one
+        type: template[string]
+        brief: >
+          this is the description of attribute template
+        examples: 'example'
+
+  - id: second_group_id
+    brief: second description
+    prefix: second
+    span_kind: client
+    extends: first_group_id
+    attributes:
+      - id: attr_two
+        type: string
+        brief: short description of attr_two
+        examples: ['example_one', 'example_two']
+  - id: first_group_part_two
+    type: resource
+    brief: first_a description
+    prefix: first
+    attributes:
+      - id: attr_one_a
+        type: int
+        brief: short description of attr_one_a
+      - ref: second.attr_two
+      - ref: third.attr_template_three
+  - id: third_group_id
+    brief: third description
+    prefix: third
+    attributes:
+      - id: attr_three
+        type: string
+        brief: short description of attr_three
+        examples: "3"
+        stability: stable
+      - id: attr_template_three
+        type: template[string]
+        brief: >
+          this is the description of attribute template
+        examples: 'example'
+  - id: forth_group_id
+    brief: forth description
+    attributes:
+      - id: attr_four
+        type: string
+        brief: short description of attr_four
+        examples: "4"
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes_and_metrics/First.java b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes_and_metrics/First.java
new file mode 100644
index 00000000..7ec15b57
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes_and_metrics/First.java
@@ -0,0 +1,19 @@
+package io.opentelemetry.instrumentation.api.semconv;
+
+import io.opentelemetry.api.metrics.Meter;
+
+class First {
+  /**
+  * short description of attr_one
+  */
+  public static final AttributeKey<Boolean> FIRST_ATTR_ONE = booleanKey("first.attr_one");
+  /**
+  * first metric description
+  * Experimental: False
+  */
+  public static final LongCounterBuilder createFirstMetric(Meter meter) {
+    return meter.counterBuilder("first.metric")
+            .setDescription("first metric description")
+            .setUnit("{one}");
+  }
+}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes_and_metrics/SecondGroup.java b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes_and_metrics/SecondGroup.java
new file mode 100644
index 00000000..20fbc0ed
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes_and_metrics/SecondGroup.java
@@ -0,0 +1,19 @@
+package io.opentelemetry.instrumentation.api.semconv;
+
+import io.opentelemetry.api.metrics.Meter;
+
+class SecondGroup {
+  /**
+  * short description of attr_two
+  */
+  public static final AttributeKey<Long> SECOND_GROUP_ATTR_TWO = longKey("second_group.attr_two");
+  /**
+  * second metric description
+  * Experimental: True
+  */
+  public static final DoubleHistogramBuilder createSecondGroupMetric(Meter meter) {
+    return meter.histogramBuilder("second_group.metric")
+            .setDescription("second metric description")
+            .setUnit("s");
+  }
+}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes_and_metrics/semconv.yml b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes_and_metrics/semconv.yml
new file mode 100644
index 00000000..3d2c670b
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes_and_metrics/semconv.yml
@@ -0,0 +1,30 @@
+groups:
+  - id: first_group_id
+    type: attribute_group
+    brief: first description
+    prefix: first
+    attributes:
+      - id: attr_one
+        type: boolean
+        brief: short description of attr_one
+
+  - id: first_metric_id
+    brief: first metric description
+    metric_name: first.metric
+    instrument: counter
+    type: metric
+    unit: "{one}"
+    stability: stable
+    extends: first_group_id
+
+  - id: second_group_id
+    brief: second metric description
+    metric_name: second_group.metric
+    type: metric
+    instrument: histogram
+    unit: "s"
+    prefix: second_group
+    attributes:
+      - id: attr_two
+        type: int
+        brief: short description of attr_two
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes_and_metrics/template b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes_and_metrics/template
new file mode 100644
index 00000000..f1cacd96
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/attributes_and_metrics/template
@@ -0,0 +1,76 @@
+{%- macro to_java_return_type(type) -%}
+  {%- if type == "string" -%}
+    String
+  {%- elif type == "string[]" -%}
+    List<String>
+  {%- elif type == "boolean" -%}
+    boolean
+  {%- elif type == "int" -%}
+    long
+  {%- elif type == "double" -%}
+    double
+  {%- else -%}
+    {{type}}
+  {%- endif -%}
+{%- endmacro %}
+{%- macro to_java_key_type(type) -%}
+  {%- if type == "string" -%}
+    stringKey
+  {%- elif type == "string[]" -%}
+    stringArrayKey
+  {%- elif type == "boolean" -%}
+    booleanKey
+  {%- elif type == "int" -%}
+    longKey
+  {%- elif type == "double" -%}
+    doubleKey
+  {%- else -%}
+    {{ type | to_camelcase(False)}}Key
+  {%- endif -%}
+{%- endmacro %}
+{%- macro to_java_instrument_builder_factory(instrument) -%}
+  {%- if instrument == "counter" -%}
+    counterBuilder
+  {%- elif instrument == "histogram" -%}
+    histogramBuilder
+  {%- elif instrument == "updowncounter" -%}
+    upDownCounterBuilder
+  {%- elif instrument == "gauge" -%}
+    gaugeBuilder
+  {%- endif -%}
+{%- endmacro %}
+{%- macro to_java_instrument_builder_type(instrument) -%}
+  {%- if instrument == "counter" -%}
+    LongCounterBuilder
+  {%- elif instrument == "histogram" -%}
+    DoubleHistogramBuilder
+  {%- elif instrument == "updowncounter" -%}
+    LongUpDownCounterBuilder
+  {%- elif instrument == "gauge" -%}
+    DoubleGaugeBuilder
+  {%- endif -%}
+{%- endmacro %}
+package io.opentelemetry.instrumentation.api.semconv;
+
+import io.opentelemetry.api.metrics.Meter;
+
+class {{ root_namespace | to_camelcase(True) }} {
+{%- for attribute in attributes_and_templates %}
+
+  /**
+  * {{attribute.brief | render_markdown(code="{{@code {0}}}", paragraph="{0}")}}
+  */
+  public static final AttributeKey<{{ to_java_return_type(attribute.instantiated_type | string) | first_up }}> {{attribute.fqn | to_const_name}} = {{to_java_key_type(attribute.instantiated_type | string)}}("{{attribute.fqn}}");
+{% endfor %}
+{%- for metric in metrics %}
+  /**
+  * {{metric.brief | to_doc_brief}}
+  * Experimental: {{ metric | is_experimental }}
+  */
+  public static final {{ to_java_instrument_builder_type(metric.instrument) }} create{{metric.metric_name | to_camelcase(True)}}(Meter meter) {
+    return meter.{{to_java_instrument_builder_factory(metric.instrument)}}("{{ metric.metric_name }}")
+            .setDescription("{{ metric.brief }}")
+            .setUnit("{{ metric.unit }}");
+  }
+{% endfor %}
+}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/no_group_prefix/FooAttributes.java b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/no_group_prefix/FooAttributes.java
new file mode 100644
index 00000000..b09c7dc5
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/no_group_prefix/FooAttributes.java
@@ -0,0 +1,13 @@
+package io.opentelemetry.instrumentation.api.semconv;
+
+class FooAttributes {
+  /**
+  * short description of attr_one
+  */
+  public static final AttributeKey<Boolean> FOO_ATTR_ONE = booleanKey("foo.attr_one");
+
+  /**
+  * short description of foo.attr_two
+  */
+  public static final AttributeKey<String> FOO_ATTR_TWO = stringKey("foo.attr_two");
+}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/no_group_prefix/OtherAttributes.java b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/no_group_prefix/OtherAttributes.java
new file mode 100644
index 00000000..9a7b38b2
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/no_group_prefix/OtherAttributes.java
@@ -0,0 +1,8 @@
+package io.opentelemetry.instrumentation.api.semconv;
+
+class OtherAttributes {
+  /**
+  * short description of bar_attr
+  */
+  public static final AttributeKey<String> BAR_ATTR = stringKey("bar_attr");
+}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/no_group_prefix/attributes_no_group_prefix.yml b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/no_group_prefix/attributes_no_group_prefix.yml
new file mode 100644
index 00000000..d2dcb72e
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/no_group_prefix/attributes_no_group_prefix.yml
@@ -0,0 +1,20 @@
+groups:
+  - id: group_with_prefix
+    type: attribute_group
+    brief: description
+    prefix: foo
+    attributes:
+      - id: attr_one
+        type: boolean
+        brief: short description of attr_one
+  - id: group_with_no_prefix
+    brief: description
+    attributes:
+      - id: foo.attr_two
+        type: string
+        brief: short description of foo.attr_two
+        examples: "foo"
+      - id: bar_attr
+        type: string
+        brief: short description of bar_attr
+        examples: "bar"
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/single_file/All.java b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/single_file/All.java
new file mode 100644
index 00000000..cd1cabeb
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/single_file/All.java
@@ -0,0 +1,34 @@
+package io.opentelemetry.instrumentation.api.semconv;
+
+class AllAttributes {
+  class FirstAttributes {
+    /**
+    * short description of attr_one
+    */
+    public static final AttributeKey<Boolean> FIRST_ATTR_ONE = booleanKey("first.attr_one");
+
+    /**
+    * short description of attr_one_a
+    */
+    public static final AttributeKey<Long> FIRST_ATTR_ONE_A = longKey("first.attr_one_a");
+
+    /**
+    * this is the description of attribute template
+    */
+    public static final AttributeKeyTemplate<String> FIRST_ATTR_TEMPLATE_ONE = stringKey("first.attr_template_one");
+  }
+  class SecondAttributes {
+    /**
+    * short description of attr_two
+    */
+    public static final AttributeKey<String> SECOND_ATTR_TWO = stringKey("second.attr_two");
+  }
+  /**
+  * short description of attr_four
+  */
+  public static final AttributeKey<String> ATTR_FOUR = stringKey("attr_four");
+  /**
+  * first metric description
+  */
+  public static final String FIRST_METRIC_NAME = "first.metric.name";
+}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/single_file/semconv.yml b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/single_file/semconv.yml
new file mode 100644
index 00000000..37d33fc2
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/single_file/semconv.yml
@@ -0,0 +1,51 @@
+groups:
+  - id: first_group_id
+    type: attribute_group
+    brief: first description
+    prefix: first
+    attributes:
+      - id: attr_one
+        type: boolean
+        brief: short description of attr_one
+      - id: attr_template_one
+        type: template[string]
+        brief: >
+          this is the description of attribute template
+        examples: 'example'
+
+  - id: second_group_id
+    brief: second description
+    prefix: second
+    span_kind: client
+    extends: first_group_id
+    attributes:
+      - id: attr_two
+        type: string
+        brief: short description of attr_two
+        examples: ['example_one', 'example_two']
+
+  - id: first_group_part_two
+    type: resource
+    brief: first_a description
+    prefix: first
+    attributes:
+      - id: attr_one_a
+        type: int
+        brief: short description of attr_one_a
+      - ref: second.attr_two
+
+  - id: forth_group_id
+    brief: forth description
+    attributes:
+      - id: attr_four
+        type: string
+        brief: short description of attr_four
+        examples: "4"
+
+  - id: first_metric_id
+    brief: first metric description
+    metric_name: first.metric.name
+    instrument: counter
+    type: metric
+    unit: "{one}"
+    extends: first_group_id
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/single_file/template_single_file b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/single_file/template_single_file
new file mode 100644
index 00000000..986ec3d2
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/single_file/template_single_file
@@ -0,0 +1,74 @@
+{%- macro to_java_return_type(type) -%}
+  {%- if type == "string" -%}
+    String
+  {%- elif type == "string[]" -%}
+    List<String>
+  {%- elif type == "boolean" -%}
+    boolean
+  {%- elif type == "int" -%}
+    long
+  {%- elif type == "double" -%}
+    double
+  {%- else -%}
+    {{type}}
+  {%- endif -%}
+{%- endmacro %}
+{%- macro to_java_key_type(type) -%}
+  {%- if type == "string" -%}
+    stringKey
+  {%- elif type == "string[]" -%}
+    stringArrayKey
+  {%- elif type == "boolean" -%}
+    booleanKey
+  {%- elif type == "int" -%}
+    longKey
+  {%- elif type == "double" -%}
+    doubleKey
+  {%- else -%}
+    {{ type | to_camelcase(False)}}Key
+  {%- endif -%}
+{%- endmacro %}
+package io.opentelemetry.instrumentation.api.semconv;
+
+class AllAttributes {
+{%- for root_ns in attributes_and_templates %}
+
+  {% if root_ns != "" %}
+  class {{root_ns | first_up}}Attributes {
+    {%- for attribute in attributes_and_templates[root_ns] %}
+
+    /**
+    * {{attribute.brief | render_markdown(code="{{@code {0}}}", paragraph="{0}")}}
+    */
+      {% if attribute | is_template %}
+    public static final AttributeKeyTemplate<{{ to_java_return_type(attribute.instantiated_type | string) | first_up}}> {{attribute.fqn | to_const_name}} = {{to_java_key_type(attribute.instantiated_type | string)}}("{{attribute.fqn}}");
+      {% else %}
+    public static final AttributeKey<{{ to_java_return_type(attribute.instantiated_type | string) | first_up }}> {{attribute.fqn | to_const_name}} = {{to_java_key_type(attribute.instantiated_type | string)}}("{{attribute.fqn}}");
+      {% endif %}
+
+    {%- endfor %}
+  }
+  {%- endif %}
+{%- endfor %}
+{# non-namespaced attributes #}
+{%- for attribute in attributes_and_templates[""] %}
+  /**
+  * {{attribute.brief | render_markdown(code="{{@code {0}}}", paragraph="{0}")}}
+  */
+    {% if attribute | is_template %}
+  public static final AttributeKeyTemplate<{{ to_java_return_type(attribute.instantiated_type | string) | first_up}}> {{attribute.fqn | to_const_name}} = {{to_java_key_type(attribute.instantiated_type | string)}}("{{attribute.fqn}}");
+    {% else %}
+  public static final AttributeKey<{{ to_java_return_type(attribute.instantiated_type | string) | first_up }}> {{attribute.fqn | to_const_name}} = {{to_java_key_type(attribute.instantiated_type | string)}}("{{attribute.fqn}}");
+    {% endif %}
+
+{%- endfor %}
+{%- for id in semconvs %}
+{%- if semconvs[id] | is_metric %}
+{% set metric = semconvs[id] %}
+  /**
+  * {{metric.brief | to_doc_brief}}
+  */
+  public static final String {{metric.metric_name | to_const_name}} = "{{metric.metric_name}}";
+{% endif %}
+{% endfor %}
+}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/stable/ThirdAttributesStable.java b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/stable/ThirdAttributesStable.java
new file mode 100644
index 00000000..71263bf3
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/stable/ThirdAttributesStable.java
@@ -0,0 +1,8 @@
+package io.opentelemetry.instrumentation.api.semconv;
+
+class ThirdAttributes {
+  /**
+  * short description of attr_three
+  */
+  public static final AttributeKey<String> THIRD_ATTR_THREE = stringKey("third.attr_three");
+}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/stable/template_only_stable b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/stable/template_only_stable
new file mode 100644
index 00000000..deb83073
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/stable/template_only_stable
@@ -0,0 +1,49 @@
+{%- macro to_java_return_type(type) -%}
+  {%- if type == "string" -%}
+    String
+  {%- elif type == "string[]" -%}
+    List<String>
+  {%- elif type == "boolean" -%}
+    boolean
+  {%- elif type == "int" -%}
+    long
+  {%- elif type == "double" -%}
+    double
+  {%- else -%}
+    {{type}}
+  {%- endif -%}
+{%- endmacro %}
+{%- macro to_java_key_type(type) -%}
+  {%- if type == "string" -%}
+    stringKey
+  {%- elif type == "string[]" -%}
+    stringArrayKey
+  {%- elif type == "boolean" -%}
+    booleanKey
+  {%- elif type == "int" -%}
+    longKey
+  {%- elif type == "double" -%}
+    doubleKey
+  {%- else -%}
+    {{ type | to_camelcase(False)}}Key
+  {%- endif -%}
+{%- endmacro %}
+{%- set stable_attributes_and_templates = attributes_and_templates | select("is_stable") | list %}
+
+{%- if stable_attributes_and_templates | count > 0 %}
+package io.opentelemetry.instrumentation.api.semconv;
+
+class {{ root_namespace | to_camelcase(True) }}Attributes {
+{%- for attribute in stable_attributes_and_templates %}
+
+  /**
+  * {{attribute.brief | render_markdown(code="{{@code {0}}}", paragraph="{0}")}}
+  */
+  {% if attribute | is_template %}
+  public static final AttributeKeyTemplate<{{ to_java_return_type(attribute.instantiated_type | string) | first_up}}> {{attribute.fqn | to_const_name}} = {{to_java_key_type(attribute.instantiated_type | string)}}("{{attribute.fqn}}");
+  {% else %}
+  public static final AttributeKey<{{ to_java_return_type(attribute.instantiated_type | string) | first_up }}> {{attribute.fqn | to_const_name}} = {{to_java_key_type(attribute.instantiated_type | string)}}("{{attribute.fqn}}");
+  {% endif %}
+{% endfor %}
+}
+{%- endif %}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/template_all b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/template_all
new file mode 100644
index 00000000..2b26c2a7
--- /dev/null
+++ b/semantic-conventions/src/tests/data/jinja/group_by_root_namespace/template_all
@@ -0,0 +1,45 @@
+{%- macro to_java_return_type(type) -%}
+  {%- if type == "string" -%}
+    String
+  {%- elif type == "string[]" -%}
+    List<String>
+  {%- elif type == "boolean" -%}
+    boolean
+  {%- elif type == "int" -%}
+    long
+  {%- elif type == "double" -%}
+    double
+  {%- else -%}
+    {{type}}
+  {%- endif -%}
+{%- endmacro %}
+{%- macro to_java_key_type(type) -%}
+  {%- if type == "string" -%}
+    stringKey
+  {%- elif type == "string[]" -%}
+    stringArrayKey
+  {%- elif type == "boolean" -%}
+    booleanKey
+  {%- elif type == "int" -%}
+    longKey
+  {%- elif type == "double" -%}
+    doubleKey
+  {%- else -%}
+    {{ type | to_camelcase(False)}}Key
+  {%- endif -%}
+{%- endmacro %}
+package io.opentelemetry.instrumentation.api.semconv;
+
+class {{ root_namespace | to_camelcase(True) }}Attributes {
+{%- for attribute in attributes_and_templates %}
+
+  /**
+  * {{attribute.brief | render_markdown(code="{{@code {0}}}", paragraph="{0}")}}
+  */
+  {% if attribute | is_template %}
+  public static final AttributeKeyTemplate<{{ to_java_return_type(attribute.instantiated_type | string) | first_up}}> {{attribute.fqn | to_const_name}} = {{to_java_key_type(attribute.instantiated_type | string)}}("{{attribute.fqn}}");
+  {% else %}
+  public static final AttributeKey<{{ to_java_return_type(attribute.instantiated_type | string) | first_up }}> {{attribute.fqn | to_const_name}} = {{to_java_key_type(attribute.instantiated_type | string)}}("{{attribute.fqn}}");
+  {% endif %}
+{% endfor %}
+}
\ No newline at end of file
diff --git a/semantic-conventions/src/tests/semconv/templating/test_code.py b/semantic-conventions/src/tests/semconv/templating/test_code.py
index 643505c9..e60eb927 100644
--- a/semantic-conventions/src/tests/semconv/templating/test_code.py
+++ b/semantic-conventions/src/tests/semconv/templating/test_code.py
@@ -1,4 +1,5 @@
-import io
+import os
+import tempfile
 
 from opentelemetry.semconv.model.semantic_convention import SemanticConventionSet
 from opentelemetry.semconv.templating.code import CodeRenderer
@@ -12,9 +13,10 @@ def test_codegen_units(test_file_path, read_test_file):
     template_path = test_file_path("jinja", "metrics", "units_template")
     renderer = CodeRenderer({}, trim_whitespace=False)
 
-    output = io.StringIO()
-    renderer.render(semconv, template_path, output, None)
-    result = output.getvalue()
+    filename = os.path.join(tempfile.mkdtemp(), "Attributes.java")
+    renderer.render(semconv, template_path, filename, None)
+    with open(filename, "r", encoding="utf-8") as f:
+        result = f.read()
 
     expected = read_test_file("jinja", "metrics", "expected.java")
 
@@ -32,9 +34,10 @@ def test_strip_blocks_enabled(test_file_path, read_test_file):
     )
     renderer = CodeRenderer({}, trim_whitespace=True)
 
-    output = io.StringIO()
-    renderer.render(semconv, template_path, output, None)
-    result = output.getvalue()
+    filename = os.path.join(tempfile.mkdtemp(), "Attributes.java")
+    renderer.render(semconv, template_path, filename, None)
+    with open(filename, "r", encoding="utf-8") as f:
+        result = f.read()
 
     expected = read_test_file(
         "jinja", "metrics", "expected_trim_whitespace_enabled.java"
@@ -53,10 +56,131 @@ def test_codegen_attribute_templates(test_file_path, read_test_file):
     template_path = test_file_path("jinja", "attribute_templates", "template")
     renderer = CodeRenderer({}, trim_whitespace=False)
 
-    output = io.StringIO()
-    renderer.render(semconv, template_path, output, None)
-    result = output.getvalue()
-
+    filename = os.path.join(tempfile.mkdtemp(), "Attributes.java")
+    renderer.render(semconv, template_path, filename, None)
+    with open(filename, "r", encoding="utf-8") as f:
+        result = f.read()
     expected = read_test_file("jinja", "attribute_templates", "expected.java")
 
     assert result == expected
+
+
+def test_codegen_attribute_root_ns(test_file_path, read_test_file):
+    semconv = SemanticConventionSet(debug=False)
+
+    semconv.parse(test_file_path("jinja", "group_by_root_namespace", "attributes.yml"))
+    semconv.finish()
+
+    template_path = test_file_path("jinja", "group_by_root_namespace", "template_all")
+    renderer = CodeRenderer({}, trim_whitespace=True)
+
+    test_path = os.path.join("group_by_root_namespace", "all")
+    tmppath = tempfile.mkdtemp()
+    renderer.render(
+        semconv,
+        template_path,
+        os.path.join(tmppath, "Attributes.java"),
+        "root_namespace",
+    )
+
+    first = read_test_file("jinja", test_path, "FirstAttributes.java")
+    check_file(tmppath, "FirstAttributes.java", first)
+
+    second = read_test_file("jinja", test_path, "SecondAttributes.java")
+    check_file(tmppath, "SecondAttributes.java", second)
+
+    third = read_test_file("jinja", test_path, "ThirdAttributes.java")
+    check_file(tmppath, "ThirdAttributes.java", third)
+
+
+def test_codegen_attribute_root_ns_stable(test_file_path, read_test_file):
+    semconv = SemanticConventionSet(debug=False)
+    semconv.parse(test_file_path("jinja", "group_by_root_namespace", "attributes.yml"))
+    semconv.finish()
+
+    test_path = os.path.join("group_by_root_namespace", "stable")
+    template_path = test_file_path("jinja", test_path, "template_only_stable")
+    renderer = CodeRenderer({}, trim_whitespace=True)
+
+    tmppath = tempfile.mkdtemp()
+    renderer.render(
+        semconv,
+        template_path,
+        os.path.join(tmppath, "Attributes.java"),
+        "root_namespace",
+    )
+
+    thirdStable = read_test_file("jinja", test_path, "ThirdAttributesStable.java")
+    check_file(tmppath, "ThirdAttributes.java", thirdStable)
+    assert not os.path.isfile(os.path.join(tmppath, "FirstAttributes.java"))
+    assert not os.path.isfile(os.path.join(tmppath, "SecondAttributes.java"))
+
+
+def test_codegen_attribute_root_ns_no_group_prefix(test_file_path, read_test_file):
+    semconv = SemanticConventionSet(debug=False)
+
+    test_path = os.path.join("group_by_root_namespace", "no_group_prefix")
+    semconv.parse(test_file_path("jinja", test_path, "attributes_no_group_prefix.yml"))
+    semconv.finish()
+
+    template_path = test_file_path("jinja", "group_by_root_namespace", "template_all")
+    renderer = CodeRenderer({}, trim_whitespace=True)
+
+    tmppath = tempfile.mkdtemp()
+    renderer.render(
+        semconv,
+        template_path,
+        os.path.join(tmppath, "Attributes.java"),
+        "root_namespace",
+    )
+
+    res = read_test_file("jinja", test_path, "FooAttributes.java")
+    check_file(tmppath, "FooAttributes.java", res)
+
+    other = read_test_file("jinja", test_path, "OtherAttributes.java")
+    check_file(tmppath, "OtherAttributes.java", other)
+
+
+def test_codegen_attribute_root_ns_single_file(test_file_path, read_test_file):
+    semconv = SemanticConventionSet(debug=False)
+
+    test_path = os.path.join("group_by_root_namespace", "single_file")
+    semconv.parse(test_file_path("jinja", test_path, "semconv.yml"))
+    semconv.finish()
+
+    template_path = test_file_path("jinja", test_path, "template_single_file")
+    renderer = CodeRenderer({}, trim_whitespace=True)
+
+    tmppath = tempfile.mkdtemp()
+    renderer.render(semconv, template_path, os.path.join(tmppath, "All.java"), None)
+
+    result = read_test_file("jinja", test_path, "All.java")
+    check_file(tmppath, "All.java", result)
+
+
+def test_codegen_attribute_root_ns_metrics(test_file_path, read_test_file):
+    semconv = SemanticConventionSet(debug=False)
+
+    test_path = os.path.join("group_by_root_namespace", "attributes_and_metrics")
+    semconv.parse(test_file_path("jinja", test_path, "semconv.yml"))
+    semconv.finish()
+
+    template_path = test_file_path("jinja", test_path, "template")
+    renderer = CodeRenderer({}, trim_whitespace=True)
+
+    tmppath = tempfile.mkdtemp()
+    renderer.render(
+        semconv, template_path, os.path.join(tmppath, ".java"), "root_namespace"
+    )
+
+    first = read_test_file("jinja", test_path, "First.java")
+    check_file(tmppath, "First.java", first)
+
+    second = read_test_file("jinja", test_path, "SecondGroup.java")
+    check_file(tmppath, "SecondGroup.java", second)
+
+
+def check_file(tmppath, actual_filename, expected_content):
+    with open(os.path.join(tmppath, actual_filename), "r", encoding="utf-8") as f:
+        actual = f.read()
+        assert actual == expected_content