feat(samples): add community templates sample app with version 0.1 templates and interactive studio

agent_sdks/python/a2ui_agent/README.md

@@ -28,6 +28,13 @@ The following directories contain the base protocol logic, parsing, and schema o
 - **`provider.py`**: Implementation of `BasicCatalog` for handling the basic
   A2UI components.
 
+## Experimental Templates (`src/a2ui/inference_formats/experimental/template`)
+
+- **`models.py`**: Typed models (`StaticTemplate`, `DynamicTemplate`, `Param`, `ParamType`, AST expressions) and signature-based parameter inference.
+- **`processor.py`**: `TemplateProcessor` for generating synthetic inference catalogs and expanding template invocations into A2UI primitives.
+- **`format.py`**: `TemplateInferenceFormat` integrating template-aware prompt generation and synchronous parsing.
+- Reference schema: Located at `specification/proposals/templates/schema/template_definition.json`.
+
 ## A2A (`src/a2ui/a2a`)
 
 - **`extension.py`**: Utilities for managing the A2UI extension URI and activation logic.

agent_sdks/python/a2ui_agent/pyproject.toml

@@ -25,7 +25,9 @@ dependencies = [
   "google-adk>=1.28.1",
   "google-genai>=1.27.0",
   "httpx>=0.27.0",
-  "jsonschema>=4.0.0"
+  "jsonschema>=4.0.0",
+  "nest-asyncio>=1.6.0",
+  "pyyaml>=6.0"
 ]
 
 [project.scripts]
@@ -65,4 +67,5 @@ dev = [
     "antlr4-tools>=0.2.1",
     "hatchling>=1.30.1",
     "types-jsonschema",
+    "types-pyyaml",
 ]

agent_sdks/python/a2ui_agent/src/a2ui/inference_formats/experimental/template/README.md

@@ -0,0 +1,124 @@
+# A2UI Python Template Engine (`a2ui.inference_formats.experimental.template`)
+
+The `a2ui.inference_formats.experimental.template` package provides server-side UI template expansion and synthetic catalog compilation for the A2UI Python Agent SDK.
+
+For the language-agnostic protocol specification, JSON schemas, and multi-platform design guidelines, see:
+👉 **[`specification/proposals/templates/README.md`](../../../../../../../../specification/proposals/templates/README.md)**
+
+---
+
+## Python API Reference
+
+### 1. `StaticTemplate`
+
+Represents a declarative, immutable UI template parsed from YAML or a dictionary.
+
+```python
+from a2ui.inference_formats.experimental.template import StaticTemplate
+
+# Load from single or multi-document ('---') YAML files
+templates = StaticTemplate.from_yaml_file("path/to/templates.yaml")
+
+# Load directly from a YAML string
+single_template = StaticTemplate.from_yaml(yaml_string)
+```
+
+### 2. `DynamicTemplate`
+
+Extends templates with server-side execution. Supports two modes:
+
+#### A. Data-Binding Mode (`resolver + layout`)
+
+Takes a lookup argument (e.g. `employeeId`), runs a resolver callback, and injects the result into a static YAML presentation layout:
+
+```python
+from a2ui.inference_formats.experimental.template import DynamicTemplate, StaticTemplate
+
+layout = StaticTemplate.from_yaml_file("salary_card.yaml")[0]
+
+def resolve_compensation(employeeId: str) -> dict:
+    return db.fetch_employee_salary(employeeId)
+
+dynamic_salary = DynamicTemplate(
+    template_id="EmployeeSalaryCard",
+    resolver=resolve_compensation,
+    layout=layout,
+    description="Verified compensation. Pass only employeeId.",
+    sample_data={"employeeId": "emp_101"},
+)
+```
+
+#### B. Programmatic Render Mode (`render`)
+
+Bypasses static layouts and runs native Python logic (loops, arithmetic, conditionals) returning a component AST:
+
+```python
+from a2ui.inference_formats.experimental.template import DynamicTemplate
+
+def render_server_health(serverId: str, includeDisks: bool = True) -> dict:
+    status_icon = "check_circle" if serverId == "srv_01" else "warning"
+    return {
+        "component": "Card",
+        "child": {
+            "component": "Column",
+            "children": [
+                {"component": "Text", "text": f"Server {serverId}", "variant": "h3"},
+                {"component": "Icon", "name": status_icon},
+            ]
+        }
+    }
+
+server_template = DynamicTemplate(
+    template_id="ServerHealthCard",
+    render=render_server_health,
+    description="Live server diagnostics.",
+    sample_data={"serverId": "srv_01", "includeDisks": True},
+)
+```
+
+### 3. `TemplateProcessor`
+
+The core synchronous template expansion and catalog generation engine.
+
+```python
+from a2ui.inference_formats.experimental.template import (
+    TemplateProcessor,
+    TemplateId,
+    A2UIComponentList,
+)
+
+processor = TemplateProcessor(templates=[user_profile, dynamic_salary, server_template])
+
+# 1. Synthesize virtual A2UI component catalog for LLMs
+synthetic_catalog = processor.generate_inference_catalog()
+
+# 2. Synchronously expand template invocations into standard A2UI primitives
+expanded_components: A2UIComponentList = processor.expand_template(
+    instance_id="root",
+    template_id="ServerHealthCard",
+    passed_params={"serverId": "srv_01", "includeDisks": True},
+)
+```
+
+### 4. `TemplateInferenceFormat`
+
+Integrates templates seamlessly with LLM prompting and parsing.
+
+```python
+from a2ui.inference_formats.experimental.template import TemplateInferenceFormat
+
+format_instance = TemplateInferenceFormat(
+    templates=[user_profile, dynamic_salary],
+    surface_id="main",
+    version="0.9.1",
+)
+
+# Generate system prompt instructions with template signatures
+system_prompt = format_instance.prompt_generator.generate(
+    role_description="You are an A2UI assistant.",
+    include_schema=True,
+)
+
+# Parse response & synchronously expand templates to standard A2UI messages
+messages = format_instance.parser.parse_response(llm_response_text)
+```

agent_sdks/python/a2ui_agent/src/a2ui/inference_formats/experimental/template/__init__.py

@@ -0,0 +1,81 @@
+# Copyright 2024 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""A2UI Template module providing parameterized component expansion and dynamic resolvers."""
+
+from .models import (
+    Template,
+    StaticTemplate,
+    DynamicTemplate,
+    dynamic_template,
+    BaseTemplate,
+    Param,
+    ParamType,
+    ParamRef,
+    Concat,
+    FormatExpr,
+    TemplateLoop,
+    TemplateComponent,
+    normalize_a2ui_type_to_jsonschema,
+    flatten_nested_layout,
+    normalize_node,
+)
+from .processor import (
+    TemplateProcessor,
+    TemplateId,
+    InstanceId,
+    ComponentId,
+    ParamPath,
+    TemplateParams,
+    TemplateNodeDict,
+    A2UIComponent,
+    A2UIComponentList,
+    A2UIMessage,
+    CatalogSchema,
+    JSONSchemaDict,
+)
+from .format import TemplateInferenceFormat, A2uiTemplateManager, TemplateParser
+
+__all__ = [
+    "Template",
+    "StaticTemplate",
+    "DynamicTemplate",
+    "dynamic_template",
+    "BaseTemplate",
+    "Param",
+    "ParamType",
+    "ParamRef",
+    "Concat",
+    "FormatExpr",
+    "TemplateLoop",
+    "TemplateComponent",
+    "normalize_a2ui_type_to_jsonschema",
+    "flatten_nested_layout",
+    "normalize_node",
+    "TemplateProcessor",
+    "TemplateId",
+    "InstanceId",
+    "ComponentId",
+    "ParamPath",
+    "TemplateParams",
+    "TemplateNodeDict",
+    "A2UIComponent",
+    "A2UIComponentList",
+    "A2UIMessage",
+    "CatalogSchema",
+    "JSONSchemaDict",
+    "TemplateInferenceFormat",
+    "A2uiTemplateManager",
+    "TemplateParser",
+]