Add InputData.type_metadata Field Feature

Add InputData.type_metadata Field Feature

Overview

This feature adds an optional type_metadata string field to InputData that flows through to UIBlockConfiguration as data_type_metadata. The primary use case is passing tool call arguments used to load data, enabling the frontend to refresh data using the same parameters.

Core Type Changes

1. Update [libs/next_gen_ui_agent/types.py](libs/next_gen_ui_agent/types.py)

InputData TypedDict (line ~268):

• Add new optional field: type_metadata: NotRequired[str | None]
• Description: "Optional type specific metadata, passed to the renderer. For example Tool call arguments used to load these data can be passed this way."

UIBlockConfiguration Pydantic model (line ~399):

• Add new optional field: data_type_metadata: Optional[str]
• Description: "Optional type specific metadata from InputData, passed to the renderer. For example Tool call arguments used to load the data can be used by frontend to refresh data."
• Place after data_type field for logical grouping

Agent Core Logic

2. Update [libs/next_gen_ui_agent/agent.py](libs/next_gen_ui_agent/agent.py)

In construct_UIBlockConfiguration method (line ~206):

• Extract type_metadata from input_data using input_data.get("type_metadata")
• Pass it to UIBlockConfiguration constructor as data_type_metadata parameter
• Location: Around line 240 where UIBlockConfiguration is created

Agent Core Tests

3. Update [libs/next_gen_ui_agent/agent_test.py](libs/next_gen_ui_agent/agent_test.py)

Add new test in TestConstructUIBlockConfiguration class (after line ~887):

• Test name: test_construct_UIBlockConfiguration_with_type_metadata
• Create InputData with type_metadata='{"arg1": "value1"}'
• Create UIComponentMetadata with standard fields
• Call agent.construct_UIBlockConfiguration()
• Assert configuration.data_type_metadata == '{"arg1": "value1"}'

Update existing test (line ~620):

• test_construct_UIBlockConfiguration_all_info: Add type_metadata to input and assert it's preserved
• Add assertion: assert configuration.data_type_metadata == <expected_value>

Documentation

4. Update [docs/guide/input_data/index.md](docs/guide/input_data/index.md)

In "InputData object fields" section (after line ~22):

• Add new bullet point after type field description
• Content: * type_metadata - optional string with type specific metadata passed to the renderer. Example: JSON-serialized tool call arguments used to load the data, enabling frontend to refresh data with same parameters.

MCP Protocol Integration

5. Update [libs/next_gen_ui_mcp/agent.py](libs/next_gen_ui_mcp/agent.py)

In generate_ui_component tool (line ~270):

• Add new parameter after data_type (around line ~302):
  • Name: data_type_metadata
  • Type: Annotated[str | None, Field(...)]
  • Default: None
  • Description via _get_argument_description(): "Arguments of tool call used for 'data' argument. COPY of tool arguments. Do not change anything! NEVER generate this."
• Pass type_metadata=data_type_metadata when creating InputData object (line ~329)

In generate_ui_multiple_components tool (line ~372):

• Update structured_data argument description to mention the new type_metadata field
• The field should already work since InputData TypedDict is used directly

6. Update [libs/next_gen_ui_mcp/README.md](libs/next_gen_ui_mcp/README.md)

In generate_ui_component section (line ~330):

• Add new parameter documentation after data_type (around line ~341):
  • data_type_metadata (str, optional): Arguments of tool call used for 'data' argument

In generate_ui_multiple_components section (line ~231):

• Update structured_data description (line ~243) to mention: "Each object has to have id, data, type, and optionally type_metadata field."

MCP Tests

7. Update [libs/next_gen_ui_mcp/agent_test.py](libs/next_gen_ui_mcp/agent_test.py)

Add test in TestGenerateUIComponent class:

• Test name: test_data_type_metadata_passed_through
• Call generate_ui_component with data_type_metadata='{"tool": "search", "query": "test"}'
• Assert output.blocks[0].configuration.data_type_metadata == '{"tool": "search", "query": "test"}'

Update existing test (around line ~273):

• test_data_configuration: Add data_type_metadata to tool call and verify in assertion

Add test in TestGenerateUIMultipleComponents class:

• Test name: test_structured_data_with_type_metadata
• Create input_data with type_metadata field
• Call tool and verify it's preserved in output configuration

A2A Protocol Integration

8. Update [libs/next_gen_ui_a2a/agent_executor.py](libs/next_gen_ui_a2a/agent_executor.py)

In _data_selection method (line ~18):

• Extract type_metadata from metadata the same way type is extracted
• Around line ~40-42: Add check for metadata.get("type_metadata") and store in type_metadata variable
• Pass type_metadata=type_metadata when creating InputData (line ~44-49)
• For DataPart metadata (line ~54-55): Extract type_metadata similarly
• Pass to InputData creation at line ~57-59

9. Update [libs/next_gen_ui_a2a/README.md](libs/next_gen_ui_a2a/README.md)

In "Input" section (line ~176):

• Update description (around line ~180) to mention type_metadata metadata item can be provided alongside data and type

A2A Tests

10. Update [libs/next_gen_ui_a2a/agent_executor_test.py](libs/next_gen_ui_a2a/agent_executor_test.py)

Add new test:

• Test name: test_agent_executor_with_type_metadata
• Create message with TextPart containing metadata with data, type, and type_metadata
• Execute and verify ui_block.configuration.data_type_metadata matches input

Update existing test (line ~55):

• test_agent_executor_one_part_input_with_metadata: Add type_metadata to metadata and assert it appears in output

Implementation Notes

• The field is optional everywhere, so backward compatibility is maintained
• No database migrations needed (all in-memory data structures)
• The value is passed through unchanged - no transformation or validation
• Example usage: {"tool": "search_movies", "args": {"title": "Toy Story"}}
• Frontend can deserialize this JSON to make refresh calls with same parameters