tool_schema_generator 0.2.0

Annotations and a code generator for automatic LLM tool schema generation. Mark functions with @Tool() and parameters with @Describe() to generate JSON Schema Draft 2020-12 definitions and a type-safe [...]

0.2.0

New: Tool Dispatcher & Subclass Schema Getters

This release adds a complete dispatcher layer so you can invoke tools by name with the raw argument maps your LLM returns — with no boilerplate.

• Named Schema Getters: The code generator now emits a private subclass of ToolRegistry that provides strongly-typed getters for each tool schema. You can now use toolRegistry.myToolName instead of manually importing the <myToolName>ToolSchema constant.
• Added schemaFor(String name) and allSchemas to ToolRegistry. You can now pass toolRegistry.allSchemas directly to your LLM framework.

New public API

ToolRegistry

• Future<ToolResult> call(String name, Map<String, dynamic> args) — dispatch a tool call
• Future<ToolResult>? callOrNull(String name, Map<String, dynamic> args) — returns null for unknown tools instead of throwing
• bool contains(String name) — check if a tool is registered
• Iterable<String> get toolNames — enumerate registered tools

ToolResult (sealed class)

• ToolSuccess(dynamic value) — tool ran successfully
• ToolError({String code, String message, String? field, dynamic expected, dynamic actual}) — structured, machine-readable failure

Error codes emitted by ToolError:

Code	Trigger
UNKNOWN_TOOL	No tool with that name is registered (throws UnknownToolException)
INVALID_ARGUMENT	LLM sent a wrong type for a parameter
MISSING_ARGUMENT	A required parameter was absent
INTERNAL_ERROR	Unexpected exception inside the tool function

ToolArgumentException — thrown internally by generated parsers; caught at registry boundary.

UnknownToolException — thrown by ToolRegistry.call() when the name is not registered. Includes available list.

Generator changes

The generator now emits, alongside each schema constant, a final toolRegistry = ToolRegistry({...}) containing a handler closure per tool. Handlers:

• Cast every parameter safely with as Type (or (num).toDouble() for double)
• Respect nullable/optional params with ?? defaultValue fallbacks
• Generate _parseEnum<T> helpers for enum-typed params (deduplicated)
• Generate _parse<ClassName> helpers for custom class params (user-defined only)
• Wrap all invocations in Future.sync(...) for uniform Future<dynamic> return type

Usage

final result = await toolRegistry.call(toolCall.name, toolCall.arguments);
switch (result) {
  case ToolSuccess(:final value): submitToModel(value.toString());
  case ToolError(:final code, :final message): print('$code: $message');
}

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0.1.0

• Initial Release: First version of tool_schema_generator.

• Initial Release: First version of tool_schema_generator.

• Introduced @Tool() and @Describe() annotations for Dart functions.

• Full integration with build_runner and source_gen:combining_builder (works seamlessly alongside json_serializable).

• Support for primitive types, enums, nullables, lists, maps, and nested classes.

• Generates JSON Schema Draft 2020-12 compatible maps.