SimpleTool is a lightweight Python framework designed for creating simple, strict, and explicit type-safe tools with minimal complexity. It supports both synchronous and asynchronous execution patterns, with the async functionality available in the dedicated simpletool.asyncio
module. It embodies some of the Python design Zen principles, such as "Simple is better than complex" and "Explicit is better than implicit".
- 🛠️ Under active development: Expect frequent updates, bugs, and breaking changes.
- 🤓 Check the release notes: Always check the release notes to verify if there are any breaking changes.
Simpletool is a powerful SDK that provides a structured approach to building tools with:
- Standardized input and output content types
- Automatic JSON schema generation
- Both synchronous and asynchronous support
- Environment variable handling
- Timeout management in asyncio (def. 60s)
classDiagram
class Content {
<<abstract>>
+type: Literal["text", "image", "file", "error"]
AutoValidation
}
class TextContent {
+text: str
}
class ImageContent {
+data: str
+description: str
+mime_type: str
}
class FileContent {
+data: str
+file_name: str
+mime_type: str
AutoValidation
}
class ErrorContent {
+code: int
+message: str
+data: Any
}
class SimpleTool {
<<abstract>>
+name: str
+description: str
+input_model: Type[SimpleInputModel]
+input_schema: Dict (auto generated)
+output_schema: Dict (auto generated)
+get_env(arguments: dict, prefix: str)
+run(arguments: dict) Sequence[Content]
}
class AsyncSimpleTool {
<<abstract>>
+name: str
+description: str
+input_model: Type[SimpleInputModel]
+input_schema: Dict (auto generated)
+output_schema: Dict (auto generated)
+get_env(arguments: dict, prefix: str)
+run(arguments: dict) Sequence[Content]
}
class SimpleInputModel {
<<interface>>
AutoValidation
}
SimpleTool <-- SimpleInputModel: arguments (Dict[str, Any])
SimpleTool <-- SimpleInputModel: input_model (Type[SimpleInputModel])_
AsyncSimpleTool <-- SimpleInputModel: arguments (Dict[str, Any])
AsyncSimpleTool <-- SimpleInputModel: input_model (Type[SimpleInputModel])_
Content --|> TextContent
Content --|> ImageContent
Content --|> FileContent
Content --|> ErrorContent
SimpleTool --> Content: returns Sequence[Content]
AsyncSimpleTool --> Content: returns Sequence[Content]
The SimpleTool
class provides a robust framework for building tools with the following key features:
-
Input Validation:
- Uses Pydantic models for strict input validation (SimpleInputModel)
- Automatic type checking and conversion based on Pydantic models
- SimpleInputModel have own model_json_schema (removes
titles
anddescriptions
from the schema) for easy dump to text schema
-
Output Type Management:
- Supports multiple content types (text, image, file, resource, error) for flexible output representation
- Strict output type checking allow List or Seqence of Content Types Objects
-
Dynamic Schema Generation:
- Input model needs to be defined as child of
SimpleInputModel
Type and assign toinput_model
attribute insideSimpleTool
- them magic begins and automaticly:- Automatically creates output JSON schemas (
output_schema
/output_model
) based on the definedrun
method typing - Automatically creates input JSON schemas (
input_schema
) based on the input model
- Automatically creates output JSON schemas (
- Input model needs to be defined as child of
-
Execution Models:
- Synchronous Execution: Default mode with the standard
run
method - Asynchronous Execution: Available via the
simpletool.asyncio
module with theAsyncSimpleTool
class - Configurable timeout management
- Context manager for easy resource management release
- Synchronous Execution: Default mode with the standard
-
Environment Integration:
- Easy retrieval of environment variables via the
env
parameter - Support for random API key selection from provided list of API keys
- Easy retrieval of environment variables via the
Simpletool defines several content types to standardize tool inputs and outputs:
TextContent
: Represents text-based contentImageContent
: Handles base64 encoded images with optional metadataFileContent
: Represents files with base64 encoded dataResourceContent
: Manages external resource referencesErrorContent
: Provides structured error reportingBoolContents
: Simple boolean content type
Install the package using pip:
pip install simpletool
from simpletool import SimpleTool, SimpleInputModel, Sequence, Field
from simpletool.types import TextContent
class InputModel(SimpleInputModel):
name: str = Field(description="Name to greet")
class MyTool(SimpleTool):
name = "greeting_tool"
description = "A simple greeting tool"
input_model = InputModel
def run(self, arguments: dict) -> Sequence[TextContent]:
# Validation and parsing of input arguments
arg: InputModel = InputModel(**arguments)
return [TextContent(text=f"Hello, {arg.name}!")]
from simpletool.asyncio import AsyncSimpleTool
from simpletool import SimpleInputModel, Sequence, Field
from simpletool.types import TextContent
class InputModel(SimpleInputModel):
name: str = Field(description="Name to greet")
class MyAsyncTool(AsyncSimpleTool):
name = "greeting_tool"
description = "A simple greeting tool"
input_model = InputModel
async def run(self, arguments: dict) -> Sequence[TextContent]:
# Validation and parsing of input arguments
arg: InputModel = InputModel(**arguments)
return [TextContent(text=f"Hello, {arg.name}!")]
- Inherit Tool model from
SimpleTool
(orAsyncSimpleTool
for async tools) - Define an
input_model
using Pydantic (SimpleInputModel
) - Implement the
run
method (synchronous or asynchronous depending on your base class) - Return a list/sequence of content types
- Use the
env
parameter for environment variables
Contributions are welcome! Please follow Python best practices and maintain the existing code style.
This project is licensed under the MIT License.
Contributions are welcome! Please submit a pull request with your changes.