Files
nanobot/nanobot/agent/tools/base.py
T

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4.2 KiB
Python

"""Base class for agent tools."""
from abc import ABC, abstractmethod
from typing import Any
class Tool(ABC):
"""
Abstract base class for agent tools.
Tools are capabilities that the agent can use to interact with
the environment, such as reading files, executing commands, etc.
"""
_TYPE_MAP = {
"string": str,
"integer": int,
"number": (int, float),
"boolean": bool,
"array": list,
"object": dict,
}
@property
@abstractmethod
def name(self) -> str:
"""Tool name used in function calls."""
pass
@property
@abstractmethod
def description(self) -> str:
"""Description of what the tool does."""
pass
@property
@abstractmethod
def parameters(self) -> dict[str, Any]:
"""JSON Schema for tool parameters."""
pass
@abstractmethod
async def execute(self, **kwargs: Any) -> str:
"""
Execute the tool with given parameters.
Args:
**kwargs: Tool-specific parameters.
Returns:
String result of the tool execution.
"""
pass
def validate_params(self, params: dict[str, Any]) -> list[str]:
"""
Lightweight JSON schema validation for tool parameters.
Returns a list of error strings (empty if valid).
Unknown params are ignored.
"""
schema = self.parameters or {}
# Default to an object schema if type is missing, and fail fast on unsupported top-level types.
if "type" not in schema:
schema = {"type": "object", **schema}
elif schema.get("type") != "object":
raise ValueError(
f"Tool parameter schemas must have top-level type 'object'; got {schema.get('type')!r}"
)
return self._validate_schema(params, schema, path="")
def _validate_schema(self, value: Any, schema: dict[str, Any], path: str) -> list[str]:
errors: list[str] = []
expected_type = schema.get("type")
label = path or "parameter"
if expected_type in self._TYPE_MAP and not isinstance(value, self._TYPE_MAP[expected_type]):
return [f"{label} should be {expected_type}"]
if "enum" in schema and value not in schema["enum"]:
errors.append(f"{label} must be one of {schema['enum']}")
if expected_type in ("integer", "number"):
if "minimum" in schema and value < schema["minimum"]:
errors.append(f"{label} must be >= {schema['minimum']}")
if "maximum" in schema and value > schema["maximum"]:
errors.append(f"{label} must be <= {schema['maximum']}")
if expected_type == "string":
if "minLength" in schema and len(value) < schema["minLength"]:
errors.append(f"{label} must be at least {schema['minLength']} chars")
if "maxLength" in schema and len(value) > schema["maxLength"]:
errors.append(f"{label} must be at most {schema['maxLength']} chars")
if expected_type == "object":
properties = schema.get("properties", {})
for key in schema.get("required", []):
if key not in value:
errors.append(f"missing required {path}.{key}" if path else f"missing required {key}")
for key, item in value.items():
if key in properties:
errors.extend(self._validate_schema(item, properties[key], f"{path}.{key}" if path else key))
if expected_type == "array":
items_schema = schema.get("items")
if items_schema:
for idx, item in enumerate(value):
errors.extend(self._validate_schema(item, items_schema, f"{path}[{idx}]" if path else f"[{idx}]"))
return errors
def to_schema(self) -> dict[str, Any]:
"""Convert tool to OpenAI function schema format."""
return {
"type": "function",
"function": {
"name": self.name,
"description": self.description,
"parameters": self.parameters,
}
}