dograh/api/services/workflow/tools/custom_tool.py
Abhishek 3e55af9256
feat: user defined custom tools as part of workflow execution (#94)
* feat: add custom tools functionality

* Show tools in nodes

* integrate tool calling with pipeline engine
2026-01-02 13:11:02 +05:30

180 lines
5.5 KiB
Python

"""Custom tool execution for user-defined HTTP API tools."""
import re
from typing import Any, Dict, Optional
import httpx
from loguru import logger
from api.db import db_client
from api.utils.credential_auth import build_auth_header
# Map tool parameter types to JSON schema types
TYPE_MAP = {
"string": "string",
"number": "number",
"boolean": "boolean",
}
def tool_to_function_schema(tool: Any) -> Dict[str, Any]:
"""Convert a ToolModel to an LLM function schema.
Args:
tool: ToolModel instance with name, description, and definition
Returns:
Function schema dict compatible with OpenAI/Anthropic function calling
"""
definition = tool.definition or {}
config = definition.get("config", {})
parameters = config.get("parameters", []) or []
# Build properties and required list from parameters
properties = {}
required = []
for param in parameters:
param_name = param.get("name", "")
param_type = param.get("type", "string")
param_desc = param.get("description", "")
param_required = param.get("required", True)
if not param_name:
continue
properties[param_name] = {
"type": TYPE_MAP.get(param_type, "string"),
"description": param_desc,
}
if param_required:
required.append(param_name)
# Sanitize tool name for function name (lowercase, underscores only)
function_name = re.sub(r"[^a-z0-9_]", "_", tool.name.lower())
# Remove consecutive underscores and trim
function_name = re.sub(r"_+", "_", function_name).strip("_")
return {
"type": "function",
"function": {
"name": function_name,
"description": tool.description or f"Execute {tool.name} tool",
"parameters": {
"type": "object",
"properties": properties,
"required": required,
},
},
"_tool_uuid": tool.tool_uuid,
}
async def execute_http_tool(
tool: Any,
arguments: Dict[str, Any],
call_context_vars: Optional[Dict[str, Any]] = None,
organization_id: Optional[int] = None,
) -> Dict[str, Any]:
"""Execute an HTTP API tool.
Args:
tool: ToolModel instance
arguments: Arguments passed by the LLM (parameter name -> value)
call_context_vars: Additional context variables from the call (unused for now)
organization_id: Organization ID for credential lookup
Returns:
Result dict with response data or error
"""
definition = tool.definition or {}
config = definition.get("config", {})
# Get HTTP method and URL
method = config.get("method", "POST").upper()
url = config.get("url", "")
# Get headers from config
headers = dict(config.get("headers", {}) or {})
# Add auth header if credential is configured
credential_uuid = config.get("credential_uuid")
if credential_uuid and organization_id:
try:
credential = await db_client.get_credential_by_uuid(
credential_uuid, organization_id
)
if credential:
auth_header = build_auth_header(credential)
headers.update(auth_header)
logger.debug(f"Applied credential '{credential.name}' to tool request")
else:
logger.warning(
f"Credential {credential_uuid} not found for tool '{tool.name}'"
)
except Exception as e:
logger.error(f"Failed to fetch credential for tool '{tool.name}': {e}")
# Get timeout
timeout_ms = config.get("timeout_ms", 5000)
timeout_seconds = timeout_ms / 1000
# Build request: JSON body for POST/PUT/PATCH, query params for GET/DELETE
body = None
params = None
if method in ("POST", "PUT", "PATCH"):
body = arguments
elif method in ("GET", "DELETE") and arguments:
params = arguments
logger.info(
f"Executing custom tool '{tool.name}' ({tool.tool_uuid}): {method} {url}"
)
logger.debug(f"Request body: {body}, params: {params}")
try:
async with httpx.AsyncClient(timeout=timeout_seconds) as client:
response = await client.request(
method=method,
url=url,
headers=headers,
json=body,
params=params,
)
# Try to parse JSON response
try:
response_data = response.json()
except Exception:
response_data = {"raw_response": response.text}
result = {
"status": "success",
"status_code": response.status_code,
"data": response_data,
}
logger.debug(
f"Custom tool '{tool.name}' completed with status {response.status_code}"
)
return result
except httpx.TimeoutException:
logger.error(f"Custom tool '{tool.name}' timed out after {timeout_seconds}s")
return {
"status": "error",
"error": f"Request timed out after {timeout_seconds} seconds",
}
except httpx.RequestError as e:
logger.error(f"Custom tool '{tool.name}' request failed: {e}")
return {
"status": "error",
"error": f"Request failed: {str(e)}",
}
except Exception as e:
logger.error(f"Custom tool '{tool.name}' execution failed: {e}")
return {
"status": "error",
"error": f"Tool execution failed: {str(e)}",
}