update_variable
Modify existing variables in Prefect workflows by updating their values or tags to maintain accurate configuration and metadata.
Instructions
Update a variable.
Args: name: The variable name value: New value tags: New tags
Returns: Details of the updated variable
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| tags | No | ||
| value | No |
Implementation Reference
- src/mcp_prefect/variable.py:111-157 (handler)The @mcp.tool decorated async function implementing the 'update_variable' MCP tool. It updates a Prefect variable by name, optionally changing its value and tags, using the Prefect client. Handles existence check, updates, and returns confirmation with updated details.
@mcp.tool async def update_variable( name: str, value: Optional[Any] = None, tags: Optional[List[str]] = None, ) -> List[Union[types.TextContent, types.ImageContent, types.EmbeddedResource]]: """ Update a variable. Args: name: The variable name value: New value (can be any JSON-serializable type) tags: New tags Returns: Confirmation message or error """ try: async with get_client() as client: from prefect.client.schemas.actions import VariableUpdate # Check if variable exists first existing_variable = await client.read_variable_by_name(name) if existing_variable is None: return [types.TextContent(type="text", text=json.dumps({"error": f"Variable '{name}' not found"}, indent=2))] # Prepare update data update_data = {} if value is not None: update_data["value"] = value if tags is not None: update_data["tags"] = tags # Create update object variable_update = VariableUpdate(name=name, **update_data) await client.update_variable(variable=variable_update) # Read the updated variable to return its details updated_variable = await client.read_variable_by_name(name) return [types.TextContent(type="text", text=json.dumps({ "message": f"Variable '{name}' updated successfully", "variable": updated_variable.model_dump() }, indent=2, default=str))] except Exception as e: return [types.TextContent(type="text", text=json.dumps({"error": str(e)}, indent=2))]