sections: plugin_hooks:plugin-hook-startup

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id	page	ref	title	content	breadcrumbs	references
plugin_hooks:plugin-hook-startup	plugin_hooks	plugin-hook-startup	startup(datasette)	This hook fires when the Datasette application server first starts up. You can implement a regular function, for example to validate required plugin configuration: @hookimpl def startup(datasette): config = datasette.plugin_config("my-plugin") or {} assert ( "required-setting" in config ), "my-plugin requires setting required-setting" Or you can return an async function which will be awaited on startup. Use this option if you need to make any database queries: @hookimpl def startup(datasette): async def inner(): db = datasette.get_database() if "my_table" not in await db.table_names(): await db.execute_write( """ create table my_table (mycol text) """ ) return inner Potential use-cases: Run some initialization code for the plugin Create database tables that a plugin needs on startup Validate the metadata configuration for a plugin on startup, and raise an error if it is invalid If you are writing unit tests for a plugin that uses this hook and doesn't exercise Datasette by sending any simulated requests through it you will need to explicitly call await ds.invoke_startup() in your tests. An example: @pytest.mark.asyncio async def test_my_plugin(): ds = Datasette() await ds.invoke_startup() # Rest of test goes here Examples: datasette-saved-queries , datasette-init	["Plugin hooks"]	[{"href": "https://datasette.io/plugins/datasette-saved-queries", "label": "datasette-saved-queries"}, {"href": "https://datasette.io/plugins/datasette-init", "label": "datasette-init"}]