The Datasette JSON API

Datasette provides a JSON API for your SQLite databases. Anything you can do through the Datasette user interface can also be accessed as JSON via the API.

To access the API for a page, either click on the .json link on that page or edit the URL and add a .json extension to it.

If you started Datasette with the --cors option, each JSON endpoint will be served with the following additional HTTP header:

Access-Control-Allow-Origin: *

This means JavaScript running on any domain will be able to make cross-origin requests to fetch the data.

If you start Datasette without the --cors option only JavaScript running on the same domain as Datasette will be able to access the API.

Different shapes

The default JSON representation of data from a SQLite table or custom query looks like this:

{
    "database": "sf-trees",
    "table": "qSpecies",
    "columns": [
        "id",
        "value"
    ],
    "rows": [
        [
            1,
            "Myoporum laetum :: Myoporum"
        ],
        [
            2,
            "Metrosideros excelsa :: New Zealand Xmas Tree"
        ],
        [
            3,
            "Pinus radiata :: Monterey Pine"
        ]
    ],
    "truncated": false,
    "next": "100",
    "next_url": "http://127.0.0.1:8001/sf-trees-02c8ef1/qSpecies.json?_next=100",
    "query_ms": 1.9571781158447266
}

The columns key lists the columns that are being returned, and the rows key then returns a list of lists, each one representing a row. The order of the values in each row corresponds to the columns.

The _shape parameter can be used to access alternative formats for the rows key which may be more convenient for your application. There are three options:

• ?_shape=arrays - "rows" is the default option, shown above
• ?_shape=objects - "rows" is a list of JSON key/value objects
• ?_shape=array - the entire response is an array of objects
• ?_shape=object - the entire response is a JSON object keyed using the primary keys of the rows

objects looks like this:

{
    "database": "sf-trees",
    ...
    "rows": [
        {
            "id": 1,
            "value": "Myoporum laetum :: Myoporum"
        },
        {
            "id": 2,
            "value": "Metrosideros excelsa :: New Zealand Xmas Tree"
        },
        {
            "id": 3,
            "value": "Pinus radiata :: Monterey Pine"
        }
    ]
}

array looks like this:

[
    {
        "id": 1,
        "value": "Myoporum laetum :: Myoporum"
    },
    {
        "id": 2,
        "value": "Metrosideros excelsa :: New Zealand Xmas Tree"
    },
    {
        "id": 3,
        "value": "Pinus radiata :: Monterey Pine"
    }
]

object looks like this:

{
    "1": {
        "id": 1,
        "value": "Myoporum laetum :: Myoporum"
    },
    "2": {
        "id": 2,
        "value": "Metrosideros excelsa :: New Zealand Xmas Tree"
    },
    "3": {
        "id": 3,
        "value": "Pinus radiata :: Monterey Pine"
    }
]

The object shape is only available for queries against tables - custom SQL queries and views do not have an obvious primary key so cannot be returned using this format.

The object keys are always strings. If your table has a compound primary key, the object keys will be a comma-separated string.

Special table arguments

The Datasette table view takes a number of special querystring arguments:

?_size=1000 or ?_size=max

Sets a custom page size. This cannot exceed the max_returned_rows limit passed to datasette serve. Use max to get max_returned_rows.

?_sort=COLUMN

Sorts the results by the specified column.

?_sort_desc=COLUMN

Sorts the results by the specified column in descending order.

?_search=keywords

For SQLite tables that have been configured for full-text search executes a search with the provided keywords.

?_search_COLUMN=keywords

Like _search= but allows you to specify the column to be searched, as opposed to searching all columns that have been indexed by FTS.

?_group_count=COLUMN

Executes a SQL query that returns a count of the number of rows matching each unique value in that column, with the most common ordered first.

?_group_count=COLUMN1&_group_count=column2

You can pass multiple _group_count columns to return counts against unique combinations of those columns.

?_timelimit=MS

Sets a custom time limit for the query in ms. You can use this for optimistic queries where you would like Datasette to give up if the query takes too long, for example if you want to implement autocomplete search but only if it can be executed in less than 10ms.

?_next=TOKEN

Pagination by continuation token - pass the token that was returned in the "next" property by the previous page.