• Writable canned queries now expose a JSON API, see JSON API for writable canned queries. (#880)
• New mechanism for defining page templates with custom path parameters - a template file called pages/about/{slug}.html will be used to render any requests to /about/something. See Path parameters for pages. (#944)
• register_output_renderer() render functions can now return a Response. (#953)
• New --upgrade option for datasette install. (#945)
• New datasette --pdb option. (#962)
• datasette --get exit code now reflects the internal HTTP status code. (#947)
• New raise_404() template function for returning 404 errors. (#964)
• datasette publish heroku now deploys using Python 3.8.5
• Upgraded CodeMirror to 5.57.0. (#948)
• Upgraded code style to Black 20.8b1. (#958)
• Fixed bug where selected facets were not correctly persisted in hidden form fields on the table page. (#963)
• Renamed the default error template from 500.html to error.html.
• Custom error pages are now documented, see Custom error pages. (#965)