Generating TypeScript Types
How to generate types for your API and Supabase libraries.
Supabase APIs are generated from your database, which means that we can use database introspection to generate type-safe API definitions.
Generating types from project dashboard
Supabase allows you to generate and download TypeScript types directly from the project dashboard.
Generating types using Supabase CLI
The Supabase CLI is a single binary Go application that provides everything you need to setup a local development environment.
You can install the CLI via npm or other supported package managers. The minimum required version of the CLI is v1.8.1.
_10npm i supabase@">=1.8.1" --save-dev
Login with your Personal Access Token:
_10npx supabase login
Before generating types, ensure you initialize your Supabase project:
_10npx supabase init
Generate types for your project to produce the database.types.ts file:
_10npx supabase gen types typescript --project-id "$PROJECT_REF" --schema public > database.types.ts
or in case of local development:
_10npx supabase gen types typescript --local > database.types.ts
These types are generated from your database schema. Given a table public.movies, the generated types will look like:
_10create table public.movies (_10 id bigint generated always as identity primary key,_10 name text not null,_10 data jsonb null_10);
Using TypeScript type definitions
You can supply the type definitions to supabase-js like so:
Helper types for tables and joins
You can use the following helper types to make the generated TypeScript types easier to use.
Sometimes the generated types are not what you expect. For example, a view's column may show up as nullable when you expect it to be not null. Using type-fest, you can override the types like so:
To use MergeDeep, set compilerOptions.strictNullChecks to true in your tsconfig.json.
You can also override the type of an individual successful response if needed:
_10const { data } = await supabase.from('countries').select().returns<MyType>()
Type shorthands
The generated types provide shorthands for accessing tables and enums.
Response types for complex queries
supabase-js always returns a data object (for success), and an error object (for unsuccessful requests).
These helper types provide the result types from any query, including nested types for database joins.
Given the following schema with a relation between cities and countries:
_10create table countries (_10 "id" serial primary key,_10 "name" text_10);_10_10create table cities (_10 "id" serial primary key,_10 "name" text,_10 "country_id" int references "countries"_10);
We can get the nested CountriesWithCities type like this:
_15import { QueryResult, QueryData, QueryError } from '@supabase/supabase-js'_15_15const countriesWithCitiesQuery = supabase.from('countries').select(`_15 id,_15 name,_15 cities (_15 id,_15 name_15 )_15`)_15type CountriesWithCities = QueryData<typeof countriesWithCitiesQuery>_15_15const { data, error } = await countriesWithCitiesQuery_15if (error) throw error_15const countriesWithCities: CountriesWithCities = data
Update types automatically with GitHub Actions
One way to keep your type definitions in sync with your database is to set up a GitHub action that runs on a schedule.
Add the following script to your package.json to run it using npm run update-types
_10"update-types": "npx supabase gen types --lang=typescript --project-id \"$PROJECT_REF\" > database.types.ts"
Create a file .github/workflows/update-types.yml with the following snippet to define the action along with the environment variables. This script will commit new type changes to your repo every night.
_41name: Update database types_41_41on:_41 schedule:_41 # sets the action to run daily. You can modify this to run the action more or less frequently_41 - cron: '0 0 * * *'_41_41jobs:_41 update:_41 runs-on: ubuntu-latest_41 permissions:_41 contents: write_41 env:_41 SUPABASE_ACCESS_TOKEN: ${{ secrets.ACCESS_TOKEN }}_41 PROJECT_REF: <your-project-id>_41 steps:_41 - uses: actions/checkout@v2_41 with:_41 persist-credentials: false_41 fetch-depth: 0_41 - uses: actions/setup-node@v2.1.5_41 with:_41 node-version: 16_41 - run: npm run update-types_41 - name: check for file changes_41 id: git_status_41 run: |_41 echo "status=$(git status -s)" >> $GITHUB_OUTPUT_41 - name: Commit files_41 if: ${{contains(steps.git_status.outputs.status, ' ')}}_41 run: |_41 git add database.types.ts_41 git config --local user.email "41898282+github-actions[bot]@users.noreply.github.com"_41 git config --local user.name "github-actions[bot]"_41 git commit -m "Update database types" -a_41 - name: Push changes_41 if: ${{contains(steps.git_status.outputs.status, ' ')}}_41 uses: ad-m/github-push-action@master_41 with:_41 github_token: ${{ secrets.GITHUB_TOKEN }}_41 branch: ${{ github.ref }}
Alternatively, you can use a community-supported GitHub action: generate-supabase-db-types-github-action.