pgjwt: JSON Web Tokens - Supabase

Supabase creates and handles JWT for you. It is built into the platform. If you use Postgres version 15 or earlier, you don't need the pgjwt extension, and it is safe to disable. For more information on how Supabase handles JWTs, read the Supabase and JWTs documentation

</Admonition> <Admonition type="deprecation">

The pgjwt extension is deprecated in projects using Postgres 17. It continues to be supported in projects using Postgres 15, but will need to dropped before those projects are upgraded to Postgres 17. See the Upgrading to Postgres 17 notes for more information.

</Admonition>

The pgjwt (Postgres JSON Web Token) extension allows you to create and parse JSON Web Tokens (JWTs) within a Postgres database. JWTs are commonly used for authentication and authorization in web applications and services.

Enable the extension

<Tabs scrollable size="small" type="underlined" defaultActiveId="dashboard" queryGroup="database-method"

Go to the Database page in the Dashboard.
Click on Extensions in the sidebar.
Search for pgjwt and enable the extension.

</TabPanel> <TabPanel id="sql" label="SQL"> ```sql -- Enable the "pgjwt" extension create extension pgjwt schema extensions;

-- Disable the "pgjwt" extension drop extension if exists pgjwt;


Even though the SQL code is `create extension`, this is the equivalent of enabling the extension.
To disable an extension you can call `drop extension`.

It's good practice to create the extension within a separate schema (like `extensions`) to keep the `public` schema clean.

</TabPanel>
</Tabs>

## API

- [`sign(payload json, secret text, algorithm text default 'HSA256')`](https://github.com/michelp/pgjwt#usage): Signs a JWT containing _payload_ with _secret_ using _algorithm_.
- [`verify(token text, secret text, algorithm text default 'HSA256')`](https://github.com/michelp/pgjwt#usage): Decodes a JWT _token_ that was signed with _secret_ using _algorithm_.

Where:

- `payload` is an encrypted JWT represented as a string.
- `secret` is the private/secret passcode which is used to sign the JWT and verify its integrity.
- `algorithm` is the method used to sign the JWT using the secret.
- `token` is an encrypted JWT represented as a string.

## Usage

Once the extension is installed, you can use its functions to create and parse JWTs. Here's an example of how you can use the `sign` function to create a JWT:
```sql
select
  extensions.sign(
    payload   := '{"sub":"1234567890","name":"John Doe","iat":1516239022}',
    secret    := 'secret',
    algorithm := 'HS256'
  );

The pgjwt_encode function returns a string that represents the JWT, which can then be safely transmitted between parties.

              sign
---------------------------------
 eyJhbGciOiJIUzI1NiIsInR5cCI6IkpX
 VCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiw
 ibmFtZSI6IkpvaG4gRG9lIiwiaWF0Ijo
 xNTE2MjM5MDIyfQ.XbPfbIHMI6arZ3Y9
 22BhjWgQzWXcXNrz0ogtVhfEd2o
(1 row)

To parse a JWT and extract its claims, you can use the verify function. Here's an example:

sql

select
  extensions.verify(
    token := 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJuYW1lIjoiRm9vIn0.Q8hKjuadCEhnCPuqIj9bfLhTh_9QSxshTRsA5Aq4IuM',
    secret    := 'secret',
    algorithm := 'HS256'
  );

Which returns the decoded contents and some associated metadata.

sql

           header            |    payload     | valid
-----------------------------+----------------+-------
 {"alg":"HS256","typ":"JWT"} | {"name":"Foo"} | t
(1 row)

Resources

Official pgjwt documentation