"supabase_functions.http_request" does not exist when called in function

[stefan-girlich]

When a user registers I want to trigger sending the corresponding email via a REST API. This is not supported by Supabase, so I want to achieve this via a webhook calling an edge function. Webhooks with edge functions are not supported in a local setup and require hard-coding URLs and credentials, so I want to use a custom function which accesses credentials from vault.

I would appreciate any hint, thanks!

Function and hook

CREATE OR REPLACE FUNCTION public.trigger_edge_function()
RETURNS TRIGGER AS $$
DECLARE
    base_url TEXT;
    service_key TEXT;
    request_url TEXT;
    auth_header jsonb;
BEGIN
    SELECT decrypted_secret
    INTO base_url
    FROM vault.decrypted_secrets
    WHERE name = 'supabase_functions_base_url';

    SELECT decrypted_secret
    INTO service_key
    FROM vault.decrypted_secrets
    WHERE name = 'service_role_key';

    request_url := base_url || '/dummy';
    auth_header := '{"Content-type":"application/json","Authorization":"Bearer ' || service_key || '"}';

    select supabase_functions.http_request(
        request_url,
        'POST',
        auth_header,
        '{}',
        '1000'
    );

    RETURN NEW;
END;
$$ LANGUAGE plpgsql
SECURITY DEFINER
SET search_path = supabase_functions, extensions, public, pg_temp;

CREATE OR REPLACE TRIGGER dummy_hook
AFTER INSERT ON public.my_users_table
FOR EACH ROW
EXECUTE FUNCTION public.trigger_edge_function();

Error

ERROR: 42883: function supabase_functions.http_request(text, unknown, jsonb, unknown, unknown) does not exist
HINT: No function matches the given name and argument types. You might need to add explicit type casts.

Further observations

The following webhook/trigger created via UI works as expected:

CREATE TRIGGER foo AFTER INSERT ON public.my_users_table FOR EACH ROW EXECUTE FUNCTION supabase_functions.http_request('http://host.docker.internal:54321/functions/v1/dummy', 'POST', '{"Content-type":"application/json"}', '{}', '1000')

The following standalone statement fails with the original error (except all fields are "unknown" in the function signature):

select supabase_functions.http_request('http://host.docker.internal:54321/functions/v1/dummy', 'POST', '{"Content-type":"application/json"}', '{}', '1000')

[GaryAustin1]

Why don't you just use the http or pg_net extension instead of trying to get the webhook code involved.

[stefan-girlich]

I was hoping to use an existing function to avoid re-writing. Thanks for the hint; I ended up copy-pasting the original function definition end it worked as expected.

[DreamwareDevelopment]

Same, Supabase can be a pain to work with sometimes.