Error: connect ECONNREFUSED 127.0.0.1:5432 How to fix it.

What it means

127.0.0.1 is the machine the app runs on, and 5432 is the usual Postgres port. On your laptop, a local Postgres may be running there. On the server, nothing is. The app was told to look for a database on its own machine.

How to fix it

1. Make sure your app has a database

   Ask your agent: "Add a Postgres database to this project." Antideploy creates one beside your app and sets DATABASE_URL. See how to add a Postgres database.

2. Read DATABASE_URL

   Your code must use the variable and not a fixed address.

3. Remove the localhost fallback

   A line such as process.env.DATABASE_URL || "postgres://localhost/mydb" quietly uses localhost when the variable is missing. Remove the fallback, so a missing variable fails loudly.

const pool = new pg.Pool({
  connectionString: process.env.DATABASE_URL,
});

If you use your own database

If you use Supabase, your own Neon project or another Postgres, save its connection string as DATABASE_URL. A value you set yourself always wins, and Antideploy creates nothing.