Postgres Bindings

JavaScript/TypeScript native W7S backends can declare managed Postgres bindings in w7s.json. These bindings let backend modules connect to external Postgres databases through the W7S-managed connection layer.

W7S currently binds existing managed Postgres configs by ID. It does not create those configs or rotate database credentials yet.

Working example repository:

• w7s-io/example-postgres-binding: backend source, build workflow, runtime compatibility metadata, and manual deploy workflow for a managed Postgres binding.

Create a Postgres binding config

Create or request the managed Postgres binding config from the W7S operator, then copy its ID:

postgres://user:password@host:5432/database

Declare the binding

Add bindings.hyperdrive to w7s.json:

w7s.json

{
  "bindings": {
    "hyperdrive": [
      {
        "binding": "DB",
        "id": "postgres-binding-id"
      }
    ]
  }
}

W7S exposes this binding to the backend at env.DB.

Use it from a backend

Most Postgres clients need to be bundled in CI before deployment. A typical backend uses the managed connection string:

backend/index.ts

import postgres from "postgres";

type Env = {
  DB: {
    connectionString: string;
  };
};

export default {
  async fetch(_request: Request, env: Env) {
    const sql = postgres(env.DB.connectionString);
    const rows = await sql`select now() as now`;

    return Response.json({
      now: rows[0]?.now
    });
  }
};

Because W7S does not install dependencies or bundle apps during deploy, run your build in GitHub Actions before w7s-io/w7s-cloud@v1.

Compatibility flags

Many Postgres drivers require Node.js compatibility in edge runtimes. If your build emits dist/server/index.js, include runtime compatibility metadata with the backend output:

runtime compatibility metadata

{
  "compatibility_flags": ["nodejs_compat_v2"]
}

W7S reads supported compatibility flags from the backend output when uploading the backend module.

Limitations

• Managed Postgres bindings require a JavaScript or TypeScript native backend deployment.
• W7S does not create or update managed Postgres configs yet.
• W7S does not manage origin database credentials.
• The shared example is manual-deploy because a useful live smoke test requires a real external database and managed Postgres binding config ID.