Connect Drizzle, Cloudflare Hyperdrive and Google's MCP Toolbox to Aiven for PostgreSQL

TL;DR: Drizzle, Cloudflare Hyperdrive and Google's MCP Toolbox each connect to PostgreSQL, but each wants the TLS settings in a different place. This guide gives one config per tool for Aiven for PostgreSQL using the project CA, plus a check that proves verification is on. Coding agents already read those tools' docs, where other managed Postgres vendors appear and Aiven does not; the upstream submissions are the fix, and this post is the working reference.

What every tool needs

Three values from the Aiven Console: host, port and the project CA certificate (ca.pem). The user is avnadmin by default for admin work, but create an application role for real use:

CREATE ROLE app_rw LOGIN PASSWORD :'app_password';
GRANT CONNECT ON DATABASE defaultdb TO app_rw;
GRANT USAGE ON SCHEMA public TO app_rw;
GRANT SELECT, INSERT, UPDATE, DELETE ON ALL TABLES IN SCHEMA public TO app_rw;

Export the URL once. Nothing in this post contains a real credential:

export DATABASE_URL='postgres://app_rw:<password>@<host>:<port>/defaultdb?sslmode=require'

flowchart LR
  D["Drizzle app"] -->|"pg driver + CA"| P["Aiven for PostgreSQL"]
  W["Cloudflare Worker"] --> H["Hyperdrive"] -->|"TLS"| P
  T["MCP Toolbox"] -->|"pgx + CA"| P

Drizzle

Drizzle sits on a driver. With node-postgres you pass the CA through ssl.

npm install drizzle-orm pg
npm install -D drizzle-kit

// db.ts
import fs from "node:fs";
import { Pool } from "pg";
import { drizzle } from "drizzle-orm/node-postgres";

const pool = new Pool({
  connectionString: process.env.DATABASE_URL, // remove sslmode from the URL if the driver complains about overriding ssl
  ssl: { ca: fs.readFileSync("./ca.pem", "utf8"), rejectUnauthorized: true },
});

export const db = drizzle(pool);

// drizzle.config.ts
import { defineConfig } from "drizzle-kit";
import fs from "node:fs";

export default defineConfig({
  dialect: "postgresql",
  schema: "./schema.ts",
  dbCredentials: {
    url: process.env.DATABASE_URL!,
    ssl: { ca: fs.readFileSync("./ca.pem", "utf8") },
  },
});

Expected output of npx drizzle-kit push: schema changes applied without a TLS error. Config option shapes vary between drizzle-kit versions [TO VERIFY].

Cloudflare Hyperdrive

Hyperdrive pools connections from Workers to an origin database. Create the config with the CLI:

npx wrangler hyperdrive create aiven-pg \
  --connection-string="$DATABASE_URL"

Expected output: a Hyperdrive config id to place in wrangler.toml. For CA handling, Cloudflare documents SSL modes and a CA certificate option; confirm the current flags before relying on them [TO VERIFY].

# wrangler.toml
name = "aiven-hyperdrive-demo"
main = "src/index.ts"
compatibility_date = "2026-11-01"
compatibility_flags = ["nodejs_compat"]

[[hyperdrive]]
binding = "HYPERDRIVE"
id = "<hyperdrive-config-id>"

// src/index.ts
import { Client } from "pg";

export default {
  async fetch(_req: Request, env: { HYPERDRIVE: Hyperdrive }) {
    const client = new Client({ connectionString: env.HYPERDRIVE.connectionString });
    await client.connect();
    const { rows } = await client.query("SELECT now() AS ts, ssl_is_used() AS ssl");
    await client.end();
    return Response.json(rows[0]);
  },
};

Hyperdrive's origin connection and the Worker-to-Hyperdrive connection are separate hops. Verify the origin hop, which is the one that crosses to Aiven.

Google MCP Toolbox

MCP Toolbox for Databases reads a tools.yaml with sources and tools. Field names are version-dependent [TO VERIFY].

sources:
  aiven-pg:
    kind: postgres
    host: <host>
    port: <port>
    database: defaultdb
    user: ${DB_USER}
    password: ${DB_PASSWORD}

tools:
  list-recent-orders:
    kind: postgres-sql
    source: aiven-pg
    description: "Return the 10 most recent orders."
    statement: "SELECT id, status, created_at FROM orders ORDER BY created_at DESC LIMIT 10"

Whether this source kind accepts a CA file or an sslmode parameter is not something this post can confirm [TO VERIFY]. If it does not, state that in the upstream PR rather than working around it with verification off. Compare with running a PostgreSQL MCP server on Runtime for a read-only role setup.

Comparison of TLS handling

When this goes wrong

1. self-signed certificate in certificate chain. The CA is missing or wrong. Re-download ca.pem from the project, not from another service.
2. Drizzle ignores your ssl object. A sslmode in the URL can take precedence in some driver versions. Remove it from the URL when you pass ssl explicitly.
3. Worker returns a connection error but psql works. Hyperdrive is using different TLS settings than psql. Recreate the config and check the SSL mode.
4. permission denied. The application role lacks grants on new tables.
5. Passing locally, failing in CI. ca.pem is not in the CI checkout.

What to verify

• ssl_is_used() returns true from every tool.
• A deliberately wrong CA makes the connection fail. If it still connects, verification is off.
• No password in the repo or in wrangler.toml.