# AlloyDB

> Run AlloyDB locally with LocalCloud: connection settings, supported workflows, known limits, and code examples.
>
> Source: https://local.cloud/services/alloydb/

AlloyDB is Google Cloud’s PostgreSQL-compatible database service. LocalCloud combines AlloyDB resource metadata with a local PostgreSQL connection for application tests.

## Typical uses

Use when an application depends on PostgreSQL SQL, drivers, and transactions, and its production deployment targets AlloyDB. Exercise resource provisioning alongside SQL application tests locally.

Examples

- PostgreSQL application backends
- Database provisioning and connection tests

Connection

Environment variable

`ALLOYDB_EMULATOR_HOST=localhost:5380`

Runtime details

- **Endpoints:** gRPC :5380
- **Minimum tier:** Community
- **Persistence:** metadata
- **Implementation:** Local Facade

## Example usage

Service ID: `alloydb`. Starts by default. Use an already running LocalCloud runtime for the examples below.

Export the local project and mapped endpoints in your client process, then use the client settings below. [First-time setup](https://local.cloud/docs/)

```bash
# Export GOOGLE_CLOUD_PROJECT and ALLOYDB_EMULATOR_HOST
eval "$(localcloud env)"
```

REST gateway examples use the generated HTTP address in `SERVICE_USAGE_EMULATOR_HOST`; native SDKs can use a different protocol.

Java · REST:

### Java · REST

### List database clusters

List database clusters; AlloyDB gives PostgreSQL applications a managed relational database model.

Call the Google Cloud REST API with the JDK HTTP client. Requires JDK 17+. Results reflect resources already created in your local project.

Discovery check · reads existing local state.

#### Save as Hello.java

```java
import java.net.URI;
import java.net.http.*;
import java.time.Duration;
import java.util.Objects;

public class Hello {
  public static void main(String[] args) throws Exception {
    var project = Objects.requireNonNull(System.getenv("GOOGLE_CLOUD_PROJECT"));
    var endpoint = Objects.requireNonNull(System.getenv("SERVICE_USAGE_EMULATOR_HOST"));
    var url = URI.create(endpoint.replaceAll("/+$", "") + "/v1/projects/" + project + "/locations/us-central1/clusters");
    var request = HttpRequest.newBuilder(url).timeout(Duration.ofSeconds(30)).GET().build();
    var client = HttpClient.newBuilder().connectTimeout(Duration.ofSeconds(10)).build();
    var response = client.send(request, HttpResponse.BodyHandlers.ofString());
    if (response.statusCode() >= 400) {
      throw new IllegalStateException(response.statusCode() + ": " + response.body());
    }
    System.out.println(response.body());
  }
}
```

#### Run the example

```bash
java Hello.java
```

#### Verify the result

The request succeeds. An empty list or no printed rows is valid before matching resources exist. Continue with the documented workflows for a resource test.

gcloud CLI:

### gcloud CLI

### List database clusters

List database clusters; AlloyDB gives PostgreSQL applications a managed relational database model.

Use the Google Cloud CLI against the local gateway in its default open IAM mode. Run these exports in a terminal dedicated to local development.

Discovery check · reads existing local state.

#### Configure gcloud CLI

```bash
: "${SERVICE_USAGE_EMULATOR_HOST:?Export the LocalCloud environment first}"
export CLOUDSDK_CORE_PROJECT="${GOOGLE_CLOUD_PROJECT:?Export the LocalCloud environment first}"
export CLOUDSDK_AUTH_DISABLE_CREDENTIALS=true
export CLOUDSDK_API_ENDPOINT_OVERRIDES_ALLOYDB="${SERVICE_USAGE_EMULATOR_HOST%/}/"
```

#### Run in your terminal

```bash
gcloud alloydb clusters list --region=us-central1
```

#### Verify the result

The request succeeds. An empty list or no printed rows is valid before matching resources exist. Continue with the documented workflows for a resource test.

Verify a resource workflow by creating isolated state, performing the operation, and reading the result back. Run cleanup even after a failure; delete only test-owned resources.

Connection failed? Check `localcloud status --verbose`, enabled services, and client exports. Stop accidental Google Cloud calls; correct local routing before retrying.

## Documented workflows

- ### Cluster/instance CRUD and local PostgreSQL access

    Create a cluster and instance, then connect to the local PostgreSQL data path. Apply a small schema and assert application reads and writes.

- ### Configuration patching, flag discovery, and backup metadata restore

    Patch cluster configuration and inspect flag discovery. Create backup metadata and restore its configuration, checking resource fields rather than expecting database contents to be restored.

## Service boundaries

- Backup restore applies metadata; advanced engine behavior and replicas are unavailable
- Managed regional failover requires Google Cloud

## Code examples and integrations

- [Build an integration test loop](https://local.cloud/gcp-integration-testing/): Start the runtime, verify readiness, exercise your SDK, and clean up test state.

Agent testing

## Use AlloyDB with an AI agent

Before the agent changes application logic, have it create local AlloyDB state, read it back with the project SDK, and note which feature the check covered. That first local call catches accidental production routing and needs no GCP account, service-account key, or billing project.

### Configure this repo

```
Set up this repository to use LocalCloud for local GCP development. First read https://local.cloud/ai/agents.md, then inspect this repo, identify the GCP services and SDK language, configure emulator environment variables, and run the narrowest integration test against localhost. Do not use real GCP credentials or production endpoints.
```

Production endpoints, auth, IAM, quotas, regional behavior, and final release validation still need the target Google Cloud project.

[Agent resources](https://local.cloud/ai/) has more prompts and the AGENTS.md template.

## Related guides

- [Compatibility](https://local.cloud/compatibility/): compare all 27 service guides.
- [Configuration](https://local.cloud/docs/configuration/): service selection and runtime settings.
- [Official AlloyDB documentation](https://docs.cloud.google.com/alloydb/docs/overview): service concepts and cloud usage.