docs: add Spanner PG Connector (spgc) section to README

README.md

@@ -188,6 +188,20 @@ class PGProxyRunner {
 See [samples/java/jdbc](samples/java/jdbc) for a small sample application that adds
 PGAdapter as a compile-time dependency and runs it together with the main application.
 
+### Spanner PG Connector (`spgc`)
+
+`spanner-pg-connector` (aliased as `spgc`) is a CLI tool designed to make working with existing
+PostgreSQL command-line tools (such as `psql` or `pg_dump`) against Cloud Spanner
+easier. It bundles PGAdapter and a minimal Java runtime—so you do not need Java or Docker installed
+locally—and automatically starts and stops PGAdapter in the background when running your tool.
+
+```shell
+spgc psql -d "projects/my-project/instances/my-instance/databases/my-database"
+```
+
+See [spanner-pg-connector/README.md](spanner-pg-connector/README.md) for installation instructions,
+environment variables, and more examples.
+
 ## Emulator
 A pre-built Docker image that contains both PGAdapter and the Spanner Emulator can be started with
 these commands:

spanner-pg-connector/README.md

@@ -0,0 +1,85 @@
+# Spanner PG Connector (`spgc`)
+
+`spanner-pg-connector` (aliased as `spgc`) is a CLI tool designed to make working with existing
+PostgreSQL command-line tools (such as `psql` or `pg_dump`) against Cloud Spanner
+easier. It bundles PGAdapter and a minimal Java runtime—so you do not need Java or Docker installed
+locally—and automatically starts PGAdapter in the background on a dynamically assigned localhost
+port, configures the standard PostgreSQL environment variables (`PGHOST` and `PGPORT`), runs your
+PostgreSQL tool against it, and stops PGAdapter when the tool exits.
+
+The PostgreSQL client tool itself (for example `psql`) is not bundled and must be installed and
+available on your `PATH`.
+
+## Installation
+
+### Linux (`x86_64`) and macOS (`aarch64` / `x86_64`)
+
+```shell
+curl -fsSL https://raw.githubusercontent.com/GoogleCloudPlatform/pgadapter/postgresql-dialect/spanner-pg-connector/install.sh | sh
+```
+
+### Windows (`x86_64`, PowerShell)
+
+```powershell
+irm https://raw.githubusercontent.com/GoogleCloudPlatform/pgadapter/postgresql-dialect/spanner-pg-connector/install.ps1 | iex
+```
+
+By default, the installer downloads the latest release into `~/.spanner-pg-connector` and adds it
+to your `PATH`. You can customize the installation with `VERSION` and `INSTALL_DIR`:
+
+<!--- {x-version-update-start:google-cloud-spanner-pgadapter:released} -->
+```shell
+curl -fsSL https://raw.githubusercontent.com/GoogleCloudPlatform/pgadapter/postgresql-dialect/spanner-pg-connector/install.sh \
+  | VERSION=v0.55.3 INSTALL_DIR="$HOME/.spanner-pg-connector" sh
+```
+<!--- {x-version-update-end} -->
+
+### Manual Installation (Without the Installer Script)
+
+You can also download and extract the release archive directly and add the extracted directory to
+your `PATH` (both `spanner-pg-connector` and `spgc` are included in the archive):
+
+<!--- {x-version-update-start:google-cloud-spanner-pgadapter:released} -->
+```shell
+VERSION=v0.55.3
+PLATFORM=linux-x64 # linux-x64, mac-aarch64, or mac-x64
+mkdir -p ~/.spanner-pg-connector
+curl -fsSL "https://artifactregistry.googleapis.com/v1/projects/cloud-spanner-pg-adapter/locations/us/repositories/spanner-pg-connector/files/spanner-pg-connector:${VERSION}:spanner-pg-connector-${PLATFORM}.tar.gz:download?alt=media" \
+  | tar -xz -C ~/.spanner-pg-connector
+export PATH="$HOME/.spanner-pg-connector:$PATH"
+```
+<!--- {x-version-update-end} -->
+
+## Usage
+
+Pass the client command and its arguments directly to `spgc` (or `spanner-pg-connector`):
+
+```shell
+spgc psql -d "projects/my-project/instances/my-instance/databases/my-database"
+```
+
+### Environment Variables
+
+You can configure the project, instance, default database, or Cloud Spanner Emulator via
+environment variables:
+
+* `GOOGLE_CLOUD_PROJECT`: Google Cloud project ID.
+* `SPANNER_INSTANCE`: Cloud Spanner instance ID.
+* `SPANNER_DATABASE`: Default Cloud Spanner database ID (used if the command does not specify `-d` or `--dbname`).
+* `SPANNER_EMULATOR_HOST`: If set, connects to the Cloud Spanner Emulator at `host:port` (for example `localhost:9010`) instead of Cloud Spanner. Must be unset when connecting to Cloud Spanner.
+
+### Examples
+
+```shell
+export GOOGLE_CLOUD_PROJECT=my-project
+export SPANNER_INSTANCE=my-instance
+
+# Start an interactive psql session
+spgc psql -d my-database
+
+# Run a single query
+spgc psql -d my-database -c "SELECT 1"
+
+# Connect to the Cloud Spanner Emulator
+SPANNER_EMULATOR_HOST=localhost:9010 spgc psql -d test-database
+```

spanner-pg-connector/install.ps1

@@ -16,7 +16,7 @@
 # PowerShell script to install Spanner PG Connector on Windows
 
 $Project = if ($env:PROJECT_ID) { $env:PROJECT_ID } else { "cloud-spanner-pg-adapter" }
-$Location = if ($env:AR_LOCATION) { $env:AR_LOCATION } else { "us-central1" }
+$Location = if ($env:AR_LOCATION) { $env:AR_LOCATION } else { "us" }
 $Repository = if ($env:AR_REPOSITORY) { $env:AR_REPOSITORY } else { "spanner-pg-connector" }
 $Package = "spanner-pg-connector"
 $Version = $env:VERSION

spanner-pg-connector/install.sh

@@ -21,7 +21,7 @@ set -e
 # Configuration (Supports env overrides)
 VERSION="${VERSION:-}"
 PROJECT_ID="${PROJECT_ID:-cloud-spanner-pg-adapter}"
-AR_LOCATION="${AR_LOCATION:-us-central1}"
+AR_LOCATION="${AR_LOCATION:-us}"
 AR_REPOSITORY="${AR_REPOSITORY:-spanner-pg-connector}"
 INSTALL_DIR="${INSTALL_DIR:-${HOME}/.spanner-pg-connector}"