Claude Code on Google Vertex AI

gclaude.md

gclaude — Claude Code on Google Vertex AI

This gist contains setup-gclaude.sh, a small installer that:

• Writes ~/.config/gclaude/env with your GCP project, region, and service-account key path
• Installs gclaude to ~/.local/bin, a wrapper around the claude CLI with Vertex AI enabled (CLAUDE_CODE_USE_VERTEX=1, etc.)

You run gclaude the same way you would claude; authentication uses a service account JSON key (not the Anthropic API key flow).

Docs: Claude Code on Google Vertex AI

Install

curl -fsSL 'https://bit.ly/4sWf5Ua' | bash

(That short link redirects to the raw setup-gclaude.sh on gist.github.com.)

Ensure ~/.local/bin is on your PATH if the script reminds you to add it.

What you need

• Claude Code (claude on your PATH)
• Python 3 (to validate the JSON key)
• A GCP project with Vertex AI / Claude access, and a service account key JSON with something like roles/aiplatform.user

The script will ask for your project ID, region (default global), and how to provide the key (file path, paste, or macOS clipboard).

After setup

gclaude

Same flags and behavior as claude, using Vertex via your saved config.

setup-gclaude.sh

#!/usr/bin/env bash
# Interactive bootstrap for gclaude (Claude Code + Vertex AI).
# Run: bash setup-gclaude.sh
# Remote: curl -fsSL 'RAW_URL' | bash
# Prompts use /dev/tty so keyboard input works even when stdin is the script pipe.
# See GIST.md for gist.github.com.
# Docs: https://code.claude.com/docs/en/google-vertex-ai
set -euo pipefail

CONFIG_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/gclaude"
LOCAL_BIN="${HOME}/.local/bin"
KEY_FILE="${CONFIG_DIR}/gcp-key.json"
ENV_FILE="${CONFIG_DIR}/env"
GCLAUDE_BIN="${LOCAL_BIN}/gclaude"

die() {
    echo "setup-gclaude: $*" >&2
    exit 1
}

# Read from /dev/tty so prompts work when stdin is a pipe (e.g. curl | bash).
read_tty() {
    read -r "$@" </dev/tty
}

validate_json_file() {
    python3 -c 'import json, sys; json.load(open(sys.argv[1], encoding="utf-8"))' "$1" ||
        die "invalid JSON: $1"
}

prompt_yes() {
    local reply
    read_tty -p "$1 [y/N] " reply
    case "${reply}" in
        [yY]|[yY][eE][sS]) return 0 ;;
        *) return 1 ;;
    esac
}

echo "=== gclaude bootstrap ==="
echo

read_tty -p "GCP project ID (ANTHROPIC_VERTEX_PROJECT_ID): " PROJECT_ID
[[ -n "${PROJECT_ID}" ]] || die "project ID is required"

read_tty -p "Vertex region [global]: " REGION
REGION="${REGION:-global}"

echo
echo "Service account JSON key — choose how to provide it:"
echo "  1) Path to a file on disk (recommended)"
echo "  2) Paste in this terminal (full JSON; end with Ctrl-D, often twice if the cursor is mid-line)"
if command -v pbpaste >/dev/null 2>&1; then
    echo "  3) Use macOS clipboard (copy the JSON in another app first, then choose 3)"
fi
read_tty -p "Choice [1]: " KEY_MODE
KEY_MODE="${KEY_MODE:-1}"

mkdir -p "${CONFIG_DIR}"

case "${KEY_MODE}" in
    1)
        read_tty -p "Absolute path to JSON key file: " KEY_PATH
        [[ -n "${KEY_PATH}" ]] || die "path is required for option 1"
        [[ -f "${KEY_PATH}" ]] || die "file not found: ${KEY_PATH}"
        cp "${KEY_PATH}" "${KEY_FILE}"
        ;;
    2)
        echo
        echo "Paste the entire JSON key below, then press Ctrl-D to finish."
        # Read from /dev/tty so a multi-line paste is never split across bash \`read\` + \`cat\`, and Ctrl-D ends input on the terminal.
        python3 - "${KEY_FILE}" <<'PY'
import sys

path = sys.argv[1]
try:
    with open("/dev/tty", encoding="utf-8", errors="replace") as tty:
        data = tty.read()
except OSError:
    # No controlling tty (e.g. CI); read pasted input from stdin instead.
    data = sys.stdin.read()
if not data.strip():
    print("setup-gclaude: no key content received (empty after Ctrl-D)", file=sys.stderr)
    sys.exit(1)
open(path, "w", encoding="utf-8").write(data)
PY
        ;;
    3)
        command -v pbpaste >/dev/null 2>&1 || die "pbpaste not available; use option 1 or 2"
        pbpaste >"${KEY_FILE}" || die "pbpaste failed"
        ;;
    *)
        die "invalid choice: ${KEY_MODE}"
        ;;
esac

validate_json_file "${KEY_FILE}"
chmod 600 "${KEY_FILE}"

if [[ -f "${ENV_FILE}" ]] && ! prompt_yes "Overwrite existing ${ENV_FILE}?"; then
    die "aborted"
fi

mkdir -p "${CONFIG_DIR}"
{
    echo '# Generated by setup-gclaude.sh — https://code.claude.com/docs/en/google-vertex-ai'
    printf 'ANTHROPIC_VERTEX_PROJECT_ID=%q\n' "${PROJECT_ID}"
    printf 'GOOGLE_APPLICATION_CREDENTIALS=%q\n' "${KEY_FILE}"
    printf 'CLOUD_ML_REGION=%q\n' "${REGION}"
} >"${ENV_FILE}"
chmod 600 "${ENV_FILE}"

if [[ -f "${GCLAUDE_BIN}" ]] && ! prompt_yes "Overwrite existing ${GCLAUDE_BIN}?"; then
    die "aborted before installing gclaude"
fi

mkdir -p "${LOCAL_BIN}"
cat >"${GCLAUDE_BIN}" <<'GCLAUDE'
#!/usr/bin/env bash
# Thin wrapper: run Claude Code against Vertex AI with sane defaults.
# Docs: https://code.claude.com/docs/en/google-vertex-ai
set -euo pipefail

gclaude_load_env_file() {
    local path="$1"
    if [[ -f "$path" ]]; then
        set -a
        # shellcheck disable=SC1090
        source "$path"
        set +a
    fi
}

if [[ -n "${GCLAUDE_ENV_FILE:-}" ]]; then
    gclaude_load_env_file "${GCLAUDE_ENV_FILE}"
else
    gclaude_load_env_file "${XDG_CONFIG_HOME:-$HOME/.config}/gclaude/env"
fi

export CLAUDE_CODE_USE_VERTEX=1
export CLOUD_ML_REGION="${CLOUD_ML_REGION:-global}"

if [[ -n "${GCLAUDE_GOOGLE_APPLICATION_CREDENTIALS:-}" ]]; then
    export GOOGLE_APPLICATION_CREDENTIALS="${GCLAUDE_GOOGLE_APPLICATION_CREDENTIALS}"
fi

CLAUDE_BIN="${GCLAUDE_CLAUDE_BIN:-claude}"

if ! command -v "${CLAUDE_BIN}" >/dev/null 2>&1; then
    echo "gclaude: '${CLAUDE_BIN}' not found on PATH. Install Claude Code or set GCLAUDE_CLAUDE_BIN." >&2
    exit 127
fi

if [[ -z "${ANTHROPIC_VERTEX_PROJECT_ID:-}" ]]; then
    echo "gclaude: set ANTHROPIC_VERTEX_PROJECT_ID (GCP project ID)." >&2
    echo "  Tip: run setup-gclaude.sh or edit ~/.config/gclaude/env" >&2
    exit 1
fi

if [[ -z "${GOOGLE_APPLICATION_CREDENTIALS:-}" ]]; then
    echo "gclaude: set GOOGLE_APPLICATION_CREDENTIALS to your service account JSON key path," >&2
    echo "  or set GCLAUDE_GOOGLE_APPLICATION_CREDENTIALS to the same path." >&2
    exit 1
fi

if [[ ! -f "${GOOGLE_APPLICATION_CREDENTIALS}" ]]; then
    echo "gclaude: credentials file not found: ${GOOGLE_APPLICATION_CREDENTIALS}" >&2
    exit 1
fi

exec "${CLAUDE_BIN}" "$@"
GCLAUDE
chmod +x "${GCLAUDE_BIN}"

echo
echo "Done."
echo "  Config: ${ENV_FILE}"
echo "  Key:    ${KEY_FILE}"
echo "  CLI:    ${GCLAUDE_BIN}"
echo
if [[ ":${PATH}:" != *":${LOCAL_BIN}:"* ]]; then
    echo "Add ~/.local/bin to PATH, e.g. in ~/.zshrc:"
    echo "  export PATH=\"\${HOME}/.local/bin:\${PATH}\""
    echo
fi
echo "Run: gclaude  (same arguments as claude)"