Drop-In Upgrade or Silent Production Trap? Gemini 4 Hydrogen GA Deep Dive, 57% Terminal-Bench & Zero-Downtime Migration Guide (With 3-OS Audit Scripts)

# pip install -U "google-genai>=2.34.0"
from google import genai
from google.genai import types

client = genai.Client()

# Pattern A: High-throughput routing / classification (override default=high -> low)
fast_resp = client.models.generate_content(
    model="gemini-4-hydrogen",
    contents=static_4096_prefix + "\n" + user_query,
    config=types.GenerateContentConfig(
        thinking_level="low",
        max_output_tokens=16384,  # covers thinking + JSON output cleanly
        response_mime_type="application/json",
        response_schema=MyStrictSchema,  # replaces ignored temperature=0
    ),
)

# Pattern B: Multi-file >64K generation via Interactions API Long Decode
long_job = client.interactions.create(
    model="gemini-4-hydrogen",
    input=massive_spec,
    background=True,
    store=True,
    generation_config={"max_output_tokens": 180000, "thinking_level": "high"},
)

agy --model gemini-4-hydrogen --effort xhigh
# Or via official shorthand alias
agy --model gemini-4-hydrogen-xhigh

npx skills add google-gemini/gemini-skills --skill gemini-api-dev --global
# Or attach the hosted Gemini API MCP endpoint: https://aistudio.google.com/mcp

<#
.SYNOPSIS
  Gemini 4 Hydrogen (GA) Migration & Agentic Pre-Flight Audit — Windows 11 PowerShell 5.1 / 7+
  Zero third-party dependencies (uses built-in Get-ChildItem, Select-String, Invoke-RestMethod).
.EXAMPLE
  Human Interactive: .\gemini4_hydrogen_audit_windows11.ps1
  Agent Automated:   .\gemini4_hydrogen_audit_windows11.ps1 -Target .\repo -Auto -Json
#>
[CmdletBinding()]
param(
  [string]$Target = ".",
  [switch]$Auto,
  [switch]$Json,
  [switch]$Probe,
  [switch]$WritePlan,
  [switch]$Help
)

$ErrorActionPreference = "Stop"

if ($Help) {
  Write-Output "Usage: .\gemini4_hydrogen_audit_windows11.ps1 [-Target <dir>] [-Auto] [-Json] [-Probe] [-WritePlan]"
  exit 0
}

if ($Json) { $Auto = $true }

if (-not (Test-Path -Path $Target -PathType Container)) {
  Write-Error "Target directory not found: $Target"
  exit 2
}

$TargetAbs = (Resolve-Path -Path $Target).Path

if (-not $Auto) {
  Write-Host "=====================================================================" -ForegroundColor Cyan
  Write-Host " Gemini 4 Hydrogen (GA) Pre-Flight Audit - Windows 11 Interactive" -ForegroundColor Blue
  Write-Host "=====================================================================" -ForegroundColor Cyan
  $inputDir = Read-Host "Target project [$TargetAbs] (Press Enter to keep)"
  if ($inputDir -and $inputDir.Trim() -ne "") {
    if (-not (Test-Path -Path $inputDir -PathType Container)) {
      Write-Error "Directory not found: $inputDir"
      exit 2
    }
    $TargetAbs = (Resolve-Path -Path $inputDir).Path
  }
  $probeAns = Read-Host "Run optional live check if GEMINI_API_KEY / agy CLI present? [y/N]"
  if ($probeAns -match "^[Yy]") { $Probe = $true }
  $planAns = Read-Host "Write sanitized migration plan JSON into target folder? [y/N]"
  if ($planAns -match "^[Yy]") { $WritePlan = $true }
}

$TargetBase = Split-Path -Path $TargetAbs -Leaf
$Extensions = @("*.py","*.ts","*.tsx","*.js","*.jsx","*.mjs","*.go","*.java","*.cs","*.rs","*.json","*.yaml","*.yml","*.toml",".env*","requirements*.txt","go.mod","pyproject.toml")
$SkipDirsRegex = '\\(\.git|node_modules|\.venv|venv|__pycache__|dist|build|\.next)(\\|$)'

$Files = Get-ChildItem -Path $TargetAbs -Recurse -File -Include $Extensions -ErrorAction SilentlyContinue |
  Where-Object { $_.FullName -notmatch $SkipDirsRegex -and $_.Name -ne ".gemini4-migration-plan.json" }

function Invoke-RuleScan {
  param([string]$Pattern)
  $matchesList = @()
  if ($Files) {
    $matchesList = $Files | Select-String -Pattern $Pattern -AllMatches -ErrorAction SilentlyContinue
  }
  $count = 0
  $sample = ""
  if ($matchesList) {
    $count = ($matchesList | ForEach-Object { $_.Matches.Count } | Measure-Object -Sum).Sum
    $first = $matchesList | Select-Object -First 1
    if ($first) {
      $relPath = $first.Path.Substring($TargetAbs.Length).TrimStart('\','/') -replace '\\','/'
      $lineSnippet = ($first.Line.Trim() -replace '[\r\n]+', ' ')
      if ($lineSnippet.Length -gt 80) { $lineSnippet = $lineSnippet.Substring(0, 80) }
      $sample = "${relPath}:$($first.LineNumber):$lineSnippet"
    }
  }
  return [PSCustomObject]@{ Count = [int]$count; Sample = $sample }
}

$rSampling   = Invoke-RuleScan '["'']?(temperature|top_p|topP|top_k|topK)["'']?\s*[:=]'
$rMinimal    = Invoke-RuleScan 'thinking_?[lL]evel["''\s:=]+(MINIMAL|minimal)'
$rLowCap     = Invoke-RuleScan '["'']?max_?[oO]utput_?[tT]okens["'']?\s*[:=]\s*([1-9][0-9]{0,3}|16384)([^0-9]|$)'
$rCache      = Invoke-RuleScan 'cachedContents|caches\.create|cached_content'
$rLegacy     = Invoke-RuleScan 'gemini-(2\.5-pro|3\.8-flash|4-carbon|4-argon)'
$rTokenTrap  = Invoke-RuleScan 'total_input_tokens'
$rOldSdk     = Invoke-RuleScan 'google-generativeai|import google\.generativeai|@google/generative-ai'
$rLiveMedia  = Invoke-RuleScan 'bidiGenerateContent|aio\.live|IMAGE_GENERATION|response_modalities.*AUDIO|gemini-4-hydrogen.*(IMAGE|AUDIO)'

$TotalIssues = $rSampling.Count + $rMinimal.Count + $rLowCap.Count + $rCache.Count + $rLegacy.Count + $rTokenTrap.Count + $rOldSdk.Count + $rLiveMedia.Count

$PythonGenAiVer = "not_installed"
if (Get-Command python -ErrorAction SilentlyContinue) {
  try {
    $ver = & python -c "import importlib.metadata as m; print(m.version('google-genai'))" 2>$null
    if ($ver) { $PythonGenAiVer = $ver.Trim() }
  } catch {}
} elseif (Get-Command py -ErrorAction SilentlyContinue) {
  try {
    $ver = & py -3 -c "import importlib.metadata as m; print(m.version('google-genai'))" 2>$null
    if ($ver) { $PythonGenAiVer = $ver.Trim() }
  } catch {}
}

$AgyStatus = "not_found"
if (Get-Command agy -ErrorAction SilentlyContinue) {
  try {
    $AgyStatus = (& agy --version 2>$null | Select-Object -First 1).ToString().Trim()
    if (-not $AgyStatus) { $AgyStatus = "installed" }
  } catch { $AgyStatus = "installed" }
}

$ApiProbeStatus = "skipped"
if ($Probe) {
  if ($env:GEMINI_API_KEY) {
    try {
      $resp = Invoke-WebRequest -Uri "https://generativelanguage.googleapis.com/v1beta/models/gemini-4-hydrogen" `
        -Headers @{ "x-goog-api-key" = $env:GEMINI_API_KEY } -TimeoutSec 8 -UseBasicParsing
      $ApiProbeStatus = "ok_http_$($resp.StatusCode)"
    } catch {
      $ApiProbeStatus = "probe_error"
    }
  } else {
    $ApiProbeStatus = "no_GEMINI_API_KEY_in_env"
  }
}

$Payload = [ordered]@{
  tool             = "gemini4-hydrogen-audit"
  os               = "Windows 11 (PowerShell)"
  model_target     = "gemini-4-hydrogen"
  project_basename = $TargetBase
  total_findings   = $TotalIssues
  environment      = [ordered]@{
    google_genai_python_sdk    = $PythonGenAiVer
    recommended_min_python_sdk = "2.34.0"
    antigravity_cli            = $AgyStatus
    api_model_metadata_probe   = $ApiProbeStatus
  }
  checks           = @(
    @{ id = "G4H-TRAP-01"; severity = "SILENT_HTTP_200";      title = "Ignored sampling overrides (temperature/top_p/top_k)"; count = $rSampling.Count;  sample = $rSampling.Sample },
    @{ id = "G4H-TRAP-02"; severity = "LOUD_ERROR";           title = "Unsupported minimal thinking_level (defaults to high on Hydrogen)"; count = $rMinimal.Count; sample = $rMinimal.Sample },
    @{ id = "G4H-TRAP-03"; severity = "SILENT_TRUNCATION";    title = "Low max_output_tokens <=16384 starves thinking + output budget"; count = $rLowCap.Count; sample = $rLowCap.Sample },
    @{ id = "G4H-TRAP-04"; severity = "UNSUPPORTED_FEATURE";  title = "Explicit caching calls (use implicit >=4096 token cache on Hydrogen)"; count = $rCache.Count; sample = $rCache.Sample },
    @{ id = "G4H-TRAP-05"; severity = "COST_OR_DEPRECATION";  title = "Legacy Gemini model IDs facing Dec 1 / Jan 1 price or routing shifts"; count = $rLegacy.Count; sample = $rLegacy.Sample },
    @{ id = "G4H-TRAP-06"; severity = "COMPACTION_BUG";       title = "total_input_tokens used in Long Decode multi-hop accounting"; count = $rTokenTrap.Count; sample = $rTokenTrap.Sample },
    @{ id = "G4H-TRAP-07"; severity = "RETIRED_SDK";          title = "Retired google-generativeai / @google/generative-ai package"; count = $rOldSdk.Count; sample = $rOldSdk.Sample },
    @{ id = "G4H-TRAP-08"; severity = "UNSUPPORTED_MODALITY"; title = "Live API / native image or audio generation markers"; count = $rLiveMedia.Count; sample = $rLiveMedia.Sample }
  )
}

$JsonText = $Payload | ConvertTo-Json -Depth 5

if ($WritePlan) {
  $PlanPath = Join-Path -Path $TargetAbs -ChildPath ".gemini4-migration-plan.json"
  Set-Content -Path $PlanPath -Value $JsonText -Encoding UTF8
}

if ($Json) {
  Write-Output $JsonText
} else {
  Write-Host "`nTarget folder: $TargetBase   Findings: $TotalIssues"
  Write-Host "Python google-genai SDK: $PythonGenAiVer (min >= 2.34.0 for Long Decode client continuation)"
  Write-Host "Antigravity CLI (agy): $AgyStatus   API Metadata Probe: $ApiProbeStatus"
  Write-Host "---------------------------------------------------------------------"
  "{0,-13} | {1,-19} | {2,5} | {3}" -f "Check ID", "Behavior", "Hits", "First Relative Hit" | Write-Host
  Write-Host "---------------------------------------------------------------------"
  foreach ($chk in $Payload.checks) {
    $samp = if ($chk.sample) { $chk.sample } else { "-" }
    "{0,-13} | {1,-19} | {2,5} | {3}" -f $chk.id, $chk.severity, $chk.count, $samp | Write-Host
  }
  Write-Host "---------------------------------------------------------------------"
  if ($WritePlan) {
    Write-Host "Saved migration plan: $TargetBase/.gemini4-migration-plan.json" -ForegroundColor Green
  }
}

if ($rMinimal.Count -gt 0 -or $rOldSdk.Count -gt 0) { exit 1 }
exit 0

#!/usr/bin/env bash
# ==============================================================================
# Gemini 4 Hydrogen (GA) Migration & Agentic Pre-Flight Audit — Ubuntu 26.04
# Zero third-party dependencies (standard bash, grep, awk, sed, curl)
# Modes:
#   Human Interactive: bash gemini4_hydrogen_audit_ubuntu2604.sh [--target ./repo]
#   Agent Automated:   bash gemini4_hydrogen_audit_ubuntu2604.sh --target ./repo --auto --json
# ==============================================================================
set -euo pipefail

TARGET_DIR="."
AUTO_MODE=0
JSON_MODE=0
PROBE_API=0
WRITE_PLAN=0

print_usage() {
  cat <<'USAGE'
Usage: bash gemini4_hydrogen_audit_ubuntu2604.sh [options]
  --target <dir>    Directory to scan (default: current directory)
  --auto            Non-interactive mode (no prompts; ideal for CI / AI Agents)
  --json            Emit machine-readable JSON summary to stdout
  --probe           Run optional read-only API/Antigravity CLI check if configured
  --write-plan      Write sanitized migration checklist to .gemini4-migration-plan.json
  -h, --help        Show this help message
USAGE
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --target)
      shift
      [[ $# -gt 0 ]] || { echo "Error: --target requires a directory" >&2; exit 2; }
      TARGET_DIR="$1"
      ;;
    --auto) AUTO_MODE=1 ;;
    --json) JSON_MODE=1; AUTO_MODE=1 ;;
    --probe) PROBE_API=1 ;;
    --write-plan) WRITE_PLAN=1 ;;
    -h|--help) print_usage; exit 0 ;;
    *) echo "Unknown option: $1" >&2; print_usage >&2; exit 2 ;;
  esac
  shift
done

[[ -d "$TARGET_DIR" ]] || { echo "Error: Target directory not found: $TARGET_DIR" >&2; exit 2; }
TARGET_ABS="$(cd "$TARGET_DIR" && pwd)"
TARGET_BASE="$(basename "$TARGET_ABS")"

if [[ "$AUTO_MODE" -eq 0 ]]; then
  printf '\033[36m=====================================================================\033[0m\n'
  printf '\033[1;34m Gemini 4 Hydrogen (GA) Pre-Flight Audit — Ubuntu 26.04 Interactive\033[0m\n'
  printf '\033[36m=====================================================================\033[0m\n'
  read -r -p "Target project [${TARGET_ABS}] (Press Enter to keep): " input_dir || true
  if [[ -n "${input_dir:-}" ]]; then
    [[ -d "$input_dir" ]] || { echo "Directory not found: $input_dir" >&2; exit 2; }
    TARGET_ABS="$(cd "$input_dir" && pwd)"
    TARGET_BASE="$(basename "$TARGET_ABS")"
  fi
  read -r -p "Run optional live check if GEMINI_API_KEY / agy CLI present? [y/N]: " probe_ans || true
  [[ "${probe_ans:-n}" == [Yy]* ]] && PROBE_API=1
  read -r -p "Write sanitized migration plan JSON into target folder? [y/N]: " plan_ans || true
  [[ "${plan_ans:-n}" == [Yy]* ]] && WRITE_PLAN=1
fi

EXCLUDE_ARGS=(
  --exclude-dir=.git --exclude-dir=node_modules --exclude-dir=.venv
  --exclude-dir=venv --exclude-dir=__pycache__ --exclude-dir=dist
  --exclude-dir=build --exclude-dir=.next --exclude=.gemini4-migration-plan.json
)
INCLUDE_ARGS=(
  --include='*.py' --include='*.ts' --include='*.tsx' --include='*.js' --include='*.jsx'
  --include='*.mjs' --include='*.go' --include='*.java' --include='*.cs' --include='*.rs'
  --include='*.json' --include='*.yaml' --include='*.yml' --include='*.toml' --include='*.env*'
  --include='requirements*.txt' --include='go.mod' --include='pyproject.toml'
)

scan_count_and_sample() {
  local pattern="$1"
  local matches total first_rel sq="'"
  matches="$(grep -rnE "${EXCLUDE_ARGS[@]}" "${INCLUDE_ARGS[@]}" -- "$pattern" "$TARGET_ABS" 2>/dev/null | grep -vE '(^|/)\.gemini4-migration-plan\.json:' || true)"
  if [[ -z "$matches" ]]; then
    echo "0|"
    return
  fi
  total="$(printf '%s\n' "$matches" | wc -l | tr -d ' ')"
  first_rel="${matches%%$'\n'*}"
  first_rel="${first_rel#"$TARGET_ABS"/}"
  first_rel="${first_rel//\"/$sq}"
  first_rel="$(printf '%s' "$first_rel" | sed -E 's/:([0-9]+):[[:space:]]*/:\1: /' | cut -c1-84)"
  echo "${total}|${first_rel}"
}

r_sampling="$(scan_count_and_sample '["'\'']?(temperature|top_p|topP|top_k|topK)["'\'']?[[:space:]]*[:=]')"
r_minimal="$(scan_count_and_sample 'thinking_?[lL]evel["'\''[:space:]:=]+(MINIMAL|minimal)')"
r_lowcap="$(scan_count_and_sample '["'\'']?max_?[oO]utput_?[tT]okens["'\'']?[[:space:]]*[:=][[:space:]]*([1-9][0-9]{0,3}|16384)([^0-9]|$)')"
r_explicit_cache="$(scan_count_and_sample 'cachedContents|caches\.create|cached_content')"
r_legacy_models="$(scan_count_and_sample 'gemini-(2\.5-pro|3\.8-flash|4-carbon|4-argon)')"
r_token_trap="$(scan_count_and_sample 'total_input_tokens')"
r_old_sdk="$(scan_count_and_sample 'google-generativeai|import google\.generativeai|@google/generative-ai')"
r_live_media="$(scan_count_and_sample 'bidiGenerateContent|aio\.live|IMAGE_GENERATION|response_modalities.*AUDIO|gemini-4-hydrogen.*(IMAGE|AUDIO)')"

C_SAMPLING="${r_sampling%%|*}";     S_SAMPLING="${r_sampling#*|}"
C_MINIMAL="${r_minimal%%|*}";       S_MINIMAL="${r_minimal#*|}"
C_LOWCAP="${r_lowcap%%|*}";         S_LOWCAP="${r_lowcap#*|}"
C_CACHE="${r_explicit_cache%%|*}";  S_CACHE="${r_explicit_cache#*|}"
C_LEGACY="${r_legacy_models%%|*}";  S_LEGACY="${r_legacy_models#*|}"
C_TOKENTRAP="${r_token_trap%%|*}";  S_TOKENTRAP="${r_token_trap#*|}"
C_OLDSDK="${r_old_sdk%%|*}";        S_OLDSDK="${r_old_sdk#*|}"
C_LIVEMEDIA="${r_live_media%%|*}";  S_LIVEMEDIA="${r_live_media#*|}"

TOTAL_ISSUES=$(( C_SAMPLING + C_MINIMAL + C_LOWCAP + C_CACHE + C_LEGACY + C_TOKENTRAP + C_OLDSDK + C_LIVEMEDIA ))

PYTHON_GENAI_VER="not_installed"
if command -v python3 >/dev/null 2>&1; then
  PYTHON_GENAI_VER="$(python3 -c 'import importlib.metadata as m; print(m.version("google-genai"))' 2>/dev/null || echo "not_installed")"
fi

AGY_CLI_STATUS="not_found"
if command -v agy >/dev/null 2>&1; then
  AGY_CLI_STATUS="$(agy --version 2>/dev/null | head -n 1 || echo "installed")"
fi

API_PROBE_STATUS="skipped"
if [[ "$PROBE_API" -eq 1 ]]; then
  if [[ -n "${GEMINI_API_KEY:-}" ]]; then
    http_code="$(curl -sS -o /dev/null -w "%{http_code}" --max-time 8 \
      -H "x-goog-api-key: ${GEMINI_API_KEY}" \
      "https://generativelanguage.googleapis.com/v1beta/models/gemini-4-hydrogen" || echo "000")"
    API_PROBE_STATUS="http_${http_code}"
    [[ "$http_code" == "200" ]] && API_PROBE_STATUS="ok_http_200"
  else
    API_PROBE_STATUS="no_GEMINI_API_KEY_in_env"
  fi
fi

json_escape() {
  printf '%s' "$1" | sed 's/\\/\\\\/g; s/"/\\"/g' | tr -d '\r\n'
}

build_json_payload() {
  cat <<JSON
{
  "tool": "gemini4-hydrogen-audit",
  "os": "Ubuntu 26.04 (Bash)",
  "model_target": "gemini-4-hydrogen",
  "project_basename": "$(json_escape "$TARGET_BASE")",
  "total_findings": ${TOTAL_ISSUES},
  "environment": {
    "google_genai_python_sdk": "$(json_escape "$PYTHON_GENAI_VER")",
    "recommended_min_python_sdk": "2.34.0",
    "antigravity_cli": "$(json_escape "$AGY_CLI_STATUS")",
    "api_model_metadata_probe": "$(json_escape "$API_PROBE_STATUS")"
  },
  "checks": [
    {"id": "G4H-TRAP-01", "severity": "SILENT_HTTP_200", "title": "Ignored sampling overrides (temperature/top_p/top_k)", "count": ${C_SAMPLING}, "sample": "$(json_escape "$S_SAMPLING")"},
    {"id": "G4H-TRAP-02", "severity": "LOUD_ERROR", "title": "Unsupported minimal thinking_level (defaults to high on Hydrogen)", "count": ${C_MINIMAL}, "sample": "$(json_escape "$S_MINIMAL")"},
    {"id": "G4H-TRAP-03", "severity": "SILENT_TRUNCATION", "title": "Low max_output_tokens <=16384 starves thinking + output budget", "count": ${C_LOWCAP}, "sample": "$(json_escape "$S_LOWCAP")"},
    {"id": "G4H-TRAP-04", "severity": "UNSUPPORTED_FEATURE", "title": "Explicit caching calls (use implicit >=4096 token cache on Hydrogen)", "count": ${C_CACHE}, "sample": "$(json_escape "$S_CACHE")"},
    {"id": "G4H-TRAP-05", "severity": "COST_OR_DEPRECATION", "title": "Legacy Gemini model IDs facing Dec 1 / Jan 1 price or routing shifts", "count": ${C_LEGACY}, "sample": "$(json_escape "$S_LEGACY")"},
    {"id": "G4H-TRAP-06", "severity": "COMPACTION_BUG", "title": "total_input_tokens used in Long Decode multi-hop accounting", "count": ${C_TOKENTRAP}, "sample": "$(json_escape "$S_TOKENTRAP")"},
    {"id": "G4H-TRAP-07", "severity": "RETIRED_SDK", "title": "Retired google-generativeai / @google/generative-ai package", "count": ${C_OLDSDK}, "sample": "$(json_escape "$S_OLDSDK")"},
    {"id": "G4H-TRAP-08", "severity": "UNSUPPORTED_MODALITY", "title": "Live API / native image or audio generation markers", "count": ${C_LIVEMEDIA}, "sample": "$(json_escape "$S_LIVEMEDIA")"}
  ]
}
JSON
}

if [[ "$WRITE_PLAN" -eq 1 ]]; then
  build_json_payload > "${TARGET_ABS}/.gemini4-migration-plan.json"
fi

if [[ "$JSON_MODE" -eq 1 ]]; then
  build_json_payload
else
  printf '\nTarget folder: %s   Findings: %d\n' "$TARGET_BASE" "$TOTAL_ISSUES"
  printf 'Python google-genai SDK: %s (min >= 2.34.0 for Long Decode client continuation)\n' "$PYTHON_GENAI_VER"
  printf 'Antigravity CLI (agy): %s   API Metadata Probe: %s\n' "$AGY_CLI_STATUS" "$API_PROBE_STATUS"
  echo "---------------------------------------------------------------------"
  printf "%-13s | %-19s | %5s | %s\n" "Check ID" "Behavior" "Hits" "First Relative Hit"
  echo "---------------------------------------------------------------------"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-01" "SILENT_HTTP_200"     "$C_SAMPLING"   "${S_SAMPLING:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-02" "LOUD_ERROR"          "$C_MINIMAL"    "${S_MINIMAL:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-03" "SILENT_TRUNCATION"   "$C_LOWCAP"     "${S_LOWCAP:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-04" "UNSUPPORTED_FEATURE" "$C_CACHE"      "${S_CACHE:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-05" "COST_DEPRECATION"    "$C_LEGACY"     "${S_LEGACY:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-06" "COMPACTION_BUG"      "$C_TOKENTRAP"  "${S_TOKENTRAP:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-07" "RETIRED_SDK"         "$C_OLDSDK"     "${S_OLDSDK:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-08" "UNSUPPORTED_MOD"     "$C_LIVEMEDIA"  "${S_LIVEMEDIA:--}"
  echo "---------------------------------------------------------------------"
  if [[ "$WRITE_PLAN" -eq 1 ]]; then
    echo "Saved migration plan: ${TARGET_BASE}/.gemini4-migration-plan.json"
  fi
fi

if [[ "$C_MINIMAL" -gt 0 || "$C_OLDSDK" -gt 0 ]]; then
  exit 1
fi
exit 0

#!/usr/bin/env zsh
# ==============================================================================
# Gemini 4 Hydrogen (GA) Migration & Agentic Pre-Flight Audit — macOS 27 (Zsh)
# Zero third-party dependencies (macOS 27 built-in zsh, grep, awk, sed, curl)
# Modes:
#   Human Interactive: zsh gemini4_hydrogen_audit_macos27.zsh [--target ./repo]
#   Agent Automated:   zsh gemini4_hydrogen_audit_macos27.zsh --target ./repo --auto --json
# ==============================================================================
emulate -L zsh
setopt PIPE_FAIL NO_UNSET

TARGET_DIR="."
AUTO_MODE=0
JSON_MODE=0
PROBE_API=0
WRITE_PLAN=0

print_usage() {
  cat <<'USAGE'
Usage: zsh gemini4_hydrogen_audit_macos27.zsh [options]
  --target <dir>    Directory to scan (default: current directory)
  --auto            Non-interactive mode (no prompts; ideal for CI / AI Agents)
  --json            Emit machine-readable JSON summary to stdout
  --probe           Run optional read-only API/Antigravity CLI check if configured
  --write-plan      Write sanitized migration checklist to .gemini4-migration-plan.json
  -h, --help        Show this help message
USAGE
}

while (( $# > 0 )); do
  case "$1" in
    --target)
      shift
      [[ $# -gt 0 ]] || { echo "Error: --target requires a directory" >&2; exit 2; }
      TARGET_DIR="$1"
      ;;
    --auto) AUTO_MODE=1 ;;
    --json) JSON_MODE=1; AUTO_MODE=1 ;;
    --probe) PROBE_API=1 ;;
    --write-plan) WRITE_PLAN=1 ;;
    -h|--help) print_usage; exit 0 ;;
    *) echo "Unknown option: $1" >&2; print_usage >&2; exit 2 ;;
  esac
  shift
done

if [[ ! -d "$TARGET_DIR" ]]; then
  echo "Error: Target directory does not exist: $TARGET_DIR" >&2
  exit 2
fi

TARGET_ABS="$(cd "$TARGET_DIR" && pwd)"

if (( AUTO_MODE == 0 )); then
  print -P "%F{cyan}=====================================================================%f"
  print -P "%B%F{blue} Gemini 4 Hydrogen (GA) Pre-Flight Audit — macOS 27 Interactive%f%b"
  print -P "%F{cyan}=====================================================================%f"
  printf "Target project [%s] (Press Enter to keep): " "$TARGET_ABS"
  read -r input_dir || true
  if [[ -n "${input_dir:-}" ]]; then
    [[ -d "$input_dir" ]] || { echo "Directory not found: $input_dir" >&2; exit 2; }
    TARGET_ABS="$(cd "$input_dir" && pwd)"
  fi
  printf "Run optional live check if GEMINI_API_KEY / agy CLI present? [y/N]: "
  read -r probe_ans || true
  [[ "${probe_ans:-n}" == [Yy]* ]] && PROBE_API=1
  printf "Write sanitized migration plan JSON into target folder? [y/N]: "
  read -r plan_ans || true
  [[ "${plan_ans:-n}" == [Yy]* ]] && WRITE_PLAN=1
fi

typeset -a EXCLUDE_ARGS
EXCLUDE_ARGS=(
  "--exclude-dir=.git"
  "--exclude-dir=node_modules"
  "--exclude-dir=.venv"
  "--exclude-dir=venv"
  "--exclude-dir=__pycache__"
  "--exclude-dir=dist"
  "--exclude-dir=build"
  "--exclude-dir=.next"
  "--exclude=.gemini4-migration-plan.json"
)

typeset -a INCLUDE_ARGS
INCLUDE_ARGS=(
  "--include=*.py" "--include=*.ts" "--include=*.tsx" "--include=*.js" "--include=*.jsx"
  "--include=*.mjs" "--include=*.go" "--include=*.java" "--include=*.cs" "--include=*.rs"
  "--include=*.json" "--include=*.yaml" "--include=*.yml" "--include=*.toml" "--include=*.env*"
  "--include=requirements*.txt" "--include=go.mod" "--include=pyproject.toml"
)

scan_count_and_sample() {
  local pattern="$1"
  local matches total first_rel sq="'"
  matches="$(grep -rnE "${EXCLUDE_ARGS[@]}" "${INCLUDE_ARGS[@]}" -- "$pattern" "$TARGET_ABS" 2>/dev/null | grep -vE '(^|/)\.gemini4-migration-plan\.json:' || true)"
  if [[ -z "$matches" ]]; then
    echo "0|"
    return
  fi
  total="$(printf '%s\n' "$matches" | wc -l | tr -d ' ')"
  first_rel="${matches%%$'\n'*}"
  # Strip prefix paths & usernames to keep output leak-free
  first_rel="${first_rel#$TARGET_ABS/}"
  first_rel="${first_rel//\"/$sq}"
  first_rel="$(printf '%s' "$first_rel" | sed -E 's/:([0-9]+):[[:space:]]*/:\1: /' | cut -c1-84)"
  echo "${total}|${first_rel}"
}

r_sampling="$(scan_count_and_sample '["'\'']?(temperature|top_p|topP|top_k|topK)["'\'']?[[:space:]]*[:=]')"
r_minimal="$(scan_count_and_sample 'thinking_?[lL]evel["'\''[:space:]:=]+(MINIMAL|minimal)')"
r_lowcap="$(scan_count_and_sample '["'\'']?max_?[oO]utput_?[tT]okens["'\'']?[[:space:]]*[:=][[:space:]]*([1-9][0-9]{0,3}|16384)([^0-9]|$)')"
r_explicit_cache="$(scan_count_and_sample 'cachedContents|caches\.create|cached_content')"
r_legacy_models="$(scan_count_and_sample 'gemini-(2\.5-pro|3\.8-flash|4-carbon|4-argon)')"
r_token_trap="$(scan_count_and_sample 'total_input_tokens')"
r_old_sdk="$(scan_count_and_sample 'google-generativeai|import google\.generativeai|@google/generative-ai')"
r_live_media="$(scan_count_and_sample 'bidiGenerateContent|aio\.live|IMAGE_GENERATION|response_modalities.*AUDIO|gemini-4-hydrogen.*(IMAGE|AUDIO)')"

split_metric() {
  local val="$1"
  echo "${val%%|*}"
}
split_sample() {
  local val="$1"
  echo "${val#*|}"
}

C_SAMPLING=$(split_metric "$r_sampling");       S_SAMPLING=$(split_sample "$r_sampling")
C_MINIMAL=$(split_metric "$r_minimal");         S_MINIMAL=$(split_sample "$r_minimal")
C_LOWCAP=$(split_metric "$r_lowcap");           S_LOWCAP=$(split_sample "$r_lowcap")
C_CACHE=$(split_metric "$r_explicit_cache");    S_CACHE=$(split_sample "$r_explicit_cache")
C_LEGACY=$(split_metric "$r_legacy_models");    S_LEGACY=$(split_sample "$r_legacy_models")
C_TOKENTRAP=$(split_metric "$r_token_trap");    S_TOKENTRAP=$(split_sample "$r_token_trap")
C_OLDSDK=$(split_metric "$r_old_sdk");          S_OLDSDK=$(split_sample "$r_old_sdk")
C_LIVEMEDIA=$(split_metric "$r_live_media");    S_LIVEMEDIA=$(split_sample "$r_live_media")

TOTAL_ISSUES=$(( C_SAMPLING + C_MINIMAL + C_LOWCAP + C_CACHE + C_LEGACY + C_TOKENTRAP + C_OLDSDK + C_LIVEMEDIA ))

# Environment checks (zero external dependencies)
PYTHON_GENAI_VER="not_installed"
if command -v python3 >/dev/null 2>&1; then
  PYTHON_GENAI_VER="$(python3 -c 'import importlib.metadata as m; print(m.version("google-genai"))' 2>/dev/null || echo "not_installed")"
fi

AGY_CLI_STATUS="not_found"
if command -v agy >/dev/null 2>&1; then
  AGY_CLI_STATUS="$(agy --version 2>/dev/null | head -n 1 || echo "installed")"
fi

API_PROBE_STATUS="skipped"
if (( PROBE_API == 1 )); then
  if [[ -n "${GEMINI_API_KEY:-}" ]]; then
    http_code="$(curl -sS -o /dev/null -w "%{http_code}" --max-time 8 \
      -H "x-goog-api-key: ${GEMINI_API_KEY}" \
      "https://generativelanguage.googleapis.com/v1beta/models/gemini-4-hydrogen" || echo "000")"
    if [[ "$http_code" == "200" ]]; then
      API_PROBE_STATUS="ok_http_200"
    else
      API_PROBE_STATUS="http_${http_code}"
    fi
  else
    API_PROBE_STATUS="no_GEMINI_API_KEY_in_env"
  fi
fi

json_escape() {
  printf '%s' "$1" | sed 's/\\/\\\\/g; s/"/\\"/g' | tr -d '\r\n'
}

build_json_payload() {
  cat <<JSON
{
  "tool": "gemini4-hydrogen-audit",
  "os": "macOS 27 (Zsh)",
  "model_target": "gemini-4-hydrogen",
  "project_basename": "$(json_escape "${TARGET_ABS:t}")",
  "total_findings": ${TOTAL_ISSUES},
  "environment": {
    "google_genai_python_sdk": "$(json_escape "$PYTHON_GENAI_VER")",
    "recommended_min_python_sdk": "2.34.0",
    "antigravity_cli": "$(json_escape "$AGY_CLI_STATUS")",
    "api_model_metadata_probe": "$(json_escape "$API_PROBE_STATUS")"
  },
  "checks": [
    {"id": "G4H-TRAP-01", "severity": "SILENT_HTTP_200", "title": "Ignored sampling overrides (temperature/top_p/top_k)", "count": ${C_SAMPLING}, "sample": "$(json_escape "$S_SAMPLING")"},
    {"id": "G4H-TRAP-02", "severity": "LOUD_ERROR", "title": "Unsupported minimal thinking_level (defaults to high on Hydrogen)", "count": ${C_MINIMAL}, "sample": "$(json_escape "$S_MINIMAL")"},
    {"id": "G4H-TRAP-03", "severity": "SILENT_TRUNCATION", "title": "Low max_output_tokens <=16384 starves thinking + output budget", "count": ${C_LOWCAP}, "sample": "$(json_escape "$S_LOWCAP")"},
    {"id": "G4H-TRAP-04", "severity": "UNSUPPORTED_FEATURE", "title": "Explicit caching calls (use implicit >=4096 token cache on Hydrogen)", "count": ${C_CACHE}, "sample": "$(json_escape "$S_CACHE")"},
    {"id": "G4H-TRAP-05", "severity": "COST_OR_DEPRECATION", "title": "Legacy Gemini model IDs facing Dec 1 / Jan 1 price or routing shifts", "count": ${C_LEGACY}, "sample": "$(json_escape "$S_LEGACY")"},
    {"id": "G4H-TRAP-06", "severity": "COMPACTION_BUG", "title": "total_input_tokens used in Long Decode multi-hop accounting", "count": ${C_TOKENTRAP}, "sample": "$(json_escape "$S_TOKENTRAP")"},
    {"id": "G4H-TRAP-07", "severity": "RETIRED_SDK", "title": "Retired google-generativeai / @google/generative-ai package", "count": ${C_OLDSDK}, "sample": "$(json_escape "$S_OLDSDK")"},
    {"id": "G4H-TRAP-08", "severity": "UNSUPPORTED_MODALITY", "title": "Live API / native image or audio generation markers", "count": ${C_LIVEMEDIA}, "sample": "$(json_escape "$S_LIVEMEDIA")"}
  ]
}
JSON
}

if (( WRITE_PLAN == 1 )); then
  build_json_payload > "${TARGET_ABS}/.gemini4-migration-plan.json"
fi

if (( JSON_MODE == 1 )); then
  build_json_payload
else
  print ""
  print -P "%BTarget folder:%b ${TARGET_ABS:t}   %BFindings:%b ${TOTAL_ISSUES}"
  print -P "%BPython google-genai SDK:%b ${PYTHON_GENAI_VER} (min >= 2.34.0 for Long Decode client continuation)"
  print -P "%BAntigravity CLI (agy):%b ${AGY_CLI_STATUS}   %BAPI Metadata Probe:%b ${API_PROBE_STATUS}"
  printf "---------------------------------------------------------------------\n"
  printf "%-13s | %-19s | %5s | %s\n" "Check ID" "Behavior" "Hits" "First Relative Hit"
  printf "---------------------------------------------------------------------\n"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-01" "SILENT_HTTP_200"     "$C_SAMPLING"   "${S_SAMPLING:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-02" "LOUD_ERROR"          "$C_MINIMAL"    "${S_MINIMAL:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-03" "SILENT_TRUNCATION"   "$C_LOWCAP"     "${S_LOWCAP:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-04" "UNSUPPORTED_FEATURE" "$C_CACHE"      "${S_CACHE:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-05" "COST_DEPRECATION"    "$C_LEGACY"     "${S_LEGACY:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-06" "COMPACTION_BUG"      "$C_TOKENTRAP"  "${S_TOKENTRAP:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-07" "RETIRED_SDK"         "$C_OLDSDK"     "${S_OLDSDK:--}"
  printf "%-13s | %-19s | %5d | %s\n" "G4H-TRAP-08" "UNSUPPORTED_MOD"     "$C_LIVEMEDIA"  "${S_LIVEMEDIA:--}"
  printf "---------------------------------------------------------------------\n"
  if (( WRITE_PLAN == 1 )); then
    print -P "%F{green}Saved migration plan:%f ${TARGET_ABS:t}/.gemini4-migration-plan.json"
  fi
fi

if (( C_MINIMAL > 0 || C_OLDSDK > 0 )); then
  exit 1
fi
exit 0