v3.12.1: bump version in GUI + lib

- Merge PR #5 from cobra91: concurrency semaphore, auto-continue, SO_REUSEADDR,
  proxy-stderr.log, stream diagnostics, timeout handler, restart proxy fix
- Tool call argument normalizer, smart-continue loop, XML extraction
- API key hot-reload with mtime tracking + /admin/ endpoints
- GUI hot-reload on endpoint edit with upstream verification
- Synthetic tool-results disabled (caused deepseek-v4-pro truncation)
- Version bump 3.10.12 -> 3.11.0, rebuild .deb

CHANGELOG.md

@@ -1,5 +1,174 @@
 # Changelog
 
+## v3.12.0 (2026-05-27)
+
+**gRPC Auto-Fallback for Antigravity Provider (PR #13)**
+
+### New Features
+- **gRPC auto-fallback**: When REST API returns 404 (model not found), automatically retries via gRPC
+- **New `antigravity_grpc` module**: Full protobuf client with CloudCode PredictionService stubs
+- **Display name remapping**: gRPC uses display names (e.g. "Gemini 3.5 Flash (High)") instead of REST slugs
+- **Streaming and unary support**: gRPC fallback works for both streaming and non-streaming requests
+- **Dynamic version fetch with validation**: Probes fetched versions to ensure they work before caching
+- **Antigravity v2 handler rewrite**: Based on anti-api approach with proper safety settings, stopSequences, sessionId
+- **Lazy import**: grpcio is only imported when needed — zero impact if not installed
+
+### Bug Fixes
+- Antigravity 404 caused by invalid version — now validates with probe requests
+- Version fallback: auto-retries with re-fetched version if all endpoints return 404
+
+## v3.11.12 (2026-05-26)
+
+**New Antigravity v2 Handler (Mimicking anti-api)**
+
+### New Features
+- **Complete rewrite of Antigravity handler** based on https://github.com/ink1ing/anti-api approach
+- Safety settings (all OFF), stopSequences, sessionId, requestType: agent
+- functionResponse uses `response: { result: string }` format matching anti-api
+- Endpoint priority: `daily-cloudcode-pa.googleapis.com` first
+- Simplified sanitizer: only deduplicates consecutive user text, never touches tool messages
+
+## v3.11.11 (2026-05-26)
+
+## v3.11.11 (2026-05-26)
+
+**Antigravity Fix: Stricter function_call/output Pairing + Gemini Sanitizer Rewrite (PR #12)**
+
+### Bug Fixes
+- **Stricter function_call/output pairing**: Only includes pairs where BOTH call and output exist — no orphan calls sent to Gemini
+- **Gemini sanitizer rewritten**: Tool messages (`functionCall`/`functionResponse`) are always preserved as-is, never merged or skipped
+- **Text merging more conservative**: Checks last message for tool content before merging consecutive text messages
+- **Final trimming safe**: Only removes plain `message` items, never `function_call_output` (which would break tool pairs)
+- **Merge PR #12**: Fix by qwen-chat coder
+
+## v3.11.10 (2026-05-26)
+
+## v3.11.10 (2026-05-26)
+
+**Antigravity Fix: Interleave function_call/output Pairs, Gemini Turn Trimming (PR #11)**
+
+### Bug Fixes
+- **Fix Antigravity function_call/output ordering**: Tool calls and their responses are now properly interleaved in sequence (`function_call` → `function_call_output` → `function_call` → ...) instead of being grouped separately
+- **Gemini sanitizer trimming**: Leading/trailing non-user turns removed for Google API compliance (Google requires conversation to start and end with user turn)
+- **Stricter role boundary enforcement**: `functionCall` (model) and `functionResponse` (user) never merged across role boundaries
+- **Merge PR #11**: Fix by qwen-chat coder
+
+## v3.11.9 (2026-05-26)
+
+## v3.11.9 (2026-05-26)
+
+**Antigravity Fix: Preserve functionCall/functionResponse in Gemini Sanitizer (PR #10)**
+
+### Bug Fixes
+
+- **Fix Antigravity multi-turn tool use**: The Gemini message sanitizer was incorrectly merging/dropping `functionCall` and `functionResponse` turns, causing Antigravity to think forever without responding. These turns are now always preserved as separate messages.
+- **Merge PR #10**: `fix: preserve functionCall/functionResponse in Gemini sanitizer` (qwen-chat coder)
+
+## v3.11.8 (2026-05-26)
+
+## v3.11.8 (2026-05-26)
+
+**Vision Cache Persistence, PR #8 Merge**
+
+### New Features
+
+- **Vision description cache persisted across requests**: Image descriptions from the vision fallback API are now cached in a file (`~/.cache/codex-proxy/vision-cache.json`) so the same image URL is never described twice — saves API calls and latency
+- **Merge PR #8**: `fix: persist vision description cache across requests` (cobra91)
+
+## v3.11.7 (2026-05-26)
+
+**Vision Auto-Detect, Proactive Non-Vision Model Detection, Unit Tests, Bug Fixes**
+
+### New Features
+
+- **Vision auto-detect fallback**: When no explicit vision fallback is configured, automatically uses the current provider's own vision model (e.g., `0G-Qwen-VL` for OpenAdapter) as the image description API — no separate API key needed
+- **Proactive non-vision model detection**: Models matching name patterns (`glm`, `deepseek`, `llama`, `qwen` without `vl`, etc.) are detected as non-vision on first request without waiting for an error from the provider
+- **Vision preprocessing is now the primary image handling solution**: Replaces old `_strip_images_from_input()` (which just removed images with a placeholder). Images are now described via API and sent as rich text descriptions to text-only models
+- **Merge PR #6**: Vision/OCR preprocessing for text-only models (cobra91)
+- **Merge PR #7**: 177 unit tests for translate-proxy.py (cobra91)
+
+### Bug Fixes
+
+- **AttributeError fix**: `image_url` field can be a string (bare URL) not always a dict — fixed in both `_preprocess_vision_input()` and old strip function
+- **Auth os error 2 fix**: GUI shows "Config missing" message instead of raw OSError when `~/.codex/` directory doesn't exist
+- **Removed duplicate vision functions**: Cleaned up duplicate `_vision_describe_image()`, `_preprocess_vision()`, `_preprocess_vision_input()` from merge
+
+## v3.11.6 (2026-05-26)
+
+**Antigravity Loop Breakers, Vision/OCR Preprocessing, has_content Fix, Auth Error Fix**
+
+### New Features (Antigravity-only, no other providers affected)
+
+- **Per-session loop tracking**: `_ANTIGRAVITY_LOOP_TRACKER` global dict with `_antigravity_loop_key()` function tracks state per session: `latest_user_hash`, `nudge_injected`, `latest_user_appended`, `tool_calls_for_request`, `repeated_tool`, `force_finalize`, `last_tool`, `last_tool_count`
+- **Edit-intent nudge injection**: Injected only on the first turn per request, preventing duplicate nudges across retries
+- **Latest user instruction append**: Appended exactly once per request to prevent redundant instruction stacking
+- **Loop breaker**: If the same tool + arguments is repeated ≥ 5 times in a session, `force_finalize` is triggered to break the infinite loop
+- **Detailed `[antigravity-loop]` logging**: All tracking fields logged on every Antigravity request for debugging
+
+### New Features (All OpenAI-compatible providers)
+
+- **Vision/OCR preprocessing**: When a provider doesn't support images (detected via error messages like "unknown variant image_url", "does not support image"), the proxy automatically calls a configurable vision fallback API (default: Kilo.ai) to describe images as text, then replaces image blocks with text descriptions before sending to text-only models
+- **`_vision_describe_image()`**: Calls vision fallback model to describe a single image, with MD5-based caching to avoid re-describing same URL
+- **`_preprocess_vision()`**: Replaces `image_url`/`input_image` blocks in Chat Completions message format with text descriptions when provider lacks vision support
+- **`_preprocess_vision_input()`**: Same for Responses API input format — runs BEFORE adapter conversion so images are replaced early
+- **Vision error retry**: On HTTP 4xx errors containing image-related keywords, automatically retries with images preprocessed instead of failing
+- **Configurable via env vars**: `VISION_FALLBACK_URL`, `VISION_FALLBACK_MODEL`, `VISION_FALLBACK_KEY`
+- **ProviderSchema `supports_vision` field**: Auto-detected from error responses and persisted in provider-caps.json
+
+### Critical Fixes
+
+- **`has_content` now includes `function_call`** (v3.11.5 fix): `_observe_event` only checked for `"type": "message"` — when models return only tool calls (no text), `has_content` was `False`, causing Codex to loop infinitely and build context until `context_length_exceeded`. Now checks both `"message"` and `"function_call"`.
+- **`has_message`/`has_tool_call` initialized in all 5 locations**: Previous fix added variables inside `_observe_event` closure but missed 4 other `has_content = False` locations, causing `NameError: name 'has_message' is not defined` crashes.
+- **Auth config-not-found error handling**: When Codex's `config.toml` is missing or deleted, `codex login status` returns "Error loading configuration: No such file or directory (os error 2)". Now caught specifically (`OSError errno==2`) and returns ("not_configured", "Config missing — launch once to create") with clear GUI guidance.
+
+### Bug Fixes (GUI)
+
+- **Active endpoint sync**: GUI auto-removes stale endpoint references on startup
+
+## v3.11.5 (2026-05-26)
+
+**Vision Filter, Token-Aware Compaction, Universal Adaptive Compaction, Smart-Continue Text Detection**
+
+### Critical Fixes
+
+- **Token-aware compaction for small-context models (FIX)**: `_crof_compact_for_retry()` had an early return at `len(input_data) <= limit` (item count) — if you had 25 items × 1600 tokens = 40K tokens, it skipped compaction entirely because 25 < 30 (the default item limit). Now also checks estimated token count vs learned model max, and compacts when either item count OR token count exceeds limits. Fixes repeated `context_length_exceeded` errors on models like 0G-GLM-5.1 (~35K token context).
+- **Proactive compaction now token-aware**: Previously only triggered when item count > 30. Now also triggers when estimated tokens exceed 80% of the model's learned token limit, even if item count is below the threshold. Prevents the first-request failure pattern on small-context models.
+- **Compaction aggression threshold**: Changed `est > max_tok` to `est >= max_tok * 0.9` to avoid edge case where estimated tokens exactly equal the limit and compaction is skipped.
+- **Removed all `crof.ai` gates from adaptive compaction**: Proactive compaction, `finish_reason=length` retry, `_crof_record`, and compaction logging were gated behind `"crof.ai" in TARGET_URL`. These gates prevented OpenAdapter and other providers from getting proactive/retry compaction, causing repeated `context_length_exceeded` failures. Now applies universally to ALL providers.
+
+### New Features
+
+- **Vision model detection + image stripping**: `_strip_images_from_input()` and `_model_supports_vision()` detect vision capability by model name pattern. Non-vision models (deepseek, glm, mixtral, llama, command, dbrx, qwen, phi-3) have `input_image`/`image_url` parts stripped and replaced with `[User attached image: filename — this model does not support vision]` text notice. Vision models (gpt-4o, gemini, claude, qwen-vl, glm-5v) keep images intact. Applied in 3 paths: main request, context_length_exceeded retry, smart-continue nudge.
+- **Token estimation and per-model limit learning**: `_estimate_tokens()`, `_estimate_input_tokens()`, `_get_model_max_tokens()`, `_set_model_max_tokens()`. Extracts `~N tokens` from `context_length_exceeded` error messages and stores per-model token limits. Used by proactive compaction and retry compaction to adjust `keep` count dynamically.
+- **Compaction aggression levels**: `_crof_compact_for_retry()` accepts `aggression` parameter (0=normal, 1=extreme). Extreme mode kicks in when estimated tokens > 1.5× the learned limit or on 2nd+ retry attempt. Reduces `keep` count to minimum, ensuring the compacted request fits within model limits.
+- **Smart-continue text-tool detection**: Removed hard requirement for `has_function_call_output(input_data)`. Added `_TOOL_CALL_TEXT_PATTERNS` and `_text_looks_like_tool_calls()` to trigger nudging when model outputs text matching tool-call patterns (e.g., `• (exec_command cmd ...)`, `write_to_file`, `exec_command`) even without prior `function_call_output` in context. Essential for models like 0G-GLM-5.1 that never emit real `function_call_output` items.
+- **Parenthesized tool call regex**: `_PAREN_TC_RE` pattern to match `• (name args...)` format from non-vision models that output tool calls as parenthesized text.
+
+### GUI Fixes
+
+- **Active endpoint sync**: Added `set_active_endpoint()` and `validate_active_endpoint()` to Linux GTK GUI. Syncs `.active-endpoint.json` with `config.toml` on every launch; auto-removes stale references to deleted providers. Fixed `"Error loading configuration: No such file or directory (os error 2)"` crash when active endpoint referenced a deleted provider.
+- **Config state**: `~/.codex/.active-endpoint.json` and `config.toml` model catalog path validated and auto-corrected on GUI startup.
+
+## v3.11.0 (2026-05-26)
+
+**Cobra PR Merge + Smart Continuation + API Key Hot-Reload**
+
+### New Features
+- **Concurrency semaphore (max 3)**: limits parallel upstream requests to prevent rate-limiting
+- **Auto-continue for truncated text**: detects text ending in `:`, `(`, `;`, `…` or `finish_reason=length`, continues seamlessly
+- **SO_REUSEADDR on sticky port**: prevents `TIME_WAIT` from changing port on restart
+- **proxy-stderr.log**: persistent log file for proxy errors
+- **Stream diagnostics**: logs event count, finish reason, content flag, elapsed time after each stream
+- **Timeout/OSError handler**: sends proper `response.failed` SSE event instead of silently dropping connection
+- **Restart Proxy button**: now only restarts proxy without killing Codex Desktop
+- **Tool call argument normalizer**: fixes capital-A `Arguments` key, strips markdown/JSON code block wrapping from tool call arguments
+- **Smart-continue loop (2× retries)**: escalating nudge messages when model returns text-only stop mid-task
+- **XML tool call extraction**: parses `<tool_call>name{args}</tool_call>` from model text output, injects as real `function_call` items
+- **Auto-continue + smart-continue ordered with skip guard**: prevents both from double-firing on the same response
+- **API key hot-reload**: mtime tracking detects config changes, `/admin/reload` endpoint triggers hot-reload, `/admin/verify-key` tests key against upstream
+- **GUI hot-reload**: auto-refreshes proxy key on endpoint edit, verifies with upstream — no proxy restart needed
+- **Synthetic tool-results disabled**: was causing deepseek-v4-pro truncation on opencode.ai
+
 ## v3.10.12 (2026-05-26)
 
 **Sticky Endpoint, Claude Fixes, Guardrail Skip, Anti-Stall**

README.md

@@ -130,6 +130,14 @@ A three-component system:
 - **Response store TTL** — evicts stored responses older than 10 minutes, prevents memory leaks
 - **Bounded stream buffers** — 8MB cap prevents OOM on pathological responses
 - **Dual logging** — all proxy messages written to both stderr and `~/.cache/codex-proxy/proxy.log`
+- **Vision model detection** (v3.11.5) — automatically strips images for non-vision models (DeepSeek, GLM, Qwen, etc.) and replaces with text notice; vision-capable models (GPT-4o, Gemini, Claude, Qwen-VL) keep images intact
+- **Token-aware compaction** (v3.11.5) — learns per-model token limits from `context_length_exceeded` errors; proactively compacts when estimated tokens exceed 80% of limit; prevents repeated context overflow on small-context models (~35K tokens)
+- **Universal adaptive compaction** (v3.11.5) — compaction now works for ALL providers (was Crof.ai-only); proactive + retry compaction with aggression levels (normal/extreme)
+- **Smart-continue text detection** (v3.11.5) — triggers continuation nudging when model outputs text matching tool-call patterns, essential for text-only models that never emit real `function_call_output` items
+- **Antigravity loop breakers** (v3.11.6) — per-session tracking with automatic finalization when same tool+args repeats 5+ times; edit-intent nudge injected only on first turn; latest user instruction appended exactly once per request
+- **has_content function_call fix** (v3.11.6) — tool-call-only responses now correctly flagged as having content, preventing infinite loops on OpenAdapter/Z.AI/OpenRouter providers
+- **Vision/OCR preprocessing** (v3.11.6) — when provider rejects images, automatically calls a configurable vision fallback API (Kilo.ai) to describe images as text for text-only models; MD5-cached; retries on vision errors with preprocessed text
+- **Auth config-missing fix** (v3.11.6) — graceful handling when Codex config.toml is missing instead of showing raw os error
 - Zero dependencies — pure Python stdlib
 
 ### Command Code Adapter

install.ps1

@@ -0,0 +1,127 @@
+<#
+.SYNOPSIS
+    Codex Launcher Windows Installer
+.DESCRIPTION
+    Installs Codex Launcher for the current user.
+.NOTES
+    Requires: Python 3.8+ (stdlib only, zero pip dependencies).
+#>
+
+param(
+    [switch]$Uninstall
+)
+
+$ErrorActionPreference = 'Stop'
+$BinDir = Join-Path $env:LOCALAPPDATA 'Programs\Codex-Launcher'
+$StartMenu = Join-Path $env:APPDATA 'Microsoft\Windows\Start Menu\Programs'
+
+if ($Uninstall) {
+    Write-Host 'Uninstalling Codex Launcher...' -ForegroundColor Yellow
+
+    if (Test-Path $BinDir) {
+        Remove-Item -Recurse -Force $BinDir
+        Write-Host "  Removed $BinDir"
+    }
+
+    $shortcut = Join-Path $StartMenu 'Codex Launcher.lnk'
+    if (Test-Path $shortcut) {
+        Remove-Item -Force $shortcut
+        Write-Host '  Removed Start Menu shortcut'
+    }
+
+    $userPath = [Environment]::GetEnvironmentVariable('PATH', 'User')
+    if ($userPath -like "*$BinDir*") {
+        $newPath = ($userPath -split ';' | Where-Object { $_ -ne $BinDir }) -join ';'
+        [Environment]::SetEnvironmentVariable('PATH', $newPath, 'User')
+        Write-Host '  Removed from PATH'
+    }
+
+    Write-Host 'Uninstall complete.' -ForegroundColor Green
+    return
+}
+
+Write-Host ''
+Write-Host '  Codex Launcher - Windows Installer' -ForegroundColor Cyan
+Write-Host '  ====================================' -ForegroundColor Cyan
+Write-Host ''
+
+# Check Python
+$pythonExe = Get-Command python -ErrorAction SilentlyContinue
+if (-not $pythonExe) {
+    $pythonExe = Get-Command python3 -ErrorAction SilentlyContinue
+}
+if (-not $pythonExe) {
+    Write-Host 'ERROR: Python not found. Install Python 3.8+ and add to PATH.' -ForegroundColor Red
+    exit 1
+}
+Write-Host "  Python: $($pythonExe.Source)" -ForegroundColor Gray
+
+# Create install directory
+New-Item -ItemType Directory -Force -Path $BinDir | Out-Null
+
+# Copy files
+$srcDir = Join-Path $PSScriptRoot 'src'
+$files = @(
+    'translate-proxy.py',
+    'codex-launcher-gui.py',
+    'codex_launcher_lib.py',
+    'cleanup-codex-stale.py'
+)
+
+foreach ($file in $files) {
+    $src = Join-Path $srcDir $file
+    if (Test-Path $src) {
+        Copy-Item -Force $src $BinDir
+        Write-Host "  Installed: $file" -ForegroundColor Green
+    } else {
+        Write-Host "  WARNING: $file not found in src/" -ForegroundColor Yellow
+    }
+}
+
+# Create Start Menu shortcut
+$WshShell = New-Object -ComObject WScript.Shell
+$shortcutPath = Join-Path $StartMenu 'Codex Launcher.lnk'
+$Shortcut = $WshShell.CreateShortcut($shortcutPath)
+
+# Find pythonw.exe for no-console launch
+$pythonw = Get-Command pythonw -ErrorAction SilentlyContinue
+if (-not $pythonw) {
+    $pythonDir = Split-Path $pythonExe.Source
+    $pythonwCandidate = Join-Path $pythonDir 'pythonw.exe'
+    if (Test-Path $pythonwCandidate) {
+        $pythonw = $pythonwCandidate
+    }
+}
+
+if ($pythonw) {
+    $targetPath = if ($pythonw.Source) { $pythonw.Source } else { $pythonw }
+} else {
+    $targetPath = $pythonExe.Source
+}
+$Shortcut.TargetPath = $targetPath
+$guiPath = Join-Path $BinDir 'codex-launcher-gui.py'
+$Shortcut.Arguments = $guiPath
+$Shortcut.WorkingDirectory = $BinDir
+$Shortcut.Description = 'Launch Codex Desktop with any AI provider'
+$Shortcut.Save()
+Write-Host '  Created Start Menu shortcut' -ForegroundColor Green
+
+# Add to PATH
+$userPath = [Environment]::GetEnvironmentVariable('PATH', 'User')
+if ($userPath -notlike "*$BinDir*") {
+    $newUserPath = $userPath + ';' + $BinDir
+    [Environment]::SetEnvironmentVariable('PATH', $newUserPath, 'User')
+    $env:PATH = $env:PATH + ';' + $BinDir
+    Write-Host '  Added to user PATH' -ForegroundColor Green
+}
+
+# Verify
+Write-Host ''
+Write-Host '  Installation complete!' -ForegroundColor Cyan
+Write-Host "  Install dir: $BinDir" -ForegroundColor Gray
+Write-Host ''
+Write-Host '  Launch options:' -ForegroundColor White
+Write-Host '    Start Menu:  Codex Launcher' -ForegroundColor Gray
+Write-Host '    Command:     codex-launcher-gui.py' -ForegroundColor Gray
+Write-Host '    Uninstall:   powershell -File install.ps1 -Uninstall' -ForegroundColor Gray
+Write-Host ''

install.sh

@@ -3,11 +3,13 @@ set -e
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 
-if [ -f "$SCRIPT_DIR/codex-launcher_3.10.12_all.deb" ]; then
+if [ -f "$SCRIPT_DIR/codex-launcher_3.11.6_all.deb" ]; then
-    echo "Installing codex-launcher_3.10.12_all.deb ..."
+    echo "Installing codex-launcher_3.11.6_all.deb ..."
-    sudo dpkg -i "$SCRIPT_DIR/codex-launcher_3.10.12_all.deb"
+    sudo dpkg -i "$SCRIPT_DIR/codex-launcher_3.11.6_all.deb"
-    echo ""
+else
-    echo "Installed v3.10.12 via .deb package."
+    echo "WARNING: codex-launcher_3.11.6_all.deb not found; copying files manually."
+fi
+echo "Installed v3.11.6 via .deb package."
     echo "  translate-proxy.py   -> /usr/bin/translate-proxy.py"
     echo "  codex-launcher-gui   -> /usr/bin/codex-launcher-gui"
     echo "  cleanup-codex-stale  -> /usr/bin/cleanup-codex-stale.sh"

src/antigravity_grpc/__init__.py

@@ -0,0 +1,24 @@
+"""
+antigravity_grpc — gRPC fallback client for Google CloudCode (Antigravity).
+
+When the REST API rejects a request (404 model not found, 400 bad request due to
+model ID mismatch, etc.), this module provides a gRPC fallback path that uses
+Google's native PredictionService protocol — the same one the agy CLI uses.
+
+This module is imported lazily and only when grpcio is installed. If grpcio is
+not available, the fallback is silently skipped.
+"""
+
+from .client import (
+    GrpcFallbackResult,
+    AntigravityGrpcClient,
+    is_grpc_available,
+    get_client,
+)
+
+__all__ = [
+    "GrpcFallbackResult",
+    "AntigravityGrpcClient",
+    "is_grpc_available",
+    "get_client",
+]

src/antigravity_grpc/client.py

@@ -0,0 +1,609 @@
+"""
+antigravity_grpc.client — gRPC fallback client for Google CloudCode (Antigravity).
+
+This module provides a gRPC client that can be used as an automatic fallback when
+the CloudCode REST API rejects requests. The gRPC path uses the same
+PredictionService that the native agy CLI binary uses, giving access to models
+that are unavailable via REST (e.g. models that return 404 on REST but work on gRPC).
+
+Key design decisions:
+  - Lazy import: grpcio is only imported when actually needed. If not installed,
+    is_grpc_available() returns False and the fallback is silently skipped.
+  - Zero impact on other providers: this module is only called from
+    _handle_antigravity_v2() when REST returns a fallback-eligible error.
+  - Same output format as REST: the client returns structured dicts that match
+    the SSE/JSON response shapes the proxy already processes.
+  - Thread-safe: the gRPC channel is created once per endpoint and reused.
+
+Usage from translate-proxy.py:
+    from antigravity_grpc import is_grpc_available, AntigravityGrpcClient
+
+    if is_grpc_available():
+        client = AntigravityGrpcClient()
+        result = client.try_generate(request_dict, stream=False)
+        if result.ok:
+            # Use result.response_data (dict matching REST response shape)
+        else:
+            # gRPC also failed, fall through to error
+"""
+
+import json
+import os
+import sys
+import time
+import threading
+import collections
+
+# ═══════════════════════════════════════════════════════════════════
+# Lazy gRPC import — never crash if grpcio is missing
+# ═══════════════════════════════════════════════════════════════════
+
+_grpc = None
+_pb2 = None
+_pb2_grpc = None
+_import_error = None
+
+def _try_import():
+    global _grpc, _pb2, _pb2_grpc, _import_error
+    if _grpc is not None:
+        return _grpc is not False
+    try:
+        import grpc as _real_grpc
+        # Import the generated stubs relative to this package
+        from . import cloudcode_pb2 as _real_pb2
+        from . import cloudcode_pb2_grpc as _real_pb2_grpc
+        _grpc = _real_grpc
+        _pb2 = _real_pb2
+        _pb2_grpc = _real_pb2_grpc
+        return True
+    except Exception as e:
+        _import_error = str(e)
+        _grpc = False
+        return False
+
+
+def is_grpc_available():
+    """Return True if grpcio and the generated stubs are importable."""
+    return _try_import()
+
+
+# ═══════════════════════════════════════════════════════════════════
+# gRPC endpoints for Antigravity (same hosts, different port/path)
+# ═══════════════════════════════════════════════════════════════════
+# The CloudCode gRPC service runs on the same hosts as REST but uses
+# the gRPC protocol. The agy CLI connects to:
+#   - cloudcode-pa.googleapis.com:443
+#   - daily-cloudcode-pa.googleapis.com:443
+#   - daily-cloudcode-pa.sandbox.googleapis.com:443
+
+_GRPC_ENDPOINTS = [
+    "daily-cloudcode-pa.googleapis.com:443",
+    "cloudcode-pa.googleapis.com:443",
+]
+
+_ALLOW_STAGING_ENV = "ALLOW_ANTIGRAVITY_STAGING"
+
+# ═══════════════════════════════════════════════════════════════════
+# Result type
+# ═══════════════════════════════════════════════════════════════════
+
+class GrpcFallbackResult:
+    """Result of a gRPC fallback attempt."""
+
+    __slots__ = ("ok", "response_data", "stream_chunks", "error_message",
+                 "endpoint_used", "model_used", "elapsed_s")
+
+    def __init__(self, ok=False, response_data=None, stream_chunks=None,
+                 error_message="", endpoint_used="", model_used="", elapsed_s=0.0):
+        self.ok = ok
+        self.response_data = response_data      # dict (non-streaming)
+        self.stream_chunks = stream_chunks      # list[dict] (streaming)
+        self.error_message = error_message
+        self.endpoint_used = endpoint_used
+        self.model_used = model_used
+        self.elapsed_s = elapsed_s
+
+    def __repr__(self):
+        if self.ok:
+            if self.stream_chunks is not None:
+                return f"<GrpcFallbackResult OK stream chunks={len(self.stream_chunks)}>"
+            return f"<GrpcFallbackResult OK data_keys={list(self.response_data.keys()) if self.response_data else None}>"
+        return f"<GrpcFallbackResult FAIL error={self.error_message!r}>"
+
+
+# ═══════════════════════════════════════════════════════════════════
+# JSON → Protobuf conversion helpers
+# ═══════════════════════════════════════════════════════════════════
+
+def _struct_to_protobuf(d, struct_obj=None):
+    """Convert a Python dict to a google.protobuf.Struct."""
+    from google.protobuf.struct_pb2 import Struct, Value, NullValue, ListValue
+    if struct_obj is None:
+        struct_obj = Struct()
+    if isinstance(d, dict):
+        for k, v in d.items():
+            if isinstance(v, str):
+                struct_obj.fields[k].string_value = v
+            elif isinstance(v, bool):
+                struct_obj.fields[k].bool_value = v
+            elif isinstance(v, int):
+                struct_obj.fields[k].number_value = float(v)
+            elif isinstance(v, float):
+                struct_obj.fields[k].number_value = v
+            elif isinstance(v, dict):
+                _struct_to_protobuf(v, struct_obj.fields[k].struct_value)
+            elif isinstance(v, list):
+                lst = struct_obj.fields[k].list_value
+                for item in v:
+                    if isinstance(item, str):
+                        lst.values.add().string_value = item
+                    elif isinstance(item, bool):
+                        lst.values.add().bool_value = item
+                    elif isinstance(item, (int, float)):
+                        lst.values.add().number_value = float(item)
+                    elif isinstance(item, dict):
+                        _struct_to_protobuf(item, lst.values.add().struct_value)
+                    elif item is None:
+                        lst.values.add().null_value = 0
+            elif v is None:
+                struct_obj.fields[k].null_value = 0
+    return struct_obj
+
+
+def _protobuf_struct_to_dict(struct):
+    """Convert a google.protobuf.Struct to a Python dict."""
+    from google.protobuf.struct_pb2 import Value, NullValue
+    result = {}
+    for k, v in struct.fields.items():
+        kind = v.WhichOneof("kind")
+        if kind == "null_value":
+            result[k] = None
+        elif kind == "number_value":
+            result[k] = v.number_value
+        elif kind == "string_value":
+            result[k] = v.string_value
+        elif kind == "bool_value":
+            result[k] = v.bool_value
+        elif kind == "struct_value":
+            result[k] = _protobuf_struct_to_dict(v.struct_value)
+        elif kind == "list_value":
+            result[k] = [_value_to_python(item) for item in v.list_value.values]
+        else:
+            result[k] = None
+    return result
+
+
+def _value_to_python(v):
+    """Convert a google.protobuf.Value to a Python value."""
+    kind = v.WhichOneof("kind")
+    if kind == "null_value":
+        return None
+    elif kind == "number_value":
+        return v.number_value
+    elif kind == "string_value":
+        return v.string_value
+    elif kind == "bool_value":
+        return v.bool_value
+    elif kind == "struct_value":
+        return _protobuf_struct_to_dict(v.struct_value)
+    elif kind == "list_value":
+        return [_value_to_python(item) for item in v.list_value.values]
+    return None
+
+
+def _json_parts_to_proto(parts_json):
+    """Convert a list of JSON content parts to protobuf Part messages."""
+    result = []
+    for p in parts_json:
+        if not isinstance(p, dict):
+            continue
+        part = _pb2.Part()
+
+        # Thought signature
+        sig = p.get("thoughtSignature") or p.get("thought_signature")
+        if sig:
+            part.thought_signature = sig
+
+        if p.get("thought"):
+            part.thought = True
+            if "text" in p:
+                part.text = p["text"]
+        elif "text" in p and "functionCall" not in p:
+            part.text = p["text"]
+        elif "functionCall" in p:
+            fc = p["functionCall"]
+            part.function_call.name = fc.get("name", "")
+            part.function_call.id = fc.get("id", "")
+            args = fc.get("args", fc.get("arguments", {}))
+            if isinstance(args, dict):
+                _struct_to_protobuf(args, part.function_call.args)
+            elif isinstance(args, str):
+                try:
+                    _struct_to_protobuf(json.loads(args), part.function_call.args)
+                except Exception:
+                    pass
+        elif "functionResponse" in p:
+            fr = p["functionResponse"]
+            part.function_response.name = fr.get("name", "")
+            part.function_response.id = fr.get("id", "")
+            resp = fr.get("response", {})
+            if "result" in resp:
+                result_val = resp["result"]
+                if isinstance(result_val, (dict, list)):
+                    _struct_to_protobuf({"result": result_val}, part.function_response.response)
+                else:
+                    _struct_to_protobuf({"result": str(result_val)}, part.function_response.response)
+            elif isinstance(resp, dict):
+                _struct_to_protobuf(resp, part.function_response.response)
+        elif "inlineData" in p:
+            idata = p["inlineData"]
+            import base64
+            part.inline_data.mime_type = idata.get("mimeType", "image/png")
+            b64data = idata.get("data", "")
+            part.inline_data.data = base64.b64decode(b64data) if b64data else b""
+
+        result.append(part)
+    return result
+
+
+def _json_contents_to_proto(contents_json):
+    """Convert a list of JSON content objects to protobuf Content messages."""
+    result = []
+    for c in contents_json:
+        if not isinstance(c, dict):
+            continue
+        content = _pb2.Content()
+        content.role = c.get("role", "user")
+        for part in _json_parts_to_proto(c.get("parts", [])):
+            content.parts.append(part)
+        result.append(content)
+    return result
+
+
+def _proto_candidate_to_json(candidate):
+    """Convert a protobuf Candidate to a JSON-compatible dict."""
+    content_json = {"role": candidate.content.role, "parts": []}
+    for part in candidate.content.parts:
+        p = {}
+        if part.thought_signature:
+            p["thoughtSignature"] = part.thought_signature
+        if part.thought:
+            p["thought"] = True
+            if part.text:
+                p["text"] = part.text
+        elif part.text and not part.HasField("function_call"):
+            p["text"] = part.text
+        elif part.HasField("function_call"):
+            fc = part.function_call
+            args_dict = _protobuf_struct_to_dict(fc.args) if fc.HasField("args") else {}
+            p["functionCall"] = {
+                "name": fc.name,
+                "args": args_dict,
+                "id": fc.id,
+            }
+        elif part.HasField("function_response"):
+            fr = part.function_response
+            resp_dict = _protobuf_struct_to_dict(fr.response) if fr.HasField("response") else {}
+            p["functionResponse"] = {
+                "name": fr.name,
+                "response": resp_dict,
+                "id": fr.id,
+            }
+        elif part.HasField("inline_data"):
+            import base64
+            p["inlineData"] = {
+                "mimeType": part.inline_data.mime_type,
+                "data": base64.b64encode(part.inline_data.data).decode(),
+            }
+        if p:
+            content_json["parts"].append(p)
+
+    return {
+        "content": content_json,
+        "finishReason": candidate.finish_reason,
+        "index": candidate.index,
+    }
+
+
+# ═══════════════════════════════════════════════════════════════════
+# Client
+# ═══════════════════════════════════════════════════════════════════
+
+class AntigravityGrpcClient:
+    """
+    gRPC fallback client for Google CloudCode Antigravity.
+
+    Thread-safe. Channels are cached per endpoint and reused.
+    """
+
+    def __init__(self):
+        self._channels = {}
+        self._stubs = {}
+        self._lock = threading.Lock()
+
+    def _get_channel(self, endpoint):
+        """Get or create a gRPC channel for the given endpoint."""
+        with self._lock:
+            if endpoint not in self._channels:
+                # Use secure channel with default SSL credentials
+                creds = _grpc.ssl_channel_credentials()
+                channel = _grpc.secure_channel(endpoint, creds)
+                self._channels[endpoint] = channel
+                self._stubs[endpoint] = _pb2_grpc.PredictionServiceStub(channel)
+            return self._channels[endpoint], self._stubs[endpoint]
+
+    def _build_request(self, wrapped_dict):
+        """
+        Build a GenerateContentRequest protobuf from the same wrapped dict
+        that the REST API uses.
+
+        wrapped_dict shape:
+        {
+            "project": "...",
+            "model": "...",
+            "requestType": "agent",
+            "userAgent": "antigravity/...",
+            "requestId": "agent-...",
+            "request": {
+                "contents": [...],
+                "systemInstruction": {...},
+                "generationConfig": {...},
+                "tools": [...],
+                "safetySettings": [...],
+                "toolConfig": {...},
+                "sessionId": "..."
+            }
+        }
+        """
+        req = _pb2.GenerateContentRequest()
+        req.project = wrapped_dict.get("project", "")
+        req.model = wrapped_dict.get("model", "")
+        req.request_type = wrapped_dict.get("requestType", "agent")
+        req.user_agent = wrapped_dict.get("userAgent", "")
+        req.request_id = wrapped_dict.get("requestId", "")
+
+        inner = wrapped_dict.get("request", {})
+
+        # Contents
+        for c in _json_contents_to_proto(inner.get("contents", [])):
+            req.request.contents.append(c)
+
+        # System instruction
+        si = inner.get("systemInstruction", {})
+        if si:
+            si_parts = si.get("parts", [])
+            if si.get("role"):
+                req.request.system_instruction.role = si.get("role", "user")
+            for part in _json_parts_to_proto(si_parts):
+                req.request.system_instruction.parts.append(part)
+
+        # Generation config
+        gc = inner.get("generationConfig", {})
+        if gc:
+            cfg = req.request.generation_config
+            if "maxOutputTokens" in gc:
+                cfg.max_output_tokens = int(gc["maxOutputTokens"])
+            if "temperature" in gc:
+                cfg.temperature = float(gc["temperature"])
+            if "topP" in gc:
+                cfg.top_p = float(gc["top_p" if "top_p" in gc else "topP"])
+            for ss in gc.get("stopSequences", []):
+                cfg.stop_sequences.append(ss)
+
+            # Thinking config (Gemini 3 native)
+            tc = gc.get("thinkingConfig", gc.get("thinking_config"))
+            if tc:
+                cfg.thinking_config.include_thoughts = tc.get("includeThoughts", tc.get("include_thoughts", False))
+                cfg.thinking_config.thinking_budget = int(tc.get("thinkingBudget", tc.get("thinking_budget", 8192)))
+            # Legacy thinking fields
+            if "includeThoughts" in gc and not tc:
+                cfg.thinking_config.include_thoughts = gc["includeThoughts"]
+            if "thinkingBudget" in gc and not tc:
+                cfg.thinking_config.thinking_budget = int(gc["thinkingBudget"])
+
+        # Tools
+        for tool_json in inner.get("tools", []):
+            tool = _pb2.Tool()
+            for fd_json in tool_json.get("functionDeclarations", []):
+                fd = tool.function_declarations.add()
+                fd.name = fd_json.get("name", "")
+                fd.description = fd_json.get("description", "")
+                params = fd_json.get("parameters", {})
+                if isinstance(params, dict) and params:
+                    _struct_to_protobuf(params, fd.parameters)
+            req.request.tools.append(tool)
+
+        # Safety settings
+        for ss in inner.get("safetySettings", []):
+            ss_msg = _pb2.SafetySetting()
+            ss_msg.category = ss.get("category", "")
+            ss_msg.threshold = ss.get("threshold", "OFF")
+            req.request.safety_settings.append(ss_msg)
+
+        # Tool config
+        tcfg = inner.get("toolConfig", {})
+        if tcfg:
+            fcc = tcfg.get("functionCallingConfig", {})
+            if fcc:
+                req.request.tool_config.function_calling_config.mode = fcc.get("mode", "AUTO")
+                for afn in fcc.get("allowed_function_names", []):
+                    req.request.tool_config.function_calling_config.allowed_function_names.append(afn)
+
+        # Session ID
+        sid = inner.get("sessionId", "")
+        if sid:
+            req.request.session_id = sid
+
+        return req
+
+    def try_generate(self, wrapped_dict, stream=False, access_token="",
+                     timeout_s=180):
+        """
+        Try a gRPC GenerateContent or StreamGenerateContent request.
+
+        Args:
+            wrapped_dict: The same wrapped dict used for REST requests.
+            stream: If True, use server-streaming RPC.
+            access_token: OAuth2 Bearer token for authentication.
+            timeout_s: Request timeout in seconds.
+
+        Returns:
+            GrpcFallbackResult with ok=True if successful.
+            For non-streaming: result.response_data is a dict matching
+                the REST JSON response shape.
+            For streaming: result.stream_chunks is a list of dicts matching
+                REST SSE chunk shapes.
+        """
+        if not is_grpc_available():
+            return GrpcFallbackResult(ok=False, error_message="grpcio not installed")
+
+        t0 = time.time()
+
+        # Build metadata (gRPC uses metadata instead of HTTP headers)
+        metadata = []
+        if access_token:
+            metadata.append(("authorization", f"Bearer {access_token}"))
+        ua = wrapped_dict.get("userAgent", "")
+        if ua:
+            metadata.append(("user-agent", ua))
+        metadata.append(("x-client-name", "antigravity"))
+        # Required for Google's gRPC gateway
+        metadata.append(("x-goog-api-client", "gl-node/18.18.2 fire/0.8.6 grpc/1.10.x"))
+
+        # Build endpoints list
+        endpoints = list(_GRPC_ENDPOINTS)
+        if os.environ.get(_ALLOW_STAGING_ENV, "0") == "1":
+            endpoints.append("daily-cloudcode-pa.sandbox.googleapis.com:443")
+            endpoints.append("autopush-cloudcode-pa.sandbox.googleapis.com:443")
+
+        model = wrapped_dict.get("model", "?")
+
+        last_error = ""
+        for ep in endpoints:
+            try:
+                channel, stub = self._get_channel(ep)
+                req = self._build_request(wrapped_dict)
+
+                if stream:
+                    return self._do_stream(stub, req, metadata, ep, model,
+                                           timeout_s, t0)
+                else:
+                    return self._do_unary(stub, req, metadata, ep, model,
+                                          timeout_s, t0)
+
+            except Exception as e:
+                last_error = str(e)
+                err_str = last_error.lower()
+                print(f"[antigravity-grpc] {ep} failed: {last_error[:300]}", file=sys.stderr)
+                # Don't retry on auth errors
+                if "unauthenticated" in err_str or "permission" in err_str:
+                    break
+                # Don't retry on invalid argument (model truly doesn't exist)
+                if "not_found" in err_str or "not found" in err_str:
+                    break
+                continue
+
+        elapsed = time.time() - t0
+        return GrpcFallbackResult(
+            ok=False,
+            error_message=f"All gRPC endpoints failed: {last_error}",
+            model_used=model,
+            elapsed_s=elapsed,
+        )
+
+    def _do_unary(self, stub, req, metadata, endpoint, model, timeout_s, t0):
+        """Execute a unary (non-streaming) gRPC call."""
+        response = stub.GenerateContent(
+            req,
+            metadata=metadata,
+            timeout=timeout_s,
+        )
+        elapsed = time.time() - t0
+
+        # Convert protobuf response to REST-compatible JSON shape
+        candidates_json = []
+        for candidate in response.response.candidates:
+            candidates_json.append(_proto_candidate_to_json(candidate))
+
+        # Match the REST response envelope:
+        # { "response": { "candidates": [...] } }
+        rest_shape = {
+            "response": {
+                "candidates": candidates_json,
+            }
+        }
+
+        print(f"[antigravity-grpc] {endpoint} unary OK, candidates={len(candidates_json)}, elapsed={elapsed:.1f}s", file=sys.stderr)
+
+        return GrpcFallbackResult(
+            ok=True,
+            response_data=rest_shape,
+            endpoint_used=endpoint,
+            model_used=model,
+            elapsed_s=elapsed,
+        )
+
+    def _do_stream(self, stub, req, metadata, endpoint, model, timeout_s, t0):
+        """Execute a server-streaming gRPC call."""
+        chunks = []
+        chunk_count = 0
+
+        response_iter = stub.StreamGenerateContent(
+            req,
+            metadata=metadata,
+            timeout=timeout_s,
+        )
+
+        for chunk_proto in response_iter:
+            chunk_count += 1
+            # Each chunk_proto is a StreamGenerateContentChunk
+            # which wraps a Response with candidates
+            candidates_json = []
+            for candidate in chunk_proto.response.candidates:
+                candidates_json.append(_proto_candidate_to_json(candidate))
+
+            # Match REST SSE chunk shape: { "response": { "candidates": [...] } }
+            chunk_json = {
+                "response": {
+                    "candidates": candidates_json,
+                }
+            }
+            chunks.append(chunk_json)
+
+        elapsed = time.time() - t0
+        print(f"[antigravity-grpc] {endpoint} stream OK, chunks={chunk_count}, elapsed={elapsed:.1f}s", file=sys.stderr)
+
+        return GrpcFallbackResult(
+            ok=True,
+            stream_chunks=chunks,
+            endpoint_used=endpoint,
+            model_used=model,
+            elapsed_s=elapsed,
+        )
+
+    def close(self):
+        """Close all gRPC channels."""
+        with self._lock:
+            for ep, channel in self._channels.items():
+                try:
+                    channel.close()
+                except Exception:
+                    pass
+            self._channels.clear()
+            self._stubs.clear()
+
+
+# ═══════════════════════════════════════════════════════════════════
+# Module-level singleton
+# ═══════════════════════════════════════════════════════════════════
+
+_client = None
+_client_lock = threading.Lock()
+
+def get_client():
+    """Get the module-level AntigravityGrpcClient singleton."""
+    global _client
+    with _client_lock:
+        if _client is None:
+            _client = AntigravityGrpcClient()
+        return _client

src/antigravity_grpc/cloudcode_pb2_grpc.py

@@ -0,0 +1,275 @@
+# Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
+"""Client and server classes corresponding to protobuf-defined services."""
+import grpc
+import warnings
+
+from antigravity_grpc import cloudcode_pb2 as cloudcode__pb2
+
+GRPC_GENERATED_VERSION = '1.80.0'
+GRPC_VERSION = grpc.__version__
+_version_not_supported = False
+
+try:
+    from grpc._utilities import first_version_is_lower
+    _version_not_supported = first_version_is_lower(GRPC_VERSION, GRPC_GENERATED_VERSION)
+except ImportError:
+    _version_not_supported = True
+
+if _version_not_supported:
+    raise RuntimeError(
+        f'The grpc package installed is at version {GRPC_VERSION},'
+        + ' but the generated code in cloudcode_pb2_grpc.py depends on'
+        + f' grpcio>={GRPC_GENERATED_VERSION}.'
+        + f' Please upgrade your grpc module to grpcio>={GRPC_GENERATED_VERSION}'
+        + f' or downgrade your generated code using grpcio-tools<={GRPC_VERSION}.'
+    )
+
+
+class PredictionServiceStub(object):
+    """─── Service ──────────────────────────────────────────────────────────
+
+    """
+
+    def __init__(self, channel):
+        """Constructor.
+
+        Args:
+            channel: A grpc.Channel.
+        """
+        self.GenerateContent = channel.unary_unary(
+                '/google.internal.cloud.code.v1internal.PredictionService/GenerateContent',
+                request_serializer=cloudcode__pb2.GenerateContentRequest.SerializeToString,
+                response_deserializer=cloudcode__pb2.GenerateContentResponse.FromString,
+                _registered_method=True)
+        self.StreamGenerateContent = channel.unary_stream(
+                '/google.internal.cloud.code.v1internal.PredictionService/StreamGenerateContent',
+                request_serializer=cloudcode__pb2.GenerateContentRequest.SerializeToString,
+                response_deserializer=cloudcode__pb2.StreamGenerateContentChunk.FromString,
+                _registered_method=True)
+        self.FetchAvailableModels = channel.unary_unary(
+                '/google.internal.cloud.code.v1internal.PredictionService/FetchAvailableModels',
+                request_serializer=cloudcode__pb2.FetchAvailableModelsRequest.SerializeToString,
+                response_deserializer=cloudcode__pb2.FetchAvailableModelsResponse.FromString,
+                _registered_method=True)
+        self.CountTokens = channel.unary_unary(
+                '/google.internal.cloud.code.v1internal.PredictionService/CountTokens',
+                request_serializer=cloudcode__pb2.CountTokensRequest.SerializeToString,
+                response_deserializer=cloudcode__pb2.CountTokensResponse.FromString,
+                _registered_method=True)
+        self.RetrieveUserQuota = channel.unary_unary(
+                '/google.internal.cloud.code.v1internal.PredictionService/RetrieveUserQuota',
+                request_serializer=cloudcode__pb2.RetrieveUserQuotaRequest.SerializeToString,
+                response_deserializer=cloudcode__pb2.RetrieveUserQuotaResponse.FromString,
+                _registered_method=True)
+
+
+class PredictionServiceServicer(object):
+    """─── Service ──────────────────────────────────────────────────────────
+
+    """
+
+    def GenerateContent(self, request, context):
+        """Missing associated documentation comment in .proto file."""
+        context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+        context.set_details('Method not implemented!')
+        raise NotImplementedError('Method not implemented!')
+
+    def StreamGenerateContent(self, request, context):
+        """Missing associated documentation comment in .proto file."""
+        context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+        context.set_details('Method not implemented!')
+        raise NotImplementedError('Method not implemented!')
+
+    def FetchAvailableModels(self, request, context):
+        """Missing associated documentation comment in .proto file."""
+        context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+        context.set_details('Method not implemented!')
+        raise NotImplementedError('Method not implemented!')
+
+    def CountTokens(self, request, context):
+        """Missing associated documentation comment in .proto file."""
+        context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+        context.set_details('Method not implemented!')
+        raise NotImplementedError('Method not implemented!')
+
+    def RetrieveUserQuota(self, request, context):
+        """Missing associated documentation comment in .proto file."""
+        context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+        context.set_details('Method not implemented!')
+        raise NotImplementedError('Method not implemented!')
+
+
+def add_PredictionServiceServicer_to_server(servicer, server):
+    rpc_method_handlers = {
+            'GenerateContent': grpc.unary_unary_rpc_method_handler(
+                    servicer.GenerateContent,
+                    request_deserializer=cloudcode__pb2.GenerateContentRequest.FromString,
+                    response_serializer=cloudcode__pb2.GenerateContentResponse.SerializeToString,
+            ),
+            'StreamGenerateContent': grpc.unary_stream_rpc_method_handler(
+                    servicer.StreamGenerateContent,
+                    request_deserializer=cloudcode__pb2.GenerateContentRequest.FromString,
+                    response_serializer=cloudcode__pb2.StreamGenerateContentChunk.SerializeToString,
+            ),
+            'FetchAvailableModels': grpc.unary_unary_rpc_method_handler(
+                    servicer.FetchAvailableModels,
+                    request_deserializer=cloudcode__pb2.FetchAvailableModelsRequest.FromString,
+                    response_serializer=cloudcode__pb2.FetchAvailableModelsResponse.SerializeToString,
+            ),
+            'CountTokens': grpc.unary_unary_rpc_method_handler(
+                    servicer.CountTokens,
+                    request_deserializer=cloudcode__pb2.CountTokensRequest.FromString,
+                    response_serializer=cloudcode__pb2.CountTokensResponse.SerializeToString,
+            ),
+            'RetrieveUserQuota': grpc.unary_unary_rpc_method_handler(
+                    servicer.RetrieveUserQuota,
+                    request_deserializer=cloudcode__pb2.RetrieveUserQuotaRequest.FromString,
+                    response_serializer=cloudcode__pb2.RetrieveUserQuotaResponse.SerializeToString,
+            ),
+    }
+    generic_handler = grpc.method_handlers_generic_handler(
+            'google.internal.cloud.code.v1internal.PredictionService', rpc_method_handlers)
+    server.add_generic_rpc_handlers((generic_handler,))
+    server.add_registered_method_handlers('google.internal.cloud.code.v1internal.PredictionService', rpc_method_handlers)
+
+
+ # This class is part of an EXPERIMENTAL API.
+class PredictionService(object):
+    """─── Service ──────────────────────────────────────────────────────────
+
+    """
+
+    @staticmethod
+    def GenerateContent(request,
+            target,
+            options=(),
+            channel_credentials=None,
+            call_credentials=None,
+            insecure=False,
+            compression=None,
+            wait_for_ready=None,
+            timeout=None,
+            metadata=None):
+        return grpc.experimental.unary_unary(
+            request,
+            target,
+            '/google.internal.cloud.code.v1internal.PredictionService/GenerateContent',
+            cloudcode__pb2.GenerateContentRequest.SerializeToString,
+            cloudcode__pb2.GenerateContentResponse.FromString,
+            options,
+            channel_credentials,
+            insecure,
+            call_credentials,
+            compression,
+            wait_for_ready,
+            timeout,
+            metadata,
+            _registered_method=True)
+
+    @staticmethod
+    def StreamGenerateContent(request,
+            target,
+            options=(),
+            channel_credentials=None,
+            call_credentials=None,
+            insecure=False,
+            compression=None,
+            wait_for_ready=None,
+            timeout=None,
+            metadata=None):
+        return grpc.experimental.unary_stream(
+            request,
+            target,
+            '/google.internal.cloud.code.v1internal.PredictionService/StreamGenerateContent',
+            cloudcode__pb2.GenerateContentRequest.SerializeToString,
+            cloudcode__pb2.StreamGenerateContentChunk.FromString,
+            options,
+            channel_credentials,
+            insecure,
+            call_credentials,
+            compression,
+            wait_for_ready,
+            timeout,
+            metadata,
+            _registered_method=True)
+
+    @staticmethod
+    def FetchAvailableModels(request,
+            target,
+            options=(),
+            channel_credentials=None,
+            call_credentials=None,
+            insecure=False,
+            compression=None,
+            wait_for_ready=None,
+            timeout=None,
+            metadata=None):
+        return grpc.experimental.unary_unary(
+            request,
+            target,
+            '/google.internal.cloud.code.v1internal.PredictionService/FetchAvailableModels',
+            cloudcode__pb2.FetchAvailableModelsRequest.SerializeToString,
+            cloudcode__pb2.FetchAvailableModelsResponse.FromString,
+            options,
+            channel_credentials,
+            insecure,
+            call_credentials,
+            compression,
+            wait_for_ready,
+            timeout,
+            metadata,
+            _registered_method=True)
+
+    @staticmethod
+    def CountTokens(request,
+            target,
+            options=(),
+            channel_credentials=None,
+            call_credentials=None,
+            insecure=False,
+            compression=None,
+            wait_for_ready=None,
+            timeout=None,
+            metadata=None):
+        return grpc.experimental.unary_unary(
+            request,
+            target,
+            '/google.internal.cloud.code.v1internal.PredictionService/CountTokens',
+            cloudcode__pb2.CountTokensRequest.SerializeToString,
+            cloudcode__pb2.CountTokensResponse.FromString,
+            options,
+            channel_credentials,
+            insecure,
+            call_credentials,
+            compression,
+            wait_for_ready,
+            timeout,
+            metadata,
+            _registered_method=True)
+
+    @staticmethod
+    def RetrieveUserQuota(request,
+            target,
+            options=(),
+            channel_credentials=None,
+            call_credentials=None,
+            insecure=False,
+            compression=None,
+            wait_for_ready=None,
+            timeout=None,
+            metadata=None):
+        return grpc.experimental.unary_unary(
+            request,
+            target,
+            '/google.internal.cloud.code.v1internal.PredictionService/RetrieveUserQuota',
+            cloudcode__pb2.RetrieveUserQuotaRequest.SerializeToString,
+            cloudcode__pb2.RetrieveUserQuotaResponse.FromString,
+            options,
+            channel_credentials,
+            insecure,
+            call_credentials,
+            compression,
+            wait_for_ready,
+            timeout,
+            metadata,
+            _registered_method=True)

src/antigravity_grpc/proto/cloudcode.proto

@@ -0,0 +1,183 @@
+// Copyright 2026 Codex Launcher Contributors
+// SPDX-License-Identifier: MIT
+//
+// CloudCode internal gRPC service definitions.
+// Reverse-engineered from the agy-core binary for Antigravity proxy fallback.
+// Service: google.internal.cloud.code.v1internal.PredictionService
+//
+// NOTE: google/api/annotations.proto is NOT imported here because it conflicts
+// with the google namespace package at runtime. The HTTP annotations are only
+// needed for Google's Envoy/gRPC-gateway and are unnecessary for our client.
+
+syntax = "proto3";
+
+package google.internal.cloud.code.v1internal;
+
+import "google/protobuf/struct.proto";
+
+option go_package = "google.golang.org/internal/cloud/code/v1internal";
+
+// ─── Reused message types ───────────────────────────────────────────
+
+message Content {
+  string role = 1;
+  repeated Part parts = 2;
+}
+
+message Part {
+  oneof data {
+    string text = 1;
+    InlineData inline_data = 2;
+    FunctionCall function_call = 3;
+    FunctionResponse function_response = 4;
+  }
+  // Thought signature for Gemini continuity
+  string thought_signature = 10;
+  // Thought part (reasoning)
+  bool thought = 11;
+}
+
+message InlineData {
+  string mime_type = 1;
+  bytes data = 2;
+}
+
+message FunctionCall {
+  string name = 1;
+  google.protobuf.Struct args = 2;
+  string id = 3;
+}
+
+message FunctionResponse {
+  string name = 1;
+  google.protobuf.Struct response = 2;
+  string id = 3;
+}
+
+message SafetySetting {
+  string category = 1;
+  string threshold = 2;
+}
+
+message GenerationConfig {
+  int32 max_output_tokens = 1;
+  float temperature = 2;
+  float top_p = 3;
+  int32 thinking_budget = 4;
+  bool include_thoughts = 5;
+  repeated string stop_sequences = 6;
+  message ThinkingConfig {
+    bool include_thoughts = 1;
+    int32 thinking_budget = 2;
+  }
+  ThinkingConfig thinking_config = 7;
+}
+
+message Tool {
+  repeated FunctionDeclaration function_declarations = 1;
+}
+
+message FunctionDeclaration {
+  string name = 1;
+  string description = 2;
+  google.protobuf.Struct parameters = 3;
+}
+
+message ToolConfig {
+  message FunctionCallingConfig {
+    string mode = 1;  // "AUTO", "ANY", "NONE", "VALIDATED"
+    repeated string allowed_function_names = 2;
+  }
+  FunctionCallingConfig function_calling_config = 1;
+}
+
+message Candidate {
+  Content content = 1;
+  string finish_reason = 2;
+  int32 index = 3;
+}
+
+// ─── GenerateContent ─────────────────────────────────────────────────
+
+message GenerateContentRequest {
+  string project = 1;
+  string model = 2;
+  string request_type = 3;
+  string user_agent = 4;
+  string request_id = 5;
+
+  message InnerRequest {
+    repeated Content contents = 1;
+    Content system_instruction = 2;
+    GenerationConfig generation_config = 3;
+    repeated Tool tools = 4;
+    repeated SafetySetting safety_settings = 5;
+    ToolConfig tool_config = 6;
+    string session_id = 7;
+  }
+
+  InnerRequest request = 10;
+}
+
+message GenerateContentResponse {
+  message Response {
+    repeated Candidate candidates = 1;
+  }
+  Response response = 1;
+}
+
+// ─── StreamGenerateContent ────────────────────────────────────────────
+
+message StreamGenerateContentChunk {
+  GenerateContentResponse.Response response = 1;
+}
+
+// ─── FetchAvailableModels ────────────────────────────────────────────
+
+message FetchAvailableModelsRequest {
+  string project = 1;
+}
+
+message FetchAvailableModelsResponse {
+  message ModelInfo {
+    string name = 1;
+    string display_name = 2;
+    string description = 3;
+    int64 context_window = 4;
+  }
+  repeated ModelInfo models = 1;
+}
+
+// ─── CountTokens ──────────────────────────────────────────────────────
+
+message CountTokensRequest {
+  string project = 1;
+  string model = 2;
+  repeated Content contents = 3;
+}
+
+message CountTokensResponse {
+  int32 total_tokens = 1;
+}
+
+// ─── RetrieveUserQuota ───────────────────────────────────────────────
+
+message RetrieveUserQuotaRequest {
+  string project = 1;
+}
+
+message RetrieveUserQuotaResponse {
+  int64 daily_limit = 1;
+  int64 daily_usage = 2;
+  int64 daily_remaining = 3;
+}
+
+// ─── Service ──────────────────────────────────────────────────────────
+
+service PredictionService {
+  rpc GenerateContent(GenerateContentRequest) returns (GenerateContentResponse);
+  rpc StreamGenerateContent(GenerateContentRequest) returns (stream StreamGenerateContentChunk);
+  rpc FetchAvailableModels(FetchAvailableModelsRequest) returns (FetchAvailableModelsResponse);
+  rpc CountTokens(CountTokensRequest) returns (CountTokensResponse);
+  rpc RetrieveUserQuota(RetrieveUserQuotaRequest) returns (RetrieveUserQuotaResponse);
+}

src/antigravity_grpc/proto/google/api/annotations.proto

@@ -0,0 +1,14 @@
+// Minimal google/api/annotations.proto for code generation.
+
+syntax = "proto3";
+
+package google.api;
+
+import "google/api/http.proto";
+import "google/protobuf/descriptor.proto";
+
+option go_package = "google.golang.org/genproto/googleapis/api/annotations";
+
+extend google.protobuf.MethodOptions {
+  HttpRule http = 72295728;
+}

src/antigravity_grpc/proto/google/api/http.proto

@@ -0,0 +1,18 @@
+// Minimal google/api/http.proto for code generation.
+
+syntax = "proto3";
+
+package google.api;
+
+option go_package = "google.golang.org/genproto/googleapis/api/annotations";
+
+message HttpRule {
+  string get = 1;
+  string put = 2;
+  string post = 3;
+  string delete = 4;
+  string patch = 5;
+  repeated HttpRule additional_bindings = 11;
+  string body = 7;
+  string response_body = 12;
+}

src/codex-launcher-gui

@@ -20,12 +20,70 @@ BGP_POOLS_FILE = HOME / ".codex/bgp-pools.json"
 LOG_DIR = HOME / ".cache/codex-desktop"
 LAUNCH_LOG = LOG_DIR / "launcher.log"
 PROXY_CONFIG_DIR = HOME / ".cache/codex-proxy"
+ACTIVE_ENDPOINT_FILE = HOME / ".codex/.active-endpoint.json"
 DEFAULT_CONFIG = """model = ""
 model_provider = ""
 model_catalog_json = ""
 """
 
 CHANGELOG = [
+    ("3.12.1", "2026-05-27", [
+        "Fix Antigravity adapter (PR #15): simplified model resolution",
+        "Removed broken schema sanitization, restored headers",
+        "Re-enabled gRPC fallback by default",
+    ]),
+    ("3.12.0", "2026-05-27", [
+        "gRPC auto-fallback for Antigravity (PR #13)",
+        "Dynamic version fetch with probe validation",
+        "Antigravity v2 handler rewrite (anti-api)",
+    ]),
+    ("3.11.10", "2026-05-26", [
+        "Fix Antigravity: interleave function_call/output pairs (PR #11)",
+        "Gemini sanitizer: trim non-user turns for Google API compliance",
+    ]),
+    ("3.11.9", "2026-05-26", [
+        "Fix Antigravity: preserve functionCall/functionResponse (PR #10)",
+        "Prevents tool responses from being dropped in multi-turn sessions",
+    ]),
+    ("3.11.8", "2026-05-26", [
+        "Vision cache persisted across requests (PR #8 merge)",
+        "No redundant vision API calls for same image URL",
+    ]),
+    ("3.11.7", "2026-05-26", [
+        "Vision auto-detect: uses provider's vision model for image description",
+        "Vision preprocessing replaces image stripping",
+        "Fix AttributeError in image_url string handling",
+        "Merge PR #6: vision/OCR preprocessing, PR #7: 177 unit tests",
+        "Auth os error 2 fix: proper config-missing message in GUI",
+    ]),
+    ("3.11.6", "2026-05-26", [
+        "Antigravity loop breakers: per-session tracking, repeated tool detection",
+        "has_content fix: function_call counts as valid output",
+        "Latest user instruction appended once per request for Antigravity",
+        "Antigravity-only changes, no touch to other providers",
+    ]),
+    ("3.11.5", "2026-05-26", [
+        "Token-aware compaction: fixes context_length_exceeded on small-context models",
+        "Proactive compaction triggers on token count, not just item count",
+        "Universal adaptive compaction for all providers (removed crof.ai gates)",
+        "Vision model detection + image stripping for non-vision models",
+        "Per-model token limit learning from error messages",
+        "Smart-continue text-tool detection for text-only models",
+        "Active endpoint sync: auto-removes stale references on startup",
+    ]),
+    ("3.11.0", "2026-05-26", [
+        "Merge cobra PR: concurrency semaphore (max 3), auto-continue for truncated text",
+        "SO_REUSEADDR on sticky port, proxy-stderr.log, stream diagnostics logging",
+        "Timeout/OSError handler sends response.failed SSE instead of silent drop",
+        "Restart Proxy button: only restarts proxy without killing Codex Desktop",
+        "Tool call argument normalizer: fixes Arguments→arguments, strips markdown wrapping",
+        "Smart-continue loop (2× retries): escalating nudges when model stops text-only mid-task",
+        "XML tool call extraction: parses <name> patterns from text, injects as real calls",
+        "Auto-continue + smart-continue ordered with skip guard to avoid double-firing",
+        "API key hot-reload with mtime tracking + /admin/reload + /admin/verify-key endpoints",
+        "GUI hot-reload: auto-refreshes proxy key on endpoint edit, verifies with upstream",
+        "Synthetic tool-results disabled: was causing deepseek-v4-pro truncation on opencode.ai",
+    ]),
     ("3.10.4", "2026-05-25", [
         "OAuth Secrets editor in GUI — update client ID/secret without editing files",
         "Secrets stored in ~/.config/codex-launcher/oauth-secrets.json (not in repo)",
@@ -361,7 +419,7 @@ PROVIDER_PRESETS = {
     },
     "Google Antigravity (OAuth)": {
         "backend_type": "gemini-oauth-antigravity",
-        "base_url": "https://daily-cloudcode-pa.sandbox.googleapis.com",
+        "base_url": "https://cloudcode-pa.googleapis.com",
         "oauth_provider": "google-antigravity",
         "models": [
             "Gemini 3.5 Flash (High)", "Gemini 3.5 Flash (Medium)", "Gemini 3.5 Flash (Low)",
@@ -910,6 +968,27 @@ def restore_config():
         shutil.copy2(str(CONFIG_BAK), str(tmp))
         os.replace(str(tmp), str(CONFIG))
 
+def set_active_endpoint(name):
+    ACTIVE_ENDPOINT_FILE.parent.mkdir(parents=True, exist_ok=True)
+    write_secure_text(ACTIVE_ENDPOINT_FILE, json.dumps({"active": name}, indent=2))
+
+def validate_active_endpoint(logfn=None):
+    if not ACTIVE_ENDPOINT_FILE.exists():
+        return
+    try:
+        d = json.loads(ACTIVE_ENDPOINT_FILE.read_text())
+        active = d.get("active", "")
+        if not active:
+            return
+        eps = load_endpoints()
+        names = {ep.get("name", "") for ep in eps}
+        if active not in names:
+            ACTIVE_ENDPOINT_FILE.unlink()
+            if logfn:
+                logfn(f"Removed stale active-endpoint '{active}' (provider no longer exists)")
+    except Exception:
+        pass
+
 def write_secure_text(path, text):
     path.parent.mkdir(parents=True, exist_ok=True)
     tmp = path.with_suffix(path.suffix + ".tmp")
@@ -1253,6 +1332,9 @@ def _check_codex_auth():
         if out.returncode == 0 and text:
             return ("logged_in", text)
         if text:
+            _tl = text.lower()
+            if "no such file" in _tl or "os error 2" in _tl or "not found" in _tl:
+                return ("not_configured", "Config missing — launch once to create")
             return ("error", text)
         return ("unknown", "No output from codex login status")
     except FileNotFoundError:
@@ -1782,6 +1864,64 @@ class AIMonitoringWindow(Gtk.Window):
 # Main window
 # ═══════════════════════════════════════════════════════════════════
 
+def _oauth_discover_project(access_token, token_path, tokens):
+    project_id = ""
+    try:
+        lr = urllib.request.Request(
+            "https://cloudcode-pa.googleapis.com/v1internal:loadCodeAssist",
+            data=json.dumps({}).encode(),
+            headers={"Content-Type": "application/json",
+                     "Authorization": f"Bearer {access_token}",
+                     "User-Agent": "google-api-nodejs-client/9.15.1"})
+        lresp = urllib.request.urlopen(lr, timeout=15)
+        ldata = json.loads(lresp.read())
+        p = ldata.get("cloudaicompanionProject", "")
+        if isinstance(p, dict):
+            project_id = p.get("id", "")
+        elif isinstance(p, str):
+            project_id = p
+    except Exception:
+        pass
+    if not project_id:
+        return ""
+    try:
+        test_url = f"https://cloudcode-pa.googleapis.com/v1internal:listModels?project={project_id}"
+        test_req = urllib.request.Request(test_url,
+            headers={"Authorization": f"Bearer {access_token}",
+                     "User-Agent": "google-api-nodejs-client/9.15.1"})
+        urllib.request.urlopen(test_req, timeout=10)
+    except urllib.error.HTTPError as e:
+        if e.code == 403 and "SERVICE_DISABLED" in (e.read().decode()[:500]):
+            print(f"[oauth] project {project_id} has API disabled, searching for valid project...", file=sys.stderr)
+            try:
+                list_req = urllib.request.Request(
+                    "https://cloudresourcemanager.googleapis.com/v1/projects?filter=lifecycleState:ACTIVE",
+                    headers={"Authorization": f"Bearer {access_token}"})
+                list_resp = urllib.request.urlopen(list_req, timeout=15)
+                projects = json.loads(list_resp.read()).get("projects", [])
+                for proj in projects:
+                    pid = proj.get("projectId", "")
+                    if not pid or pid == project_id:
+                        continue
+                    try:
+                        t2 = urllib.request.Request(
+                            f"https://cloudcode-pa.googleapis.com/v1internal:listModels?project={pid}",
+                            headers={"Authorization": f"Bearer {access_token}",
+                                     "User-Agent": "google-api-nodejs-client/9.15.1"})
+                        urllib.request.urlopen(t2, timeout=10)
+                        project_id = pid
+                        print(f"[oauth] found working project: {pid}", file=sys.stderr)
+                        break
+                    except Exception:
+                        continue
+            except Exception:
+                pass
+    tokens["project_id"] = project_id
+    with open(token_path, "w") as f:
+        json.dump(tokens, f, indent=2)
+    os.chmod(token_path, 0o600)
+    return project_id
+
 class LauncherWin(Gtk.Window):
     def __init__(self):
         super().__init__(title="Codex Launcher")
@@ -1791,6 +1931,7 @@ class LauncherWin(Gtk.Window):
         self._proc = None
         self._endpoints_data = load_endpoints()
         recover_config_if_needed()
+        validate_active_endpoint()
 
         vbox = Gtk.Box(orientation=Gtk.Orientation.VERTICAL, spacing=8)
         self.add(vbox)
@@ -1798,7 +1939,7 @@ class LauncherWin(Gtk.Window):
         # header row
         hdr = Gtk.Box(spacing=8)
         vbox.pack_start(hdr, False, False, 0)
-        lbl = Gtk.Label(label="<b>Codex Launcher v3.10.7</b>")
+        lbl = Gtk.Label(label=f"<b>Codex Launcher v{CHANGELOG[0][0]}</b>")
         lbl.set_use_markup(True)
         hdr.pack_start(lbl, False, False, 0)
         changelog_btn = Gtk.Button(label="Changelog")
@@ -2037,6 +2178,8 @@ class LauncherWin(Gtk.Window):
             self._relogin_btn.set_sensitive("cli" not in self._missing)
         elif status == "not_installed":
             self._auth_label.set_markup("<span foreground='#888'>Auth: N/A (CLI not installed)</span>")
+        elif status == "not_configured":
+            self._auth_label.set_markup("<span foreground='#d29922'>⚠ Config missing — launch once to create</span>")
         else:
             self._auth_label.set_markup(f"<span foreground='#d29922'>⚠ Auth: {msg}</span>")
             self._relogin_btn.set_sensitive("cli" not in self._missing)
@@ -2536,6 +2679,8 @@ class LauncherWin(Gtk.Window):
                 begin_config_transaction(f"launch:{ep['name']}")
                 write_config_for_native(ep, model)
 
+            set_active_endpoint(ep["name"])
+
             if target == "desktop":
                 if needs_proxy:
                     _kill_existing_desktop(self.log)
@@ -2593,6 +2738,7 @@ class LauncherWin(Gtk.Window):
 
             begin_config_transaction(f"launch:bgp:{pool['name']}")
             write_config_for_translated(bgp_ep, model, port)
+            set_active_endpoint(pool["name"])
 
             if target == "desktop":
                 _kill_existing_desktop(self.log)
@@ -2832,63 +2978,163 @@ class LauncherWin(Gtk.Window):
         _stop_proxy()
         Gtk.main_quit()
 
-    def _google_reoauth(self, provider):
+    def _google_reoauth(self, provider, parent_dlg=None):
-        secrets_path = os.path.expanduser("~/.config/codex-launcher/oauth-secrets.json")
+        import http.server
-        try:
-            with open(secrets_path) as f:
-                secrets = json.load(f)
-        except Exception:
-            secrets = {}
         is_antigravity = provider == "google-antigravity"
         sec_key = "antigravity" if is_antigravity else "gemini_cli"
-        sec = secrets.get(sec_key, {})
+        _sp = os.path.expanduser("~/.config/codex-launcher/oauth-secrets.json")
-        client_id = sec.get("client_id", "")
+        try:
-        client_secret = sec.get("client_secret", "")
+            with open(_sp) as _f:
-        if not client_id or not client_secret:
+                _secrets_data = json.load(_f)
+        except Exception:
+            _secrets_data = {}
+        sec = _secrets_data.get(sec_key, {})
+        CLIENT_ID = sec.get("client_id", "")
+        CLIENT_SECRET = sec.get("client_secret", "")
+        if not CLIENT_ID or not CLIENT_SECRET:
             self._show_error_dialog("Missing OAuth secrets",
                 f"No client_id/client_secret for {sec_key}.\nSet them in OAuth Secrets first.")
             return
         token_file = "google-antigravity-oauth-token.json" if is_antigravity else "google-cli-oauth-token.json"
         token_path = os.path.expanduser(f"~/.cache/codex-proxy/{token_file}")
-        redirect = "urn:ietf:wg:oauth:2.0:oob"
+        provider_kind = "antigravity" if is_antigravity else "cli"
-        auth_url = (f"https://accounts.google.com/o/oauth2/v2/auth?client_id={client_id}"
+
-                    f"&redirect_uri={urllib.parse.quote(redirect)}"
+        if is_antigravity:
-                    f"&response_type=code&scope={urllib.parse.quote('https://www.googleapis.com/auth/cloud-platform')}"
+            SCOPES = [
-                    f"&access_type=offline&prompt=consent")
+                "https://www.googleapis.com/auth/cloud-platform",
-        webbrowser.open(auth_url)
+                "https://www.googleapis.com/auth/userinfo.email",
-        code_dlg = Gtk.Dialog(title=f"Re-OAuth: {'Antigravity' if is_antigravity else 'Gemini CLI'}", parent=self, modal=True)
+                "https://www.googleapis.com/auth/userinfo.profile",
-        code_dlg.add_button("Cancel", Gtk.ResponseType.CANCEL)
+                "https://www.googleapis.com/auth/cclog",
-        code_dlg.add_button("Exchange", Gtk.ResponseType.OK)
+                "https://www.googleapis.com/auth/experimentsandconfigs",
-        code_dlg.set_default_size(500, 180)
+            ]
-        ca = code_dlg.get_content_area()
+            port = 51121
+            redirect_uri = f"http://localhost:{port}/oauth-callback"
+            callback_path = "/oauth-callback"
+        else:
+            SCOPES = [
+                "https://www.googleapis.com/auth/cloud-platform",
+                "https://www.googleapis.com/auth/userinfo.email",
+                "https://www.googleapis.com/auth/userinfo.profile",
+            ]
+            with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+                s.bind(("127.0.0.1", 0))
+                port = s.getsockname()[1]
+            redirect_uri = f"http://127.0.0.1:{port}/oauth2callback"
+            callback_path = "/oauth2callback"
+
+        state = secrets.token_hex(32)
+        verifier = secrets.token_urlsafe(64)
+        challenge = base64.urlsafe_b64encode(hashlib.sha256(verifier.encode()).digest()).rstrip(b"=").decode()
+
+        scope_str = " ".join(SCOPES)
+        auth_url = (
+            f"https://accounts.google.com/o/oauth2/v2/auth?"
+            f"client_id={CLIENT_ID}"
+            f"&redirect_uri={urllib.parse.quote(redirect_uri)}"
+            f"&response_type=code"
+            f"&scope={urllib.parse.quote(scope_str)}"
+            f"&access_type=offline"
+            f"&prompt=select_account%20consent"
+            f"&state={state}"
+            f"&code_challenge={challenge}"
+            f"&code_challenge_method=S256"
+        )
+
+        oauth_dlg = Gtk.Dialog(title=f"Re-OAuth: {'Antigravity' if is_antigravity else 'Gemini CLI'}", parent=parent_dlg or self, modal=True)
+        oauth_dlg.add_button("Cancel", Gtk.ResponseType.CANCEL)
+        oauth_dlg.set_default_size(520, 200)
+        ca = oauth_dlg.get_content_area()
         ca.set_margin_start(12)
         ca.set_margin_end(12)
         ca.set_spacing(6)
-        ca.pack_start(Gtk.Label(label="Browser opened for Google OAuth.\nPaste the authorization code below:", xalign=0), False, False, 0)
+        ca.pack_start(Gtk.Label(label=f"<b>Re-authenticating {'Antigravity' if is_antigravity else 'Gemini CLI'}</b>", use_markup=True, xalign=0), False, False, 0)
-        code_entry = Gtk.Entry()
+        link_lbl = Gtk.Label(label="Click here to open Google authorization", use_markup=True, xalign=0)
-        code_entry.set_placeholder_text("4/0AX...")
+        link_lbl.set_markup(f'<a href="{auth_url}">Click here to open Google authorization</a>')
-        ca.pack_start(code_entry, False, False, 4)
+        ca.pack_start(link_lbl, False, False, 4)
+        status_lbl = Gtk.Label(label="Waiting for browser callback...", xalign=0)
+        ca.pack_start(status_lbl, False, False, 4)
         ca.show_all()
-        if code_dlg.run() == Gtk.ResponseType.OK:
+
-            code = code_entry.get_text().strip()
+        code_holder = [None]
-            if code:
+        error_holder = [None]
+
+        class OAuthHandler(http.server.BaseHTTPRequestHandler):
+            def do_GET(self2):
+                qs = urllib.parse.urlparse(self2.path).query
+                params = urllib.parse.parse_qs(qs)
+                if "code" in params:
+                    if params.get("state", [None])[0] != state:
+                        self2.send_response(400)
+                        self2.end_headers()
+                        self2.wfile.write(b"CSRF state mismatch")
+                        error_holder[0] = "CSRF state mismatch"
+                        return
+                    code_holder[0] = params["code"][0]
+                    self2.send_response(302)
+                    self2.send_header("Location", "https://developers.google.com/gemini-code-assist/auth_success_gemini")
+                    self2.end_headers()
+                else:
+                    error_holder[0] = params.get("error", ["unknown"])[0]
+                    self2.send_response(302)
+                    self2.send_header("Location", "https://developers.google.com/gemini-code-assist/auth_failure_gemini")
+                    self2.end_headers()
+            def log_message(self2, fmt, *args):
+                pass
+
+        try:
+            bind_host = "localhost" if is_antigravity else "127.0.0.1"
+            server = http.server.HTTPServer((bind_host, port), OAuthHandler)
+        except OSError:
+            status_lbl.set_text(f"Port {port} in use — close other apps and retry.")
+            oauth_dlg.run()
+            oauth_dlg.destroy()
+            return
+
+        def _wait():
+            deadline = time.time() + 120
+            while code_holder[0] is None and error_holder[0] is None and time.time() < deadline:
+                server.handle_request()
+            server.server_close()
+            if code_holder[0]:
                 try:
-                    tok_req = urllib.request.Request("https://oauth2.googleapis.com/token",
+                    tok_data = urllib.parse.urlencode({
-                        data=urllib.parse.urlencode({
+                        "code": code_holder[0], "client_id": CLIENT_ID, "client_secret": CLIENT_SECRET,
-                            "code": code, "client_id": client_id, "client_secret": client_secret,
+                        "redirect_uri": redirect_uri, "grant_type": "authorization_code",
-                            "redirect_uri": redirect, "grant_type": "authorization_code"
+                        "code_verifier": verifier,
-                        }).encode(),
+                    }).encode()
+                    req = urllib.request.Request("https://oauth2.googleapis.com/token", data=tok_data,
                         headers={"Content-Type": "application/x-www-form-urlencoded"})
-                    tok_resp = urllib.request.urlopen(tok_req, timeout=30)
+                    resp = urllib.request.urlopen(req, timeout=30)
-                    tok_data = json.loads(tok_resp.read())
+                    tokens = json.loads(resp.read())
-                    tok_data["_updated"] = time.time()
+                    tokens["client_id"] = CLIENT_ID
+                    tokens["client_secret"] = CLIENT_SECRET
+                    tokens["provider_kind"] = provider_kind
+                    tokens["expires_at"] = time.time() + tokens.get("expires_in", 3600)
                     os.makedirs(os.path.dirname(token_path), exist_ok=True)
                     with open(token_path, "w") as f:
-                        json.dump(tok_data, f, indent=2)
+                        json.dump(tokens, f, indent=2)
-                    self._log(f"[oauth] Refreshed {provider} token → {token_path}")
+                    os.chmod(token_path, 0o600)
+                    project_id = _oauth_discover_project(tokens["access_token"], token_path, tokens)
+                    def _on_success():
+                        status_lbl.set_text(f"Authorization successful! Project: {project_id or 'none'}")
+                        GLib.timeout_add_seconds(2, lambda: oauth_dlg.destroy())
+                        return False
+                    GLib.idle_add(_on_success)
                 except Exception as e:
-                    self._show_error_dialog("Token exchange failed", str(e)[:300])
+                    def _on_err(exc=str(e)):
-        code_dlg.destroy()
+                        status_lbl.set_text(f"Token exchange failed: {exc[:200]}")
+                        return False
+                    GLib.idle_add(_on_err)
+            else:
+                def _on_fail(err=error_holder[0]):
+                    status_lbl.set_text(f"Failed: {err or 'No code received'}")
+                    return False
+                GLib.idle_add(_on_fail)
+
+        webbrowser.open(auth_url)
+        threading.Thread(target=_wait, daemon=True).start()
+        oauth_dlg.run()
+        oauth_dlg.destroy()
 
     def _codebuff_reoauth(self):
         self._codebuff_oauth_standalone()
@@ -3019,7 +3265,7 @@ class LauncherWin(Gtk.Window):
             hdr_row.pack_start(Gtk.Label(label=f"\n<b>{section_label}</b>", use_markup=True, xalign=0), True, True, 0)
             reauth_btn = Gtk.Button(label="Re-OAuth")
             reauth_btn.set_size_request(80, -1)
-            reauth_btn.connect("clicked", lambda b, p=oauth_prov: self._google_reoauth(p))
+            reauth_btn.connect("clicked", lambda b, p=oauth_prov: self._google_reoauth(p, dlg))
             hdr_row.pack_end(reauth_btn, False, False, 0)
             import_btn = Gtk.Button(label="Import JSON")
             import_btn.set_size_request(100, -1)
@@ -3868,32 +4114,8 @@ class EditEndpointDialog(Gtk.Dialog):
                         json.dump(tokens, f, indent=2)
                     os.chmod(token_path, 0o600)
                     _oauth_log(f"Token saved to {token_path}")
-                    project_id = ""
+                    project_id = _oauth_discover_project(tokens["access_token"], token_path, tokens)
-                    try:
+                    _oauth_log(f"Project ID: {project_id or '(none)'}")
-                        _oauth_log("Discovering project ID via loadCodeAssist...")
-                        lr = urllib.request.Request(
-                            "https://cloudcode-pa.googleapis.com/v1internal:loadCodeAssist",
-                            data=json.dumps({}).encode(),
-                            headers={
-                                "Content-Type": "application/json",
-                                "Authorization": f"Bearer {tokens['access_token']}",
-                                "User-Agent": "google-api-nodejs-client/9.15.1",
-                            })
-                        lresp = urllib.request.urlopen(lr, timeout=15)
-                        ldata = json.loads(lresp.read())
-                        p = ldata.get("cloudaicompanionProject", "")
-                        if isinstance(p, dict):
-                            project_id = p.get("id", "")
-                        elif isinstance(p, str):
-                            project_id = p
-                        _oauth_log(f"Project ID: {project_id or '(none)'}")
-                        if project_id:
-                            tokens["project_id"] = project_id
-                            with open(token_path, "w") as f2:
-                                json.dump(tokens, f2, indent=2)
-                            os.chmod(token_path, 0o600)
-                    except Exception as pe:
-                        _oauth_log(f"loadCodeAssist failed (non-fatal): {pe}")
                     if is_antigravity:
                         found_models = [
                             "gemini-2.5-flash", "gemini-2.5-pro",
@@ -3915,7 +4137,7 @@ class EditEndpointDialog(Gtk.Dialog):
                         for mc in probe_candidates:
                             try:
                                 pr = urllib.request.Request(
-                                    "https://daily-cloudcode-pa.sandbox.googleapis.com/v1internal:generateContent",
+                                    "https://cloudcode-pa.googleapis.com/v1internal:generateContent",
                                     data=json.dumps({
                                         "project": project_id,
                                         "model": mc,
@@ -4264,10 +4486,54 @@ class EditEndpointDialog(Gtk.Dialog):
                 data["default"] = name
 
         save_endpoints(data)
+        self._hot_reload_proxy_key(new_ep)
         self._parent_mgr._rebuild()
         self._parent_mgr._parent._on_endpoints_updated()
         self.destroy()
 
+    def _hot_reload_proxy_key(self, ep):
+        try:
+            ep_name = ep.get("name", "")
+            proxy_port = None
+            import glob as _glob
+            for cfg_file in _glob.glob(str(PROXY_CONFIG_DIR / "proxy-*.json")):
+                try:
+                    with open(cfg_file) as f:
+                        pcfg = json.load(f)
+                    if ep_name.lower().replace(" ", "-") in cfg_file.lower():
+                        proxy_port = pcfg.get("port")
+                        pcfg["api_key"] = ep.get("api_key", "")
+                        with open(cfg_file, "w") as f:
+                            json.dump(pcfg, f, indent=2)
+                        break
+                except Exception:
+                    continue
+            if proxy_port:
+                import urllib.request as _ur
+                try:
+                    url = f"http://127.0.0.1:{proxy_port}/admin/reload"
+                    resp = _ur.urlopen(url, timeout=3)
+                    result = json.loads(resp.read())
+                    reloaded = result.get("reloaded", False)
+                    preview = result.get("api_key_preview", "?")
+                    self._parent_mgr._parent.log(
+                        f"[hot-reload] key {'updated' if reloaded else 'unchanged'}: {preview}")
+                    if reloaded:
+                        verify_url = f"http://127.0.0.1:{proxy_port}/admin/verify-key"
+                        vresp = _ur.urlopen(verify_url, timeout=10)
+                        vresult = json.loads(vresp.read())
+                        valid = vresult.get("valid", False)
+                        if valid:
+                            self._parent_mgr._parent.log(
+                                f"[hot-reload] key verified OK ({vresult.get('models', '?')} models)")
+                        else:
+                            self._parent_mgr._parent.log(
+                                f"[hot-reload] WARNING: key verification failed: {vresult.get('error', 'unknown')}")
+                except Exception:
+                    pass
+        except Exception:
+            pass
+
     def _show_error(self, msg):
         d = Gtk.MessageDialog(self, 0, Gtk.MessageType.ERROR, Gtk.ButtonsType.OK, msg)
         d.run(); d.destroy()

src/codex_launcher_lib.py

@@ -83,6 +83,76 @@ model_catalog_json = ""
 """
 
 CHANGELOG = [
+    ("3.12.1", "2026-05-27", [
+        "Fix Antigravity adapter (PR #15): simplify model resolution",
+        "Removed broken schema sanitization, restored correct headers",
+        "Expanded model alias map for all Antigravity variants",
+        "Re-enabled gRPC fallback by default",
+    ]),
+    ("3.12.0", "2026-05-27", [
+        "gRPC auto-fallback for Antigravity provider (PR #13)",
+        "New antigravity_grpc module with protobuf client",
+        "REST 404 triggers gRPC fallback using display names",
+        "gRPC supports streaming and unary generate",
+        "Dynamic version fetch with probe validation",
+        "Antigravity v2 handler rewrite (anti-api approach)",
+        "Safety settings, stopSequences, sessionId, requestType: agent",
+    ]),
+    ("3.11.11", "2026-05-26", [
+        "Final trimming only removes plain messages, never function_call_output",
+    ]),
+    ("3.11.10", "2026-05-26", [
+        "Fix Antigravity: interleave function_call/output pairs in correct sequence (PR #11)",
+        "Fix Gemini sanitizer: trim leading/trailing non-user turns for Google API compliance",
+        "Stricter function call/response isolation — no merging across role boundaries",
+    ]),
+    ("3.11.9", "2026-05-26", [
+        "Fix Antigravity: preserve functionCall/functionResponse in Gemini sanitizer (PR #10)",
+        "Prevents tool responses from being merged/dropped in multi-turn Antigravity sessions",
+    ]),
+    ("3.11.8", "2026-05-26", [
+        "Vision description cache persisted across requests (no redundant API calls for same image)",
+        "Merge PR #8: fix vision cache persistence across requests",
+    ]),
+    ("3.11.7", "2026-05-26", [
+        "Vision auto-detect: uses provider's own vision model (e.g. 0G-Qwen-VL) as fallback for image description",
+        "Vision preprocessing replaces image stripping: images described via API instead of just removed",
+        "Fix AttributeError in image_url handling when value is string not dict",
+        "Merge PR #6: vision/OCR preprocessing for text-only models",
+        "Merge PR #7: 177 unit tests for translate-proxy.py",
+        "Auth os error 2 fix: GUI shows config-missing message instead of raw error",
+    ]),
+    ("3.11.6", "2026-05-26", [
+        "Antigravity loop breakers: per-session tracking, edit-intent nudge (first turn only)",
+        "Loop breaker: same tool+args repeated 5+ times triggers force finalization",
+        "Latest user instruction appended exactly once per request",
+        "Detailed [antigravity-loop] logging for all tracking fields",
+        "has_content fix: function_call now counts as valid output (no more infinite loops)",
+        "Antigravity-only changes, no touch to other providers",
+    ]),
+    ("3.11.5", "2026-05-26", [
+        "Token-aware compaction: fixes context_length_exceeded on small-context models (25 items x 1600 tokens)",
+        "Proactive compaction triggers on token count (>80% model limit), not just item count",
+        "Universal adaptive compaction: removed crof.ai-only gates, all providers get compaction",
+        "Vision model detection: strips images for non-vision models, keeps for vision-capable ones",
+        "Per-model token limit learning from context_length_exceeded error messages",
+        "Compaction aggression levels: normal vs extreme when tokens > 1.5x model limit",
+        "Smart-continue text-tool detection: triggers on tool-call text patterns, not just function_call_output",
+        "Active endpoint sync: GUI auto-removes stale endpoint references on startup",
+    ]),
+    ("3.11.0", "2026-05-26", [
+        "Merge cobra PR: concurrency semaphore (max 3), auto-continue for truncated text",
+        "SO_REUSEADDR on sticky port, proxy-stderr.log, stream diagnostics logging",
+        "Timeout/OSError handler sends response.failed SSE instead of silent drop",
+        "Restart Proxy button: only restarts proxy without killing Codex Desktop",
+        "Tool call argument normalizer: fixes Arguments->arguments, strips markdown wrapping",
+        "Smart-continue loop (2x retries): escalating nudges when model stops text-only mid-task",
+        "XML tool call extraction: parses patterns from text, injects as real calls",
+        "Auto-continue + smart-continue ordered with skip guard to avoid double-firing",
+        "API key hot-reload with mtime tracking + /admin/reload + /admin/verify-key endpoints",
+        "GUI hot-reload: auto-refreshes proxy key on endpoint edit, verifies with upstream",
+        "Synthetic tool-results disabled: was causing deepseek-v4-pro truncation on opencode.ai",
+    ]),
     ("3.10.12", "2026-05-26", [
         "Sticky endpoint: caches last working endpoint, sequential fallback on failure",
         "Endpoint order: cloudcode-pa first (matches agy CLI), daily-cloudcode-pa fallback",
@@ -1468,6 +1538,7 @@ def _pick_free_port():
     try:
         saved = int(_PROXY_PORT_FILE.read_text().strip())
         with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+            s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
             s.bind(("127.0.0.1", saved))
             return saved
     except (ValueError, OSError, FileNotFoundError):
@@ -1559,11 +1630,19 @@ def _start_proxy_with_config(pcfg_path, port, logfn):
     )
     _register_pgid_entry("proxy", _proxy_proc.pid)
 
+    _proxy_log_path = PROXY_CONFIG_DIR / "proxy-stderr.log"
+    _proxy_log_file = open(_proxy_log_path, "a", encoding="utf-8")
+
     def _pipe_stderr():
         if not _proxy_proc.stderr:
             return
         for line in _proxy_proc.stderr:
             logfn(f"[proxy] {line.rstrip()}")
+            try:
+                _proxy_log_file.write(line)
+                _proxy_log_file.flush()
+            except Exception:
+                pass
 
     threading.Thread(target=_pipe_stderr, daemon=True).start()
 
@@ -1681,6 +1760,10 @@ def check_codex_auth():
         return ("unknown", "No output from codex login status")
     except FileNotFoundError:
         return ("not_installed", "codex not found")
+    except OSError as e:
+        if e.errno == 2:
+            return ("not_configured", "Config not found — launch Codex once to create it")
+        return ("error", str(e))
     except Exception as e:
         return ("error", str(e))
 

tests/test_antigravity_grpc.py

@@ -0,0 +1,396 @@
+#!/usr/bin/env python3
+"""
+Unit tests for the Antigravity gRPC fallback module.
+
+Tests cover:
+1. Module import and availability detection
+2. Protobuf conversion helpers (JSON <-> protobuf)
+3. Request building from wrapped REST dict
+4. Reverse alias map correctness
+5. GrpcFallbackResult type
+6. Integration: _try_grpc_fallback triggers correctly on REST 404
+"""
+
+import json
+import os
+import sys
+import unittest
+from unittest.mock import patch, MagicMock
+
+# Add src to path so we can import the antigravity_grpc package
+_src_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), "..", "src")
+if _src_dir not in sys.path:
+    sys.path.insert(0, _src_dir)
+
+
+class TestGrpcModuleAvailability(unittest.TestCase):
+    """Tests for is_grpc_available() and module loading."""
+
+    def test_is_grpc_available_returns_bool(self):
+        """is_grpc_available should return a boolean."""
+        from antigravity_grpc import is_grpc_available
+        result = is_grpc_available()
+        self.assertIsInstance(result, bool)
+
+    def test_is_grpc_available_true_when_installed(self):
+        """If grpcio is installed and stubs are loadable, should return True."""
+        from antigravity_grpc import is_grpc_available
+        # grpcio was installed at test time, so this should be True
+        self.assertTrue(is_grpc_available())
+
+    def test_client_instantiation(self):
+        """AntigravityGrpcClient should be instantiatable."""
+        from antigravity_grpc import AntigravityGrpcClient
+        client = AntigravityGrpcClient()
+        self.assertIsNotNone(client)
+
+    def test_get_client_singleton(self):
+        """get_client should return the same singleton."""
+        from antigravity_grpc import get_client
+        c1 = get_client()
+        c2 = get_client()
+        self.assertIs(c1, c2)
+
+
+class TestGrpcFallbackResult(unittest.TestCase):
+    """Tests for GrpcFallbackResult type."""
+
+    def test_default_values(self):
+        from antigravity_grpc import GrpcFallbackResult
+        r = GrpcFallbackResult()
+        self.assertFalse(r.ok)
+        self.assertIsNone(r.response_data)
+        self.assertIsNone(r.stream_chunks)
+        self.assertEqual(r.error_message, "")
+        self.assertEqual(r.endpoint_used, "")
+        self.assertEqual(r.model_used, "")
+        self.assertEqual(r.elapsed_s, 0.0)
+
+    def test_success_result(self):
+        from antigravity_grpc import GrpcFallbackResult
+        r = GrpcFallbackResult(ok=True, response_data={"response": {"candidates": []}},
+                                endpoint_used="daily-cloudcode-pa.googleapis.com:443",
+                                model_used="Gemini 3.5 Flash (High)",
+                                elapsed_s=2.5)
+        self.assertTrue(r.ok)
+        self.assertIsNotNone(r.response_data)
+        self.assertEqual(r.elapsed_s, 2.5)
+
+    def test_failure_result(self):
+        from antigravity_grpc import GrpcFallbackResult
+        r = GrpcFallbackResult(ok=False, error_message="All gRPC endpoints failed")
+        self.assertFalse(r.ok)
+        self.assertIn("failed", r.error_message)
+
+    def test_repr(self):
+        from antigravity_grpc import GrpcFallbackResult
+        r_ok = GrpcFallbackResult(ok=True, response_data={"response": {"candidates": []}})
+        self.assertIn("OK", repr(r_ok))
+        r_fail = GrpcFallbackResult(ok=False, error_message="timeout")
+        self.assertIn("FAIL", repr(r_fail))
+
+
+class TestReverseAliasMap(unittest.TestCase):
+    """Tests for the _GRPC_REVERSE_ALIAS map in translate-proxy.py."""
+
+    def test_import_reverse_alias(self):
+        """The reverse alias map should be importable from the proxy module."""
+        import importlib
+        _spec = importlib.util.spec_from_file_location(
+            "translate_proxy",
+            os.path.join(_src_dir, "translate-proxy.py"),
+        )
+        tp = importlib.util.module_from_spec(_spec)
+        _spec.loader.exec_module(tp)
+        self.assertIsInstance(tp._GRPC_REVERSE_ALIAS, dict)
+
+    def test_key_models_have_reverse_aliases(self):
+        """All key REST model slugs should have gRPC display name mappings."""
+        import importlib
+        _spec = importlib.util.spec_from_file_location(
+            "translate_proxy",
+            os.path.join(_src_dir, "translate-proxy.py"),
+        )
+        tp = importlib.util.module_from_spec(_spec)
+        _spec.loader.exec_module(tp)
+
+        required_slugs = [
+            "gemini-3-flash",
+            "gemini-3.5-flash-low",
+            "gemini-3.1-pro-low",
+            "claude-sonnet-4-6",
+            "claude-opus-4-6-thinking",
+            "gemini-2.5-flash",
+        ]
+        for slug in required_slugs:
+            self.assertIn(slug, tp._GRPC_REVERSE_ALIAS,
+                         f"Missing reverse alias for REST slug '{slug}'")
+
+    def test_reverse_alias_values_are_display_names(self):
+        """gRPC display names should contain spaces and parentheses, not hyphens."""
+        import importlib
+        _spec = importlib.util.spec_from_file_location(
+            "translate_proxy",
+            os.path.join(_src_dir, "translate-proxy.py"),
+        )
+        tp = importlib.util.module_from_spec(_spec)
+        _spec.loader.exec_module(tp)
+
+        for slug, display_name in tp._GRPC_REVERSE_ALIAS.items():
+            # Display names typically have spaces (e.g. "Gemini 3.5 Flash (High)")
+            # while slugs use hyphens (e.g. "gemini-3-flash")
+            self.assertNotEqual(slug, display_name,
+                               f"Reverse alias for '{slug}' should differ from slug (gRPC uses display names)")
+
+
+class TestProtobufConversion(unittest.TestCase):
+    """Tests for JSON -> protobuf conversion helpers."""
+
+    def test_struct_to_protobuf(self):
+        """_struct_to_protobuf should convert a simple dict to Struct."""
+        from antigravity_grpc.client import _struct_to_protobuf
+        result = _struct_to_protobuf({"key": "value", "num": 42})
+        self.assertIsNotNone(result)
+        # Verify round-trip
+        from antigravity_grpc.client import _protobuf_struct_to_dict
+        d = _protobuf_struct_to_dict(result)
+        self.assertEqual(d["key"], "value")
+        self.assertEqual(d["num"], 42.0)
+
+    def test_struct_round_trip_nested(self):
+        """Nested dicts should survive a round-trip through protobuf."""
+        from antigravity_grpc.client import _struct_to_protobuf, _protobuf_struct_to_dict
+        original = {"outer": {"inner": "hello"}, "list_val": [1, 2, 3]}
+        proto = _struct_to_protobuf(original)
+        result = _protobuf_struct_to_dict(proto)
+        self.assertEqual(result["outer"]["inner"], "hello")
+        self.assertEqual(result["list_val"], [1.0, 2.0, 3.0])
+
+    def test_json_parts_to_proto_text(self):
+        """Text parts should convert to protobuf Part with text field."""
+        from antigravity_grpc.client import _json_parts_to_proto
+        parts = _json_parts_to_proto([{"text": "Hello world"}])
+        self.assertEqual(len(parts), 1)
+        self.assertEqual(parts[0].text, "Hello world")
+
+    def test_json_parts_to_proto_function_call(self):
+        """FunctionCall parts should convert correctly."""
+        from antigravity_grpc.client import _json_parts_to_proto
+        parts = _json_parts_to_proto([{
+            "functionCall": {
+                "name": "exec_command",
+                "args": {"cmd": "ls -la"},
+                "id": "call_123"
+            }
+        }])
+        self.assertEqual(len(parts), 1)
+        self.assertTrue(parts[0].HasField("function_call"))
+        self.assertEqual(parts[0].function_call.name, "exec_command")
+        self.assertEqual(parts[0].function_call.id, "call_123")
+
+    def test_json_parts_to_proto_function_response(self):
+        """FunctionResponse parts should convert correctly."""
+        from antigravity_grpc.client import _json_parts_to_proto
+        parts = _json_parts_to_proto([{
+            "functionResponse": {
+                "name": "exec_command",
+                "response": {"result": "file1.txt"},
+                "id": "call_123"
+            }
+        }])
+        self.assertEqual(len(parts), 1)
+        self.assertTrue(parts[0].HasField("function_response"))
+        self.assertEqual(parts[0].function_response.name, "exec_command")
+
+    def test_json_contents_to_proto(self):
+        """Content objects should convert correctly."""
+        from antigravity_grpc.client import _json_contents_to_proto
+        contents = _json_contents_to_proto([
+            {"role": "user", "parts": [{"text": "Hello"}]},
+            {"role": "model", "parts": [{"text": "Hi there"}]},
+        ])
+        self.assertEqual(len(contents), 2)
+        self.assertEqual(contents[0].role, "user")
+        self.assertEqual(contents[1].role, "model")
+
+    def test_proto_candidate_to_json(self):
+        """Protobuf candidates should convert back to JSON-compatible dicts."""
+        from antigravity_grpc.client import _json_contents_to_proto, _proto_candidate_to_json
+        from antigravity_grpc import cloudcode_pb2 as pb2
+
+        # Build a candidate manually
+        candidate = pb2.Candidate()
+        candidate.content.role = "model"
+        candidate.content.parts.add().text = "Hello from gRPC"
+        candidate.finish_reason = "STOP"
+        candidate.index = 0
+
+        result = _proto_candidate_to_json(candidate)
+        self.assertEqual(result["finishReason"], "STOP")
+        self.assertEqual(result["content"]["role"], "model")
+        self.assertEqual(result["content"]["parts"][0]["text"], "Hello from gRPC")
+
+
+class TestGrpcRequestBuilding(unittest.TestCase):
+    """Tests for _build_request (wrapped REST dict → protobuf)."""
+
+    def _get_client(self):
+        from antigravity_grpc import AntigravityGrpcClient
+        return AntigravityGrpcClient()
+
+    def test_build_request_basic(self):
+        """Basic request fields should be populated correctly."""
+        client = self._get_client()
+        wrapped = {
+            "project": "test-project-123",
+            "model": "Gemini 3.5 Flash (High)",
+            "requestType": "agent",
+            "userAgent": "antigravity/2.0.6",
+            "requestId": "agent-test123",
+            "request": {
+                "contents": [
+                    {"role": "user", "parts": [{"text": "Say hello"}]}
+                ],
+                "safetySettings": [
+                    {"category": "HARM_CATEGORY_HARASSMENT", "threshold": "OFF"},
+                ],
+            }
+        }
+        req = client._build_request(wrapped)
+        self.assertEqual(req.project, "test-project-123")
+        self.assertEqual(req.model, "Gemini 3.5 Flash (High)")
+        self.assertEqual(req.request_type, "agent")
+        self.assertEqual(len(req.request.contents), 1)
+        self.assertEqual(req.request.contents[0].role, "user")
+
+    def test_build_request_with_tools(self):
+        """Tools should be converted to function declarations."""
+        client = self._get_client()
+        wrapped = {
+            "project": "test-project",
+            "model": "gemini-3-flash",
+            "request": {
+                "contents": [],
+                "tools": [{
+                    "functionDeclarations": [{
+                        "name": "exec_command",
+                        "description": "Run a shell command",
+                        "parameters": {"type": "object", "properties": {"cmd": {"type": "string"}}}
+                    }]
+                }],
+            }
+        }
+        req = client._build_request(wrapped)
+        self.assertEqual(len(req.request.tools), 1)
+        self.assertEqual(req.request.tools[0].function_declarations[0].name, "exec_command")
+
+    def test_build_request_with_generation_config(self):
+        """Generation config should be populated correctly."""
+        client = self._get_client()
+        wrapped = {
+            "project": "test-project",
+            "model": "gemini-3-flash",
+            "request": {
+                "contents": [],
+                "generationConfig": {
+                    "maxOutputTokens": 64000,
+                    "temperature": 0.7,
+                    "stopSequences": ["\n\nHuman:"],
+                    "thinkingConfig": {
+                        "includeThoughts": True,
+                        "thinkingBudget": 8192,
+                    }
+                }
+            }
+        }
+        req = client._build_request(wrapped)
+        self.assertEqual(req.request.generation_config.max_output_tokens, 64000)
+        self.assertAlmostEqual(req.request.generation_config.temperature, 0.7, places=2)
+        self.assertTrue(req.request.generation_config.thinking_config.include_thoughts)
+        self.assertEqual(req.request.generation_config.thinking_config.thinking_budget, 8192)
+
+    def test_build_request_with_function_call_history(self):
+        """Function call/response pairs in contents should be preserved."""
+        client = self._get_client()
+        wrapped = {
+            "project": "test-project",
+            "model": "gemini-3-flash",
+            "request": {
+                "contents": [
+                    {"role": "user", "parts": [{"text": "List files"}]},
+                    {"role": "model", "parts": [{
+                        "functionCall": {"name": "exec_command", "args": {"cmd": "ls"}, "id": "call_1"}
+                    }]},
+                    {"role": "user", "parts": [{
+                        "functionResponse": {"name": "exec_command", "response": {"result": "file.txt"}, "id": "call_1"}
+                    }]},
+                ]
+            }
+        }
+        req = client._build_request(wrapped)
+        self.assertEqual(len(req.request.contents), 3)
+        # Verify function call preserved
+        self.assertTrue(req.request.contents[1].parts[0].HasField("function_call"))
+        self.assertEqual(req.request.contents[1].parts[0].function_call.name, "exec_command")
+        # Verify function response preserved
+        self.assertTrue(req.request.contents[2].parts[0].HasField("function_response"))
+        self.assertEqual(req.request.contents[2].parts[0].function_response.name, "exec_command")
+
+
+class TestGrpcEndpointsConfig(unittest.TestCase):
+    """Tests for gRPC endpoint configuration."""
+
+    def test_default_endpoints(self):
+        """Default endpoints should include production and daily."""
+        from antigravity_grpc.client import _GRPC_ENDPOINTS
+        self.assertGreaterEqual(len(_GRPC_ENDPOINTS), 2)
+        hostnames = [ep.split(":")[0] for ep in _GRPC_ENDPOINTS]
+        self.assertIn("daily-cloudcode-pa.googleapis.com", hostnames)
+        self.assertIn("cloudcode-pa.googleapis.com", hostnames)
+
+    def test_staging_env_var(self):
+        """Staging endpoints should be controlled by env var."""
+        from antigravity_grpc.client import _ALLOW_STAGING_ENV
+        self.assertEqual(_ALLOW_STAGING_ENV, "ALLOW_ANTIGRAVITY_STAGING")
+
+
+class TestProxyIntegration(unittest.TestCase):
+    """Tests for the proxy's gRPC fallback integration."""
+
+    def _load_proxy_module(self):
+        import importlib
+        _spec = importlib.util.spec_from_file_location(
+            "translate_proxy",
+            os.path.join(_src_dir, "translate-proxy.py"),
+        )
+        tp = importlib.util.module_from_spec(_spec)
+        _spec.loader.exec_module(tp)
+        return tp
+
+    def test_get_grpc_client_function_exists(self):
+        """_get_grpc_client should exist as a module-level function."""
+        tp = self._load_proxy_module()
+        self.assertTrue(callable(tp._get_grpc_client))
+
+    def test_grpc_fallback_errors_set(self):
+        """_GRPC_FALLBACK_REST_ERRORS should include 404."""
+        tp = self._load_proxy_module()
+        self.assertIn(404, tp._GRPC_FALLBACK_REST_ERRORS)
+
+    def test_versions_bug_fixed(self):
+        """The _versions[0] NameError should be fixed (should be _fetched_ver)."""
+        # Read the source file and verify _versions is not used incorrectly
+        with open(os.path.join(_src_dir, "translate-proxy.py")) as f:
+            source = f.read()
+        # The bug was: ver={_versions[0]}  -- should be ver={_fetched_ver}
+        self.assertNotIn("_versions[0]", source,
+                         "Bug: _versions[0] should have been replaced with _fetched_ver")
+
+
+if __name__ == "__main__":
+    print("=" * 70)
+    print("Antigravity gRPC Fallback - Unit Tests")
+    print("=" * 70)
+    print()
+
+    unittest.main(verbosity=2)