Antigravity ACP 502 bad gateway, but antigravity ide is working fine

Agent execution error: Error 502, Message: Bad Gateway: Failed to connect to backend API, Status: 502 Bad Gateway, Details:
request failed (code 502): Bad Gateway: Failed to connect to backend API: Error 502, Message: Bad Gateway: Failed to connect to backend API, Status: 502 Bad Gateway, Details:
request failed (code 502): Bad Gateway: Failed to connect to backend API

Linux 7.2
Zed 1.16.1
extension 1.0.0
login method: oauth-personal

tried re authenticate

logs:

Summary
[
  {
    "_direction": "outgoing",
    "_type": "request",
    "id": "b81c8daf-b99b-4de4-b6ca-cd5eff5b6610",
    "method": "session/prompt",
    "params": {
      "sessionId": "2bde7dea-bb9d-4c77-b1af-65645c5dd9b0",
      "prompt": [
        {
          "type": "text",
          "text": "Hi"
        }
      ]
    }
  },
  {
    "_direction": "incoming",
    "_type": "notification",
    "id": null,
    "method": "session/update",
    "params": {
      "sessionId": "2bde7dea-bb9d-4c77-b1af-65645c5dd9b0",
      "update": {
        "content": {
          "text": "Agent execution error: Error 502, Message: Bad Gateway: Failed to connect to backend API, Status: 502 Bad Gateway, Details: []\nrequest failed (code 502): Bad Gateway: Failed to connect to backend API: Error 502, Message: Bad Gateway: Failed to connect to backend API, Status: 502 Bad Gateway, Details: []\nrequest failed (code 502): Bad Gateway: Failed to connect to backend API",
          "type": "text"
        },
        "sessionUpdate": "agent_message_chunk"
      }
    }
  },
  {
    "_direction": "incoming",
    "_type": "response",
    "id": "b81c8daf-b99b-4de4-b6ca-cd5eff5b6610",
    "method": "session/prompt",
    "params": {
      "stopReason": "end_turn"
    }
  }
]

Not fixed as of Fri, Aug 28, 2026, at 10:54:31 AM IST.

cloudcode-pa.googleapis.com is returning

{
  "error": {
    "code": 403,
    "status": "PERMISSION_DENIED",
    "message": "You do not have a valid license of this product. Please contact your administrator to request a license. If you are not an enterprise user and believe you are receiving this message as an error, please try using the latest version and logging in again. (#3501)",
    "details": [
      {
        "@type": "type.googleapis.com/google.rpc.ErrorInfo",
        "reason": "SUBSCRIPTION_REQUIRED",
        "domain": "cloudaicompanion.googleapis.com"
      }
    ]
  }
}

even with valid creds, but acp is returning 502
this issue is only when using oauth-personal, it is working when using GEMINI_API_KEY

more logs

Summary
/home/user/.local/share/zed/external_agents/registry/antigravity-acp/v_1.0.0_92521fc3cbd964bd_fc45337c399e4ef2/agy_acp_server.par --uid= --debug
{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":1,"clientCapabilities":{"terminal":true,"fs":{"readTextFile":true,"writeTextFile":true}},"clientInfo":{"name":"zed","version":"0.1"}}}
{"jsonrpc":"2.0","id":1,"result":{"protocolVersion":1,"agentCapabilities":{"loadSession":true,"promptCapabilities":{"image":true,"audio":true,"embeddedContext":true},"mcpCapabilities":{"http":true,"sse":true},"sessionCapabilities":{"list":{},"resume":{}},"auth":{"logout":{}}},"authMethods":[{"description":"Log in with your Google account","id":"oauth-personal","name":"Log in with Google"},{"description":"Log in with your Gemini Enterprise account","id":"oauth-business","name":"Log in with Gemini Enterprise"},{"description":"Use an API key with Gemini Developer API","id":"gemini-api-key","name":"Gemini API key"},{"description":"Use Gemini Enterprise Agent Platform (formerly Vertex AI) with Application Default Credentials or an API key","id":"agent-platform","name":"Gemini Enterprise Agent Platform"}],"agentInfo":{"name":"antigravity-acp","title":"Google Antigravity","version":"agy_acp_server_20260818_01_RC01"}}}

{"jsonrpc":"2.0","id":2,"method":"session/new","params":{"cwd":"/home/user/Projects/industralist","mcpServers":[]}}

{"jsonrpc":"2.0","id":2,"result":{"sessionId":"4966b522-1353-4345-9ce8-63d844f9c957","modes":{"currentModeId":"default","availableModes":[{"id":"default","name":"Default","description":"Default permission prompt flow"},{"id":"auto_edit","name":"Auto Edit","description":"Auto-approve file edit tools"},{"id":"yolo","name":"YOLO","description":"Auto-approve all tools"}]},"models":{"availableModels":[{"modelId":"gemini-3.7-flash-high","name":"Gemini 3.7 Flash (High)","description":"gemini-3.7-flash-high"},{"modelId":"gemini-3.7-flash-medium","name":"Gemini 3.7 Flash (Medium)","description":"gemini-3.7-flash-medium"},{"modelId":"gemini-3.7-flash-low","name":"Gemini 3.7 Flash (Low)","description":"gemini-3.7-flash-low"},{"modelId":"gemini-3.6-flash-high","name":"Gemini 3.6 Flash (High)","description":"gemini-3.6-flash-high"},{"modelId":"gemini-3.6-flash-medium","name":"Gemini 3.6 Flash (Medium)","description":"gemini-3.6-flash-medium"},{"modelId":"gemini-3.6-flash-low","name":"Gemini 3.6 Flash (Low)","description":"gemini-3.6-flash-low"},{"modelId":"gemini-3-flash-agent","name":"Gemini 3.5 Flash (High)","description":"gemini-3-flash-agent"},{"modelId":"gemini-3.5-flash-low","name":"Gemini 3.5 Flash (Medium)","description":"gemini-3.5-flash-low"},{"modelId":"gemini-3.5-flash-extra-low","name":"Gemini 3.5 Flash (Low)","description":"gemini-3.5-flash-extra-low"},{"modelId":"gemini-pro-agent","name":"Gemini 3.1 Pro (High)","description":"gemini-pro-agent"},{"modelId":"gemini-3.1-pro-low","name":"Gemini 3.1 Pro (Low)","description":"gemini-3.1-pro-low"}],"currentModelId":"gemini-3.7-flash-high"},"configOptions":[{"currentValue":"gemini-3.7-flash-high","options":[{"value":"gemini-3.7-flash-high","name":"Gemini 3.7 Flash (High)","description":"gemini-3.7-flash-high"},{"value":"gemini-3.7-flash-medium","name":"Gemini 3.7 Flash (Medium)","description":"gemini-3.7-flash-medium"},{"value":"gemini-3.7-flash-low","name":"Gemini 3.7 Flash (Low)","description":"gemini-3.7-flash-low"},{"value":"gemini-3.6-flash-high","name":"Gemini 3.6 Flash (High)","description":"gemini-3.6-flash-high"},{"value":"gemini-3.6-flash-medium","name":"Gemini 3.6 Flash (Medium)","description":"gemini-3.6-flash-medium"},{"value":"gemini-3.6-flash-low","name":"Gemini 3.6 Flash (Low)","description":"gemini-3.6-flash-low"},{"value":"gemini-3-flash-agent","name":"Gemini 3.5 Flash (High)","description":"gemini-3-flash-agent"},{"value":"gemini-3.5-flash-low","name":"Gemini 3.5 Flash (Medium)","description":"gemini-3.5-flash-low"},{"value":"gemini-3.5-flash-extra-low","name":"Gemini 3.5 Flash (Low)","description":"gemini-3.5-flash-extra-low"},{"value":"gemini-pro-agent","name":"Gemini 3.1 Pro (High)","description":"gemini-pro-agent"},{"value":"gemini-3.1-pro-low","name":"Gemini 3.1 Pro (Low)","description":"gemini-3.1-pro-low"}],"id":"model","name":"Model","category":"model","type":"select"},{"currentValue":"default","options":[{"value":"default","name":"Default","description":"Default permission prompt flow"},{"value":"auto_edit","name":"Auto Edit","description":"Auto-approve file edit tools"},{"value":"yolo","name":"YOLO","description":"Auto-approve all tools"}],"id":"mode","name":"Session Mode","category":"mode","type":"select"}]}}
{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"4966b522-1353-4345-9ce8-63d844f9c957","update":{"availableCommands":[{"name":"plan","description":"Plan carefully before executing a task (generates an implementation plan artifact and awaits user approval)."},{"name":"logout","description":"Log out and clear stored credentials."}],"sessionUpdate":"available_commands_update"}}}
{"jsonrpc":"2.0","id":3,"method":"session/prompt","params":{"sessionId":"4966b522-1353-4345-9ce8-63d844f9c957","prompt":[{"type":"text","text":"hi"}]}}
{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"4966b522-1353-4345-9ce8-63d844f9c957","update":{"content":{"text":"Agent execution error: Error 502, Message: Bad Gateway: Failed to connect to backend API, Status: 502 Bad Gateway, Details: []\nrequest failed (code 502): Bad Gateway: Failed to connect to backend API: Error 502, Message: Bad Gateway: Failed to connect to backend API, Status: 502 Bad Gateway, Details: []\nrequest failed (code 502): Bad Gateway: Failed to connect to backend API","type":"text"},"sessionUpdate":"agent_message_chunk"}}}
{"jsonrpc":"2.0","id":3,"result":{"stopReason":"end_turn"}}