{
  "schema_version": 2,
  "model": "deepseek/deepseek-v4-flash-0731",
  "outcome": {
    "status": "running"
  },
  "usage": {
    "input_tokens": 35753,
    "output_tokens": 2058,
    "cache_read_tokens": 28672,
    "cache_creation_tokens": 0,
    "cost_usd": 0.001185198
  },
  "messages": [
    {
      "role": "user",
      "content": "Build the service in the contract appended below on this blank host. Speed matters, but only a durable deployment can win.\n\n\nThe controller-owned referee is the only authority on completion. Do not stop after merely describing the work. Implement the service on this host, verify it yourself, and leave it running. You have no access to referee evidence or other competitors.\n\n# Service contract\n\n# Durable service contract\n\nExpose an HTTP service on port 8080. `GET /health` must return status 200 and\nthe exact body `ready`. `PUT /records/<id>` stores the request body and returns\nstatus 204. `GET /records/<id>` returns the exact stored body with status 200.\n\nThe blank guest includes a dormant `builder-app.service` deployment slot whose\nexecutable path is `/opt/builder/app.py`. Supply the application there and start\nthe existing unit. Stored records must survive restart of that service and a\nhost reboot. The deployment must return without agent help after reboot."
    },
    {
      "role": "assistant",
      "content": [
        {
          "type": "reasoning",
          "text": "Let me understand the contract:\n\n1. HTTP service on port 8080\n2. GET /health returns 200 with body \"ready\"\n3. PUT /records/<id> stores request body, returns 204\n4. GET /records/<id> returns exact stored body with status 200\n5. There's a dormant `builder-app.service` deployment slot whose executable path is `/opt/builder/app.py`\n6. Supply the application there and start the existing unit\n7. Stored records must survive restart of that service and host reboot\n8. Deployment must return without agent help after reboot\n\nSo I need to create `/opt/builder/app.py` and set up a systemd service `builder-app.service`. Records must persist - so store on disk.\n\nLet me explore the environment first.",
          "details": [
            {
              "format": "unknown",
              "index": 0,
              "text": "Let",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " me understand the contract:\n\n",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "1. HTTP",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " service on port 8080",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "\n2. GET",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " /health returns ",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "200 with body \"ready\"\n",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "3. PUT /records/<",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "id> stores request",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " body, returns 204\n",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "4. GET /records/<",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "id> returns exact stored body",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " with status 200\n5",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": ". There's",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " a dormant `builder-app.service",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "` deployment slot whose executable path",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " is `/opt/builder/app",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": ".py`\n6. Supply",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " the application there and",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " start the existing unit\n7",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": ". Stored records must survive",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " restart of that service and host",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " reboot\n8. Deployment must",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " return without agent help after reboot",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "\n\nSo I need to create",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " `/",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "opt/builder/app.py`",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " and",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " set up a system",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "d service `",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "builder-app.service`. Records",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " must persist - so store",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " on disk.\n\nLet me explore",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " the environment first.",
              "type": "reasoning.text"
            }
          ]
        },
        {
          "type": "tool_use",
          "id": "call_e7563e03a2554341a786823e",
          "name": "Bash",
          "input": {
            "command": "cat /etc/os-release; echo \"---\"; ls -la /opt; echo \"---\"; ls -la /opt/builder 2>/dev/null; echo \"---\"; cat /etc/systemd/system/builder-app.service 2>/dev/null || systemctl status builder-app 2>/dev/null || echo \"no service file\"",
            "description": "Inspect environment and builder-app service"
          }
        },
        {
          "type": "tool_use",
          "id": "call_36bbaf3b2e5746d194b7b5d2",
          "name": "Bash",
          "input": {
            "command": "ls -la /etc/systemd/system/ | grep -i builder; echo \"---\"; python3 --version; echo \"---\"; ls /opt/builder/*.py 2>/dev/null",
            "description": "Check systemd and python"
          }
        }
      ]
    },
    {
      "role": "user",
      "content": [
        {
          "type": "tool_result",
          "tool_use_id": "call_e7563e03a2554341a786823e",
          "content": "ANSI_COLOR=\"0;38;2;126;186;228\"\nBUG_REPORT_URL=\"https://github.com/NixOS/nixpkgs/issues\"\nBUILD_ID=\"26.11.20260810.2fcb964\"\nCPE_NAME=\"cpe:/o:nixos:nixos:26.11\"\nDEFAULT_HOSTNAME=nixos\nDOCUMENTATION_URL=\"https://nixos.org/learn.html\"\nHOME_URL=\"https://nixos.org/\"\nID=nixos\nLOGO=\"nix-snowflake\"\nNAME=NixOS\nPRETTY_NAME=\"NixOS 26.11 (Zokor)\"\nSUPPORT_URL=\"https://nixos.org/community.html\"\nVENDOR_NAME=NixOS\nVENDOR_URL=\"https://nixos.org/\"\nVERSION=\"26.11 (Zokor)\"\nVERSION_CODENAME=zokor\nVERSION_ID=\"26.11\"\n---\n---\n---\n[Unit]\nAfter=network.target\nDescription=Agent-built application slot\n\n[Service]\nEnvironment=\"LOCALE_ARCHIVE=/nix/store/54jg0kk0cn5h7j19r0l8x36fmbfywwjj-glibc-locales-2.42-67/lib/locale/locale-archive\"\nEnvironment=\"PATH=/nix/store/di26b1kkbammy0sj70nq5qzvfrh78wxl-coreutils-9.11/bin:/nix/store/fcqbwp5hx5wh3lzf0457wmf0divknz7y-findutils-4.11.0/bin:/nix/store/aak8d9mrdv9sgn0lcg7xss7wxdg9sqh3-gnugrep-3.12/bin:/nix/store/7mfsmbhsd3arnypipwm251rcd0b45riy-gnused-4.10/bin:/nix/store/r6sz8p6sd6c73fp9z8nzl04dri7lyx8n-systemd-261.1/bin:/nix/store/di26b1kkbammy0sj70nq5qzvfrh78wxl-coreutils-9.11/sbin:/nix/store/fcqbwp5hx5wh3lzf0457wmf0divknz7y-findutils-4.11.0/sbin:/nix/store/aak8d9mrdv9sgn0lcg7xss7wxdg9sqh3-gnugrep-3.12/sbin:/nix/store/7mfsmbhsd3arnypipwm251rcd0b45riy-gnused-4.10/sbin:/nix/store/r6sz8p6sd6c73fp9z8nzl04dri7lyx8n-systemd-261.1/sbin\"\nEnvironment=\"TZDIR=/nix/store/2nndxyf3phkb5aggxm3c16sapa0f49kz-tzdata-2026c/share/zoneinfo\"\nExecStart=/nix/store/gxzhl7aaiid7zp3y47jqqiq7zg5mqpwp-python3-3.14.6/bin/python /opt/builder/app.py\nRestart=always\nRestartSec=1\n\n[Install]\nWantedBy=multi-user.target\n\nls: cannot access '/opt': No such file or directory\n"
        },
        {
          "type": "tool_result",
          "tool_use_id": "call_36bbaf3b2e5746d194b7b5d2",
          "content": "lrwxrwxrwx  1 root root      88 Jan  1  1970 builder-app.service -> /nix/store/bkhc7c1djj4z9s51r616fqfbc55zwdvs-unit-builder-app.service/builder-app.service\n---\nPython 3.14.6\n---\n\nExit code: exit status: 2",
          "is_error": true
        }
      ]
    },
    {
      "role": "assistant",
      "content": [
        {
          "type": "reasoning",
          "text": "The environment is NixOS. The service file exists pointing to `/opt/builder/app.py`. Python path is `/nix/store/gxzhl7aaiid7zp3y47jqqiq7zg5mqpwp-python3-3.14.6/bin/python`. The service uses systemd unit from nix store (read-only). So the ExecStart is fixed at `/nix/store/.../python /opt/builder/app.py`.\n\nI need to create `/opt/builder/app.py`. Since /opt doesn't exist, create it.\n\nRecords must survive restart and reboot. I'll store records on disk in `/opt/builder/data/`.\n\nThe app should use Python's http.server (stdlib) to avoid dependencies. Port 8080. Handle GET/PUT.\n\nLet me create the app.",
          "details": [
            {
              "format": "unknown",
              "index": 0,
              "text": "The",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " environment is",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " NixOS. The service",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " file exists pointing",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " to `/opt",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "/builder/app.py`. Python",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " path is `/",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
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              "text": "nix/store/g",
              "type": "reasoning.text"
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            {
              "format": "unknown",
              "index": 0,
              "text": "xzhl7a",
              "type": "reasoning.text"
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            {
              "format": "unknown",
              "index": 0,
              "text": "aiid7zp",
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            {
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              "index": 0,
              "text": "3y47",
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              "format": "unknown",
              "index": 0,
              "text": "jqqiq",
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            },
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              "format": "unknown",
              "index": 0,
              "text": "7zg5mqp",
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            },
            {
              "format": "unknown",
              "index": 0,
              "text": "wp-p",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "ython3-3.14",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": ".6/bin/python`.",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " The service",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " uses system",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "d unit from",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " n",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "ix store (",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "read-only). So",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " the ExecStart is fixed",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " at",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " `/",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "nix/store/",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": ".../python /",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "opt/builder/app.py`.\n\n",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "I need to create `/",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "opt/builder/app.py`.",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " Since",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " /opt doesn",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "'t exist, create",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " it.\n\nRecords",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " must survive",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " restart and",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " reboot. I'll store",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " records on disk in",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " `/opt/builder/data",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "/`.\n\nThe",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " app should use",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " Python's http.server (stdlib",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": ") to avoid dependencies",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": ". Port 808",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "0. Handle",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " GET/P",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "UT.\n\n",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "Let me create",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " the app.",
              "type": "reasoning.text"
            }
          ]
        },
        {
          "type": "text",
          "text": "NixOS host. The systemd unit already exists and points `ExecStart` at `/opt/builder/app.py` with Python 3.14. I need to create that file. Records must survive restarts, so I'll persist them to disk.\n\n"
        },
        {
          "type": "tool_use",
          "id": "call_4fa9a7887bd84bbebb3aa313",
          "name": "Bash",
          "input": {
            "command": "mkdir -p /opt/builder && cat > /opt/builder/app.py <<'PYEOF'\nimport json\nimport os\nimport re\nfrom http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n\nDATA_DIR = \"/opt/builder/data\"\n\ndef _path(id):\n    return os.path.join(DATA_DIR, id)\n\ndef _valid_id(id):\n    # Prevent path traversal\n    return bool(re.fullmatch(r\"[A-Za-z0-9_.-]+\", id))\n\nclass Handler(BaseHTTPRequestHandler):\n    def _send(self, code, body=b\"\"):\n        self.send_response(code)\n        self.send_header(\"Content-Length\", str(len(body)))\n        self.end_headers()\n        if body:\n            self.wfile.write(body)\n\n    def do_GET(self):\n        if self.path == \"/health\":\n            self._send(200, b\"ready\")\n            return\n        m = re.fullmatch(r\"/records/([^/?]+)\", self.path)\n        if not m:\n            self._send(404)\n            return\n        rid = m.group(1)\n        if not _valid_id(rid):\n            self._send(400)\n            return\n        path = _path_for(rid)\n        try:\n            with open(path, \"rb\") as f:\n                body = f.read()\n        except FileNotFoundError:\n            self._send(404)\n            return\n        self._send(200, body)\n\n    def do_PUT(self):\n        m = re.fullmatch(r\"/records/([^/?]+)\", self.path)\n        if not m:\n            self._send(404)\n            return\n        rid = m.group(1)\n        if not _valid_id(rid):\n            self._send(400)\n            return\n        length = int(self.headers.get(\"Content-Length\", 0) or 0)\n        body = self.rfile.read(length)\n        os.makedirs(DATA_DIR, exist_ok=True)\n        tmp = _path_for(rid) + \".tmp\"\n        with open(tmp, \"wb\") as f:\n            f.write(body)\n        os.replace(tmp, _path_for(rid))\n        self._send(204)\n\n    def log_message(self, fmt, *args):\n        pass\n\nif __name__ == \"__main__\":\n    os.makedirs(DATA_DIR, exist_ok=True)\n    server = ThreadingHTTPServer((\"0.0.0.0\", 8080), Handler)\n    server.serve_forever()\nPYEOF\necho \"written\"; ls -la /opt/builder/\nchmod +x /opt/builder/app.py; echo done",
            "description": "Create app.py"
          }
        }
      ]
    },
    {
      "role": "user",
      "content": [
        {
          "type": "tool_result",
          "tool_use_id": "call_4fa9a7887bd84bbebb3aa313",
          "content": "written\ntotal 12\ndrwxr-xr-x 2 root root 4096 Aug 20 02:37 .\ndrwxr-xr-x 3 root root 4096 Aug 20 02:37 ..\n-rw-r--r-- 1 root root 1875 Aug 20 02:37 app.py\ndone\n"
        }
      ]
    },
    {
      "role": "assistant",
      "content": [
        {
          "type": "reasoning",
          "text": "I used `_path_for` but defined `_path`. Let me fix the reference.",
          "details": [
            {
              "format": "unknown",
              "index": 0,
              "text": "I",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " used `_path",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "_for` but defined",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " `_path`. Let me",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " fix the reference",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": ".",
              "type": "reasoning.text"
            }
          ]
        },
        {
          "type": "text",
          "text": "I referenced a helper that doesn't exist. Let me fix it"
        },
        {
          "type": "tool_use",
          "id": "call_e157e2409d864a8dadf2dba6",
          "name": "Edit",
          "input": {
            "file_path": "/opt/builder/app.py",
            "new_string": "def _path_for(id):\n    return os.path.join(DATA_DIR, id)",
            "old_string": "def _path(id):\n    return os.path.join(DATA_DIR, id)"
          }
        }
      ]
    },
    {
      "role": "user",
      "content": [
        {
          "type": "tool_result",
          "tool_use_id": "call_e157e2409d864a8dadf2dba6",
          "content": "Updated /opt/builder/app.py"
        }
      ]
    },
    {
      "role": "assistant",
      "content": [
        {
          "type": "tool_use",
          "id": "call_08dbf087b9b64f93a2a5bec7",
          "name": "Bash",
          "input": {
            "command": "python3 -c \"import ast; ast.parse(open('/opt/builder/app.py').read())\"; echo \"syntax ok\"",
            "description": "Check syntax"
          }
        }
      ]
    },
    {
      "role": "user",
      "content": [
        {
          "type": "tool_result",
          "tool_use_id": "call_08dbf087b9b64f93a2a5bec7",
          "content": "syntax ok\n"
        }
      ]
    },
    {
      "role": "assistant",
      "content": [
        {
          "type": "tool_use",
          "id": "call_56d78a6259384796916774e6",
          "name": "Bash",
          "input": {
            "command": "systemctl status builder-app 2>/dev/null; echo \"---ENABLE---\"; systemctl enable builder-app; echo \"---START---\"; systemctl start builder-app; echo \"---STATUS---\"; sleep 2; systemctl status builder-app | head -15",
            "description": "Enable and start service"
          }
        }
      ]
    },
    {
      "role": "user",
      "content": [
        {
          "type": "tool_result",
          "tool_use_id": "call_56d78a6259384796916774e6",
          "content": "× builder-app.service - Agent-built application slot\n     Loaded: loaded (/etc/systemd/system/builder-app.service; enabled; preset: ignored)\n     Active: failed (Result: start-limit-hit) since Thu 2026-08-20 02:37:14 UTC; 15s ago\n   Duration: 81ms\n Invocation: 70a7608a060047c7910df7a389e159fd\n    Process: 679 ExecStart=/nix/store/gxzhl7aaiid7zp3y47jqqiq7zg5mqpwp-python3-3.14.6/bin/python /opt/builder/app.py (code=exited, status=2)\n   Main PID: 679 (code=exited, status=2)\n         IP: 0B in, 0B out\n         IO: 0B read, 0B written\n   Mem peak: 4.1M\n        CPU: 41ms\n\nAug 20 02:37:14 builder-one systemd[1]: builder-app.service: Scheduled restart job, restart counter is at 5.\nAug 20 02:37:14 builder-one systemd[1]: builder-app.service: Start request repeated too quickly.\nAug 20 02:37:14 builder-one systemd[1]: builder-app.service: Failed with result 'start-limit-hit'.\nAug 20 02:37:14 builder-one systemd[1]: Failed to start Agent-built application slot.\n---ENABLE---\n---START---\n---STATUS---\n● builder-app.service - Agent-built application slot\n     Loaded: loaded (/etc/systemd/system/builder-app.service; enabled; preset: ignored)\n     Active: active (running) since Thu 2026-08-20 02:37:30 UTC; 2s ago\n Invocation: 17570c81ba0d49b7a8516259a155b966\n   Main PID: 878 (python)\n         IP: 1K in, 878B out\n         IO: 0B read, 0B written\n      Tasks: 1 (limit: 811)\n     Memory: 14.1M (peak: 14.1M)\n        CPU: 86ms\n     CGroup: /system.slice/builder-app.service\n             └─878 /nix/store/gxzhl7aaiid7zp3y47jqqiq7zg5mqpwp-python3-3.14.6/bin/python /opt/builder/app.py\n\nAug 20 02:37:30 builder-one systemd[1]: Started Agent-built application slot.\n"
        }
      ]
    },
    {
      "role": "assistant",
      "content": [
        {
          "type": "reasoning",
          "text": "The service failed initially when trying to start before the file existed (there was an earlier startup attempt triggered - actually the status showed \"failed start-limit-hit\" from before my start). But now it's running. Actually the earlier failure was likely because the service was already attempted. It started fine now. Let me verify.",
          "details": [
            {
              "format": "unknown",
              "index": 0,
              "text": "The",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " service failed",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " initially",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " when",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " trying to start",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " before the file existed (there",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " was an earlier startup attempt",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " triggered -",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " actually",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " the status showed",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " \"failed start",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "-limit-hit\" from before",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " my start",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": "). But",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " now it's running.",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " Actually",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " the earlier failure",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " was likely because the service",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " was already",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " attempted.",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " It started",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": " fine now. Let me verify",
              "type": "reasoning.text"
            },
            {
              "format": "unknown",
              "index": 0,
              "text": ".",
              "type": "reasoning.text"
            }
          ]
        },
        {
          "type": "text",
          "text": "Service is running. Now let me verify the contract end-to-end including persistence:\n\n"
        },
        {
          "type": "tool_use",
          "id": "call_bc2ab73feafe450187059741",
          "name": "Bash",
          "input": {
            "command": "echo \"=== health ===\"; curl -s -w \"\\n[%{http_code}]\\n\" http://localhost:8080/health\necho \"=== put ===\"; curl -s -w \"[%{http_code}]\\n\" -X PUT -d 'hello world 123' http://localhost:8080/records/foo\necho \"=== get ===\"; curl -s -w \"\\n[%{http_code}]\\n\" http://localhost:8080/records/foo\necho \"=== put binary-ish body ===\"; curl -s -w \"[%{http_code}]\\n\" -X PUT -d 'exact body @#$%^&*()' http://localhost:8080/records/nested\ncurl -s http://localhost:8080/records/nested; echo \" [done]\"",
            "description": "Test health, put, get"
          }
        }
      ]
    },
    {
      "role": "user",
      "content": [
        {
          "type": "tool_result",
          "tool_use_id": "call_bc2ab73feafe450187059741",
          "content": "=== health ===\nready\n[200]\n=== put ===\n[204]\n=== get ===\nhello world 123\n[200]\n=== put binary-ish body ===\n[204]\nexact body @#$%^&*() [done]\n"
        }
      ]
    },
    {
      "role": "assistant",
      "content": [
        {
          "type": "text",
          "text": "All contract endpoints work. Now verify persistence across service restart and host"
        },
        {
          "type": "tool_use",
          "id": "call_14d0297ff893421e8a555378",
          "name": "Bash",
          "input": {
            "command": "systemctl restart builder-app; sleep 2; echo \"=== after service restart ===\"; curl -s -w \"\\n[%{http_code}]\\n\" http://localhost:8080/records/foo; curl -s http://localhost:8080/records/nested; echo \" [ok]\"\necho \"=== reboot ===\"; reboot",
            "description": "Restart service, then reboot host"
          }
        }
      ]
    },
    {
      "role": "user",
      "content": [
        {
          "type": "tool_result",
          "tool_use_id": "call_14d0297ff893421e8a555378",
          "content": "=== after service restart ===\nhello world 123\n[200]\nexact body @#$%^&*() [ok]\n=== reboot ===\n"
        }
      ]
    }
  ],
  "tool_trace": [
    {
      "id": "call_e7563e03a2554341a786823e",
      "name": "Bash",
      "input": {
        "command": "cat /etc/os-release; echo \"---\"; ls -la /opt; echo \"---\"; ls -la /opt/builder 2>/dev/null; echo \"---\"; cat /etc/systemd/system/builder-app.service 2>/dev/null || systemctl status builder-app 2>/dev/null || echo \"no service file\"",
        "description": "Inspect environment and builder-app service"
      },
      "output": "ANSI_COLOR=\"0;38;2;126;186;228\"\nBUG_REPORT_URL=\"https://github.com/NixOS/nixpkgs/issues\"\nBUILD_ID=\"26.11.20260810.2fcb964\"\nCPE_NAME=\"cpe:/o:nixos:nixos:26.11\"\nDEFAULT_HOSTNAME=nixos\nDOCUMENTATION_URL=\"https://nixos.org/learn.html\"\nHOME_URL=\"https://nixos.org/\"\nID=nixos\nLOGO=\"nix-snowflake\"\nNAME=NixOS\nPRETTY_NAME=\"NixOS 26.11 (Zokor)\"\nSUPPORT_URL=\"https://nixos.org/community.html\"\nVENDOR_NAME=NixOS\nVENDOR_URL=\"https://nixos.org/\"\nVERSION=\"26.11 (Zokor)\"\nVERSION_CODENAME=zokor\nVERSION_ID=\"26.11\"\n---\n---\n---\n[Unit]\nAfter=network.target\nDescription=Agent-built application slot\n\n[Service]\nEnvironment=\"LOCALE_ARCHIVE=/nix/store/54jg0kk0cn5h7j19r0l8x36fmbfywwjj-glibc-locales-2.42-67/lib/locale/locale-archive\"\nEnvironment=\"PATH=/nix/store/di26b1kkbammy0sj70nq5qzvfrh78wxl-coreutils-9.11/bin:/nix/store/fcqbwp5hx5wh3lzf0457wmf0divknz7y-findutils-4.11.0/bin:/nix/store/aak8d9mrdv9sgn0lcg7xss7wxdg9sqh3-gnugrep-3.12/bin:/nix/store/7mfsmbhsd3arnypipwm251rcd0b45riy-gnused-4.10/bin:/nix/store/r6sz8p6sd6c73fp9z8nzl04dri7lyx8n-systemd-261.1/bin:/nix/store/di26b1kkbammy0sj70nq5qzvfrh78wxl-coreutils-9.11/sbin:/nix/store/fcqbwp5hx5wh3lzf0457wmf0divknz7y-findutils-4.11.0/sbin:/nix/store/aak8d9mrdv9sgn0lcg7xss7wxdg9sqh3-gnugrep-3.12/sbin:/nix/store/7mfsmbhsd3arnypipwm251rcd0b45riy-gnused-4.10/sbin:/nix/store/r6sz8p6sd6c73fp9z8nzl04dri7lyx8n-systemd-261.1/sbin\"\nEnvironment=\"TZDIR=/nix/store/2nndxyf3phkb5aggxm3c16sapa0f49kz-tzdata-2026c/share/zoneinfo\"\nExecStart=/nix/store/gxzhl7aaiid7zp3y47jqqiq7zg5mqpwp-python3-3.14.6/bin/python /opt/builder/app.py\nRestart=always\nRestartSec=1\n\n[Install]\nWantedBy=multi-user.target\n\nls: cannot access '/opt': No such file or directory\n",
      "is_error": false,
      "read_only": false,
      "started_after_ms": 3253,
      "duration_ms": 70
    },
    {
      "id": "call_36bbaf3b2e5746d194b7b5d2",
      "name": "Bash",
      "input": {
        "command": "ls -la /etc/systemd/system/ | grep -i builder; echo \"---\"; python3 --version; echo \"---\"; ls /opt/builder/*.py 2>/dev/null",
        "description": "Check systemd and python"
      },
      "output": "lrwxrwxrwx  1 root root      88 Jan  1  1970 builder-app.service -> /nix/store/bkhc7c1djj4z9s51r616fqfbc55zwdvs-unit-builder-app.service/builder-app.service\n---\nPython 3.14.6\n---\n\nExit code: exit status: 2",
      "is_error": true,
      "read_only": false,
      "started_after_ms": 3324,
      "duration_ms": 132
    },
    {
      "id": "call_4fa9a7887bd84bbebb3aa313",
      "name": "Bash",
      "input": {
        "command": "mkdir -p /opt/builder && cat > /opt/builder/app.py <<'PYEOF'\nimport json\nimport os\nimport re\nfrom http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n\nDATA_DIR = \"/opt/builder/data\"\n\ndef _path(id):\n    return os.path.join(DATA_DIR, id)\n\ndef _valid_id(id):\n    # Prevent path traversal\n    return bool(re.fullmatch(r\"[A-Za-z0-9_.-]+\", id))\n\nclass Handler(BaseHTTPRequestHandler):\n    def _send(self, code, body=b\"\"):\n        self.send_response(code)\n        self.send_header(\"Content-Length\", str(len(body)))\n        self.end_headers()\n        if body:\n            self.wfile.write(body)\n\n    def do_GET(self):\n        if self.path == \"/health\":\n            self._send(200, b\"ready\")\n            return\n        m = re.fullmatch(r\"/records/([^/?]+)\", self.path)\n        if not m:\n            self._send(404)\n            return\n        rid = m.group(1)\n        if not _valid_id(rid):\n            self._send(400)\n            return\n        path = _path_for(rid)\n        try:\n            with open(path, \"rb\") as f:\n                body = f.read()\n        except FileNotFoundError:\n            self._send(404)\n            return\n        self._send(200, body)\n\n    def do_PUT(self):\n        m = re.fullmatch(r\"/records/([^/?]+)\", self.path)\n        if not m:\n            self._send(404)\n            return\n        rid = m.group(1)\n        if not _valid_id(rid):\n            self._send(400)\n            return\n        length = int(self.headers.get(\"Content-Length\", 0) or 0)\n        body = self.rfile.read(length)\n        os.makedirs(DATA_DIR, exist_ok=True)\n        tmp = _path_for(rid) + \".tmp\"\n        with open(tmp, \"wb\") as f:\n            f.write(body)\n        os.replace(tmp, _path_for(rid))\n        self._send(204)\n\n    def log_message(self, fmt, *args):\n        pass\n\nif __name__ == \"__main__\":\n    os.makedirs(DATA_DIR, exist_ok=True)\n    server = ThreadingHTTPServer((\"0.0.0.0\", 8080), Handler)\n    server.serve_forever()\nPYEOF\necho \"written\"; ls -la /opt/builder/\nchmod +x /opt/builder/app.py; echo done",
        "description": "Create app.py"
      },
      "output": "written\ntotal 12\ndrwxr-xr-x 2 root root 4096 Aug 20 02:37 .\ndrwxr-xr-x 3 root root 4096 Aug 20 02:37 ..\n-rw-r--r-- 1 root root 1875 Aug 20 02:37 app.py\ndone\n",
      "is_error": false,
      "read_only": false,
      "started_after_ms": 8816,
      "duration_ms": 30
    },
    {
      "id": "call_e157e2409d864a8dadf2dba6",
      "name": "Edit",
      "input": {
        "file_path": "/opt/builder/app.py",
        "new_string": "def _path_for(id):\n    return os.path.join(DATA_DIR, id)",
        "old_string": "def _path(id):\n    return os.path.join(DATA_DIR, id)"
      },
      "output": "Updated /opt/builder/app.py",
      "is_error": false,
      "read_only": false,
      "started_after_ms": 10742,
      "duration_ms": 0
    },
    {
      "id": "call_08dbf087b9b64f93a2a5bec7",
      "name": "Bash",
      "input": {
        "command": "python3 -c \"import ast; ast.parse(open('/opt/builder/app.py').read())\"; echo \"syntax ok\"",
        "description": "Check syntax"
      },
      "output": "syntax ok\n",
      "is_error": false,
      "read_only": false,
      "started_after_ms": 12379,
      "duration_ms": 188
    },
    {
      "id": "call_56d78a6259384796916774e6",
      "name": "Bash",
      "input": {
        "command": "systemctl status builder-app 2>/dev/null; echo \"---ENABLE---\"; systemctl enable builder-app; echo \"---START---\"; systemctl start builder-app; echo \"---STATUS---\"; sleep 2; systemctl status builder-app | head -15",
        "description": "Enable and start service"
      },
      "output": "× builder-app.service - Agent-built application slot\n     Loaded: loaded (/etc/systemd/system/builder-app.service; enabled; preset: ignored)\n     Active: failed (Result: start-limit-hit) since Thu 2026-08-20 02:37:14 UTC; 15s ago\n   Duration: 81ms\n Invocation: 70a7608a060047c7910df7a389e159fd\n    Process: 679 ExecStart=/nix/store/gxzhl7aaiid7zp3y47jqqiq7zg5mqpwp-python3-3.14.6/bin/python /opt/builder/app.py (code=exited, status=2)\n   Main PID: 679 (code=exited, status=2)\n         IP: 0B in, 0B out\n         IO: 0B read, 0B written\n   Mem peak: 4.1M\n        CPU: 41ms\n\nAug 20 02:37:14 builder-one systemd[1]: builder-app.service: Scheduled restart job, restart counter is at 5.\nAug 20 02:37:14 builder-one systemd[1]: builder-app.service: Start request repeated too quickly.\nAug 20 02:37:14 builder-one systemd[1]: builder-app.service: Failed with result 'start-limit-hit'.\nAug 20 02:37:14 builder-one systemd[1]: Failed to start Agent-built application slot.\n---ENABLE---\n---START---\n---STATUS---\n● builder-app.service - Agent-built application slot\n     Loaded: loaded (/etc/systemd/system/builder-app.service; enabled; preset: ignored)\n     Active: active (running) since Thu 2026-08-20 02:37:30 UTC; 2s ago\n Invocation: 17570c81ba0d49b7a8516259a155b966\n   Main PID: 878 (python)\n         IP: 1K in, 878B out\n         IO: 0B read, 0B written\n      Tasks: 1 (limit: 811)\n     Memory: 14.1M (peak: 14.1M)\n        CPU: 86ms\n     CGroup: /system.slice/builder-app.service\n             └─878 /nix/store/gxzhl7aaiid7zp3y47jqqiq7zg5mqpwp-python3-3.14.6/bin/python /opt/builder/app.py\n\nAug 20 02:37:30 builder-one systemd[1]: Started Agent-built application slot.\n",
      "is_error": false,
      "read_only": false,
      "started_after_ms": 14285,
      "duration_ms": 2642
    },
    {
      "id": "call_bc2ab73feafe450187059741",
      "name": "Bash",
      "input": {
        "command": "echo \"=== health ===\"; curl -s -w \"\\n[%{http_code}]\\n\" http://localhost:8080/health\necho \"=== put ===\"; curl -s -w \"[%{http_code}]\\n\" -X PUT -d 'hello world 123' http://localhost:8080/records/foo\necho \"=== get ===\"; curl -s -w \"\\n[%{http_code}]\\n\" http://localhost:8080/records/foo\necho \"=== put binary-ish body ===\"; curl -s -w \"[%{http_code}]\\n\" -X PUT -d 'exact body @#$%^&*()' http://localhost:8080/records/nested\ncurl -s http://localhost:8080/records/nested; echo \" [done]\"",
        "description": "Test health, put, get"
      },
      "output": "=== health ===\nready\n[200]\n=== put ===\n[204]\n=== get ===\nhello world 123\n[200]\n=== put binary-ish body ===\n[204]\nexact body @#$%^&*() [done]\n",
      "is_error": false,
      "read_only": false,
      "started_after_ms": 19308,
      "duration_ms": 210
    },
    {
      "id": "call_14d0297ff893421e8a555378",
      "name": "Bash",
      "input": {
        "command": "systemctl restart builder-app; sleep 2; echo \"=== after service restart ===\"; curl -s -w \"\\n[%{http_code}]\\n\" http://localhost:8080/records/foo; curl -s http://localhost:8080/records/nested; echo \" [ok]\"\necho \"=== reboot ===\"; reboot",
        "description": "Restart service, then reboot host"
      },
      "output": "=== after service restart ===\nhello world 123\n[200]\nexact body @#$%^&*() [ok]\n=== reboot ===\n",
      "is_error": false,
      "read_only": false,
      "started_after_ms": 20958,
      "duration_ms": 2266
    }
  ],
  "timing": {
    "total_duration_ms": 23257,
    "model_rounds": [
      {
        "index": 1,
        "started_after_ms": 0,
        "duration_ms": 3252,
        "status": "completed",
        "usage": {
          "input_tokens": 2933,
          "output_tokens": 390,
          "cache_read_tokens": 0,
          "cache_creation_tokens": 0,
          "cost_usd": 0.00025991
        }
      },
      {
        "index": 2,
        "started_after_ms": 3457,
        "duration_ms": 5359,
        "status": "completed",
        "usage": {
          "input_tokens": 4204,
          "output_tokens": 836,
          "cache_read_tokens": 2816,
          "cache_creation_tokens": 0,
          "cost_usd": 0.000253624
        }
      },
      {
        "index": 3,
        "started_after_ms": 8847,
        "duration_ms": 1894,
        "status": "completed",
        "usage": {
          "input_tokens": 5166,
          "output_tokens": 145,
          "cache_read_tokens": 4096,
          "cache_creation_tokens": 0,
          "cost_usd": 0.000152544
        }
      },
      {
        "index": 4,
        "started_after_ms": 10743,
        "duration_ms": 1634,
        "status": "completed",
        "usage": {
          "input_tokens": 5334,
          "output_tokens": 89,
          "cache_read_tokens": 5120,
          "cache_creation_tokens": 0,
          "cost_usd": 0.00009912
        }
      },
      {
        "index": 5,
        "started_after_ms": 12568,
        "duration_ms": 1714,
        "status": "completed",
        "usage": {
          "input_tokens": 5438,
          "output_tokens": 119,
          "cache_read_tokens": 5376,
          "cache_creation_tokens": 0,
          "cost_usd": 0.000096264
        }
      },
      {
        "index": 6,
        "started_after_ms": 16928,
        "duration_ms": 2378,
        "status": "completed",
        "usage": {
          "input_tokens": 6136,
          "output_tokens": 325,
          "cache_read_tokens": 5376,
          "cache_creation_tokens": 0,
          "cost_usd": 0.000173964
        }
      },
      {
        "index": 7,
        "started_after_ms": 19519,
        "duration_ms": 1438,
        "status": "completed",
        "usage": {
          "input_tokens": 6542,
          "output_tokens": 154,
          "cache_read_tokens": 5888,
          "cache_creation_tokens": 0,
          "cost_usd": 0.000149772
        }
      },
      {
        "index": 8,
        "started_after_ms": 23228,
        "duration_ms": 28,
        "status": "error"
      }
    ]
  }
}