diff --git a/archivebox/opencode/templates/opencode/agent.html b/archivebox/opencode/templates/opencode/agent.html
index e6f41a67..8a252295 100644
--- a/archivebox/opencode/templates/opencode/agent.html
+++ b/archivebox/opencode/templates/opencode/agent.html
@@ -206,78 +206,6 @@
                     });
                 })();
             </script>
-            <script>
-                (() => {
-                    const frame = document.querySelector(".opencode-agent-frame");
-                    if (!frame) return;
-
-                    const healthUrl = "{{ proxy_prefix|escapejs }}/global/health";
-                    const monitorUrl = "{{ proxy_prefix|escapejs }}/_archivebox/health";
-                    const fetchOptions = {
-                        cache: "no-store",
-                        credentials: "same-origin",
-                        redirect: "manual",
-                    };
-                    let checking = false;
-                    let waking = false;
-                    let wasUnavailable = false;
-                    let healthyChecks = 0;
-                    let knownVersion = "{{ opencode_version|escapejs }}";
-                    const wake = () => {
-                        if (waking) return;
-                        waking = true;
-                        fetch(healthUrl, fetchOptions)
-                            .catch(() => {})
-                            .finally(() => { waking = false; });
-                    };
-                    const check = async () => {
-                        if (checking || (document.hidden && wasUnavailable)) return;
-                        checking = true;
-                        try {
-                            const response = await fetch(monitorUrl, fetchOptions);
-                            if (!response.ok || response.redirected) {
-                                wasUnavailable = true;
-                                healthyChecks = 0;
-                                if (response.status === 503) {
-                                    wake();
-                                }
-                                return;
-                            }
-
-                            const health = await response.json();
-                            if (!health || health.healthy !== true) {
-                                wasUnavailable = true;
-                                healthyChecks = 0;
-                                return;
-                            }
-                            const currentVersion = typeof health.version === "string" ? health.version : "";
-                            if (knownVersion && currentVersion && currentVersion !== knownVersion) {
-                                wasUnavailable = true;
-                            }
-                            if (currentVersion) {
-                                knownVersion = currentVersion;
-                            }
-                            if (wasUnavailable && ++healthyChecks >= 2) {
-                                wasUnavailable = false;
-                                healthyChecks = 0;
-                                frame.contentWindow.location.reload();
-                            }
-                        } catch {
-                            wasUnavailable = true;
-                            healthyChecks = 0;
-                        } finally {
-                            checking = false;
-                        }
-                    };
-
-                    window.setInterval(check, 3000);
-                    window.addEventListener("online", check);
-                    document.addEventListener("visibilitychange", () => {
-                        if (!document.hidden) check();
-                    });
-                    check();
-                })();
-            </script>
         {% endif %}
     </div>
 {% endblock %}
diff --git a/archivebox/opencode/urls.py b/archivebox/opencode/urls.py
index bf8fad73..1b073502 100644
--- a/archivebox/opencode/urls.py
+++ b/archivebox/opencode/urls.py
@@ -1,11 +1,10 @@
 from django.urls import path, re_path
 
-from archivebox.opencode.views import agent_health_view, agent_view, opencode_proxy_view
+from archivebox.opencode.views import agent_view, opencode_proxy_view
 
 
 urlpatterns = [
     path("", agent_view, name="opencode-agent"),
-    path("opencode/_archivebox/health", agent_health_view, name="opencode-health"),
     re_path(
         r"^opencode(?:/(?P<path>.*))?$",
         opencode_proxy_view,
diff --git a/archivebox/opencode/views.py b/archivebox/opencode/views.py
index 49ba0de1..f2913195 100644
--- a/archivebox/opencode/views.py
+++ b/archivebox/opencode/views.py
@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import atexit
 import base64
+import json
 import logging
 import os
 import re
@@ -26,7 +27,6 @@ from django.http import (
     HttpRequest,
     HttpResponse,
     HttpResponseForbidden,
-    JsonResponse,
     StreamingHttpResponse,
 )
 from django.shortcuts import redirect, render
@@ -42,6 +42,7 @@ _PROXY_PREFIX = "/admin/agent/opencode"
 _PROXY_PREFIX_REGEX = _PROXY_PREFIX.replace("/", r"\/")
 _PROXY_PREFIX_NO_SLASH_REGEX = _PROXY_PREFIX.lstrip("/").replace("/", r"\/")
 _CONFIG_PATH = Path(opencode_plugin.__file__).with_name("config.json")
+_DEFAULT_MODEL = "opencode/big-pickle"
 
 _TEXT_CONTENT_TYPES = (
     "text/",
@@ -219,7 +220,7 @@ def _settings(config: dict) -> dict:
         str(_config_value(config, "OPENCODE_STATE_DIR", default_data_dir / "opencode")),
     ).expanduser()
     workdir = Path(
-        str(_config_value(config, "OPENCODE_WORKDIR", opencode_dir / "workdir")),
+        str(_config_value(config, "OPENCODE_WORKDIR", default_data_dir)),
     ).expanduser()
     binary = str(_config_value(config, "OPENCODE_BINARY", "opencode"))
     timeout = int(_config_value(config, "OPENCODE_TIMEOUT", 120))
@@ -321,6 +322,21 @@ def _ensure_project_files(settings: dict) -> None:
             opencode_skill_path.unlink()
         opencode_skill_path.symlink_to(editable_skill_path)
 
+    opencode_config_path = settings["config_home"] / "opencode" / "opencode.jsonc"
+    default_config = {
+        "$schema": "https://opencode.ai/config.json",
+        "model": _DEFAULT_MODEL,
+    }
+    if not opencode_config_path.exists():
+        opencode_config_path.write_text(f"{json.dumps(default_config, indent=2)}\n")
+    else:
+        try:
+            existing_config = json.loads(opencode_config_path.read_text())
+        except (OSError, ValueError):
+            existing_config = None
+        if isinstance(existing_config, dict) and set(existing_config) <= {"$schema"}:
+            opencode_config_path.write_text(f"{json.dumps(default_config, indent=2)}\n")
+
 
 def _ensure_default_session(settings: dict) -> str:
     workdir = settings["workdir"].resolve()
@@ -393,19 +409,6 @@ def _health(settings: dict, timeout: float = 2) -> bool:
         return False
 
 
-def _opencode_version(settings: dict) -> str:
-    try:
-        response = requests.get(
-            f"{settings['origin']}/global/health",
-            timeout=2,
-        )
-        response.raise_for_status()
-        data = response.json()
-        return str(data.get("version") or "") if isinstance(data, dict) else ""
-    except (requests.RequestException, ValueError):
-        return ""
-
-
 def _ensure_opencode(settings: dict) -> tuple[bool, str]:
     global _PROCESS, _PROCESS_READY
     started_process: subprocess.Popen | None = None
@@ -539,16 +542,13 @@ def agent_view(request: HttpRequest):
     settings["archivebox_api_url"] = api_url
     ok, error = _ensure_opencode(settings)
     recent_session_id = ""
-    opencode_version = ""
     if ok:
         try:
             with _SESSION_LOCK:
                 recent_session_id = _ensure_default_session(settings)
-            opencode_version = _opencode_version(settings)
-            if not opencode_version:
-                ok = False
-                error = "OpenCode health check did not report its version."
         except (requests.RequestException, RuntimeError, ValueError) as err:
+            if isinstance(err, requests.RequestException) and _owned_process_ready():
+                _stop_owned_process()
             ok = False
             error = f"OpenCode project initialization failed: {err}"
     from archivebox.core.admin_site import archivebox_admin
@@ -565,7 +565,6 @@ def agent_view(request: HttpRequest):
         # transient new-session route and appear to have lost prior sessions.
         "proxy_url": _project_route(settings["workdir"], recent_session_id),
         "proxy_prefix": _PROXY_PREFIX,
-        "opencode_version": opencode_version,
         "workdir": str(settings["workdir"].resolve()),
         "recent_session_id": recent_session_id,
     }
@@ -577,23 +576,6 @@ def agent_view(request: HttpRequest):
     )
 
 
-def agent_health_view(request: HttpRequest):
-    config = _machine_config()
-    _require_enabled(config)
-    auth_response = _require_superuser(request)
-    if auth_response:
-        return auth_response
-
-    version = _opencode_version(_settings(config))
-    healthy = bool(version)
-    response = JsonResponse(
-        {"healthy": healthy, "version": version},
-        status=200 if healthy else 503,
-    )
-    response.headers["Cache-Control"] = "no-store"
-    return response
-
-
 def _proxy_url(settings: dict, path: str | None) -> str:
     rel = "/" if not path else f"/{path}"
     return urljoin(settings["origin"], rel)
diff --git a/archivebox/tests/test_opencode_agent.py b/archivebox/tests/test_opencode_agent.py
index 0d81c15d..ff639958 100644
--- a/archivebox/tests/test_opencode_agent.py
+++ b/archivebox/tests/test_opencode_agent.py
@@ -1,4 +1,5 @@
 import asyncio
+import json
 import os
 import signal
 import socket
@@ -189,14 +190,8 @@ def test_opencode_agent_superuser_gets_admin_wrapper(admin_client, live_opencode
     assert b'id="header"' in response.content
     assert b'id="progress-monitor"' in response.content
     assert response.context["proxy_prefix"] == views._PROXY_PREFIX
-    assert response.context["opencode_version"]
-    assert b"const healthUrl" in response.content
-    assert b"/admin/agent/opencode/global/health" in response.content
-    assert b"/admin/agent/opencode/_archivebox/health" in response.content
-    assert b'redirect: "manual"' in response.content
-    assert b"let waking = false" in response.content
-    assert b"wake();" in response.content
-    assert b"frame.contentWindow.location.reload()" in response.content
+    assert b"/_archivebox/health" not in response.content
+    assert b"window.setInterval(check, 3000)" not in response.content
     assert response.headers["X-Frame-Options"] == "DENY"
     assert response.headers["Content-Security-Policy"] == "frame-ancestors 'none'"
 
@@ -210,21 +205,6 @@ def test_opencode_agent_superuser_gets_admin_wrapper(admin_client, live_opencode
     assert session.headers["Content-Security-Policy"] == "frame-ancestors 'self'"
 
 
-def test_opencode_health_monitor_does_not_start_server(admin_client, live_opencode):
-    from archivebox.opencode import views
-
-    views._stop_owned_process()
-    response = admin_client.get(
-        "/admin/agent/opencode/_archivebox/health",
-        HTTP_HOST=ADMIN_TEST_HOST,
-    )
-
-    assert response.status_code == 503
-    assert response.json() == {"healthy": False, "version": ""}
-    assert response.headers["Cache-Control"] == "no-store"
-    assert views._PROCESS is None
-
-
 def test_opencode_proxy_serves_real_project_and_session(admin_client, live_opencode):
     workdir = str(live_opencode.config.data_dir.resolve())
     encoded_workdir = quote(workdir)
@@ -422,8 +402,15 @@ def test_opencode_starts_with_isolated_state(live_opencode):
     )
     project.raise_for_status()
 
+    config = requests.get(
+        f"{live_opencode.settings['origin']}/global/config",
+        timeout=live_opencode.settings["timeout"],
+    )
+    config.raise_for_status()
+
     assert Path(live_opencode.settings["workdir"]).resolve() == Path(workdir)
     assert Path(str(project.json()["worktree"])).resolve() == Path(workdir)
+    assert config.json()["model"] == "opencode/big-pickle"
     assert live_opencode.process.poll() is None
     assert (live_opencode.config.data_dir / ".git").is_dir()
     assert (state_dir / "data" / "opencode" / "opencode.db").is_file()
@@ -455,15 +442,57 @@ def test_opencode_state_dir_is_separate_from_workdir(tmp_path):
     assert loaded_skill.is_symlink()
     assert loaded_skill.resolve() == editable_skill.resolve()
     assert f"ArchiveBox collection directory: {settings['archivebox_data_dir']}" in editable_skill.read_text()
+    assert json.loads((state_dir / "config" / "opencode" / "opencode.jsonc").read_text())["model"] == "opencode/big-pickle"
 
 
-def test_opencode_default_workdir_does_not_scan_the_collection():
+def test_opencode_preserves_existing_config(tmp_path):
+    from archivebox.opencode import views
+
+    state_dir = tmp_path / "state"
+    config_path = state_dir / "config" / "opencode" / "opencode.jsonc"
+    config_path.parent.mkdir(parents=True)
+    existing_config = '{\n  // Keep the administrator-selected model.\n  "model": "anthropic/claude-sonnet-4-5"\n}\n'
+    config_path.write_text(existing_config)
+
+    views._ensure_project_files(
+        views._settings(
+            {
+                "OPENCODE_WORKDIR": str(tmp_path / "workdir"),
+                "OPENCODE_STATE_DIR": str(state_dir),
+            },
+        ),
+    )
+
+    assert config_path.read_text() == existing_config
+
+
+def test_opencode_adds_default_model_to_schema_only_config(tmp_path):
+    from archivebox.opencode import views
+
+    state_dir = tmp_path / "state"
+    config_path = state_dir / "config" / "opencode" / "opencode.jsonc"
+    config_path.parent.mkdir(parents=True)
+    config_path.write_text('{"$schema": "https://opencode.ai/config.json"}\n')
+
+    views._ensure_project_files(
+        views._settings(
+            {
+                "OPENCODE_WORKDIR": str(tmp_path / "workdir"),
+                "OPENCODE_STATE_DIR": str(state_dir),
+            },
+        ),
+    )
+
+    assert json.loads(config_path.read_text())["model"] == "opencode/big-pickle"
+
+
+def test_opencode_defaults_to_the_archivebox_collection():
     from archivebox.opencode import views
 
     settings = views._settings({})
 
     assert settings["opencode_dir"] == settings["archivebox_data_dir"] / "opencode"
-    assert settings["workdir"] == settings["opencode_dir"] / "workdir"
+    assert settings["workdir"] == settings["archivebox_data_dir"]
     assert settings["timeout"] == 120