diff --git a/.config/opencode/plugins/herdr-agent-state.js b/.config/opencode/plugins/herdr-agent-state.js
new file mode 100644
index 0000000..9a14b3c
--- /dev/null
+++ b/.config/opencode/plugins/herdr-agent-state.js
@@ -0,0 +1,197 @@
+// installed by herdr
+// managed by herdr; reinstalling or updating the integration overwrites this file.
+// add custom hooks/plugins beside this file instead of editing it.
+// HERDR_INTEGRATION_ID=opencode
+// HERDR_INTEGRATION_VERSION=8
+
+import net from "node:net";
+
+const SOURCE = "herdr:opencode";
+const AGENT = "opencode";
+let reportSeq = Date.now() * 1000;
+
+// Subagent (task tool) sessions carry a parentID; the main agent session does
+// not. Their lifecycle events would otherwise clobber the pane's real state, so
+// learn child session ids from session.created/updated and drop their reports.
+const childSessions = new Set();
+
+function nextReportSeq() {
+  reportSeq += 1;
+  return reportSeq;
+}
+
+function sessionIDFromProperties(properties) {
+  return typeof properties?.sessionID === "string" && properties.sessionID
+    ? properties.sessionID
+    : undefined;
+}
+
+function stateFromSessionStatus(status) {
+  // session.status carries { type: "idle" | "busy" | "retry" }; older builds used a bare string.
+  const kind = typeof status === "string" ? status : status?.type;
+  if (typeof kind !== "string") return undefined;
+  switch (kind.toLowerCase()) {
+    case "idle":
+      return "idle";
+    case "active":
+    case "busy":
+    case "pending":
+    case "running":
+    case "streaming":
+    case "working":
+    case "retry":
+      return "working";
+    default:
+      return undefined;
+  }
+}
+
+function request(method, params) {
+  const paneId = process.env.HERDR_PANE_ID;
+  const socketPath = process.env.HERDR_SOCKET_PATH;
+
+  if (!paneId || !socketPath) {
+    return Promise.resolve();
+  }
+
+  const requestId = `${SOURCE}:${Date.now()}:${Math.floor(Math.random() * 1_000_000)
+    .toString()
+    .padStart(6, "0")}`;
+  const request = {
+    id: requestId,
+    method,
+    params: {
+      pane_id: paneId,
+      source: SOURCE,
+      agent: AGENT,
+      seq: nextReportSeq(),
+      ...params,
+    },
+  };
+
+  return new Promise((resolve) => {
+    const client = net.createConnection(socketPath, () => {
+      client.write(`${JSON.stringify(request)}\n`);
+    });
+
+    const finish = () => {
+      client.destroy();
+      resolve();
+    };
+
+    client.setTimeout(500, finish);
+    client.on("data", finish);
+    client.on("error", finish);
+    client.on("end", finish);
+    client.on("close", resolve);
+  });
+}
+
+function reportSession(sessionID, sessionStartSource) {
+  if (!sessionID) {
+    return Promise.resolve();
+  }
+  const params = { agent_session_id: sessionID };
+  if (sessionStartSource) {
+    params.session_start_source = sessionStartSource;
+  }
+  return request("pane.report_agent_session", params);
+}
+
+function reportState(state, sessionID) {
+  const params = { state };
+  if (sessionID) {
+    params.agent_session_id = sessionID;
+  }
+  return request("pane.report_agent", params);
+}
+
+export const HerdrAgentStatePlugin = async () => {
+  if (
+    process.env.HERDR_ENV !== "1" ||
+    !process.env.HERDR_SOCKET_PATH ||
+    !process.env.HERDR_PANE_ID
+  ) {
+    return {};
+  }
+
+  return {
+    "chat.message": async ({ sessionID }) => {
+      if (sessionID && childSessions.has(sessionID)) {
+        return;
+      }
+      await reportState("working", sessionID);
+    },
+    event: async ({ event }) => {
+      const type = event?.type;
+      const properties = event?.properties ?? {};
+      const sessionID = sessionIDFromProperties(properties);
+
+      const info = properties.info;
+      if (info?.id && info.parentID) {
+        childSessions.add(info.id);
+      }
+      if (sessionID && childSessions.has(sessionID)) {
+        // Child session events are dropped so they cannot clobber the pane's
+        // root-agent state, but a subagent waiting on the user must still
+        // surface as blocked (and clear once answered). Report state only,
+        // without an agent_session_id, so the pane keeps the root session.
+        switch (type) {
+          case "permission.asked":
+          case "question.asked":
+            await reportState("blocked");
+            break;
+          case "permission.replied":
+          case "question.replied":
+          case "question.rejected":
+            await reportState("working");
+            break;
+          default:
+            break;
+        }
+        return;
+      }
+
+      switch (type) {
+        case "session.created":
+          // A root session.created is a genuine new-session start (subagent
+          // creates are dropped above). Signal it so herdr replaces the pane's
+          // prior session id instead of treating the change as cross-talk.
+          await reportSession(sessionID, "new");
+          break;
+        case "session.updated":
+          await reportSession(sessionID);
+          break;
+        case "session.status": {
+          const state = stateFromSessionStatus(properties.status);
+          if (state) {
+            await reportState(state, sessionID);
+          } else {
+            await reportSession(sessionID);
+          }
+          break;
+        }
+        case "tool.execute.before":
+        case "tool.execute.after":
+        case "permission.replied":
+        case "question.replied":
+        case "question.rejected":
+        case "session.compacted":
+          await reportState("working", sessionID);
+          break;
+        case "permission.asked":
+        case "question.asked":
+        case "session.error":
+          await reportState("blocked", sessionID);
+          break;
+        case "session.idle":
+          await reportState("idle", sessionID);
+          break;
+        case "session.deleted":
+          break;
+        default:
+          break;
+      }
+    },
+  };
+};