feat: add a hook to monitor the skill usage

plugins/signoz/hooks/hooks.json

@@ -1,5 +1,5 @@
 {
-  "description": "Auto-allow WebFetch for official SigNoz HTTPS URLs",
+  "description": "SigNoz plugin hooks: auto-allow WebFetch for official URLs, monitor query generation via Slack",
   "hooks": {
     "PreToolUse": [
       {
@@ -11,6 +11,17 @@
           }
         ]
       }
+    ],
+    "PostToolUse": [
+      {
+        "matcher": "Skill",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "node \"${CLAUDE_PLUGIN_ROOT}/hooks/scripts/post-query-to-slack.js\""
+          }
+        ]
+      }
     ]
   }
 }

plugins/signoz/hooks/scripts/post-query-to-slack.js

@@ -0,0 +1,105 @@
+#!/usr/bin/env node
+
+import { request } from "https";
+
+const SKILL_NAME = "signoz-clickhouse-query";
+
+function postToSlack(webhookUrl, message) {
+  return new Promise((resolve) => {
+    const url = new URL(webhookUrl);
+    const body = JSON.stringify(message);
+
+    const req = request(
+      {
+        hostname: url.hostname,
+        path: url.pathname,
+        method: "POST",
+        headers: {
+          "Content-Type": "application/json",
+          "Content-Length": Buffer.byteLength(body),
+        },
+      },
+      () => resolve(),
+    );
+
+    req.on("error", () => resolve());
+    req.setTimeout(5000, () => {
+      req.destroy();
+      resolve();
+    });
+
+    req.write(body);
+    req.end();
+  });
+}
+
+function extractQuery(toolResponse) {
+  if (typeof toolResponse === "string") {
+    return toolResponse;
+  }
+
+  if (toolResponse?.content) {
+    return typeof toolResponse.content === "string"
+      ? toolResponse.content
+      : JSON.stringify(toolResponse.content);
+  }
+
+  return JSON.stringify(toolResponse);
+}
+
+const chunks = [];
+
+process.stdin.setEncoding("utf8");
+process.stdin.on("data", (chunk) => chunks.push(chunk));
+process.stdin.on("end", async () => {
+  const webhookUrl = process.env.SLACK_WEBHOOK_URL;
+  if (!webhookUrl) {
+    process.exit(0);
+  }
+
+  try {
+    const payload = JSON.parse(chunks.join(""));
+
+    if (payload?.tool_name !== "Skill") {
+      process.exit(0);
+    }
+
+    const skillName = payload?.tool_input?.skill;
+    if (skillName !== SKILL_NAME) {
+      process.exit(0);
+    }
+
+    const query = extractQuery(payload?.tool_response);
+    const slackMessage = {
+      blocks: [
+        {
+          type: "header",
+          text: {
+            type: "plain_text",
+            text: "ClickHouse Query Generated",
+          },
+        },
+        {
+          type: "section",
+          text: {
+            type: "mrkdwn",
+            text: `*Skill:* \`${skillName}\`\n*Session:* \`${payload?.session_id || "unknown"}\``,
+          },
+        },
+        {
+          type: "section",
+          text: {
+            type: "mrkdwn",
+            text: `*Generated Output:*\n\`\`\`\n${query.slice(0, 2900)}\n\`\`\``,
+          },
+        },
+      ],
+    };
+
+    await postToSlack(webhookUrl, slackMessage);
+  } catch {
+    // Fail silently — monitoring should never block the workflow.
+  }
+
+  process.exit(0);
+});