diff --git a/jsr.json b/jsr.json
index 83e70f33..994c7805 100644
--- a/jsr.json
+++ b/jsr.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperpolymath/boj-server",
-  "version": "0.4.1",
+  "version": "0.4.2",
   "description": "Bundle of Joy — cartridge-based MCP server with 100 domain cartridges, formally verified (Idris2) coord core",
   "license": "MPL-2.0",
   "exports": "./mcp-bridge/main.js",
diff --git a/mcp-bridge/lib/logger.js b/mcp-bridge/lib/logger.js
index 314f3b55..2122a18b 100644
--- a/mcp-bridge/lib/logger.js
+++ b/mcp-bridge/lib/logger.js
@@ -7,7 +7,22 @@
 // MCP JSON-RPC messages). Log level controlled via BOJ_LOG_LEVEL env.
 
 const LOG_LEVELS = { debug: 0, info: 1, warn: 2, error: 3, silent: 4 };
-const currentLevel = LOG_LEVELS[process.env.BOJ_LOG_LEVEL || "info"] ?? LOG_LEVELS.info;
+let currentLevel = LOG_LEVELS[process.env.BOJ_LOG_LEVEL || "info"] ?? LOG_LEVELS.info;
+
+/**
+ * Update the minimum log level at runtime. Used by the MCP
+ * `logging/setLevel` handler to honour client-requested verbosity.
+ * Unknown levels are ignored (no-op).
+ * @param {"debug"|"info"|"warn"|"error"|"silent"} level
+ * @returns {boolean} true if the level was recognised and applied
+ */
+function setLevel(level) {
+  if (level in LOG_LEVELS) {
+    currentLevel = LOG_LEVELS[level];
+    return true;
+  }
+  return false;
+}
 
 /**
  * Emit a structured log entry to stderr.
@@ -38,4 +53,4 @@ function warn(msg, fields) { log("warn", msg, fields); }
 /** @param {string} msg @param {Record<string, unknown>} [fields] */
 function error(msg, fields) { log("error", msg, fields); }
 
-export { debug, error, info, log, warn };
+export { debug, error, info, log, setLevel, warn };
diff --git a/mcp-bridge/lib/version.js b/mcp-bridge/lib/version.js
index 089db0d4..704696c6 100644
--- a/mcp-bridge/lib/version.js
+++ b/mcp-bridge/lib/version.js
@@ -4,4 +4,4 @@
 // Single source of truth for server version and name.
 
 export const SERVER_NAME = "boj-server";
-export const SERVER_VERSION = "0.4.0";
+export const SERVER_VERSION = "0.4.2";
diff --git a/mcp-bridge/main.js b/mcp-bridge/main.js
index 40b65d3c..00aaaa27 100755
--- a/mcp-bridge/main.js
+++ b/mcp-bridge/main.js
@@ -35,7 +35,7 @@ import {
   tryParseEnvelope,
   validateEnvelope,
 } from "./lib/nickel-validator.js";
-import { info, warn, error as logError } from "./lib/logger.js";
+import { info, warn, error as logError, setLevel as setLogLevel } from "./lib/logger.js";
 
 const BOJ_BASE = process.env.BOJ_URL || "http://localhost:7700";
 const SERVER_NAME = "boj-server";
@@ -338,7 +338,10 @@ async function handleMessage(line) {
       info("MCP initialize", { client: params?.clientInfo?.name });
       sendResult(id, {
         protocolVersion: "2024-11-05",
-        capabilities: { tools: { listChanged: false } },
+        capabilities: {
+          tools: { listChanged: false },
+          logging: {},
+        },
         serverInfo: { name: SERVER_NAME, version: SERVER_VERSION },
       });
       break;
@@ -347,6 +350,18 @@ async function handleMessage(line) {
     case "notifications/initialized":
       break;
 
+    case "logging/setLevel": {
+      const level = params?.level;
+      const applied = setLogLevel(level);
+      if (!applied) {
+        sendError(id, -32602, `Unknown log level: ${level}. Expected debug|info|warn|error|silent.`);
+      } else {
+        info("MCP logging/setLevel", { level });
+        sendResult(id, {});
+      }
+      break;
+    }
+
     case "tools/list": {
       const tools = buildToolList();
       sendResult(id, { tools });
diff --git a/mcp-bridge/package.json b/mcp-bridge/package.json
index 5abce67d..8dad7a4c 100644
--- a/mcp-bridge/package.json
+++ b/mcp-bridge/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperpolymath/boj-server",
-  "version": "0.4.1",
+  "version": "0.4.2",
   "description": "Bundle of Joy (BoJ) MCP Server — cartridge-based DevOps + multi-agent coordination toolkit with 100 domain cartridges (database, container, git, k8s, observability, secrets, IaC, multi-instance AI coord, and more). Formally verified (Idris2) core; MPL-2.0.",
   "license": "MPL-2.0",
   "author": "Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>",
diff --git a/package.json b/package.json
index 4a3ee68d..f339e7cb 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperpolymath/boj-server",
-  "version": "0.4.1",
+  "version": "0.4.2",
   "description": "Bundle of Joy (BoJ) MCP Server — cartridge-based DevOps + multi-agent coordination toolkit with 100 domain cartridges (database, container, git, k8s, observability, secrets, IaC, multi-instance AI coord, and more). Formally verified (Idris2) core; MPL-2.0.",
   "license": "MPL-2.0",
   "author": "Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>",