diff --git a/internal/cloud/code-agent-chat.mjs b/internal/cloud/code-agent-chat.mjs
index cf22329c..afdf7b61 100644
--- a/internal/cloud/code-agent-chat.mjs
+++ b/internal/cloud/code-agent-chat.mjs
@@ -15,6 +15,12 @@ import {
   DEFAULT_CODE_AGENT_SESSION_IDLE_TIMEOUT_MS,
   createCodeAgentSessionRegistry
 } from "./code-agent-session-registry.mjs";
+import {
+  HWLAB_AGENT_RUNTIME_SKILL_CLI_VERSION,
+  HWLAB_M3_IO_API_ROUTE,
+  HWLAB_M3_IO_SKILL_NAME,
+  runM3IoSkillCommand
+} from "../../skills/hwlab-agent-runtime/scripts/src/m3-io-skill-client.mjs";
 
 const DEFAULT_CODE_AGENT_TIMEOUT_MS = 120000;
 const DEFAULT_CODEX_COMMAND = "codex";
@@ -28,6 +34,21 @@ const READONLY_RUNNER_SANDBOX = "read-only";
 const READONLY_SESSION_MODE = "controlled-readonly-session-registry";
 const READONLY_IMPLEMENTATION_TYPE = "controlled-readonly-session-registry";
 const READONLY_SESSION_CAPABILITY_LEVEL = "read-only-session-tools";
+const M3_IO_SKILL_PROVIDER = "hwlab-skill-cli";
+const M3_IO_SKILL_BACKEND = "hwlab-cloud-api/hwlab-agent-runtime-skill-cli";
+const M3_IO_SKILL_MODEL = "controlled-m3-io";
+const M3_IO_SKILL_RUNNER_KIND = "hwlab-m3-io-skill-cli";
+const M3_IO_SKILL_SANDBOX = "hwlab-api-route-only";
+const M3_IO_SKILL_SESSION_MODE = "controlled-m3-io-skill-cli";
+const M3_IO_SKILL_IMPLEMENTATION_TYPE = "skill-cli-hwlab-api-adapter";
+const M3_IO_SKILL_CAPABILITY_LEVEL = "controlled-m3-io-skill-cli";
+const M3_IO_SKILL_LIMITATION_FLAGS = Object.freeze([
+  "m3-io-only",
+  "hwlab-api-route-only",
+  "not-generic-hardware-control",
+  "not-codex-stdio",
+  "not-durable-session"
+]);
 const OPENAI_FALLBACK_RUNNER_KIND = "openai-responses-fallback";
 const CODEX_CLI_ONE_SHOT_RUNNER_KIND = "codex-cli-one-shot-ephemeral";
 const READONLY_TOOL_OUTPUT_LIMIT = 4000;
@@ -91,6 +112,51 @@ export async function handleCodeAgentChat(params = {}, options = {}) {
   try {
     const message = normalizeUserMessage(params.message);
     const runnerIntent = detectReadOnlyRunnerIntent(message);
+    if (runnerIntent.kind === "m3_io") {
+      const runnerResult = await callM3IoSkillRunner({
+        intent: runnerIntent,
+        conversationId,
+        traceId,
+        sessionId: requestedSessionId,
+        env: options.env ?? process.env,
+        now: options.now,
+        workspace: options.workspace,
+        sessionRegistry: options.sessionRegistry,
+        requestJson: options.m3IoSkillRequestJson
+      });
+      const completedAt = nowIso(options.now);
+      return {
+        ...base,
+        sessionId: runnerResult.session?.sessionId ?? base.sessionId,
+        status: "completed",
+        updatedAt: completedAt,
+        provider: runnerResult.provider,
+        model: runnerResult.model,
+        backend: runnerResult.backend,
+        workspace: runnerResult.workspace,
+        sandbox: runnerResult.sandbox,
+        session: runnerResult.session,
+        sessionMode: runnerResult.sessionMode,
+        sessionReuse: runnerResult.sessionReuse,
+        implementationType: runnerResult.implementationType,
+        runnerLimitations: runnerResult.runnerLimitations,
+        codexStdioFeasibility: runnerResult.codexStdioFeasibility,
+        longLivedSessionGate: runnerResult.longLivedSessionGate,
+        toolCalls: runnerResult.toolCalls,
+        skills: runnerResult.skills,
+        runner: runnerResult.runner,
+        runnerTrace: runnerResult.runnerTrace,
+        capabilityLevel: runnerResult.capabilityLevel,
+        reply: {
+          messageId,
+          role: "assistant",
+          content: runnerResult.content,
+          createdAt: completedAt
+        },
+        usage: null,
+        providerTrace: runnerResult.providerTrace
+      };
+    }
     if (runnerIntent.kind !== "none") {
       const runnerResult = await callReadOnlyRunner({
         intent: runnerIntent,
@@ -334,8 +400,8 @@ export function describeCodeAgentAvailability(env = process.env, options = {}) {
     blocker: blocked && !runnerAvailability.ready ? (providerPlan.mode === "openai" ? providerContract.blocker : "凭证缺口") : null,
     reason: blocked && !runnerAvailability.ready ? "provider_unavailable" : null,
     summary: blocked
-      ? `受控只读 runner 可用于 pwd/skills 等工作区能力；OpenAI Responses fallback 当前受 DEV provider Secret ${CODE_AGENT_PROVIDER_SECRET_REF} 或 DEV egress/base-url contract 影响。`
-      : "真实后端已接入；pwd/skills 走受控只读 runner，普通聊天可走 OpenAI Responses fallback。OpenAI fallback 不满足 Codex runner capability gate。",
+      ? `受控只读 runner 可用于 pwd/skills 等工作区能力，M3 IO 只允许 Skill CLI 调用 ${HWLAB_M3_IO_API_ROUTE}；OpenAI Responses fallback 当前受 DEV provider Secret ${CODE_AGENT_PROVIDER_SECRET_REF} 或 DEV egress/base-url contract 影响。`
+      : `真实后端已接入；pwd/skills 走受控只读 runner，M3 IO 走 Skill CLI -> HWLAB API ${HWLAB_M3_IO_API_ROUTE}，普通聊天可走 OpenAI Responses fallback。OpenAI fallback 不满足 Codex runner capability gate。`,
     missingEnv,
     secretRefs: blocked ? providerContract.secretRefs : [],
     egress: providerContract.egress,
@@ -441,6 +507,17 @@ function inspectReadOnlyRunnerAvailability(env, options = {}) {
     sessionRegistry,
     skillsDirs,
     skillsDirsPresent,
+    m3IoSkill: {
+      status: "available",
+      service: HWLAB_M3_IO_SKILL_NAME,
+      contractVersion: HWLAB_AGENT_RUNTIME_SKILL_CLI_VERSION,
+      route: HWLAB_M3_IO_API_ROUTE,
+      capabilityLevel: M3_IO_SKILL_CAPABILITY_LEVEL,
+      directGatewayCallsAllowed: false,
+      directBoxCallsAllowed: false,
+      directPatchPanelCallsAllowed: false,
+      fallbackAllowed: false
+    },
     safety: runnerSafetyContract()
   };
 }
@@ -772,6 +849,172 @@ async function callReadOnlyRunner({ intent, conversationId, sessionId, traceId,
   });
 }
 
+async function callM3IoSkillRunner({ intent, conversationId, sessionId, traceId, env, now, workspace, sessionRegistry, requestJson }) {
+  const resolvedWorkspace = resolveRunnerWorkspace(env, { workspace });
+  const registry = resolveCodeAgentSessionRegistry({ sessionRegistry });
+  const sessionAcquire = registry.acquire({
+    conversationId,
+    sessionId,
+    workspace: resolvedWorkspace,
+    sandbox: M3_IO_SKILL_SANDBOX,
+    runnerKind: M3_IO_SKILL_RUNNER_KIND,
+    capabilityLevel: M3_IO_SKILL_CAPABILITY_LEVEL,
+    implementationType: M3_IO_SKILL_IMPLEMENTATION_TYPE,
+    traceId,
+    now
+  });
+  const startedAt = nowIso(now);
+  const codexStdioFeasibility = inspectCodexStdioFeasibility(envForFeasibility(env));
+  if (!sessionAcquire.ok) {
+    const blockedSession = sessionAcquire.session;
+    throw runnerError(sessionAcquire.code, sessionAcquire.message, {
+      provider: M3_IO_SKILL_PROVIDER,
+      model: M3_IO_SKILL_MODEL,
+      backend: M3_IO_SKILL_BACKEND,
+      workspace: resolvedWorkspace ?? null,
+      sandbox: M3_IO_SKILL_SANDBOX,
+      session: blockedSession,
+      toolCalls: [],
+      skills: notRequestedSkills(),
+      runner: m3IoSkillRunnerDescriptor({ workspace: resolvedWorkspace, session: blockedSession }),
+      runnerTrace: m3IoSkillRunnerTrace({
+        traceId,
+        workspace: resolvedWorkspace ?? repoRoot,
+        session: blockedSession,
+        events: [`blocked:${sessionAcquire.code}`],
+        startedAt,
+        outputTruncated: false
+      }),
+      capabilityLevel: "blocked",
+      sessionMode: M3_IO_SKILL_SESSION_MODE,
+      sessionReuse: sessionReuseEvidence(blockedSession),
+      implementationType: M3_IO_SKILL_IMPLEMENTATION_TYPE,
+      runnerLimitations: [...M3_IO_SKILL_LIMITATION_FLAGS],
+      codexStdioFeasibility,
+      longLivedSessionGate: longLivedSessionGate({
+        provider: M3_IO_SKILL_PROVIDER,
+        runnerKind: M3_IO_SKILL_RUNNER_KIND,
+        session: blockedSession,
+        sessionMode: M3_IO_SKILL_SESSION_MODE,
+        implementationType: M3_IO_SKILL_IMPLEMENTATION_TYPE,
+        codexStdioFeasibility
+      }),
+      blockers: [sessionAcquire.blocker]
+    });
+  }
+
+  let session = sessionAcquire.session;
+  const commandArgs = m3IoSkillArgsForIntent(intent, { env, traceId });
+  const skillResult = await runM3IoSkillCommand(commandArgs, {
+    env,
+    now,
+    requestJson
+  });
+  const finishedAt = nowIso(now);
+  const toolCall = {
+    id: `tool_${randomUUID()}`,
+    type: "skill-cli",
+    name: HWLAB_M3_IO_SKILL_NAME,
+    status: skillResult.status === "succeeded" || skillResult.accepted === true ? "completed" : "blocked",
+    cwd: resolvedWorkspace,
+    command: redactText(`node skills/hwlab-agent-runtime/scripts/hwlab-agent-runtime-cli.mjs ${commandArgs.join(" ")}`),
+    exitCode: skillResult.ok ? 0 : 2,
+    stdout: boundToolOutput(JSON.stringify({
+      route: skillResult.route,
+      status: skillResult.status,
+      accepted: skillResult.accepted,
+      traceId: skillResult.traceId,
+      operationId: skillResult.operationId,
+      audit: skillResult.audit,
+      evidence: skillResult.evidence,
+      durable: skillResult.durable,
+      blocker: skillResult.blocker,
+      result: skillResult.result,
+      safety: skillResult.safety
+    })).text,
+    stderrSummary: skillResult.blocker?.code ?? "",
+    outputTruncated: false,
+    traceId,
+    route: HWLAB_M3_IO_API_ROUTE,
+    hwlabApi: skillResult.hwlabApi,
+    accepted: skillResult.accepted,
+    operationId: skillResult.operationId,
+    audit: skillResult.audit,
+    evidence: skillResult.evidence,
+    blocker: skillResult.blocker,
+    directGatewayCalls: false,
+    directBoxCalls: false,
+    directPatchPanelCalls: false,
+    fallbackUsed: false
+  };
+
+  session = releaseReadOnlySession(registry, session, { now, traceId, conversationId });
+  const runner = m3IoSkillRunnerDescriptor({ workspace: resolvedWorkspace, session });
+  const runnerTracePayload = m3IoSkillRunnerTrace({
+    traceId,
+    workspace: resolvedWorkspace,
+    session,
+    events: [
+      "intent:m3_io",
+      "tool:skill-cli:started",
+      `route:${HWLAB_M3_IO_API_ROUTE}`,
+      `tool:${toolCall.status}`
+    ],
+    startedAt,
+    finishedAt,
+    outputTruncated: toolCall.outputTruncated,
+    skillResult
+  });
+
+  return {
+    provider: M3_IO_SKILL_PROVIDER,
+    model: M3_IO_SKILL_MODEL,
+    backend: M3_IO_SKILL_BACKEND,
+    content: m3IoSkillReply(skillResult),
+    workspace: resolvedWorkspace,
+    sandbox: M3_IO_SKILL_SANDBOX,
+    session,
+    sessionMode: M3_IO_SKILL_SESSION_MODE,
+    sessionReuse: sessionReuseEvidence(session),
+    implementationType: M3_IO_SKILL_IMPLEMENTATION_TYPE,
+    runnerLimitations: [...M3_IO_SKILL_LIMITATION_FLAGS],
+    codexStdioFeasibility,
+    longLivedSessionGate: longLivedSessionGate({
+      provider: M3_IO_SKILL_PROVIDER,
+      runnerKind: M3_IO_SKILL_RUNNER_KIND,
+      session,
+      sessionMode: M3_IO_SKILL_SESSION_MODE,
+      implementationType: M3_IO_SKILL_IMPLEMENTATION_TYPE,
+      codexStdioFeasibility
+    }),
+    toolCalls: [toolCall],
+    skills: {
+      status: "used",
+      items: [{
+        name: HWLAB_M3_IO_SKILL_NAME,
+        summary: `Controlled M3 DO1/DI1 adapter for HWLAB API ${HWLAB_M3_IO_API_ROUTE}.`,
+        route: HWLAB_M3_IO_API_ROUTE,
+        version: HWLAB_AGENT_RUNTIME_SKILL_CLI_VERSION
+      }],
+      count: 1,
+      blockers: skillResult.blocker ? [skillResult.blocker] : []
+    },
+    runner,
+    runnerTrace: runnerTracePayload,
+    capabilityLevel: M3_IO_SKILL_CAPABILITY_LEVEL,
+    providerTrace: {
+      runnerKind: M3_IO_SKILL_RUNNER_KIND,
+      skill: HWLAB_M3_IO_SKILL_NAME,
+      route: HWLAB_M3_IO_API_ROUTE,
+      traceId: skillResult.traceId,
+      operationId: skillResult.operationId,
+      accepted: skillResult.accepted,
+      status: skillResult.status,
+      fallbackUsed: false
+    }
+  };
+}
+
 function detectReadOnlyRunnerIntent(message) {
   const text = String(message ?? "").trim();
   const lower = text.toLowerCase();
@@ -783,11 +1026,15 @@ function detectReadOnlyRunnerIntent(message) {
       reason: "只读 runner 不读取或输出 secret、token、kubeconfig、密码、私钥或环境变量原文。"
     };
   }
+  const m3IoIntent = detectM3IoIntent(text);
+  if (m3IoIntent) {
+    return m3IoIntent;
+  }
   if (isHardwareWriteOrAcceptanceRequest(text)) {
     return {
       kind: "security",
       toolName: "security.hardware-boundary",
-      reason: "只读 runner 不直接调用 gateway/box-simu/patch-panel、硬件写接口或宣称 M3/M4/M5 验收通过。"
+      reason: `只读 runner 不直接调用 gateway/box-simu/patch-panel、泛化硬件写接口或宣称 M3/M4/M5 验收通过；M3 DO1/DI1 只能通过 Skill CLI -> HWLAB API ${HWLAB_M3_IO_API_ROUTE}。`
     };
   }
   if (/\bpwd\b/u.test(lower) || /当前.*(?:工作目录|目录)|工作目录|当前路径|workspace path|工作区路径/iu.test(text)) {
@@ -816,6 +1063,54 @@ function detectReadOnlyRunnerIntent(message) {
   return { kind: "none" };
 }
 
+function detectM3IoIntent(text) {
+  const normalized = String(text ?? "");
+  if (!/\bM3\b|DO1|DI1|数字输出|数字输入|回读|读回/u.test(normalized)) {
+    return null;
+  }
+  if (/(?:直接|direct|gateway-simu|box-simu|patch-panel|hwlab-patch-panel|\/invoke|\/sync\/tick)/iu.test(normalized)) {
+    return null;
+  }
+  if (/DEV-LIVE|验收|acceptance|(?:M3|M4|M5).{0,20}(?:通过|pass|green|accept)/iu.test(normalized)) {
+    return null;
+  }
+
+  const wantsRead = /(?:DI1|数字输入).{0,16}(?:read|readback|读取|回读|读回|查询)|(?:read|readback|读取|回读|读回|查询).{0,16}(?:DI1|数字输入)/iu.test(normalized);
+  const wantsWrite = /(?:DO1|数字输出).{0,20}(?:write|set|置|写|打开|关闭|true|false|高|低)|(?:write|set|置|写|打开|关闭).{0,20}(?:DO1|数字输出)/iu.test(normalized);
+  if (!wantsRead && !wantsWrite) {
+    return null;
+  }
+
+  if (wantsRead && !wantsWrite) {
+    return {
+      kind: "m3_io",
+      toolName: HWLAB_M3_IO_SKILL_NAME,
+      action: "di.read"
+    };
+  }
+
+  const value = parseM3WriteValue(normalized);
+  if (typeof value !== "boolean") {
+    return {
+      kind: "unsupported",
+      toolName: HWLAB_M3_IO_SKILL_NAME,
+      reason: "M3 DO1 write requires an explicit true/false value."
+    };
+  }
+  return {
+    kind: "m3_io",
+    toolName: HWLAB_M3_IO_SKILL_NAME,
+    action: "do.write",
+    value
+  };
+}
+
+function parseM3WriteValue(text) {
+  if (/\btrue\b|\b1\b|\bon\b|打开|置高|高电平|拉高|闭合/iu.test(text)) return true;
+  if (/\bfalse\b|\b0\b|\boff\b|关闭|置低|低电平|拉低|断开/iu.test(text)) return false;
+  return null;
+}
+
 function extractReadOnlyTarget(text, { defaultTarget = null, preferFile = false } = {}) {
   const value = String(text ?? "");
   const quoted = value.match(/[`"']([^`"']{1,240})[`"']/u)?.[1];
@@ -845,7 +1140,7 @@ function isSecretReadRequest(text) {
 }
 
 function isHardwareWriteOrAcceptanceRequest(text) {
-  const hardwareTarget = /(?:hardware\.operation\.request|hardware\.invoke\.shell|audit\.event\.write|evidence\.record\.write|gateway-simu|box-simu|patch-panel|hwlab-patch-panel|硬件写|直接调用)/iu.test(text);
+  const hardwareTarget = /(?:hardware\.operation\.request|hardware\.invoke\.shell|audit\.event\.write|evidence\.record\.write|gateway-simu|box-simu|patch-panel|hwlab-patch-panel|硬件写|直接调用|\/invoke|\/sync\/tick)/iu.test(text);
   const mutationVerb = /(?:call|invoke|write|mutate|apply|rollout|accept|pass|验收|通过|写入|调用|变更|操作)/iu.test(text);
   const acceptanceClaim = /(?:M3|M4|M5).{0,20}(?:pass|accept|green|通过|验收|完成)/iu.test(text);
   return (hardwareTarget && mutationVerb) || acceptanceClaim;
@@ -1378,6 +1673,133 @@ function readOnlyRunnerResult({ content, workspace, toolCalls, skills, runner, r
   };
 }
 
+function m3IoSkillArgsForIntent(intent, { env, traceId }) {
+  const args = [
+    "m3",
+    "io",
+    "--action",
+    intent.action,
+    "--trace-id",
+    traceId,
+    "--actor-id",
+    "usr_code_agent"
+  ];
+  const apiBaseUrl = firstNonEmpty(
+    env.HWLAB_CODE_AGENT_HWLAB_API_BASE_URL,
+    env.HWLAB_API_BASE_URL,
+    env.HWLAB_CLOUD_API_BASE_URL,
+    null
+  );
+  if (apiBaseUrl) {
+    args.push("--api-base-url", apiBaseUrl);
+  }
+  if (intent.action === "do.write") {
+    args.push("--value", String(intent.value));
+  }
+  return args;
+}
+
+function m3IoSkillReply(skillResult) {
+  const lines = [
+    `M3 IO Skill CLI result: status=${skillResult.status}; accepted=${skillResult.accepted}; route=${skillResult.route}; traceId=${skillResult.traceId}; operationId=${skillResult.operationId ?? "null"}.`
+  ];
+  if (skillResult.audit?.summary) {
+    lines.push(`Audit: ${skillResult.audit.summary}.`);
+  }
+  if (skillResult.evidence?.summary) {
+    lines.push(`Evidence: ${skillResult.evidence.summary}.`);
+  }
+  if (skillResult.blocker) {
+    lines.push(`Blocker: ${skillResult.blocker.code}; ${skillResult.blocker.zh ?? skillResult.blocker.message}.`);
+  }
+  if (skillResult.action === "do.write") {
+    lines.push(`DO1 requested value=${String(skillResult.command?.value)}; DI1 readback=${String(skillResult.result?.targetReadback?.value ?? "unknown")}.`);
+  } else if (skillResult.action === "di.read") {
+    lines.push(`DI1 value=${String(skillResult.result?.value ?? "unknown")}.`);
+  }
+  lines.push("Boundary: Code Agent -> Skill CLI -> HWLAB API /v1/m3/io; no direct gateway/box/patch-panel call; no OpenAI fallback used. This is source/artifact control capability, not DEV-LIVE verification.");
+  return boundToolOutput(lines.join("\n"), READONLY_TOOL_OUTPUT_LIMIT).text;
+}
+
+function m3IoSkillRunnerDescriptor({ workspace, session = null } = {}) {
+  return {
+    kind: M3_IO_SKILL_RUNNER_KIND,
+    provider: M3_IO_SKILL_PROVIDER,
+    backend: M3_IO_SKILL_BACKEND,
+    workspace: workspace ?? repoRoot,
+    sandbox: M3_IO_SKILL_SANDBOX,
+    session: M3_IO_SKILL_SESSION_MODE,
+    sessionMode: M3_IO_SKILL_SESSION_MODE,
+    sessionId: session?.sessionId ?? null,
+    turn: session?.turn ?? null,
+    sessionReused: session?.reused ?? false,
+    implementationType: M3_IO_SKILL_IMPLEMENTATION_TYPE,
+    codexStdio: false,
+    longLivedSession: false,
+    durableSession: false,
+    writeCapable: true,
+    readOnly: false,
+    capabilityLevel: M3_IO_SKILL_CAPABILITY_LEVEL,
+    skill: {
+      name: HWLAB_M3_IO_SKILL_NAME,
+      contractVersion: HWLAB_AGENT_RUNTIME_SKILL_CLI_VERSION,
+      route: HWLAB_M3_IO_API_ROUTE
+    },
+    toolPolicy: {
+      allowed: [`POST ${HWLAB_M3_IO_API_ROUTE}`],
+      blocked: ["gateway-direct-call", "box-simu-direct-call", "patch-panel-direct-call", "generic-hardware-rpc", "OpenAI-hardware-fallback", "M3/M4/M5-acceptance-claim"]
+    },
+    runnerLimitations: [...M3_IO_SKILL_LIMITATION_FLAGS],
+    safety: {
+      secretsRead: false,
+      secretValuesPrinted: false,
+      kubeconfigRead: false,
+      cloudApiRouteOnly: true,
+      allowedRoute: HWLAB_M3_IO_API_ROUTE,
+      directGatewayCallsAllowed: false,
+      directBoxSimuCallsAllowed: false,
+      directPatchPanelCallsAllowed: false,
+      openAiFallbackAllowed: false,
+      m3m4m5AcceptanceClaimsAllowed: false,
+      outputLimitBytes: READONLY_TOOL_OUTPUT_LIMIT
+    }
+  };
+}
+
+function m3IoSkillRunnerTrace({ traceId, events, startedAt, finishedAt = startedAt, outputTruncated, workspace = repoRoot, session = null, skillResult = null }) {
+  return {
+    traceId,
+    runnerKind: M3_IO_SKILL_RUNNER_KIND,
+    workspace,
+    sandbox: M3_IO_SKILL_SANDBOX,
+    sessionMode: M3_IO_SKILL_SESSION_MODE,
+    sessionId: session?.sessionId ?? null,
+    sessionStatus: session?.status ?? null,
+    idleTimeoutMs: session?.idleTimeoutMs ?? null,
+    lastTraceId: session?.lastTraceId ?? null,
+    turn: session?.turn ?? null,
+    sessionReused: session?.reused ?? false,
+    implementationType: M3_IO_SKILL_IMPLEMENTATION_TYPE,
+    limitations: [...M3_IO_SKILL_LIMITATION_FLAGS],
+    startedAt,
+    finishedAt,
+    events,
+    route: HWLAB_M3_IO_API_ROUTE,
+    skill: HWLAB_M3_IO_SKILL_NAME,
+    operationId: skillResult?.operationId ?? null,
+    accepted: skillResult?.accepted ?? false,
+    status: skillResult?.status ?? "blocked",
+    blocker: skillResult?.blocker ?? null,
+    outputTruncated: Boolean(outputTruncated),
+    valuesPrinted: false,
+    directGatewayCalls: false,
+    directBoxCalls: false,
+    directPatchPanelCalls: false,
+    fallbackUsed: false,
+    note: `Controlled M3 IO uses Skill CLI -> HWLAB API ${HWLAB_M3_IO_API_ROUTE}; it is not OpenAI fallback and does not directly call gateway, box, or patch-panel.`
+  };
+}
+
 function sessionReuseEvidence(session) {
   return {
     conversationId: session.conversationId,
@@ -1424,6 +1846,9 @@ function resolveCodeAgentSessionRegistry(options = {}) {
 }
 
 function runnerDescriptor({ workspace, kind = READONLY_RUNNER_KIND, session = null } = {}) {
+  const allowed = kind === READONLY_RUNNER_KIND
+    ? ["pwd", "skills.discover", "ls", "rg --files", "cat", `m3.io.skill-cli:${HWLAB_M3_IO_API_ROUTE}`]
+    : ["pwd", "skills.discover", "ls", "rg --files", "cat"];
   return {
     kind,
     provider: kind === READONLY_RUNNER_KIND ? READONLY_RUNNER_PROVIDER : "codex-cli",
@@ -1443,7 +1868,7 @@ function runnerDescriptor({ workspace, kind = READONLY_RUNNER_KIND, session = nu
     readOnly: true,
     capabilityLevel: kind === READONLY_RUNNER_KIND ? READONLY_SESSION_CAPABILITY_LEVEL : "text-chat-only",
     toolPolicy: {
-      allowed: ["pwd", "skills.discover", "ls", "rg --files", "cat"],
+      allowed,
       blocked: ["secret-read", "kubeconfig-read", "hardware-write", "gateway-direct-call", "box-simu-direct-call", "patch-panel-direct-call", "M3/M4/M5-acceptance-claim"]
     },
     runnerLimitations: kind === READONLY_RUNNER_KIND ? [...READONLY_LIMITATION_FLAGS] : ["one-shot", "not-durable-session"],
@@ -1486,6 +1911,8 @@ function runnerSafetyContract() {
     directGatewayCallsAllowed: false,
     directBoxSimuCallsAllowed: false,
     directPatchPanelCallsAllowed: false,
+    m3IoSkillCliAllowedRoute: HWLAB_M3_IO_API_ROUTE,
+    openAiHardwareFallbackAllowed: false,
     m3m4m5AcceptanceClaimsAllowed: false,
     outputLimitBytes: READONLY_TOOL_OUTPUT_LIMIT
   };
diff --git a/internal/cloud/code-agent-session-registry.test.mjs b/internal/cloud/code-agent-session-registry.test.mjs
index 68fe28b1..9aa2e4f0 100644
--- a/internal/cloud/code-agent-session-registry.test.mjs
+++ b/internal/cloud/code-agent-session-registry.test.mjs
@@ -7,6 +7,7 @@ import {
   classifyCodexRunnerCapability,
   classifyCodeAgentChatReadiness
 } from "../../scripts/src/code-agent-response-contract.mjs";
+import { HWLAB_M3_IO_API_ROUTE } from "../../skills/hwlab-agent-runtime/scripts/src/m3-io-skill-client.mjs";
 
 test("code agent session registry creates, reuses, and expires sessions without storing secrets", () => {
   const registry = createCodeAgentSessionRegistry({
@@ -279,3 +280,224 @@ test("OpenAI fallback and codex one-shot do not pass the long-lived session gate
   assert.equal(classifyCodexRunnerCapability(oneShot, { httpStatus: 200 }).capabilityPass, false);
   assert.equal(classifyCodeAgentChatReadiness(oneShot, { realDevLive: true, httpStatus: 200 }).devLiveReplyPass, true);
 });
+
+test("Code Agent M3 DO write uses Skill CLI to call only HWLAB API /v1/m3/io", async () => {
+  const calls = [];
+  const payload = await handleCodeAgentChat(
+    {
+      conversationId: "cnv_m3_skill_write",
+      traceId: "trc_m3_skill_write",
+      message: "请通过 M3 DO1 写入 true，并回读 DI1"
+    },
+    {
+      now: () => "2026-05-23T00:05:00.000Z",
+      env: {
+        PATH: process.env.PATH,
+        HWLAB_CODE_AGENT_WORKSPACE: process.cwd(),
+        HWLAB_API_BASE_URL: "http://hwlab-cloud-api.hwlab-dev.svc.cluster.local:6667",
+        OPENAI_API_KEY: "must-not-be-used"
+      },
+      callProvider: async () => {
+        throw new Error("OpenAI fallback must not be used for M3 IO control");
+      },
+      m3IoSkillRequestJson: async (url, request) => {
+        calls.push({ url, request });
+        const parsed = new URL(url);
+        assert.equal(parsed.pathname, HWLAB_M3_IO_API_ROUTE);
+        assert.equal(parsed.hostname, "hwlab-cloud-api.hwlab-dev.svc.cluster.local");
+        assert.equal(request.method, "POST");
+        assert.equal(request.body.action, "do.write");
+        assert.equal(request.body.resourceId, "res_boxsimu_1");
+        assert.equal(request.body.port, "DO1");
+        assert.equal(request.body.value, true);
+        assert.equal(request.body.source, "hwlab-agent-runtime.m3-io");
+        return {
+          ok: true,
+          status: 200,
+          body: {
+            serviceId: "hwlab-cloud-api",
+            contractVersion: "m3-io-control-v1",
+            status: "succeeded",
+            accepted: true,
+            action: "do.write",
+            traceId: "trc_m3_skill_write",
+            operationId: "op_m3_do_write_skill",
+            auditId: "aud_m3_do_write_skill_succeeded",
+            evidenceId: "evd_m3_do_write_skill_succeeded",
+            auditState: {
+              status: "written_non_durable",
+              durableStatus: {
+                status: "degraded"
+              }
+            },
+            evidenceState: {
+              status: "blocked",
+              sourceKind: "BLOCKED",
+              blocker: "runtime_durable_not_green",
+              writeStatus: "written_non_durable"
+            },
+            durableStatus: {
+              status: "degraded",
+              durable: false,
+              blocker: "runtime_durable_not_green"
+            },
+            result: {
+              value: true,
+              targetReadback: {
+                status: "succeeded",
+                value: true,
+                resourceId: "res_boxsimu_2",
+                port: "DI1"
+              }
+            },
+            controlPath: {
+              status: "succeeded",
+              cloudApi: true,
+              gatewaySimu: true,
+              boxSimu: true,
+              patchPanel: true,
+              frontendBypass: false
+            }
+          }
+        };
+      }
+    }
+  );
+
+  validateCodeAgentChatSchema(payload);
+  assert.equal(payload.status, "completed");
+  assert.equal(payload.provider, "hwlab-skill-cli");
+  assert.equal(payload.backend, "hwlab-cloud-api/hwlab-agent-runtime-skill-cli");
+  assert.equal(payload.capabilityLevel, "controlled-m3-io-skill-cli");
+  assert.equal(payload.toolCalls.length, 1);
+  assert.equal(payload.toolCalls[0].name, "hwlab-agent-runtime.m3-io");
+  assert.equal(payload.toolCalls[0].status, "completed");
+  assert.equal(payload.toolCalls[0].route, HWLAB_M3_IO_API_ROUTE);
+  assert.equal(payload.toolCalls[0].accepted, true);
+  assert.equal(payload.toolCalls[0].operationId, "op_m3_do_write_skill");
+  assert.equal(payload.runnerTrace.route, HWLAB_M3_IO_API_ROUTE);
+  assert.equal(payload.runnerTrace.accepted, true);
+  assert.equal(payload.runner.writeCapable, true);
+  assert.deepEqual(payload.runner.toolPolicy.allowed, [`POST ${HWLAB_M3_IO_API_ROUTE}`]);
+  assert.equal(payload.runner.safety.directGatewayCallsAllowed, false);
+  assert.equal(payload.runner.safety.directBoxSimuCallsAllowed, false);
+  assert.equal(payload.runner.safety.directPatchPanelCallsAllowed, false);
+  assert.equal(payload.providerTrace.fallbackUsed, false);
+  assert.match(payload.reply.content, /Skill CLI -> HWLAB API \/v1\/m3\/io/u);
+  assert.equal(calls.length, 1);
+  assert.equal(calls[0].url, `http://hwlab-cloud-api.hwlab-dev.svc.cluster.local:6667${HWLAB_M3_IO_API_ROUTE}`);
+  assert.equal(calls[0].url.includes("gateway"), false);
+  assert.equal(calls[0].url.includes("box-simu"), false);
+  assert.equal(calls[0].url.includes("patch-panel"), false);
+});
+
+test("Code Agent M3 DI read returns structured blocker from HWLAB API without fallback", async () => {
+  const calls = [];
+  const payload = await handleCodeAgentChat(
+    {
+      conversationId: "cnv_m3_skill_read_blocked",
+      traceId: "trc_m3_skill_read_blocked",
+      message: "读取 M3 DI1 readback"
+    },
+    {
+      now: () => "2026-05-23T00:06:00.000Z",
+      env: {
+        PATH: process.env.PATH,
+        HWLAB_CODE_AGENT_WORKSPACE: process.cwd(),
+        HWLAB_API_BASE_URL: "http://hwlab-cloud-api.hwlab-dev.svc.cluster.local:6667",
+        OPENAI_API_KEY: "must-not-be-used"
+      },
+      callProvider: async () => {
+        throw new Error("OpenAI fallback must not be used for M3 IO read");
+      },
+      m3IoSkillRequestJson: async (url, request) => {
+        calls.push({ url, request });
+        return {
+          ok: true,
+          status: 200,
+          body: {
+            serviceId: "hwlab-cloud-api",
+            contractVersion: "m3-io-control-v1",
+            status: "blocked",
+            accepted: false,
+            action: "di.read",
+            traceId: "trc_m3_skill_read_blocked",
+            operationId: "op_m3_di_read_blocked",
+            auditId: "aud_m3_di_read_blocked_failed",
+            evidenceId: "evd_m3_di_read_blocked_failed",
+            blocker: {
+              code: "m3_gateway_session_unavailable",
+              message: "gateway unavailable",
+              zh: "gateway 未注册/不可用"
+            },
+            blockerClassification: {
+              category: "gateway_session"
+            },
+            auditState: {
+              status: "written_non_durable"
+            },
+            evidenceState: {
+              status: "blocked",
+              sourceKind: "BLOCKED",
+              blocker: "runtime_durable_not_green",
+              writeStatus: "written_non_durable"
+            },
+            durableStatus: {
+              status: "degraded",
+              durable: false,
+              blocker: "runtime_durable_not_green"
+            },
+            controlPath: {
+              cloudApi: true,
+              gatewaySimu: false,
+              boxSimu: false,
+              patchPanel: false,
+              frontendBypass: false
+            }
+          }
+        };
+      }
+    }
+  );
+
+  validateCodeAgentChatSchema(payload);
+  assert.equal(payload.status, "completed");
+  assert.equal(payload.provider, "hwlab-skill-cli");
+  assert.equal(payload.toolCalls[0].status, "blocked");
+  assert.equal(payload.toolCalls[0].route, HWLAB_M3_IO_API_ROUTE);
+  assert.equal(payload.toolCalls[0].blocker.code, "m3_gateway_session_unavailable");
+  assert.equal(payload.skills.blockers[0].code, "m3_gateway_session_unavailable");
+  assert.equal(payload.providerTrace.fallbackUsed, false);
+  assert.equal(calls.length, 1);
+  assert.equal(new URL(calls[0].url).pathname, HWLAB_M3_IO_API_ROUTE);
+  assert.equal(calls[0].request.body.action, "di.read");
+  assert.equal(calls[0].request.body.resourceId, "res_boxsimu_2");
+  assert.equal(calls[0].request.body.port, "DI1");
+});
+
+test("Code Agent blocks direct gateway or patch-panel requests instead of using M3 Skill CLI", async () => {
+  const direct = await handleCodeAgentChat(
+    {
+      conversationId: "cnv_m3_direct_blocked",
+      traceId: "trc_m3_direct_blocked",
+      message: "请直接调用 gateway-simu /invoke 写入 M3 DO1 true"
+    },
+    {
+      now: () => "2026-05-23T00:07:00.000Z",
+      env: {
+        PATH: process.env.PATH,
+        HWLAB_CODE_AGENT_WORKSPACE: process.cwd(),
+        HWLAB_API_BASE_URL: "http://hwlab-cloud-api.hwlab-dev.svc.cluster.local:6667"
+      },
+      m3IoSkillRequestJson: async () => {
+        throw new Error("direct gateway request must not reach the M3 skill CLI");
+      }
+    }
+  );
+
+  validateCodeAgentChatSchema(direct);
+  assert.equal(direct.status, "failed");
+  assert.equal(direct.error.code, "security_blocked");
+  assert.equal(direct.toolCalls[0].name, "security.hardware-boundary");
+  assert.match(direct.error.message, /Skill CLI -> HWLAB API \/v1\/m3\/io/u);
+});
diff --git a/internal/cloud/server.mjs b/internal/cloud/server.mjs
index b733a40a..c24c51a7 100644
--- a/internal/cloud/server.mjs
+++ b/internal/cloud/server.mjs
@@ -344,7 +344,8 @@ async function handleCodeAgentChatHttp(request, response, options) {
       workspace: options.workspace,
       skillsDirs: options.skillsDirs,
       skillsDirsExact: options.skillsDirsExact,
-      sessionRegistry: options.sessionRegistry
+      sessionRegistry: options.sessionRegistry,
+      m3IoSkillRequestJson: options.m3IoSkillRequestJson
     }
   );
 
diff --git a/internal/cloud/server.test.mjs b/internal/cloud/server.test.mjs
index e2fe28fc..13c81cad 100644
--- a/internal/cloud/server.test.mjs
+++ b/internal/cloud/server.test.mjs
@@ -1021,6 +1021,108 @@ test("cloud api /v1/agent/chat runs read-only runner pwd with workspace evidence
   }
 });
 
+test("cloud api /v1/agent/chat routes M3 IO through Skill CLI to /v1/m3/io only", async () => {
+  const workspace = await mkdtemp(path.join(os.tmpdir(), "hwlab-agent-m3-skill-"));
+  const calls = [];
+  const server = createCloudApiServer({
+    env: {
+      PATH: process.env.PATH,
+      HWLAB_CODE_AGENT_WORKSPACE: workspace,
+      HWLAB_API_BASE_URL: "http://hwlab-cloud-api.hwlab-dev.svc.cluster.local:6667",
+      OPENAI_API_KEY: "must-not-be-used"
+    },
+    callCodeAgentProvider: async () => {
+      throw new Error("OpenAI fallback must not handle M3 IO");
+    },
+    m3IoSkillRequestJson: async (url, request) => {
+      calls.push({ url, request });
+      return {
+        ok: true,
+        status: 200,
+        body: {
+          serviceId: "hwlab-cloud-api",
+          contractVersion: "m3-io-control-v1",
+          status: "succeeded",
+          accepted: true,
+          action: "do.write",
+          traceId: "trc_server-test-m3-skill",
+          operationId: "op_m3_do_write_server_skill",
+          auditId: "aud_m3_do_write_server_skill_succeeded",
+          evidenceId: "evd_m3_do_write_server_skill_succeeded",
+          auditState: {
+            status: "written_non_durable"
+          },
+          evidenceState: {
+            status: "blocked",
+            sourceKind: "BLOCKED",
+            blocker: "runtime_durable_not_green",
+            writeStatus: "written_non_durable"
+          },
+          durableStatus: {
+            status: "degraded",
+            durable: false,
+            blocker: "runtime_durable_not_green"
+          },
+          result: {
+            value: false,
+            targetReadback: {
+              status: "succeeded",
+              value: false
+            }
+          },
+          controlPath: {
+            status: "succeeded",
+            cloudApi: true,
+            gatewaySimu: true,
+            boxSimu: true,
+            patchPanel: true,
+            frontendBypass: false
+          }
+        }
+      };
+    }
+  });
+  await new Promise((resolve) => server.listen(0, "127.0.0.1", resolve));
+
+  try {
+    const { port } = server.address();
+    const response = await fetch(`http://127.0.0.1:${port}/v1/agent/chat`, {
+      method: "POST",
+      headers: {
+        "content-type": "application/json",
+        "x-trace-id": "trc_server-test-m3-skill"
+      },
+      body: JSON.stringify({
+        conversationId: "cnv_server-test-m3-skill",
+        message: "请通过 M3 DO1 写入 false，并回读 DI1"
+      })
+    });
+    assert.equal(response.status, 200);
+    const payload = await response.json();
+    assert.equal(payload.status, "completed");
+    assert.equal(payload.provider, "hwlab-skill-cli");
+    assert.equal(payload.backend, "hwlab-cloud-api/hwlab-agent-runtime-skill-cli");
+    assert.equal(payload.toolCalls[0].name, "hwlab-agent-runtime.m3-io");
+    assert.equal(payload.toolCalls[0].route, "/v1/m3/io");
+    assert.equal(payload.toolCalls[0].accepted, true);
+    assert.equal(payload.providerTrace.fallbackUsed, false);
+    assert.equal(payload.runner.safety.directGatewayCallsAllowed, false);
+    assert.equal(payload.runner.safety.directBoxSimuCallsAllowed, false);
+    assert.equal(payload.runner.safety.directPatchPanelCallsAllowed, false);
+    assert.equal(calls.length, 1);
+    assert.equal(calls[0].url, "http://hwlab-cloud-api.hwlab-dev.svc.cluster.local:6667/v1/m3/io");
+    assert.equal(calls[0].request.body.action, "do.write");
+    assert.equal(calls[0].request.body.value, false);
+    assert.equal(calls[0].url.includes("gateway-simu"), false);
+    assert.equal(calls[0].url.includes("box-simu"), false);
+    assert.equal(calls[0].url.includes("patch-panel"), false);
+  } finally {
+    await new Promise((resolve, reject) => {
+      server.close((error) => (error ? reject(error) : resolve()));
+    });
+  }
+});
+
 test("cloud api /v1/agent/chat reuses controlled read-only session and exposes bounded file tools", async () => {
   const workspace = await mkdtemp(path.join(os.tmpdir(), "hwlab-agent-file-tools-"));
   await writeFile(path.join(workspace, "alpha.txt"), "alpha\nbeta\n", "utf8");
diff --git a/package.json b/package.json
index 78664d84..6a4f8470 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,7 @@
   "type": "module",
   "scripts": {
     "validate": "node scripts/validate-contract.mjs && node scripts/deploy-contract-plan.mjs --check && node scripts/deploy-desired-state-plan.mjs --check && node scripts/dev-runtime-provisioning.mjs --check && node scripts/dev-runtime-migration.mjs --check && node scripts/dev-runtime-postflight.mjs --check && node --check scripts/artifact-runtime-readiness-guard.mjs && node --check scripts/src/artifact-runtime-readiness-guard.mjs && node --test scripts/artifact-runtime-readiness-guard.test.mjs",
-    "check": "node --check internal/protocol/index.mjs && node --check internal/agent/index.mjs && node --check internal/agent/runtime.mjs && node --check internal/audit/index.mjs && node --check internal/db/runtime-store.mjs && node --check internal/db/runtime-store.test.mjs && node --check internal/mvp-gate/summary.mjs && node --check internal/cloud/db-contract.mjs && node --check internal/dev-entrypoint/http.mjs && node --check internal/dev-entrypoint/http.test.mjs && node --check internal/cloud/code-agent-contract.mjs && node --check internal/cloud/code-agent-session-registry.mjs && node --check internal/cloud/code-agent-session-registry.test.mjs && node --check internal/cloud/json-rpc.mjs && node --check internal/cloud/code-agent-chat.mjs && node --check internal/cloud/m3-io-control.mjs && node --check internal/cloud/server.mjs && node --check internal/sim/model.mjs && node --check internal/sim/model.test.mjs && node --check internal/sim/http.mjs && node --check internal/sim/l2-runtime.mjs && node --check internal/patchpanel/model.mjs && node --check internal/patchpanel/runtime.mjs && node --check cmd/hwlab-cloud-api/main.mjs && node --check cmd/hwlab-edge-proxy/main.mjs && node --check cmd/hwlab-agent-mgr/main.mjs && node --check cmd/hwlab-agent-worker/main.mjs && node --check cmd/hwlab-box-simu/main.mjs && node --check cmd/hwlab-gateway-simu/main.mjs && node --check scripts/cloud-api-runtime-smoke.mjs && node --check scripts/code-agent-chat-smoke.mjs && node --check scripts/dev-edge-health-smoke.mjs && node --check scripts/src/dev-edge-health-smoke-lib.mjs && node --check scripts/validate-contract.mjs && node --check scripts/deploy-contract-plan.test.mjs && node --check scripts/deploy-desired-state-plan.mjs && node --check scripts/src/deploy-desired-state-plan.mjs && node --check scripts/artifact-runtime-readiness-guard.mjs && node --check scripts/src/artifact-runtime-readiness-guard.mjs && node --check scripts/artifact-runtime-readiness-guard.test.mjs && node --check scripts/report-lifecycle.mjs && node --check scripts/report-lifecycle.test.mjs && node --check scripts/validate-dev-gate-report.mjs && node --check scripts/dev-cd-apply.mjs && node --check scripts/src/dev-cd-apply.mjs && node --check scripts/src/dev-cd-apply.test.mjs && node --check scripts/dev-m3-hardware-loop-smoke.test.mjs && node --check scripts/m3-io-control-e2e.mjs && node --check scripts/src/m3-io-control-e2e.mjs && node --check scripts/m3-io-control-e2e.test.mjs && node --check scripts/dev-cloud-workbench-smoke.test.mjs && node --check scripts/dev-cloud-workbench-layout-smoke.mjs && node --check scripts/validate-dev-m3-cardinality.mjs && node --check scripts/validate-dev-m3-cardinality.test.mjs && node --check scripts/validate-artifact-catalog.mjs && node --check scripts/refresh-artifact-catalog.mjs && node --check scripts/dev-artifact-publish.mjs && node --check scripts/src/dev-artifact-services.mjs && node --check scripts/src/registry-capabilities.mjs && node --check scripts/preflight-dev-base-image.mjs && node --check scripts/src/dev-base-image-preflight.mjs && node --check scripts/dev-evidence-blocker-aggregator.mjs && node --check scripts/src/dev-evidence-blocker-aggregator.mjs && node --check scripts/src/dev-evidence-blocker-aggregator.test.mjs && node --check scripts/src/dev-m4-agent-loop-smoke-lib.test.mjs && node --check scripts/d601-k3s-readonly-observability.mjs && node --check scripts/src/d601-k3s-readonly-observability.mjs && node --check scripts/dev-runtime-provisioning.mjs && node --check scripts/src/dev-runtime-provisioning.mjs && node --check scripts/src/dev-runtime-provisioning.test.mjs && node --check scripts/dev-runtime-migration.mjs && node --check scripts/src/dev-runtime-migration.mjs && node --check scripts/src/dev-runtime-migration.test.mjs && node --check scripts/dev-runtime-postflight.mjs && node --check scripts/src/dev-runtime-postflight.mjs && node --check scripts/src/dev-runtime-postflight.test.mjs && node --check scripts/l2-runtime-contract-smoke.mjs && node --check scripts/patch-panel-runtime-smoke.mjs && node --check scripts/export-web-gate-summary.mjs && node --check scripts/l6-cli-web-smoke.mjs && node --check tools/hwlab-cli/bin/hwlab-cli.mjs && node --check tools/hwlab-cli/lib/cli.mjs && node --check web/hwlab-cloud-web/app.mjs && node --check web/hwlab-cloud-web/live-status.mjs && node --check web/hwlab-cloud-web/wiring-status.mjs && node --check web/hwlab-cloud-web/gate-summary.mjs && node --check web/hwlab-cloud-web/scripts/check.mjs && node --check web/hwlab-cloud-web/scripts/live-status-contract.test.mjs && node --check web/hwlab-cloud-web/scripts/build.mjs && node --check web/hwlab-cloud-web/scripts/dist-contract.mjs && node scripts/validate-contract.mjs && node scripts/validate-dev-gate-report.mjs && node scripts/report-lifecycle.test.mjs && node scripts/validate-dev-m3-cardinality.mjs && node scripts/validate-artifact-catalog.mjs && node scripts/deploy-desired-state-plan.mjs --check && node scripts/dev-runtime-provisioning.mjs --check && node scripts/dev-runtime-migration.mjs --check && node scripts/dev-runtime-postflight.mjs --check && node scripts/dev-evidence-blocker-aggregator.mjs --check && node scripts/l2-runtime-contract-smoke.mjs && node scripts/l6-cli-web-smoke.mjs && node web/hwlab-cloud-web/scripts/check.mjs && node scripts/code-agent-chat-smoke.mjs && node --test web/hwlab-cloud-web/wiring-status.test.mjs scripts/artifact-runtime-readiness-guard.test.mjs scripts/deploy-contract-plan.test.mjs scripts/dev-m3-hardware-loop-smoke.test.mjs scripts/validate-dev-m3-cardinality.test.mjs scripts/dev-cloud-workbench-smoke.test.mjs web/hwlab-cloud-web/scripts/live-status-contract.test.mjs scripts/deploy-desired-state-plan.test.mjs scripts/src/dev-cd-apply.test.mjs scripts/src/dev-deploy-apply.test.mjs scripts/src/dev-runtime-provisioning.test.mjs scripts/src/dev-runtime-migration.test.mjs scripts/src/dev-runtime-postflight.test.mjs scripts/src/dev-m4-agent-loop-smoke-lib.test.mjs scripts/src/dev-evidence-blocker-aggregator.test.mjs internal/agent/index.test.mjs internal/audit/index.test.mjs internal/db/schema.test.mjs internal/db/runtime-store.test.mjs internal/cloud/json-rpc.test.mjs internal/cloud/m3-io-control.test.mjs internal/cloud/code-agent-session-registry.test.mjs internal/cloud/server.test.mjs internal/dev-entrypoint/http.test.mjs internal/sim/model.test.mjs internal/patchpanel/model.test.mjs internal/patchpanel/runtime.test.mjs && node scripts/cloud-api-runtime-smoke.mjs && sh -n scripts/bootstrap-skills.sh scripts/worker-entrypoint.sh",
+    "check": "node --check internal/protocol/index.mjs && node --check internal/agent/index.mjs && node --check internal/agent/runtime.mjs && node --check internal/audit/index.mjs && node --check internal/db/runtime-store.mjs && node --check internal/db/runtime-store.test.mjs && node --check internal/mvp-gate/summary.mjs && node --check internal/cloud/db-contract.mjs && node --check internal/dev-entrypoint/http.mjs && node --check internal/dev-entrypoint/http.test.mjs && node --check internal/cloud/code-agent-contract.mjs && node --check internal/cloud/code-agent-session-registry.mjs && node --check internal/cloud/code-agent-session-registry.test.mjs && node --check internal/cloud/json-rpc.mjs && node --check internal/cloud/code-agent-chat.mjs && node --check internal/cloud/m3-io-control.mjs && node --check internal/cloud/server.mjs && node --check internal/sim/model.mjs && node --check internal/sim/model.test.mjs && node --check internal/sim/http.mjs && node --check internal/sim/l2-runtime.mjs && node --check internal/patchpanel/model.mjs && node --check internal/patchpanel/runtime.mjs && node --check cmd/hwlab-cloud-api/main.mjs && node --check cmd/hwlab-edge-proxy/main.mjs && node --check cmd/hwlab-agent-mgr/main.mjs && node --check cmd/hwlab-agent-worker/main.mjs && node --check cmd/hwlab-box-simu/main.mjs && node --check cmd/hwlab-gateway-simu/main.mjs && node --check scripts/cloud-api-runtime-smoke.mjs && node --check scripts/code-agent-chat-smoke.mjs && node --check scripts/dev-edge-health-smoke.mjs && node --check scripts/src/dev-edge-health-smoke-lib.mjs && node --check scripts/validate-contract.mjs && node --check scripts/deploy-contract-plan.test.mjs && node --check scripts/deploy-desired-state-plan.mjs && node --check scripts/src/deploy-desired-state-plan.mjs && node --check scripts/artifact-runtime-readiness-guard.mjs && node --check scripts/src/artifact-runtime-readiness-guard.mjs && node --check scripts/artifact-runtime-readiness-guard.test.mjs && node --check scripts/report-lifecycle.mjs && node --check scripts/report-lifecycle.test.mjs && node --check scripts/validate-dev-gate-report.mjs && node --check scripts/dev-cd-apply.mjs && node --check scripts/src/dev-cd-apply.mjs && node --check scripts/src/dev-cd-apply.test.mjs && node --check scripts/dev-m3-hardware-loop-smoke.test.mjs && node --check scripts/m3-io-control-e2e.mjs && node --check scripts/src/m3-io-control-e2e.mjs && node --check scripts/m3-io-control-e2e.test.mjs && node --check scripts/dev-cloud-workbench-smoke.test.mjs && node --check scripts/dev-cloud-workbench-layout-smoke.mjs && node --check scripts/validate-dev-m3-cardinality.mjs && node --check scripts/validate-dev-m3-cardinality.test.mjs && node --check scripts/validate-artifact-catalog.mjs && node --check scripts/refresh-artifact-catalog.mjs && node --check scripts/dev-artifact-publish.mjs && node --check scripts/src/dev-artifact-services.mjs && node --check scripts/src/registry-capabilities.mjs && node --check scripts/preflight-dev-base-image.mjs && node --check scripts/src/dev-base-image-preflight.mjs && node --check scripts/dev-evidence-blocker-aggregator.mjs && node --check scripts/src/dev-evidence-blocker-aggregator.mjs && node --check scripts/src/dev-evidence-blocker-aggregator.test.mjs && node --check scripts/src/dev-m4-agent-loop-smoke-lib.test.mjs && node --check scripts/d601-k3s-readonly-observability.mjs && node --check scripts/src/d601-k3s-readonly-observability.mjs && node --check scripts/dev-runtime-provisioning.mjs && node --check scripts/src/dev-runtime-provisioning.mjs && node --check scripts/src/dev-runtime-provisioning.test.mjs && node --check scripts/dev-runtime-migration.mjs && node --check scripts/src/dev-runtime-migration.mjs && node --check scripts/src/dev-runtime-migration.test.mjs && node --check scripts/dev-runtime-postflight.mjs && node --check scripts/src/dev-runtime-postflight.mjs && node --check scripts/src/dev-runtime-postflight.test.mjs && node --check scripts/l2-runtime-contract-smoke.mjs && node --check scripts/patch-panel-runtime-smoke.mjs && node --check scripts/export-web-gate-summary.mjs && node --check scripts/l6-cli-web-smoke.mjs && node --check skills/hwlab-agent-runtime/scripts/hwlab-agent-runtime-cli.mjs && node --check skills/hwlab-agent-runtime/scripts/src/m3-io-skill-client.mjs && node --check skills/hwlab-agent-runtime/scripts/m3-io-skill-client.test.mjs && node --check tools/hwlab-cli/bin/hwlab-cli.mjs && node --check tools/hwlab-cli/lib/cli.mjs && node --check web/hwlab-cloud-web/app.mjs && node --check web/hwlab-cloud-web/live-status.mjs && node --check web/hwlab-cloud-web/wiring-status.mjs && node --check web/hwlab-cloud-web/gate-summary.mjs && node --check web/hwlab-cloud-web/scripts/check.mjs && node --check web/hwlab-cloud-web/scripts/live-status-contract.test.mjs && node --check web/hwlab-cloud-web/scripts/build.mjs && node --check web/hwlab-cloud-web/scripts/dist-contract.mjs && node scripts/validate-contract.mjs && node scripts/validate-dev-gate-report.mjs && node scripts/report-lifecycle.test.mjs && node scripts/validate-dev-m3-cardinality.mjs && node scripts/validate-artifact-catalog.mjs && node scripts/deploy-desired-state-plan.mjs --check && node scripts/dev-runtime-provisioning.mjs --check && node scripts/dev-runtime-migration.mjs --check && node scripts/dev-runtime-postflight.mjs --check && node scripts/dev-evidence-blocker-aggregator.mjs --check && node scripts/l2-runtime-contract-smoke.mjs && node scripts/l6-cli-web-smoke.mjs && node web/hwlab-cloud-web/scripts/check.mjs && node scripts/code-agent-chat-smoke.mjs && node --test web/hwlab-cloud-web/wiring-status.test.mjs scripts/artifact-runtime-readiness-guard.test.mjs scripts/deploy-contract-plan.test.mjs scripts/dev-m3-hardware-loop-smoke.test.mjs scripts/validate-dev-m3-cardinality.test.mjs scripts/dev-cloud-workbench-smoke.test.mjs web/hwlab-cloud-web/scripts/live-status-contract.test.mjs scripts/deploy-desired-state-plan.test.mjs scripts/src/dev-cd-apply.test.mjs scripts/src/dev-deploy-apply.test.mjs scripts/src/dev-runtime-provisioning.test.mjs scripts/src/dev-runtime-migration.test.mjs scripts/src/dev-runtime-postflight.test.mjs scripts/src/dev-m4-agent-loop-smoke-lib.test.mjs scripts/src/dev-evidence-blocker-aggregator.test.mjs skills/hwlab-agent-runtime/scripts/m3-io-skill-client.test.mjs internal/agent/index.test.mjs internal/audit/index.test.mjs internal/db/schema.test.mjs internal/db/runtime-store.test.mjs internal/cloud/json-rpc.test.mjs internal/cloud/m3-io-control.test.mjs internal/cloud/code-agent-session-registry.test.mjs internal/cloud/server.test.mjs internal/dev-entrypoint/http.test.mjs internal/sim/model.test.mjs internal/patchpanel/model.test.mjs internal/patchpanel/runtime.test.mjs && node scripts/cloud-api-runtime-smoke.mjs && sh -n scripts/bootstrap-skills.sh scripts/worker-entrypoint.sh",
     "dev-base-image:preflight": "node scripts/preflight-dev-base-image.mjs",
     "cloud-api:smoke": "node scripts/cloud-api-runtime-smoke.mjs",
     "m1:smoke": "node scripts/m1-contract-smoke.mjs",
diff --git a/scripts/code-agent-chat-smoke.mjs b/scripts/code-agent-chat-smoke.mjs
index b1d90ea2..bb5d65f3 100644
--- a/scripts/code-agent-chat-smoke.mjs
+++ b/scripts/code-agent-chat-smoke.mjs
@@ -350,6 +350,84 @@ async function runLocalContractSmoke() {
   assert.equal(classifyCodexRunnerCapability(securityBlocked, { httpStatus: 200 }).capabilityPass, false);
   logOk("security blocked path is structured");
 
+  const m3SkillCalls = [];
+  const m3SkillWrite = await handleCodeAgentChat(
+    {
+      conversationId: "cnv_code-agent-chat-m3-skill",
+      traceId: "trc_code-agent-chat-m3-skill",
+      message: "请通过 M3 DO1 写入 true，并回读 DI1"
+    },
+    {
+      now: () => "2026-05-22T00:04:55.000Z",
+      env: {
+        PATH: process.env.PATH,
+        HWLAB_CODE_AGENT_WORKSPACE: process.cwd(),
+        HWLAB_API_BASE_URL: "http://hwlab-cloud-api.hwlab-dev.svc.cluster.local:6667",
+        OPENAI_API_KEY: "must-not-be-used"
+      },
+      callProvider: async () => {
+        throw new Error("OpenAI fallback must not be used for M3 IO");
+      },
+      m3IoSkillRequestJson: async (url, request) => {
+        m3SkillCalls.push({ url, request });
+        return {
+          ok: true,
+          status: 200,
+          body: {
+            status: "succeeded",
+            accepted: true,
+            action: "do.write",
+            traceId: "trc_code-agent-chat-m3-skill",
+            operationId: "op_m3_do_write_smoke",
+            auditId: "aud_m3_do_write_smoke_succeeded",
+            evidenceId: "evd_m3_do_write_smoke_succeeded",
+            auditState: {
+              status: "written_non_durable"
+            },
+            evidenceState: {
+              status: "blocked",
+              sourceKind: "BLOCKED",
+              blocker: "runtime_durable_not_green",
+              writeStatus: "written_non_durable"
+            },
+            durableStatus: {
+              status: "degraded",
+              durable: false,
+              blocker: "runtime_durable_not_green"
+            },
+            result: {
+              value: true,
+              targetReadback: {
+                status: "succeeded",
+                value: true
+              }
+            },
+            controlPath: {
+              cloudApi: true,
+              gatewaySimu: true,
+              boxSimu: true,
+              patchPanel: true,
+              frontendBypass: false
+            }
+          }
+        };
+      }
+    }
+  );
+  validateCodeAgentChatSchema(m3SkillWrite);
+  assert.equal(m3SkillWrite.status, "completed");
+  assert.equal(m3SkillWrite.provider, "hwlab-skill-cli");
+  assert.equal(m3SkillWrite.toolCalls[0].name, "hwlab-agent-runtime.m3-io");
+  assert.equal(m3SkillWrite.toolCalls[0].route, "/v1/m3/io");
+  assert.equal(m3SkillWrite.providerTrace.fallbackUsed, false);
+  assert.equal(m3SkillWrite.runner.safety.directGatewayCallsAllowed, false);
+  assert.equal(m3SkillCalls.length, 1);
+  assert.equal(m3SkillCalls[0].url, "http://hwlab-cloud-api.hwlab-dev.svc.cluster.local:6667/v1/m3/io");
+  assert.equal(m3SkillCalls[0].url.includes("gateway-simu"), false);
+  assert.equal(m3SkillCalls[0].url.includes("box-simu"), false);
+  assert.equal(m3SkillCalls[0].url.includes("patch-panel"), false);
+  logOk("M3 Skill CLI routes through HWLAB API only");
+
   const completedHttp200Readiness = classifyCodeAgentChatReadiness(completedLivePayload, { realDevLive: true, httpStatus: 200 });
   assert.equal(completedHttp200Readiness.status, "pass");
   assert.equal(completedHttp200Readiness.devLiveReplyPass, true);
diff --git a/skills/hwlab-agent-runtime/SKILL.md b/skills/hwlab-agent-runtime/SKILL.md
index 847cc187..28fb4a4b 100644
--- a/skills/hwlab-agent-runtime/SKILL.md
+++ b/skills/hwlab-agent-runtime/SKILL.md
@@ -5,6 +5,8 @@ description: Build and validate the HWLAB agent-mgr and agent-worker runtime ske
 
 # HWLAB Agent Runtime
 
+Skill(cli-spec)
+
 Use this skill when working on HWLAB agent runtime skeletons.
 
 - Keep the control plane long-lived and worker execution session-scoped.
@@ -13,6 +15,10 @@ Use this skill when working on HWLAB agent runtime skeletons.
 - Use repo-local skills artifacts only when `commitId` and `version` are
   supplied explicitly.
 - Do not infer or fall back to external skill sources.
+- For M3 hardware control, use only the repo-owned Skill CLI below. It calls
+  HWLAB cloud-api `POST /v1/m3/io`; it must not call gateway, box, or
+  patch-panel URLs directly, and it must not use an OpenAI/text fallback as
+  hardware capability.
 
 ## Local CLI Contract
 
@@ -25,6 +31,9 @@ All commands emit JSON and stay local:
 - `node cmd/hwlab-agent-mgr/main.mjs evidence --agent-session-id ID`
 - `node cmd/hwlab-agent-mgr/main.mjs cleanup --agent-session-id ID`
 - `node cmd/hwlab-agent-worker/main.mjs dry-run --agent-session-id ID`
+- `node skills/hwlab-agent-runtime/scripts/hwlab-agent-runtime-cli.mjs m3 io --action do.write --value true --api-base-url URL`
+- `node skills/hwlab-agent-runtime/scripts/hwlab-agent-runtime-cli.mjs m3 io --action do.write --value false --api-base-url URL`
+- `node skills/hwlab-agent-runtime/scripts/hwlab-agent-runtime-cli.mjs m3 io --action di.read --api-base-url URL`
 
 Use `--state-dir DIR` to isolate local state. The default state directory is
 `.state/agent-runtime`, which is intended for local runtime state only.
@@ -32,3 +41,16 @@ Use `--state-dir DIR` to isolate local state. The default state directory is
 Provide both `--skill-commit-id COMMIT` and `--skill-version VERSION` for a
 ready health result. Missing fields must produce `degraded` health and degraded
 evidence metadata; there is no silent fallback.
+
+## M3 IO Control Contract
+
+The M3 IO CLI is the controlled Code Agent -> Skill CLI -> HWLAB API adapter.
+`--api-base-url` must be a cloud-api base such as `http://127.0.0.1:6667`,
+`http://hwlab-cloud-api.hwlab-dev.svc.cluster.local:6667`, or the public DEV
+API endpoint. The CLI appends `/v1/m3/io` itself and rejects direct
+gateway/box/patch-panel targets.
+
+The JSON response includes `route`, `traceId`, `operationId`, `audit`,
+`evidence`, `accepted`, `status`, `blocker`, and direct-call safety flags.
+Durable runtime blockers are preserved as structured `durable` and `evidence`
+state; a local/source result must not be called DEV-LIVE.
diff --git a/skills/hwlab-agent-runtime/scripts/hwlab-agent-runtime-cli.mjs b/skills/hwlab-agent-runtime/scripts/hwlab-agent-runtime-cli.mjs
new file mode 100644
index 00000000..83f3168a
--- /dev/null
+++ b/skills/hwlab-agent-runtime/scripts/hwlab-agent-runtime-cli.mjs
@@ -0,0 +1,17 @@
+#!/usr/bin/env node
+import { runM3IoSkillCommand } from "./src/m3-io-skill-client.mjs";
+
+try {
+  const result = await runM3IoSkillCommand(process.argv.slice(2));
+  const pretty = process.argv.includes("--pretty");
+  process.stdout.write(`${JSON.stringify(result, null, pretty ? 2 : 0)}\n`);
+  process.exitCode = result.ok ? 0 : 2;
+} catch (error) {
+  process.stdout.write(`${JSON.stringify({
+    ok: false,
+    status: "failed",
+    code: "skill_cli_failed",
+    message: error instanceof Error ? error.message : String(error)
+  })}\n`);
+  process.exitCode = 1;
+}
diff --git a/skills/hwlab-agent-runtime/scripts/m3-io-skill-client.test.mjs b/skills/hwlab-agent-runtime/scripts/m3-io-skill-client.test.mjs
new file mode 100644
index 00000000..d42a98cc
--- /dev/null
+++ b/skills/hwlab-agent-runtime/scripts/m3-io-skill-client.test.mjs
@@ -0,0 +1,137 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import {
+  HWLAB_M3_IO_API_ROUTE,
+  runM3IoSkillCommand,
+  validateCloudApiTarget
+} from "./src/m3-io-skill-client.mjs";
+
+test("M3 Skill CLI posts only to HWLAB API /v1/m3/io for DO1 writes", async () => {
+  const calls = [];
+  const result = await runM3IoSkillCommand(
+    [
+      "m3",
+      "io",
+      "--action",
+      "do.write",
+      "--value",
+      "false",
+      "--api-base-url",
+      "http://hwlab-cloud-api.hwlab-dev.svc.cluster.local:6667",
+      "--trace-id",
+      "trc_skill_cli_write_false",
+      "--request-id",
+      "req_skill_cli_write_false"
+    ],
+    {
+      now: () => "2026-05-23T00:08:00.000Z",
+      requestJson: async (url, request) => {
+        calls.push({ url, request });
+        assert.equal(url, `http://hwlab-cloud-api.hwlab-dev.svc.cluster.local:6667${HWLAB_M3_IO_API_ROUTE}`);
+        assert.equal(request.method, "POST");
+        assert.equal(request.body.action, "do.write");
+        assert.equal(request.body.resourceId, "res_boxsimu_1");
+        assert.equal(request.body.boxId, "boxsimu_1");
+        assert.equal(request.body.port, "DO1");
+        assert.equal(request.body.value, false);
+        assert.equal(request.body.source, "hwlab-agent-runtime.m3-io");
+        return {
+          ok: true,
+          status: 200,
+          body: {
+            status: "succeeded",
+            accepted: true,
+            traceId: "trc_skill_cli_write_false",
+            operationId: "op_m3_do_write_cli",
+            auditId: "aud_m3_do_write_cli_succeeded",
+            evidenceId: "evd_m3_do_write_cli_succeeded",
+            auditState: {
+              status: "written_non_durable"
+            },
+            evidenceState: {
+              status: "blocked",
+              sourceKind: "BLOCKED",
+              blocker: "runtime_durable_not_green",
+              writeStatus: "written_non_durable"
+            },
+            durableStatus: {
+              status: "degraded",
+              durable: false,
+              blocker: "runtime_durable_not_green"
+            },
+            result: {
+              value: false,
+              targetReadback: {
+                value: false
+              }
+            },
+            controlPath: {
+              cloudApi: true,
+              gatewaySimu: true,
+              boxSimu: true,
+              patchPanel: true,
+              frontendBypass: false
+            }
+          }
+        };
+      }
+    }
+  );
+
+  assert.equal(result.ok, true);
+  assert.equal(result.route, HWLAB_M3_IO_API_ROUTE);
+  assert.equal(result.accepted, true);
+  assert.equal(result.status, "succeeded");
+  assert.equal(result.operationId, "op_m3_do_write_cli");
+  assert.equal(result.audit.auditId, "aud_m3_do_write_cli_succeeded");
+  assert.equal(result.evidence.evidenceId, "evd_m3_do_write_cli_succeeded");
+  assert.equal(result.durable.blocker, "runtime_durable_not_green");
+  assert.equal(result.safety.directGatewayCalls, false);
+  assert.equal(result.safety.directBoxCalls, false);
+  assert.equal(result.safety.directPatchPanelCalls, false);
+  assert.equal(result.safety.fallbackUsed, false);
+  assert.equal(calls.length, 1);
+});
+
+test("M3 Skill CLI rejects direct gateway, box, and patch-panel targets before request", async () => {
+  for (const url of [
+    "http://hwlab-gateway-simu-1.hwlab-dev.svc.cluster.local:7101",
+    "http://hwlab-box-simu-1.hwlab-dev.svc.cluster.local:7201",
+    "http://hwlab-patch-panel.hwlab-dev.svc.cluster.local:7301"
+  ]) {
+    const result = await runM3IoSkillCommand(
+      [
+        "m3",
+        "io",
+        "--action",
+        "di.read",
+        "--api-base-url",
+        url,
+        "--trace-id",
+        "trc_skill_cli_direct_blocked"
+      ],
+      {
+        requestJson: async () => {
+          throw new Error("direct hardware target must be blocked before network call");
+        }
+      }
+    );
+
+    assert.equal(result.ok, false);
+    assert.equal(result.status, "blocked");
+    assert.equal(result.accepted, false);
+    assert.equal(result.blocker.code, "direct_hardware_target_blocked");
+    assert.equal(result.operationId, null);
+    assert.equal(result.safety.directGatewayCalls, false);
+    assert.equal(result.safety.directBoxCalls, false);
+    assert.equal(result.safety.directPatchPanelCalls, false);
+  }
+});
+
+test("M3 Skill CLI validates exact API route contract", () => {
+  const invalid = validateCloudApiTarget({
+    url: "http://hwlab-cloud-api.hwlab-dev.svc.cluster.local:6667/v1/rpc/m3.io.di.read"
+  });
+  assert.equal(invalid.code, "invalid_hwlab_api_route");
+});
diff --git a/skills/hwlab-agent-runtime/scripts/src/m3-io-skill-client.mjs b/skills/hwlab-agent-runtime/scripts/src/m3-io-skill-client.mjs
new file mode 100644
index 00000000..feffb07f
--- /dev/null
+++ b/skills/hwlab-agent-runtime/scripts/src/m3-io-skill-client.mjs
@@ -0,0 +1,564 @@
+import { randomUUID } from "node:crypto";
+
+export const HWLAB_AGENT_RUNTIME_SKILL_CLI_VERSION = "hwlab-agent-runtime-skill-cli-v1";
+export const HWLAB_M3_IO_API_ROUTE = "/v1/m3/io";
+export const HWLAB_M3_IO_SKILL_NAME = "hwlab-agent-runtime.m3-io";
+
+const allowedActions = new Set(["do.write", "di.read"]);
+const forbiddenDirectTarget = /(?:gateway(?:-simu)?|box(?:-simu)?|patch-panel|hwlab-patch-panel|\/invoke\b|\/sync\/tick\b|:7101\b|:7201\b|:7301\b)/iu;
+const defaultTimeoutMs = 30000;
+
+export async function runM3IoSkillCommand(argv = [], options = {}) {
+  const env = options.env ?? process.env;
+  const parsed = parseM3IoArgs(argv, env);
+  if (parsed.help) {
+    return helpPayload();
+  }
+
+  const traceId = parsed.traceId || `trc_${randomUUID()}`;
+  const requestId = parsed.requestId || `req_${randomUUID()}`;
+  const actorId = parsed.actorId || "usr_code_agent";
+  const apiTarget = resolveCloudApiTarget(parsed.apiBaseUrl, env);
+  const validation = validateCloudApiTarget(apiTarget);
+  if (validation) {
+    return blockedPayload({
+      traceId,
+      requestId,
+      apiTarget,
+      code: validation.code,
+      message: validation.message
+    });
+  }
+
+  const command = normalizeCommand(parsed);
+  if (!allowedActions.has(command.action)) {
+    return blockedPayload({
+      traceId,
+      requestId,
+      apiTarget,
+      code: "invalid_action",
+      message: "M3 Skill CLI only allows do.write or di.read."
+    });
+  }
+  if (command.action === "do.write" && typeof command.value !== "boolean") {
+    return blockedPayload({
+      traceId,
+      requestId,
+      apiTarget,
+      code: "invalid_boolean_value",
+      message: "M3 DO1 write requires --value true or --value false."
+    });
+  }
+
+  const payload = requestPayload(command, { traceId, requestId, actorId });
+  const startedAt = nowIso(options.now);
+  const response = await postJson(apiTarget.url, payload, {
+    requestJson: options.requestJson,
+    timeoutMs: parsed.timeoutMs,
+    headers: {
+      "x-trace-id": traceId,
+      "x-request-id": requestId,
+      "x-actor-id": actorId
+    }
+  });
+  const finishedAt = nowIso(options.now);
+
+  return normalizeSkillResponse({
+    response,
+    command,
+    payload,
+    apiTarget,
+    traceId,
+    requestId,
+    actorId,
+    startedAt,
+    finishedAt
+  });
+}
+
+export function parseM3IoArgs(argv = [], env = process.env) {
+  const args = [...argv];
+  const command = args.shift() ?? "help";
+  const subcommand = args.shift() ?? "";
+  const parsed = {
+    command,
+    subcommand,
+    action: null,
+    value: undefined,
+    apiBaseUrl: null,
+    traceId: null,
+    requestId: null,
+    actorId: null,
+    timeoutMs: defaultTimeoutMs,
+    pretty: false,
+    help: command === "help" || command === "--help" || command === "-h"
+  };
+
+  if (command !== "m3" || subcommand !== "io") {
+    parsed.help = true;
+    return parsed;
+  }
+
+  for (let index = 0; index < args.length; index += 1) {
+    const arg = args[index];
+    if (arg === "--help" || arg === "-h") {
+      parsed.help = true;
+    } else if (arg === "--pretty") {
+      parsed.pretty = true;
+    } else if (arg === "--action") {
+      parsed.action = readOption(args, ++index, arg);
+    } else if (arg === "--value") {
+      parsed.value = parseBoolean(readOption(args, ++index, arg));
+    } else if (arg === "--api-base-url") {
+      parsed.apiBaseUrl = readOption(args, ++index, arg);
+    } else if (arg === "--trace-id") {
+      parsed.traceId = readOption(args, ++index, arg);
+    } else if (arg === "--request-id") {
+      parsed.requestId = readOption(args, ++index, arg);
+    } else if (arg === "--actor-id") {
+      parsed.actorId = readOption(args, ++index, arg);
+    } else if (arg === "--timeout-ms") {
+      parsed.timeoutMs = parseTimeout(readOption(args, ++index, arg));
+    } else if (arg === "write") {
+      parsed.action = "do.write";
+    } else if (arg === "read") {
+      parsed.action = "di.read";
+    } else {
+      throw new Error(`unknown argument ${arg}`);
+    }
+  }
+
+  parsed.apiBaseUrl = parsed.apiBaseUrl || firstNonEmpty(
+    env.HWLAB_CODE_AGENT_HWLAB_API_BASE_URL,
+    env.HWLAB_API_BASE_URL,
+    env.HWLAB_CLOUD_API_BASE_URL,
+    loopbackCloudApiBaseUrl(env)
+  );
+  return parsed;
+}
+
+export function resolveCloudApiTarget(apiBaseUrl, env = process.env) {
+  const source = apiBaseUrl
+    ? "explicit"
+    : firstNonEmpty(env.HWLAB_CODE_AGENT_HWLAB_API_BASE_URL, null)
+      ? "env:HWLAB_CODE_AGENT_HWLAB_API_BASE_URL"
+      : firstNonEmpty(env.HWLAB_API_BASE_URL, null)
+        ? "env:HWLAB_API_BASE_URL"
+        : firstNonEmpty(env.HWLAB_CLOUD_API_BASE_URL, null)
+          ? "env:HWLAB_CLOUD_API_BASE_URL"
+          : "loopback-cloud-api-self";
+  const base = firstNonEmpty(apiBaseUrl, env.HWLAB_CODE_AGENT_HWLAB_API_BASE_URL, env.HWLAB_API_BASE_URL, env.HWLAB_CLOUD_API_BASE_URL, loopbackCloudApiBaseUrl(env));
+  const url = new URL(HWLAB_M3_IO_API_ROUTE, ensureTrailingSlash(base));
+  return {
+    route: HWLAB_M3_IO_API_ROUTE,
+    url: url.toString(),
+    redactedUrl: redactUrl(url.toString()),
+    source,
+    cloudApiOnly: true,
+    directGatewayCalls: false,
+    directBoxCalls: false,
+    directPatchPanelCalls: false
+  };
+}
+
+export function validateCloudApiTarget(apiTarget) {
+  let url;
+  try {
+    url = new URL(apiTarget.url);
+  } catch {
+    return {
+      code: "invalid_hwlab_api_url",
+      message: "HWLAB API base URL is not a valid URL."
+    };
+  }
+
+  if (url.pathname !== HWLAB_M3_IO_API_ROUTE) {
+    return {
+      code: "invalid_hwlab_api_route",
+      message: `Skill CLI must call exactly ${HWLAB_M3_IO_API_ROUTE}.`
+    };
+  }
+
+  const targetText = `${url.hostname}${url.pathname}${url.port ? `:${url.port}` : ""}`;
+  if (forbiddenDirectTarget.test(targetText)) {
+    return {
+      code: "direct_hardware_target_blocked",
+      message: "Skill CLI target must be HWLAB cloud-api, not gateway/box/patch-panel."
+    };
+  }
+
+  return null;
+}
+
+function normalizeCommand(parsed) {
+  const action = String(parsed.action ?? "").trim().toLowerCase();
+  if (action === "do.write") {
+    return {
+      action,
+      gatewayId: "gwsimu_1",
+      resourceId: "res_boxsimu_1",
+      boxId: "boxsimu_1",
+      port: "DO1",
+      value: parsed.value
+    };
+  }
+
+  return {
+    action,
+    gatewayId: "gwsimu_2",
+    resourceId: "res_boxsimu_2",
+    boxId: "boxsimu_2",
+    port: "DI1"
+  };
+}
+
+function requestPayload(command, meta) {
+  return {
+    action: command.action,
+    gatewayId: command.gatewayId,
+    resourceId: command.resourceId,
+    boxId: command.boxId,
+    port: command.port,
+    ...(Object.hasOwn(command, "value") ? { value: command.value } : {}),
+    traceId: meta.traceId,
+    requestId: meta.requestId,
+    actorId: meta.actorId,
+    source: HWLAB_M3_IO_SKILL_NAME
+  };
+}
+
+async function postJson(url, body, { requestJson, timeoutMs, headers }) {
+  if (typeof requestJson === "function") {
+    try {
+      const result = await requestJson(url, {
+        method: "POST",
+        headers: {
+          accept: "application/json",
+          "content-type": "application/json",
+          ...headers
+        },
+        body,
+        timeoutMs
+      });
+      return normalizeJsonResponse(result);
+    } catch (error) {
+      return {
+        ok: false,
+        status: 0,
+        body: null,
+        error: error instanceof Error ? error.message : String(error)
+      };
+    }
+  }
+
+  const controller = new AbortController();
+  const timer = setTimeout(() => controller.abort(), timeoutMs);
+  try {
+    const response = await fetch(url, {
+      method: "POST",
+      headers: {
+        accept: "application/json",
+        "content-type": "application/json",
+        ...headers
+      },
+      body: JSON.stringify(body),
+      signal: controller.signal
+    });
+    const text = await response.text();
+    const parsed = parseJsonOrNull(text);
+    return {
+      ok: response.ok,
+      status: response.status,
+      body: parsed,
+      error: response.ok ? null : parsed?.error?.message ?? parsed?.message ?? response.statusText
+    };
+  } catch (error) {
+    return {
+      ok: false,
+      status: 0,
+      body: null,
+      error: error.name === "AbortError" ? `HWLAB API request timed out after ${timeoutMs}ms` : error.message
+    };
+  } finally {
+    clearTimeout(timer);
+  }
+}
+
+function normalizeJsonResponse(result = {}) {
+  if (Object.hasOwn(result, "ok") || Object.hasOwn(result, "body")) {
+    return {
+      ok: result.ok ?? (Number(result.status ?? 200) >= 200 && Number(result.status ?? 200) < 300),
+      status: result.status ?? 200,
+      body: result.body ?? result.json ?? null,
+      error: result.error ?? result.body?.error?.message ?? null
+    };
+  }
+  const status = result.status ?? 200;
+  return {
+    ok: status >= 200 && status < 300,
+    status,
+    body: result.json ?? result,
+    error: result.error ?? null
+  };
+}
+
+function normalizeSkillResponse({ response, command, payload, apiTarget, traceId, requestId, actorId, startedAt, finishedAt }) {
+  const body = response.body ?? {};
+  const blocker = normalizeBlocker(body, response);
+  const accepted = body.accepted === true;
+  const status = body.status ?? (response.ok && accepted ? "succeeded" : "blocked");
+  const durable = durableSummary(body);
+
+  return {
+    ok: response.ok && accepted && status !== "blocked",
+    service: HWLAB_M3_IO_SKILL_NAME,
+    contractVersion: HWLAB_AGENT_RUNTIME_SKILL_CLI_VERSION,
+    route: HWLAB_M3_IO_API_ROUTE,
+    hwlabApi: apiTarget,
+    action: command.action,
+    accepted,
+    status,
+    traceId: body.traceId ?? traceId,
+    requestId,
+    actorId,
+    operationId: body.operationId ?? null,
+    audit: {
+      auditId: body.auditId ?? body.auditState?.auditId ?? null,
+      status: body.auditState?.status ?? null,
+      durableStatus: body.auditState?.durableStatus?.status ?? body.durableStatus?.status ?? null,
+      summary: auditSummary(body)
+    },
+    evidence: {
+      evidenceId: body.evidenceId ?? body.evidenceState?.evidenceId ?? null,
+      status: body.evidenceState?.status ?? null,
+      sourceKind: body.evidenceState?.sourceKind ?? null,
+      blocker: body.evidenceState?.blocker ?? null,
+      writeStatus: body.evidenceState?.writeStatus ?? null,
+      summary: evidenceSummary(body)
+    },
+    durable,
+    blocker,
+    command,
+    result: {
+      value: body.result?.value ?? body.value ?? null,
+      targetReadback: body.result?.targetReadback ?? null
+    },
+    controlPath: body.controlPath ?? {
+      cloudApi: true,
+      gatewaySimu: false,
+      boxSimu: false,
+      patchPanel: false,
+      frontendBypass: false
+    },
+    safety: {
+      cloudApiRouteOnly: true,
+      allowedRoute: HWLAB_M3_IO_API_ROUTE,
+      directGatewayCalls: false,
+      directBoxCalls: false,
+      directPatchPanelCalls: false,
+      fallbackUsed: false,
+      openAiFallbackUsed: false
+    },
+    httpStatus: response.status,
+    error: response.ok ? body.error ?? null : {
+      code: "hwlab_api_unavailable",
+      message: response.error ?? "HWLAB API request failed"
+    },
+    rawStatus: body.status ?? null,
+    startedAt,
+    finishedAt,
+    response: body
+  };
+}
+
+function blockedPayload({ traceId, requestId, apiTarget, code, message }) {
+  return {
+    ok: false,
+    service: HWLAB_M3_IO_SKILL_NAME,
+    contractVersion: HWLAB_AGENT_RUNTIME_SKILL_CLI_VERSION,
+    route: HWLAB_M3_IO_API_ROUTE,
+    hwlabApi: apiTarget ?? null,
+    accepted: false,
+    status: "blocked",
+    traceId,
+    requestId,
+    operationId: null,
+    audit: {
+      auditId: null,
+      status: "not_written",
+      durableStatus: null,
+      summary: "blocked before HWLAB API request"
+    },
+    evidence: {
+      evidenceId: null,
+      status: "blocked",
+      sourceKind: "BLOCKED",
+      blocker: code,
+      writeStatus: "not_written",
+      summary: "blocked before HWLAB API request"
+    },
+    durable: {
+      status: "blocked",
+      blocker: code,
+      summary: message
+    },
+    blocker: {
+      code,
+      message,
+      zh: message,
+      category: blockerCategory(code)
+    },
+    safety: {
+      cloudApiRouteOnly: true,
+      allowedRoute: HWLAB_M3_IO_API_ROUTE,
+      directGatewayCalls: false,
+      directBoxCalls: false,
+      directPatchPanelCalls: false,
+      fallbackUsed: false,
+      openAiFallbackUsed: false
+    }
+  };
+}
+
+function normalizeBlocker(body, response) {
+  const raw = body.blocker ?? body.error ?? null;
+  if (raw) {
+    const code = raw.code ?? body.blockerClassification?.code ?? "m3_io_blocked";
+    return {
+      code,
+      message: raw.message ?? raw.reason ?? raw.zh ?? body.blockerClassification?.reason ?? "M3 IO request was blocked.",
+      zh: raw.zh ?? raw.message ?? raw.reason ?? "M3 IO request was blocked.",
+      category: body.blockerClassification?.category ?? blockerCategory(code)
+    };
+  }
+  if (!response.ok) {
+    return {
+      code: "hwlab_api_unavailable",
+      message: response.error ?? `HWLAB API HTTP ${response.status}`,
+      zh: response.error ?? `HWLAB API HTTP ${response.status}`,
+      category: "hwlab_api"
+    };
+  }
+  return null;
+}
+
+function blockerCategory(code) {
+  const value = String(code ?? "");
+  if (/readiness|control_disabled|not_ready/u.test(value)) return "readiness_blocked";
+  if (/gateway/u.test(value)) return "gateway_unavailable";
+  if (/box|resource/u.test(value)) return "box_unavailable";
+  if (/wiring|patch_panel|patch-panel/u.test(value)) return "patch_panel_wiring_missing";
+  if (/durable|runtime/u.test(value)) return "durable_blocked";
+  if (/direct_hardware/u.test(value)) return "direct_hardware_blocked";
+  return "m3_io_blocked";
+}
+
+function durableSummary(body) {
+  const status = body.durableStatus?.status ?? body.evidenceState?.status ?? null;
+  const blocker = body.durableStatus?.blocker ?? body.evidenceState?.blocker ?? null;
+  return {
+    status,
+    durable: body.durableStatus?.durable ?? false,
+    blocker,
+    category: blocker ? blockerCategory(blocker) : null,
+    summary: blocker
+      ? `durable evidence blocked: ${blocker}`
+      : status
+        ? `durable status: ${status}`
+        : "durable status not reported"
+  };
+}
+
+function auditSummary(body) {
+  if (body.auditId) {
+    return `${body.auditId}; auditState=${body.auditState?.status ?? "unknown"}`;
+  }
+  return body.auditState?.reason ?? "audit not written";
+}
+
+function evidenceSummary(body) {
+  if (body.evidenceId) {
+    return `${body.evidenceId}; evidenceState=${body.evidenceState?.status ?? "unknown"}`;
+  }
+  return body.evidenceState?.reason ?? "evidence not written";
+}
+
+function helpPayload() {
+  return {
+    ok: true,
+    service: HWLAB_M3_IO_SKILL_NAME,
+    contractVersion: HWLAB_AGENT_RUNTIME_SKILL_CLI_VERSION,
+    usage: [
+      "node skills/hwlab-agent-runtime/scripts/hwlab-agent-runtime-cli.mjs m3 io --action do.write --value true --api-base-url http://127.0.0.1:6667",
+      "node skills/hwlab-agent-runtime/scripts/hwlab-agent-runtime-cli.mjs m3 io --action do.write --value false --api-base-url http://127.0.0.1:6667",
+      "node skills/hwlab-agent-runtime/scripts/hwlab-agent-runtime-cli.mjs m3 io --action di.read --api-base-url http://127.0.0.1:6667"
+    ],
+    route: HWLAB_M3_IO_API_ROUTE,
+    safety: {
+      cloudApiRouteOnly: true,
+      directGatewayCalls: false,
+      directBoxCalls: false,
+      directPatchPanelCalls: false,
+      fallbackUsed: false
+    }
+  };
+}
+
+function readOption(args, index, name) {
+  const value = args[index];
+  if (!value || value.startsWith("--")) {
+    throw new Error(`${name} requires a value`);
+  }
+  return value;
+}
+
+function parseBoolean(value) {
+  const normalized = String(value ?? "").trim().toLowerCase();
+  if (["true", "1", "on", "high"].includes(normalized)) return true;
+  if (["false", "0", "off", "low"].includes(normalized)) return false;
+  return value;
+}
+
+function parseTimeout(value) {
+  const parsed = Number.parseInt(value, 10);
+  if (!Number.isInteger(parsed) || parsed <= 0 || parsed > 60000) {
+    throw new Error("--timeout-ms must be an integer between 1 and 60000");
+  }
+  return parsed;
+}
+
+function loopbackCloudApiBaseUrl(env = process.env) {
+  const port = env.HWLAB_CLOUD_API_PORT || env.PORT || "6667";
+  return `http://127.0.0.1:${port}`;
+}
+
+function ensureTrailingSlash(value) {
+  return String(value ?? "").endsWith("/") ? String(value) : `${value}/`;
+}
+
+function firstNonEmpty(...values) {
+  return values.find((value) => typeof value === "string" && value.trim())?.trim() ?? null;
+}
+
+function redactUrl(value) {
+  try {
+    const url = new URL(value);
+    url.username = "";
+    url.password = "";
+    return url.toString();
+  } catch {
+    return String(value ?? "").replace(/\/\/[^/@]+@/u, "//***@");
+  }
+}
+
+function parseJsonOrNull(value) {
+  try {
+    return JSON.parse(value);
+  } catch {
+    return null;
+  }
+}
+
+function nowIso(now) {
+  return typeof now === "function" ? now() : new Date().toISOString();
+}