diff --git a/docs/cli/acp.md b/docs/cli/acp.md
index 429862407c2..7dba803f1bc 100644
--- a/docs/cli/acp.md
+++ b/docs/cli/acp.md
@@ -21,6 +21,24 @@ If you want an external MCP client to talk directly to OpenClaw channel
 conversations instead of hosting an ACP harness session, use
 [`openclaw mcp serve`](/cli/mcp) instead.
 
+## What this is not
+
+This page is often confused with ACP harness sessions.
+
+`openclaw acp` means:
+
+- OpenClaw acts as an ACP server
+- an IDE or ACP client connects to OpenClaw
+- OpenClaw forwards that work into a Gateway session
+
+This is different from [ACP Agents](/tools/acp-agents), where OpenClaw runs an
+external harness such as Codex or Claude Code through `acpx`.
+
+Quick rule:
+
+- editor/client wants to talk ACP to OpenClaw: use `openclaw acp`
+- OpenClaw should launch Codex/Claude/Gemini as an ACP harness: use `/acp spawn` and [ACP Agents](/tools/acp-agents)
+
 ## Compatibility Matrix
 
 | ACP area                                                              | Status      | Notes                                                                                                                                                                                                                                            |
diff --git a/docs/gateway/cli-backends.md b/docs/gateway/cli-backends.md
index 6877daab490..fb3b8c96e6d 100644
--- a/docs/gateway/cli-backends.md
+++ b/docs/gateway/cli-backends.md
@@ -20,6 +20,10 @@ rate-limited, or temporarily misbehaving. This is intentionally conservative:
 This is designed as a **safety net** rather than a primary path. Use it when you
 want “always works” text responses without relying on external APIs.
 
+If you want a full harness runtime with ACP session controls, background tasks,
+thread/conversation binding, and persistent external coding sessions, use
+[ACP Agents](/tools/acp-agents) instead. CLI backends are not ACP.
+
 ## Beginner-friendly quick start
 
 You can use Claude Code CLI **without any config** (the bundled Anthropic plugin
diff --git a/docs/tools/acp-agents.md b/docs/tools/acp-agents.md
index ae987cd24db..5c5ffebdda4 100644
--- a/docs/tools/acp-agents.md
+++ b/docs/tools/acp-agents.md
@@ -19,6 +19,36 @@ If you want Codex or Claude Code to connect as an external MCP client directly
 to existing OpenClaw channel conversations, use [`openclaw mcp serve`](/cli/mcp)
 instead of ACP.
 
+## Which page do I want?
+
+There are three nearby surfaces that are easy to confuse:
+
+| You want to...                                                                     | Use this                              | Notes                                                                                                       |
+| ---------------------------------------------------------------------------------- | ------------------------------------- | ----------------------------------------------------------------------------------------------------------- |
+| Run Codex, Claude Code, Gemini CLI, or another external harness _through_ OpenClaw | This page: ACP agents                 | Chat-bound sessions, `/acp spawn`, `sessions_spawn({ runtime: "acp" })`, background tasks, runtime controls |
+| Expose an OpenClaw Gateway session _as_ an ACP server for an editor or client      | [`openclaw acp`](/cli/acp)            | Bridge mode. IDE/client talks ACP to OpenClaw over stdio/WebSocket                                          |
+| Reuse a local AI CLI as a text-only fallback model                                 | [CLI Backends](/gateway/cli-backends) | Not ACP. No OpenClaw tools, no ACP controls, no harness runtime                                             |
+
+## Does this work out of the box?
+
+Usually, yes.
+
+- Fresh installs now ship the bundled `acpx` runtime plugin enabled by default.
+- The bundled `acpx` plugin prefers its plugin-local pinned `acpx` binary.
+- On startup, OpenClaw probes that binary and self-repairs it if needed.
+- Start with `/acp doctor` if you want a fast readiness check.
+
+What can still happen on first use:
+
+- A target harness adapter may be fetched on demand with `npx` the first time you use that harness.
+- Vendor auth still has to exist on the host for that harness.
+- If the host has no npm/network access, first-run adapter fetches can fail until caches are pre-warmed or the adapter is installed another way.
+
+Examples:
+
+- `/acp spawn codex`: OpenClaw should be ready to bootstrap `acpx`, but the Codex ACP adapter may still need a first-run fetch.
+- `/acp spawn claude`: same story for the Claude ACP adapter, plus Claude-side auth on that host.
+
 ## Fast operator flow
 
 Use this when you want a practical `/acp` runbook:
@@ -70,6 +100,26 @@ Use ACP when you want an external harness runtime. Use sub-agents when you want
 
 See also [Sub-agents](/tools/subagents).
 
+## How ACP runs Claude Code
+
+For Claude Code through ACP, the stack is:
+
+1. OpenClaw ACP session control plane
+2. bundled `acpx` runtime plugin
+3. Claude ACP adapter
+4. Claude-side runtime/session machinery
+
+Important distinction:
+
+- ACP Claude is not the same thing as the direct `claude-cli/...` fallback runtime.
+- ACP Claude is a harness session with ACP controls, session resume, background-task tracking, and optional conversation/thread binding.
+- `claude-cli/...` is a text-only local CLI backend. See [CLI Backends](/gateway/cli-backends).
+
+For operators, the practical rule is:
+
+- want `/acp spawn`, bindable sessions, runtime controls, or persistent harness work: use ACP
+- want simple local text fallback through the raw CLI: use CLI backends
+
 ## Bound sessions
 
 ### Current-conversation binds
@@ -614,7 +664,17 @@ See [Configuration Reference](/gateway/configuration-reference).
 
 ## Plugin setup for acpx backend
 
-Install and enable plugin:
+Fresh installs ship the bundled `acpx` runtime plugin enabled by default, so ACP
+usually works without a manual plugin install step.
+
+Start with:
+
+```text
+/acp doctor
+```
+
+If you disabled `acpx`, denied it via `plugins.allow` / `plugins.deny`, or want
+to switch to a local development checkout, use the explicit plugin path:
 
 ```bash
 openclaw plugins install acpx
diff --git a/extensions/acpx/openclaw.plugin.json b/extensions/acpx/openclaw.plugin.json
index 8029c1fd0dc..922e997c63e 100644
--- a/extensions/acpx/openclaw.plugin.json
+++ b/extensions/acpx/openclaw.plugin.json
@@ -1,5 +1,6 @@
 {
   "id": "acpx",
+  "enabledByDefault": true,
   "name": "ACPX Runtime",
   "description": "ACP runtime backend powered by acpx with configurable command path and version policy.",
   "skills": ["./skills"],
diff --git a/src/secrets/runtime-config-collectors-plugins.test.ts b/src/secrets/runtime-config-collectors-plugins.test.ts
index d3040a62e06..4c6ba71aeb9 100644
--- a/src/secrets/runtime-config-collectors-plugins.test.ts
+++ b/src/secrets/runtime-config-collectors-plugins.test.ts
@@ -250,7 +250,7 @@ describe("collectPluginConfigAssignments", () => {
     );
   });
 
-  it("keeps bundled acpx inactive unless explicitly enabled", () => {
+  it("treats bundled acpx as active by default", () => {
     const config = asConfig({
       plugins: {
         enabled: true,
@@ -274,9 +274,11 @@ describe("collectPluginConfigAssignments", () => {
       loadablePluginOrigins: loadablePluginOrigins([["acpx", "bundled"]]),
     });
 
-    expect(context.assignments).toHaveLength(0);
+    expect(context.assignments).toHaveLength(1);
+    expect(context.assignments[0]?.path).toBe("plugins.entries.acpx.config.mcpServers.s1.env.K");
+    expect(context.assignments[0]?.ref.id).toBe("K");
     expect(context.warnings.some((w) => w.code === "SECRETS_REF_IGNORED_INACTIVE_SURFACE")).toBe(
-      true,
+      false,
     );
   });
 
diff --git a/src/secrets/runtime-config-collectors-plugins.ts b/src/secrets/runtime-config-collectors-plugins.ts
index 66d374a3c55..01c5d5c5acb 100644
--- a/src/secrets/runtime-config-collectors-plugins.ts
+++ b/src/secrets/runtime-config-collectors-plugins.ts
@@ -9,6 +9,7 @@ import {
 import { isRecord } from "./shared.js";
 
 const ACPX_PLUGIN_ID = "acpx";
+const ACPX_ENABLED_BY_DEFAULT = true;
 
 /**
  * Walk plugin config entries and collect SecretRef assignments for MCP server
@@ -63,7 +64,14 @@ export function collectPluginConfigAssignments(params: {
       continue;
     }
 
-    const enableState = resolveEnableState(pluginId, pluginOrigin ?? "config", normalizedConfig);
+    const enableState = resolveEnableState(
+      pluginId,
+      pluginOrigin ?? "config",
+      normalizedConfig,
+      pluginId === ACPX_PLUGIN_ID && pluginOrigin === "bundled"
+        ? ACPX_ENABLED_BY_DEFAULT
+        : undefined,
+    );
     collectMcpServerEnvAssignments({
       pluginId,
       pluginConfig,