diff --git a/integrations/openclaw/README.md b/integrations/openclaw/README.md
index 8dc0258d..1fe774ae 100644
--- a/integrations/openclaw/README.md
+++ b/integrations/openclaw/README.md
@@ -125,14 +125,21 @@ Then enable it in `~/.openclaw/openclaw.json`:
 
 What the plugin does:
 
-- recalls relevant long-term memory before the agent starts
-- captures completed conversation turns after the agent finishes
+- claims the `plugins.slots.memory = "agentmemory"` slot via `api.registerMemoryCapability({ promptBuilder })` so OpenClaw recognises it as the active memory plugin
+- recalls relevant long-term memory before the agent starts (via the `before_agent_start` hook)
+- captures completed conversation turns after the agent finishes (via the `agent_end` hook)
 - shares the same backend with Claude Code, Codex CLI, Gemini CLI, Hermes, pi, and other agents
 
+### Memory runtime (current scope)
+
+The plugin currently registers a `promptBuilder` only — not a full `MemoryPluginRuntime` adapter. OpenClaw's `MemoryRuntimeBackendConfig` type today is `{ backend: "builtin" }` or `{ backend: "qmd" }`; both are openclaw-internal backends that don't fit agentmemory's external REST shape. The hook-driven recall + capture flow above is the working integration path. If you need OpenClaw's in-process memory-runtime APIs (e.g. `getMemorySearchManager`) backed by agentmemory, file an upstream request against `openclaw` for an `"external"` backend type and we'll wire `runtime` here once the contract supports it.
+
 ## Troubleshooting
 
 **Plugin validates but does not load** — make sure the folder contains `package.json`, `openclaw.plugin.json`, and `plugin.mjs`, and that `plugins.slots.memory` is set to `agentmemory`.
 
+**`plugins.slots.memory = "agentmemory"` reports `unavailable`** — upgrade to v0.9.11+. Older versions of this plugin registered hooks but never called `api.registerMemoryCapability(...)`, so the memory-slot machinery did not consider the slot claimed. The current plugin registers a memory capability (prompt builder) at startup, which is the documented OpenClaw API for occupying the slot.
+
 **Connection refused on port 3111** — the agentmemory server is not running. Start it with `npx @agentmemory/agentmemory`.
 
 **No memories returned** — open `http://localhost:3113` and verify observations are being captured.
diff --git a/integrations/openclaw/plugin.mjs b/integrations/openclaw/plugin.mjs
index 1ed9a3b5..7579a9d8 100644
--- a/integrations/openclaw/plugin.mjs
+++ b/integrations/openclaw/plugin.mjs
@@ -2,8 +2,9 @@
  * agentmemory plugin for OpenClaw
  *
  * Deeper integration than raw MCP:
- * - recalls relevant memories before the agent starts
- * - captures completed conversation turns after the agent finishes
+ * - claims the plugins.slots.memory slot via api.registerMemoryCapability({ promptBuilder })
+ * - recalls relevant memories before the agent starts (before_agent_start hook)
+ * - captures completed conversation turns after the agent finishes (agent_end hook)
  *
  * Requires the agentmemory server on localhost:3111.
  * Start it with: npx @agentmemory/agentmemory
@@ -120,6 +121,21 @@ const plugin = {
     };
     const client = createClient(cfg, api);
 
+    if (typeof api.registerMemoryCapability === "function") {
+      api.registerMemoryCapability({
+        // OpenClaw passes { availableTools: Set<string>, citationsMode? }. We
+        // don't currently branch on tool availability, but accept the params
+        // object so the signature matches MemoryPromptSectionBuilder exactly.
+        promptBuilder: (_params) => [
+          "Long-term memory provider: agentmemory (external REST service on " +
+            client.baseUrl +
+            ").",
+          "agentmemory recalls relevant prior observations before each turn via the before_agent_start hook and captures completed turns via agent_end.",
+          "Treat recalled context as background, not authoritative — prefer current workspace state and explicit user instructions when they conflict.",
+        ],
+      });
+    }
+
     api.on("before_agent_start", async (event) => {
       if (!cfg.enabled) return;
       const prompt = typeof event?.prompt === "string" ? event.prompt.trim() : "";
diff --git a/test/openclaw-plugin.test.ts b/test/openclaw-plugin.test.ts
new file mode 100644
index 00000000..ed95d493
--- /dev/null
+++ b/test/openclaw-plugin.test.ts
@@ -0,0 +1,62 @@
+import { describe, expect, it, vi } from "vitest";
+
+type Capability = {
+  promptBuilder?: (params: {
+    availableTools: Set<string>;
+  }) => string[] | undefined;
+};
+
+type RegisterFn = (capability: Capability) => void;
+
+interface FakeApi {
+  registerMemoryCapability: RegisterFn;
+  on: ReturnType<typeof vi.fn>;
+  pluginConfig: Record<string, unknown>;
+  logger: { warn: ReturnType<typeof vi.fn> };
+}
+
+function makeApi(overrides: Partial<FakeApi> = {}): FakeApi {
+  return {
+    registerMemoryCapability: vi.fn(),
+    on: vi.fn(),
+    pluginConfig: { base_url: "http://localhost:3111" },
+    logger: { warn: vi.fn() },
+    ...overrides,
+  };
+}
+
+describe("openclaw plugin — memory capability registration (closes #286 follow-up)", () => {
+  it("calls api.registerMemoryCapability with a promptBuilder when the host supports it", async () => {
+    const mod = await import("../integrations/openclaw/plugin.mjs");
+    const plugin = (mod as unknown as { default: { register(api: FakeApi): void } }).default;
+    const api = makeApi();
+    plugin.register(api);
+    expect(api.registerMemoryCapability).toHaveBeenCalledTimes(1);
+    const capability = (api.registerMemoryCapability as ReturnType<typeof vi.fn>).mock.calls[0][0] as Capability;
+    expect(typeof capability.promptBuilder).toBe("function");
+    const lines = capability.promptBuilder?.({ availableTools: new Set() });
+    expect(Array.isArray(lines)).toBe(true);
+    expect((lines as string[]).join(" ")).toMatch(/agentmemory/i);
+  });
+
+  it("still registers hooks and tolerates older OpenClaw builds without registerMemoryCapability", async () => {
+    const mod = await import("../integrations/openclaw/plugin.mjs");
+    const plugin = (mod as unknown as { default: { register(api: FakeApi): void } }).default;
+    const api = makeApi({ registerMemoryCapability: undefined as unknown as RegisterFn });
+    expect(() => plugin.register(api)).not.toThrow();
+    expect(api.on).toHaveBeenCalled();
+    const events = (api.on as ReturnType<typeof vi.fn>).mock.calls.map((c) => c[0]);
+    expect(events).toContain("before_agent_start");
+    expect(events).toContain("agent_end");
+  });
+
+  it("promptBuilder returns lines that mention the configured base_url", async () => {
+    const mod = await import("../integrations/openclaw/plugin.mjs");
+    const plugin = (mod as unknown as { default: { register(api: FakeApi): void } }).default;
+    const api = makeApi({ pluginConfig: { base_url: "http://memory.internal:9999" } });
+    plugin.register(api);
+    const capability = (api.registerMemoryCapability as ReturnType<typeof vi.fn>).mock.calls[0][0] as Capability;
+    const lines = capability.promptBuilder?.({ availableTools: new Set() }) ?? [];
+    expect(lines.join("\n")).toMatch(/memory\.internal:9999/);
+  });
+});