diff --git a/packages/x402-mcp/README.md b/packages/x402-mcp/README.md
index 10afe0f1..faf4703d 100644
--- a/packages/x402-mcp/README.md
+++ b/packages/x402-mcp/README.md
@@ -68,8 +68,7 @@ npx openpay-x402-mcp@0.15.0
       "command": "npx",
       "args": ["openpay-x402-mcp@0.15.0"],
       "env": {
-        "SIGNER_MODE": "env-key",
-        "BUYER_PRIVATE_KEY": "0x...",
+        "SIGNER_MODE": "keystore",
         "MAX_PER_CALL_JPYC": "10",
         "MAX_SESSION_JPYC": "100",
         "ALLOWED_HOSTS": "open-pay.jp"
@@ -88,8 +87,7 @@ npx openpay-x402-mcp@0.15.0
       "command": "npx",
       "args": ["openpay-x402-mcp@0.15.0"],
       "env": {
-        "SIGNER_MODE": "env-key",
-        "BUYER_PRIVATE_KEY": "0x...",
+        "SIGNER_MODE": "keystore",
         "MAX_PER_CALL_JPYC": "10",
         "MAX_SESSION_JPYC": "100",
         "ALLOWED_HOSTS": "open-pay.jp"
@@ -99,6 +97,13 @@ npx openpay-x402-mcp@0.15.0
 }
 ```
 
+These examples use the local wallet (`SIGNER_MODE=keystore`): no private key goes
+into the configuration. After the host restarts, call `wallet_init` to create the
+wallet on this machine, then fund the returned address — see
+[Local wallet](#local-wallet-signer_modekeystore). Do not put a placeholder such as
+`"BUYER_PRIVATE_KEY": "0x..."` in the configuration: the server rejects it at startup.
+`env-key` and `steward` are described under [Signer Modes](#signer-modes).
+
 During local development from this repository:
 
 ```bash
@@ -252,10 +257,7 @@ Use this explicit mode to avoid pasting a private key into MCP configuration:
 }
 ```
 
-These examples target the coordinated SDK 0.9.0 / MCP 0.15.0 release. Publish
-SDK first, then MCP, then update Web setup after a real-host smoke. Publication
-requires explicit human review and a real-host `wallet_init → funding →
-wallet_status → x402_pay` check. Keep the package version pinned.
+Requires openpay-x402-mcp 0.15.0 or later (SDK 0.9.0). Keep the package version pinned.
 
 1. Register the MCP server, restart the host, and call `wallet_status {}` to
    confirm it starts. If startup fails, report the error verbatim.
diff --git a/tests/packages/x402-mcp-wallet-docs.test.ts b/tests/packages/x402-mcp-wallet-docs.test.ts
index c29574e1..8d5a40c1 100644
--- a/tests/packages/x402-mcp-wallet-docs.test.ts
+++ b/tests/packages/x402-mcp-wallet-docs.test.ts
@@ -16,4 +16,15 @@ describe('wallet release documentation', () => {
       expect(changelog).toContain(text);
     }
   });
+
+  it('x402 profile の設定例は keystore で、コピーすると起動時に停止する仮の秘密鍵を含まない', async () => {
+    const readme = await readFile('packages/x402-mcp/README.md', 'utf8');
+    const profile = readme.slice(readme.indexOf('## x402 profile'), readme.indexOf('\n## Quickstart'));
+    const jsonBlocks = [...profile.matchAll(/```json\n([\s\S]*?)```/g)].map((m) => m[1]);
+    expect(jsonBlocks.length).toBeGreaterThanOrEqual(2);
+    for (const block of jsonBlocks) {
+      expect(block).toContain('"SIGNER_MODE": "keystore"');
+      expect(block).not.toContain('BUYER_PRIVATE_KEY');
+    }
+  });
 });