com.blackwalltier/blackwall-x402-guardrail
REMOTE · MCP.BLACKWALLTIER.COM · SCANNED SEP 20
Keyless hosted MCP: pre-signature x402 payment verdict (GO/HOLD/STOP) with a signed receipt.
Available components
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security46
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation not fully verified: no authorisation is required to call this server, and 1 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe. See how to fix → View diagnostics → Unverified
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability77
- AI-judged instruction clarity (excellent).Pass
- Tool/resource definitions use about 197 tokens (~197/item across 1 items; 1 tools + 0 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
- No destabilizing schema changes in the last 30 days.Pass
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 1 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 1 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
How do I install the com.blackwalltier/blackwall-x402-guardrail MCP server?
com.blackwalltier/blackwall-x402-guardrail is a hosted endpoint at https://mcp.blackwalltier.com/, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · mcp.blackwalltier.com
claude mcp add --transport http com-blackwalltier-blackwall-x402-guardrail 'https://mcp.blackwalltier.com/'
{
"mcpServers": {
"com-blackwalltier-blackwall-x402-guardrail": {
"url": "https://mcp.blackwalltier.com/"
}
}
} {
"servers": {
"com-blackwalltier-blackwall-x402-guardrail": {
"type": "http",
"url": "https://mcp.blackwalltier.com/"
}
}
} [mcp_servers.com-blackwalltier-blackwall-x402-guardrail] url = "https://mcp.blackwalltier.com/"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"com-blackwalltier-blackwall-x402-guardrail": {
"type": "remote",
"url": "https://mcp.blackwalltier.com/",
"enabled": true
}
}
} openclaw mcp add com-blackwalltier-blackwall-x402-guardrail --url 'https://mcp.blackwalltier.com/' --transport streamable-http
mcp_servers:
com-blackwalltier-blackwall-x402-guardrail:
url: "https://mcp.blackwalltier.com/" {
"McpServers": {
"com-blackwalltier-blackwall-x402-guardrail": {
"Transport": "http",
"Url": "https://mcp.blackwalltier.com/"
}
}
} assistant mcp add com-blackwalltier-blackwall-x402-guardrail -t streamable-http -u 'https://mcp.blackwalltier.com/'
{
"mcpServers": {
"com-blackwalltier-blackwall-x402-guardrail": {
"type": "http",
"url": "https://mcp.blackwalltier.com/"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 26 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 25 Aug 26 +1
- Stability: 0.97 → pass security
- The server changed its declared name: blackwall-remote-mcp → blackwall-x402-mcp security
- 23 Aug 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.
- 11 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 31 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 27 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 26 Jul 26 0
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 20 Sept 2026 · Probed https://mcp.blackwalltier.com
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=blackwalltier.com | CN=WE1,O=Google Trust Services,C=US | 5 Sept 2026 | 4 Dec 2026 | ECDSA 256 | ECDSA-SHA256 | 400f6ebcc7c8558113670f930928b6ed |
| SANs: blackwalltier.com, mcp.blackwalltier.com, *.mcp.blackwalltier.com | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of mcp.blackwalltier.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| blackwalltier.com. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://mcp.blackwalltier.com | Verified | 200 | |
| http (plaintext) | http://mcp.blackwalltier.com | Inconclusive | 405 |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
forecast_payment ~197
Pre-signature x402 payment verdict: GO / HOLD / STOP for paying a counterparty, from settlement reputation, price-anomaly (quoted vs the payee's own median), and OFAC sanctions — with a third-party-verifiable Ed25519 signed receipt. Verdict only; never takes custody. Free under $10 at risk; over that, returns an x402 payment challenge.
| Name | Type | Req | Description |
|---|---|---|---|
| agent_id | string | – | caller DID/identity |
| amount | string | yes | amount as a decimal string, e.g. "0.09" |
| asset | string | yes | e.g. USDC |
| chain | string | yes | e.g. base |
| context | object | – | {quoted_price_history, expected_recipient} |
| counterparty | string | yes | recipient wallet from the 402 |
| payer | string | – | agent's EVM wallet (optional; binds settlement) |
| resource | string | – | what's being paid for |
No output schema declared.
No examples provided.
What is the com.blackwalltier/blackwall-x402-guardrail MCP server?
com.blackwalltier/blackwall-x402-guardrail is an MCP server listed in the public MCP registry as com.blackwalltier/blackwall-x402-guardrail. Keyless hosted MCP: pre-signature x402 payment verdict (GO/HOLD/STOP) with a signed receipt. This page covers its hosted endpoint (https://mcp.blackwalltier.com).
Is the com.blackwalltier/blackwall-x402-guardrail MCP server safe to use?
com.blackwalltier/blackwall-x402-guardrail scores 74 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the com.blackwalltier/blackwall-x402-guardrail MCP server expose?
com.blackwalltier/blackwall-x402-guardrail exposes 1 tool: forecast_payment. Their descriptions and schemas cost roughly 197 tokens of context every time the server is loaded.
Does the com.blackwalltier/blackwall-x402-guardrail MCP server require authentication?
No. We connected to com.blackwalltier/blackwall-x402-guardrail without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the com.blackwalltier/blackwall-x402-guardrail MCP server still maintained?
com.blackwalltier/blackwall-x402-guardrail is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.