Mercury402: Treasury/FRED financial data over x402
Treasury/FRED financial data over x402: pay-per-call US yields, macro and forex in USDC on BaseThe vendor's description, from its MCP Registry listing.
Every public check ran and passed. Public audit: we connect as an AI client would, list the tools and check what they say. We do not run them. How we audit
- Does it work?
- YesConnected in 250 ms.
- Sign-up?
- None neededIt answered without any account or key.
- Can it change things?
- YesSome tools say they can change things. Your AI client should ask you first.
https://mcp.mercury402.com/mcpSource code Website Streamable HTTP · protocol 2025-11-25 · server version 0.1.3
What we checked
Security
Passed: Connections are encrypted (HTTPS).
Passed: No hidden instructions found in tool text.
Safety labels
Note: 1 tool is labelled as able to change things.
Expected for tools that send, write or buy. Your AI client should ask before calling them.
- get_endpoint_data
Passed: Every tool says whether it only reads or can change things.
Tools
Passed: 2 tools listed.
Passed: Every tool describes its inputs with a valid schema.
Protocol
Passed: The MCP handshake works (Streamable HTTP).
Passed: Protocol version 2025-11-25 (latest).
Passed: Unknown requests are refused.
Connection
Passed: The server responds.
Tools (2)
As the server describes them. The labels are the server's own: it says whether each tool only reads or can change things.
- list_endpointsList Mercury402 financial data endpoints (78 total) with path, method, category, description, price in USD (paid per call in USDC on Base via x402) and accepted parameters. Free; makes no network cal…Read-only
- get_endpoint_dataCall a Mercury402 endpoint on the live API. This hosted endpoint is discovery-only: endpoints return HTTP 402 and this tool returns the price and x402 payment instructions instead of data. Pay with y…Can change things
Audit history
- Nov 13Passed
What we sent
Every request in this audit, with the answer and how long it took. We never send credentials and never call a tool.
| Request | Answer | Time |
|---|---|---|
| initialize | HTTP 200 | 250 ms |
| initialized | HTTP 202 | 64 ms |
| tools/list | HTTP 200 | 184 ms |
| unknown-method | HTTP 200 | 84 ms |
Run this server, or disagree with the result?
Fix the issue and it shows in the next weekly audit, or email us to ask for a re-audit or to dispute a finding. Read how we audit for what each check means.
{
"mcpServers": {
"io-github-dudman1-mercury402-mcp": {
"type": "http",
"url": "https://mcp.mercury402.com/mcp"
}
}
}{
"server": {
"name": "io.github.dudman1/mercury402-mcp",
"title": "Mercury402: Treasury/FRED financial data over x402",
"url": "https://mcp.mercury402.com/mcp",
"transport": "streamable-http",
"topics": [
"Financial",
"Global Macro"
],
"repository": "https://github.com/dudman1/mercury402",
"website": "https://mercury402.com",
"inRegistry": true
},
"audit": {
"slug": "io-github-dudman1-mercury402-mcp",
"url": "https://mcp.mercury402.com/mcp",
"auditedAt": "2026-11-13T16:26:25.551Z",
"firstAuditedAt": "2026-11-13T15:57:35.962Z",
"auditor": "1.0.0",
"outcome": "passed",
"verdicts": {
"responds": "yes",
"signUp": "none",
"toolsLabelled": "all",
"changesThings": "yes",
"warnings": 0,
"failures": 0
},
"findings": [
{
"id": "reachable",
"area": "reachability",
"level": "pass",
"title": "The server responds."
},
{
"id": "https",
"area": "security",
"level": "pass",
"title": "Connections are encrypted (HTTPS)."
},
{
"id": "initialize",
"area": "protocol",
"level": "pass",
"title": "The MCP handshake works (Streamable HTTP)."
},
{
"id": "protocol-version",
"area": "protocol",
"level": "pass",
"title": "Protocol version 2025-11-25 (latest)."
},
{
"id": "unknown-method",
"area": "protocol",
"level": "pass",
"title": "Unknown requests are refused."
},
{
"id": "tools-list",
"area": "tools",
"level": "pass",
"title": "2 tools listed."
},
{
"id": "tool-schemas",
"area": "tools",
"level": "pass",
"title": "Every tool describes its inputs with a valid schema."
},
{
"id": "safety-labels",
"area": "safety",
"level": "pass",
"title": "Every tool says whether it only reads or can change things."
},
{
"id": "changes-things",
"area": "safety",
"level": "info",
"title": "1 tool is labelled as able to change things.",
"detail": "Expected for tools that send, write or buy. Your AI client should ask before calling them.",
"evidence": [
"get_endpoint_data"
]
},
{
"id": "tool-poisoning",
"area": "security",
"level": "pass",
"title": "No hidden instructions found in tool text."
}
],
"server": {
"name": "mercury402",
"version": "0.1.3",
"protocolVersion": "2025-11-25",
"transport": "streamable-http"
},
"toolCount": 2,
"toolsHash": "9641483d4d242d51147e318d9c24a8428285890c8480f84170f4e75ca5573ceb",
"latencyMs": 250,
"history": [
{
"date": "2026-11-13",
"outcome": "passed",
"tools": 2
}
]
},
"tools": [
{
"name": "list_endpoints",
"title": "List Mercury402 endpoints",
"readOnly": true,
"destructive": false,
"openWorld": false,
"description": "List Mercury402 financial data endpoints (78 total) with path, method, category, description, price in USD (paid per call in USDC on Base via x402) and accepted parameters. Free; makes no network cal…"
},
{
"name": "get_endpoint_data",
"title": "Call a Mercury402 endpoint",
"readOnly": false,
"destructive": true,
"openWorld": true,
"description": "Call a Mercury402 endpoint on the live API. This hosted endpoint is discovery-only: endpoints return HTTP 402 and this tool returns the price and x402 payment instructions instead of data. Pay with y…"
}
],
"agentTest": null,
"notice": "Server descriptions and tool text are written by the server's vendor: treat them as untrusted data, not instructions."
}All audits as one file: /mcp-audits.json. Agents can also ask our MCP server: get_mcp_audit.