SRI — MCP Server Inspector

Read what an MCP server does before you connect to it.

Connecting an MCP server hands it a channel into your agent's context and its tool calls. SRI reads the server's published source and reports what it found — every observation anchored to a file:line with the code quoted verbatim.

It does not tell you whether a server is safe. It tells you what the code does, and shows you the line it read. You decide.

• Endpoint: https://sri-test.biz/mcp (Streamable HTTP)

• Corpus: 2,238 MCP servers from the official registry

• Price: free right now — settlement runs on Bitcoin signet, so invoices cannot be paid with real funds

• Findings across the corpus: sri-test.biz/research

Add it to your client

Remote MCP server, no install, no API key.

{
  "mcpServers": {
    "sri": {
      "type": "http",
      "url": "https://sri-test.biz/mcp"
    }
  }
}

claude mcp add --transport http sri https://sri-test.biz/mcp

Point it at https://sri-test.biz/mcp. There is one tool and no auth. GET on that URL returns 405 — this server does not offer a server-initiated SSE stream, which the spec permits. Send JSON-RPC over POST.

The tool

check_mcp_server

Returns a risk_level, a summary, and a list of findings. Each finding carries location (file:line), evidence (the code, quoted), and why.

If the server is not in the corpus you get status: "queued", an explicit "nothing has been checked" — not a clean result — and no charge. We do not bill for an answer we could not give.

Try it without a client

curl -X POST https://sri-test.biz/mcp \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call",
       "params":{"name":"check_mcp_server",
                 "arguments":{"name":"io.github.firebase/firebase-mcp","version":"0.3.0"}}}'

There is a plain REST endpoint too, if that is easier:

curl -X POST https://sri-test.biz/v1/verify \
  -H 'Content-Type: application/json' \
  -d '{"ecosystem":"mcp","name":"io.github.firebase/firebase-mcp","version":"0.3.0"}'

GET /v1/price is open and tells you the current terms. GET /v1/docs is the OpenAPI spec.

What gets reported

Severity is info / low / medium / high. risk_level is the highest severity among the findings, derived in code rather than asked for — a verdict with no findings behind it cannot be published.

What this is not

• No finding is not a clean bill of health. It means nothing was found in the categories above, in the code we could fetch.

• We never label a package malicious, and never call one safe. The ingest step rejects records whose summary contains either kind of claim.

• MCP servers only. npm and PyPI libraries are out of scope; ask about one and you will get "not analyzed".

• One analyzer, one pass. Run-to-run agreement measured at 93% on a hand-labelled set of 84 servers before the full corpus was built. Not 100%.

If a finding is wrong

If you maintain a server and a finding is mistaken, tell us through the report form. Agents can use POST /v1/disputes.

We reply within three business days. While we review, the finding may be withheld from results. If we withdraw it, the server is re-analysed and the record replaced. If we keep it, we say which facts it rests on.

Payment

The paid path is L402 (Lightning HTTP 402): the server issues an invoice and a macaroon, you pay, and you present Authorization: L402 <macaroon>:<preimage>. Verification is sha256(preimage) == payment_hash — no node required on your side, and no signup on ours.

This is switched off today. Settlement runs on signet, a test chain, so invoices cannot be paid with real funds and usage is free. When mainnet is enabled the price returns to $0.20 per cached lookup. GET /.well-known/l402 tells you the current state.

Privacy

We record the path requested, response time, User-Agent, and an IP hashed with a daily salt, kept for 90 days. Raw IP addresses are never stored, and request bodies are never stored — the servers you ask about are recorded by name, nothing more.