MCP Server Test

These three requests cover the full MCP handshake — from protocol init through a tool call.

# 1. initialize — protocol handshake
curl -sS -X POST "https://mcp.dlptest.com/" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "initialize",
    "params": {
      "protocolVersion": "2025-06-18",
      "capabilities": {},
      "clientInfo": { "name": "curl", "version": "0.0.1" }
    }
  }'

# 2. tools/list — discover available tools
curl -sS -X POST "https://mcp.dlptest.com/" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/list"}'

# 3. tools/call — invoke a tool (response-side DLP test)
curl -sS -X POST "https://mcp.dlptest.com/" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 3,
    "method": "tools/call",
    "params": {
      "name": "generate_pii_ssn_ccn",
      "arguments": { "count": 5, "format": "csv" }
    }
  }'

Most DLP products only inspect the response body. But in a real agent pipeline, sensitive content can also flow outward in the tool-call arguments — for example, a user pastes a document containing real SSNs and that text gets forwarded as a tool argument.

echo_sensitive_data — outbound argument inspection

Accepts any text as a payload argument and echoes it back unchanged. PII travels in the outbound request — a DLP product that only inspects responses will miss it.

# echo_sensitive_data — PII travels in the *request* arguments
curl -sS -X POST "https://mcp.dlptest.com/" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 4,
    "method": "tools/call",
    "params": {
      "name": "echo_sensitive_data",
      "arguments": {
        "label": "test-run-1",
        "payload": "Patient: Jane Smith  SSN: 123-45-6789  CCN: 4111111111111111"
      }
    }
  }'

generate_prompt_context — RAG / system-prompt simulation

Returns prose paragraphs with PII embedded inline, mimicking how sensitive data arrives via RAG retrieval or an injected system prompt. Scenarios: medical-record, financial-statement, hr-file, customer-list.

# generate_prompt_context — simulate RAG / system-prompt PII
curl -sS -X POST "https://mcp.dlptest.com/" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 5,
    "method": "tools/call",
    "params": {
      "name": "generate_prompt_context",
      "arguments": { "scenario": "medical-record", "count": 3, "format": "text" }
    }
  }'

probe_request — verify interception point

Returns the User-Agent, client IP, and timestamp seen by the server. Use it to confirm your proxy or endpoint agent is on the expected network leg.

# probe_request — verify DLP is on the right network leg
curl -sS -X POST "https://mcp.dlptest.com/" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":6,"method":"tools/call","params":{"name":"probe_request","arguments":{}}}'

To test internal traffic inspection separately from internet egress, clone this repo and run npm run dev. The MCP endpoint is available at http://localhost:4321/api/mcp/.

// Local instance (npm run dev → http://localhost:4321)
{
  "mcpServers": {
    "dlptest-local": {
      "type": "http",
      "url": "http://localhost:4321/api/mcp/"
    }
  }
}

After running a few tool calls, check whether your product:

• Caught synthetic SSNs, CCNs, or IBANs in the response body.
• Caught PII in the request body (tool-call arguments) — use echo_sensitive_data to test this specifically.
• Saw PII arriving as prose context, not tabular data — use generate_prompt_context.
• Logged a connection to mcp.dlptest.com as an outbound MCP server contact.
• Surfaced the tools/list handshake — a keyword-rich signal for pattern scanners.
• Flagged the initial connection to an unapproved external MCP endpoint (CASB / network policy).

Tool	Data returned
generate_pii_ssn_ccn	Name + SSN + credit card
generate_pii_ssn_dob	Name + SSN + date of birth
generate_pci_credit_card	Name + ZIP + CCN + expiry
generate_pii_email	Name + DOB + email
generate_hipaa_phi	Name + DOB + MRN + ICD-10 + CPT + phone
generate_banking	Name + routing + account + phone
generate_uk_identity	Name + UK NI + NHS + DOB
generate_canada_sin	Name + Canadian SIN + province + DOB
generate_passport	Name + passport + country + DOB + expiry
generate_eu_vat	Name + EU VAT + IBAN + country
generate_npi_provider	Name + NPI + DEA + specialty
generate_driver_license	Name + DL + state + DOB
generate_custom	Arbitrary fields. Takes a fields array of { name, type, blankPct?, delimiter?, cardBrands? } — same types as the /generate/ page.