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FHI MCP Security Monitoring – Change Evidence
x402
FHI MCP Security Monitoring – Change Evidence is a paid API for AI agents from polished-truth-c514.fhi-llc-1118.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-12).
Detects and reports changes to a remote MCP endpoint's tools and capabilities, returning a risk score delta and change evidence with stateful tracking across calls.
Price / call$0.003
Success—
StatusUnknown
How this service works
Stateful remote-MCP change evidence, payable per call with x402 Base USDC.
Output
Returns a JSON object indicating whether the MCP endpoint changed since last observation, listing added/changed/removed tools, a risk score delta, the current aggregate risk score with a verdict (e.g. CAUTION), the monitoring state (e.g. change_detected), specific change signals, and whether this is the first observation for this endpoint.
Example use cases
Detecting unexpected tool additions on a production MCP server
“Has the MCP server at https://myprod-agent.example.com/mcp had any tools added or removed since the last scan? Flag anything that looks risky.”
Auditing a third-party MCP endpoint before connecting an agent
“Before I let my agent connect to https://partner-tools.acme.io/mcp, can you check if it has changed recently and give me a risk verdict on its current tool set?”
Ongoing prompt-injection monitoring for an agent fleet
“Run a change-evidence check on https://internal-tools.mycompany.com/mcp and tell me if any tool descriptions were modified — I'm worried about prompt injection slipping in through description changes.”
Technical details
Endpoint
POSThttps://polished-truth-c514.fhi-llc-1118.workers.dev/api/v1/mcp-change-evidence?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need stateful, per-call change detection for remote MCP servers — especially when monitoring for security regressions like unauthorized tool additions, tool description mutations (potential prompt injection vectors), or unexpected capability removals. It combines change diffing with risk scoring in a single call, making it ideal for agentic security pipelines that need to validate third-party or internal MCP endpoints before use or on a recurring basis.
Side effects
- Invalid or unreachable MCP server URL returns an error without change data
- First-time observations set firstObservation=true with no delta, since there is no prior state to compare
- Payment failure via x402 blocks the call entirely
- Private or firewall-protected endpoints may time out or return access errors
- Endpoints returning non-standard MCP schemas may produce incomplete change detection
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| serverUrl | string | Public HTTPS streamable-HTTP MCP endpoint |
Output
Schema · Response
{
"type": "json",
"example": {
"changed": true,
"changes": {
"addedTools": [
"send_email"
],
"changedTools": [
{
"name": "search",
"fields": [
"description"
]
}
],
"removedTools": [],
"riskScoreDelta": 18
},
"current": {
"score": 54,
"verdict": "CAUTION"
},
"endpoint": "https://example.com/mcp",
"monitoring": {
"state": "change_detected",
"signals": [
"tool_added",
"tool_description_changed"
]
},
"firstObservation": false
}
}Tags
x402
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