# FSV — website security scanner (pypi · fsv)

Scan your own website for vulnerabilities: DNS takeover, compromised CDNs, debug mode and more.

- Trust score: 70/100 (medium)
- Change this week: −11
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- pypi · `fsv`: 70/100 (this document), [markdown](https://verifymcp.io/servers/twayst0-fsv/fsv.md), [page](https://verifymcp.io/servers/twayst0-fsv/fsv)

## Channel facts

- Registry: `pypi`
- Package: `fsv`
- Version: `2.4.0`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Supply Chain Security**: 50/100
  - Malware scan not yet available for this package.
  - No known CVEs affecting this package version or its production dependencies.
  - Runs setuptools.build_meta at install time, a recognised build step with no custom scripting around it.
  - 3 of 64 dependencies flagged as unhealthy.
- **Provenance & Transparency**: 100/100
  - Source repository is publicly reachable at the declared URL.
  - Cryptographically verified build provenance (signed, bound to twayst0/fsv).
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 6 days ago).
  - Publishes a security disclosure policy (SECURITY.md).
- **Schema Quality & AI Usability**: 77/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 1461 tokens (~121/item across 12 items; 12 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 37/100
  - Stability observed for 11 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 71/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 0% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 12 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 13 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a current MCP spec version (2026-07-28).

## Install

### How do I install the FSV — website security scanner MCP server?

FSV — website security scanner runs locally as a PyPI package, launched with uvx fsv. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add twayst0-fsv -- uvx fsv
```

### Cursor

```json
{
  "mcpServers": {
    "twayst0-fsv": {
      "command": "uvx",
      "args": [
        "fsv"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "twayst0-fsv": {
      "command": "uvx",
      "args": [
        "fsv"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add twayst0-fsv -- uvx fsv
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "twayst0-fsv": {
      "type": "local",
      "command": [
        "uvx",
        "fsv"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add twayst0-fsv --command uvx --arg fsv
```

### Hermes

```yaml
mcp_servers:
  twayst0-fsv:
    command: "uvx"
    args: ["fsv"]
```

### Netclaw

```json
{
  "McpServers": {
    "twayst0-fsv": {
      "Transport": "stdio",
      "Command": "uvx",
      "Arguments": [
        "fsv"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add twayst0-fsv -t stdio -c uvx -a fsv
```

### Other

```json
{
  "mcpServers": {
    "twayst0-fsv": {
      "command": "uvx",
      "args": [
        "fsv"
      ]
    }
  }
}
```

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-05 (score 70, −14)

- [security regression] Malware scan: pass → unverified

### 2026-11-03 (score 84, +1)

No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-01 (score 83, +1)

No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-30 (score 82, +1)

No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-29 (score 81, +15)

- [security regression] Tool safety: pass → unverified
- [security regression] Stability: 0.10 → unverified
- [security improvement] Malware scan: unverified → pass
- [functional regression] Capabilities: pass → unverified
- [functional regression] Tool coverage: 100 → unverified
- [functional regression] Schema quality: 100 → unverified
- [functional] Package version: 2.3.0 → 2.4.0

### 2026-10-28 (score 66, +2)

- [functional improvement] Stability: unverified → 0.10
- [functional improvement] Security disclosure: unverified → pass
- [functional] Licence: AGPL-3.0-only → MIT
- [functional] Package version: 2.2.1 → 2.3.0

### 2026-10-27 (score 64, −1)

- [functional regression] Security disclosure: pass → unverified

### 2026-10-25 (score 65)

First indexed and scored.

## MCP tools (12)

### `fsv_scan` (~422 tokens)

Run a web vulnerability scan against a target URL. Crawls the site (same-origin, skips logout/asset links) and runs modules by profile: 'passive' sends no payloads (headers, SSL/TLS, DNS, cookies, WAF, fingerprint, JWT, CSP, SRI, security.txt); 'balanced' (default) adds safe active checks (XSS, SQLi, CORS, open-redirect, SSTI, host-header); 'aggressive' is the same modules at higher rate/concurrency; 'deep' is thorough (wider crawl, hidden-parameter discovery, larger exposed-file list, more payload shapes — many more requests, only for targets the user owns); 'full' is exhaustive (1000+ URLs at depth 6, ~600 guessed directories/pages, backup copies of every script, boolean SQLi, 160 parameter names — the slowest and busiest; always set max_minutes). Returns findings grouped with severity, CWE, OWASP category, confidence and remediation. Time-boxed by max_minutes (default 20; partial results are kept). use_ct_logs=true also asks Certificate Transparency logs (crt.sh) for subdomains (sends the domain to a third party — only with the user's consent); allow_external=false skips modules that contact hosts other than the target. seed_urls adds same-origin pages no link points to; headers/cookies make it an authenticated scan (use a test account, never a real user's session). Only scan targets the user owns or is authorized to test; pass authorized=true only after they confirm.

Input parameters:

- `allow_external` (boolean)
- `authorized` (boolean, required)
- `cookies`
- `crawl` (boolean)
- `depth` (integer)
- `exclude_paths`
- `headers`
- `max_minutes` (integer)
- `max_urls` (integer)
- `modules`
- `profile` (string)
- `seed_urls`
- `target` (string, required)
- `use_ct_logs` (boolean)

Output parameters:

- `result` (string)

### `fsv_quick_check` (~100 tokens)

Fast passive check of a single URL — no payloads sent. Runs security headers, SSL/TLS, cookies, clickjacking, CSP review, SRI, WAF/CDN detection, technology fingerprint, DNS (SPF/DMARC), HTTP methods, security.txt, and JWT analysis. Safe for a first look. Pass authorized=true after the user confirms authorization.

Input parameters:

- `authorized` (boolean, required)
- `target` (string, required)

Output parameters:

- `result` (string)

### `fsv_waf_check` (~79 tokens)

Detect whether a target sits behind a Web Application Firewall or CDN (Cloudflare, AWS WAF, Akamai, Imperva, Sucuri, F5, ModSecurity, Fastly, …). Passive, single request. Pass authorized=true after the user confirms.

Input parameters:

- `authorized` (boolean, required)
- `target` (string, required)

Output parameters:

- `result` (string)

### `fsv_get_report` (~101 tokens)

Get a formatted report for a completed scan. format: 'md' (default, OWASP-grouped), 'json', 'html' (self-contained), 'sarif' (for CI/code-scanning), 'csv', or 'fix-nginx' / 'fix-apache' / 'fix-caddy' / 'fix-express' / 'fix-dns'.

Input parameters:

- `format` (string)
- `scan_id` (string, required)

Output parameters:

- `result` (string)

### `fsv_list_scans` (~47 tokens)

List recent scans with IDs, targets, status, risk grade and finding counts. Optionally filter by target host substring.

Input parameters:

- `limit` (integer)
- `target`

Output parameters:

- `result` (string)

### `fsv_compare_scans` (~82 tokens)

Compare two scans by scan_id (e.g. before vs after a fix). Reports which findings were resolved, which are new, which persist, the risk-score delta and an improved/regressed verdict. Triaged-away findings are excluded, so false positives don't skew the diff.

Input parameters:

- `baseline_id` (string, required)
- `current_id` (string, required)

Output parameters:

- `result` (string)

### `fsv_target_trend` (~55 tokens)

Show the risk-score trend for a host across its scan history (oldest first) — useful for reporting whether a site's posture is improving over time.

Input parameters:

- `limit` (integer)
- `target` (string, required)

Output parameters:

- `result` (string)

### `fsv_triage` (~112 tokens)

Record a triage decision for a finding so it persists across future scans of the same host. status: 'confirmed', 'false_positive', 'accepted_risk', 'fixed', or 'open' (clears it). false_positive / accepted_risk / fixed are excluded from the risk score. Identify the finding by its id or fingerprint from a scan result.

Input parameters:

- `finding` (string, required)
- `note` (string)
- `scan_id` (string, required)
- `status` (string, required)

Output parameters:

- `result` (string)

### `fsv_fixes` (~102 tokens)

Turn a scan's findings into paste-ready remediation for one platform: 'nginx', 'apache', 'caddy', 'express' (helmet/cookies) or 'dns' (SPF/DMARC/CAA records, dangling-record removal). Only issues actually found produce a snippet; CSP is emitted report-only. Show the user the snippets and remind them to test on staging.

Input parameters:

- `scan_id` (string, required)
- `server` (string, required)

Output parameters:

- `result` (string)

### `fsv_scan_stats` (~47 tokens)

Get the HTTP statistics of a scan (requests, cache hits, coalesced requests, retries, errors, status-code breakdown, average latency).

Input parameters:

- `scan_id` (string, required)

Output parameters:

- `result` (string)

### `fsv_list_modules` (~41 tokens)

List all FSV scan modules with their category (passive/active), scope (site/url) and what each checks, plus the available scan profiles.

Output parameters:

- `result` (string)

### `fsv_verify_ownership` (~75 tokens)

Prove control of a host so payload-sending scans are allowed on deployments that require it (FSV_REQUIRE_VERIFICATION=1). check=false returns the DNS TXT record / HTTP file to publish; check=true looks for it and records the proof.

Input parameters:

- `check` (boolean)
- `host` (string, required)

Output parameters:

- `result` (string)

## Diagnostics

Captured diagnostic sections: Provenance, Install scripts, Dependencies. The full working is on the page: https://verifymcp.io/servers/twayst0-fsv/fsv#diagnostics

## Score history

- 2026-11-05: 70
- 2026-11-04: 84
- 2026-11-03: 84
- 2026-11-02: 83
- 2026-11-01: 83
- 2026-10-31: 82
- 2026-10-30: 82
- 2026-10-29: 81
- 2026-10-28: 66
- 2026-10-27: 64
- 2026-10-26: 65
- 2026-10-25: 65

## Common questions

### What is the FSV — website security scanner MCP server?

FSV — website security scanner is an MCP server listed in the public MCP registry as io.github.twayst0/fsv. Scan your own website for vulnerabilities: DNS takeover, compromised CDNs, debug mode and more. This page covers its PyPI package (fsv).

### Is the FSV — website security scanner MCP server safe to use?

FSV — website security scanner scores 70 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 5 November 2026. Its build provenance is signed and verified. 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 FSV — website security scanner MCP server expose?

FSV — website security scanner exposes 12 tools: fsv_scan, fsv_quick_check, fsv_waf_check, fsv_get_report, fsv_list_scans, and 7 more. Their descriptions and schemas cost roughly 1,263 tokens of context every time the server is loaded.

### Is the FSV — website security scanner MCP server still maintained?

FSV — website security scanner is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What licence is the FSV — website security scanner MCP server under?

FSV — website security scanner declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.

## Links

- PyPI project: https://pypi.org/project/fsv/
- Socket report: https://socket.dev/pypi/package/fsv
- Repository: https://github.com/twayst0/fsv
- Changelog RSS feed: https://verifymcp.io/servers/twayst0-fsv/fsv.xml
- Changelog JSON feed: https://verifymcp.io/servers/twayst0-fsv/fsv.json
- HTML version of this page: https://verifymcp.io/servers/twayst0-fsv/fsv