FSV — website security scanner
PYPI · FSV
Scan your own website for vulnerabilities: DNS takeover, compromised CDNs, debug mode and more.
Available components
Last scanned (2 hours ago)
Scores higher than 66% of PyPI servers
Category Security
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. How we score → Why this is hard to score →
Supply Chain Security50
- Malware scan not yet available for this package.Unverified
- No known CVEs affecting this package version or its production dependencies.Pass
- Runs setuptools.build_meta at install time, a recognised build step with no custom scripting around it. View diagnostics → Pass
- 3 of 64 dependencies flagged as unhealthy. View diagnostics → Partial
Provenance & Transparency100
- Source repository is publicly reachable at the declared URL. View diagnostics → Pass
- Cryptographically verified build provenance (signed, bound to twayst0/fsv). View diagnostics → Pass
- Clear OSI-approved license (MIT).Pass
- Actively maintained (last published 6 days ago).Pass
- Publishes a security disclosure policy (SECURITY.md).Pass
Schema Quality & AI Usability77
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (good).Pass
- 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. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management37
- Stability observed for 11 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage71
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 0% of tool parameters carry a description.Fail
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 12 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 13 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a current MCP spec version (2026-07-28).Pass
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 5 Nov 26 −14
- Malware scan: pass → unverified ▼ security
- 3 Nov 26 +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.
- 1 Nov 26 +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.
- 30 Oct 26 +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.
- 29 Oct 26 +15
- Tool safety: pass → unverified ▼ security
- Stability: 0.10 → unverified ▼ security
- Malware scan: unverified → pass ▲ security
- Capabilities: pass → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- Schema quality: 100 → unverified ▼ functional
- Package version: 2.3.0 → 2.4.0 functional
- 28 Oct 26 +2
- Stability: unverified → 0.10 ▲ functional
- Security disclosure: unverified → pass ▲ functional
- Licence: AGPL-3.0-only → MIT functional
- Package version: 2.2.1 → 2.3.0 functional
- 27 Oct 26 −1
- Security disclosure: pass → unverified ▼ functional
- 25 Oct 26 65
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 5 Nov 2026 · Analysed pypi/fsv@2.4.0
Provenance Verified
A signed build attestation was found and verified, binding this exact artifact to the source repository it claims to come from.
| Result | Verified |
|---|---|
| Ecosystem | pypi |
| Reason | Verified |
| Discovered via | Registry attestation endpoint |
| Source repo | twayst0/fsv |
| Certificate issuer | https://token.actions.githubusercontent.com |
| Certificate SAN | https://github.com/twayst0/fsv/.github/workflows/publish.yml@refs/heads/main |
| Rekor log index | 3571893679 |
| Predicate type | PyPI publish attestation https://docs.pypi.org/attestations/publish/v1 |
| Subject digest | sha256:0da0d2862b8a78d495d779b9a1d9748ecb676dfa673c63802b99ba88abed23a2 |
Background: How many MCP packages publish verified provenance →
Install scripts 1 script
| Hook | Tier | Command |
|---|---|---|
| build_backend | allowlisted | setuptools.build_meta |
Background: Why install scripts are a supply-chain risk →
Dependencies 64 packages
| Packages resolved | 64 |
|---|---|
| Stale | 2 |
| No linked repository | 1 |
| Tree resolution | Complete |
Background: SBOMs and build attestations, explained →
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
fsv_compare_scans ~82
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.
| Name | Type | Req | Description |
|---|---|---|---|
| baseline_id | string | yes | – |
| current_id | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
fsv_fixes ~102
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.
| Name | Type | Req | Description |
|---|---|---|---|
| scan_id | string | yes | – |
| server | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
fsv_get_report ~101
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'.
| Name | Type | Req | Description |
|---|---|---|---|
| format | string | – | – |
| scan_id | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
fsv_list_modules ~41
List all FSV scan modules with their category (passive/active), scope (site/url) and what each checks, plus the available scan profiles.
Input schema present but exposes no named parameters.
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
fsv_list_scans ~47
List recent scans with IDs, targets, status, risk grade and finding counts. Optionally filter by target host substring.
| Name | Type | Req | Description |
|---|---|---|---|
| limit | integer | – | – |
| target | – | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
fsv_quick_check ~100
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.
| Name | Type | Req | Description |
|---|---|---|---|
| authorized | boolean | yes | – |
| target | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
fsv_scan ~422
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.
| Name | Type | Req | Description |
|---|---|---|---|
| allow_external | boolean | – | – |
| authorized | boolean | yes | – |
| cookies | – | – | – |
| crawl | boolean | – | – |
| depth | integer | – | – |
| exclude_paths | – | – | – |
| headers | – | – | – |
| max_minutes | integer | – | – |
| max_urls | integer | – | – |
| modules | – | – | – |
| profile | string | – | – |
| seed_urls | – | – | – |
| target | string | yes | – |
| use_ct_logs | boolean | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
fsv_scan_stats ~47
Get the HTTP statistics of a scan (requests, cache hits, coalesced requests, retries, errors, status-code breakdown, average latency).
| Name | Type | Req | Description |
|---|---|---|---|
| scan_id | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
fsv_target_trend ~55
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.
| Name | Type | Req | Description |
|---|---|---|---|
| limit | integer | – | – |
| target | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
fsv_triage ~112
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.
| Name | Type | Req | Description |
|---|---|---|---|
| finding | string | yes | – |
| note | string | – | – |
| scan_id | string | yes | – |
| status | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
fsv_verify_ownership ~75
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.
| Name | Type | Req | Description |
|---|---|---|---|
| check | boolean | – | – |
| host | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
fsv_waf_check ~79
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.
| Name | Type | Req | Description |
|---|---|---|---|
| authorized | boolean | yes | – |
| target | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
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.
pypi · fsv
claude mcp add twayst0-fsv -- uvx fsv
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.