io.github.adsandcode/fbc-guard
NPM · MCP-SERVER-FBC-GUARD
Static checks for Meta _fbc, _fbp and fbclid code that cause modified click ID warnings.
Available components
Last scanned (3 hours ago)
Scores higher than 31% of npm servers
Category Marketing and SEO
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 Security81
- No malware found by supply-chain analysis.Pass
- CVE check failed: a known high-severity CVE affects zod 3.25.76, a direct dependency. A fixed version is available. View diagnostics → Fail
- No install/post-install scripts declared.Pass
- 30 of 93 dependencies flagged as unhealthy. View diagnostics → Partial
Provenance & Transparency45
- Source repository is publicly reachable at the declared URL. View diagnostics → Pass
- Provenance check failed: no build-provenance attestation is published. See how to fix → View diagnostics → Fail
- Clear OSI-approved license (MIT).Pass
- Actively maintained (last published 13 days ago).Pass
- Disclosure check failed: no security disclosure policy was found in the source repository. See how to fix → Fail
Schema Quality & AI Usability66
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 828 tokens (~414/item across 2 items; 2 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 Management0
- Stability not yet verified: not enough scan history yet (needs a 30-day window).Unverified
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 2 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 2 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Unverified: 1 category
A category scored 0 because we could not verify it: a data source with nothing on this package, evidence we could not reach, or a check we could not run. We only credit what we can confirm.
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.
- 24 Oct 26 −5
- CVE-2023-54404 affects this package: high ▼ security
- Known CVEs: pass → fail ▼ security
- 23 Oct 26 +15
- Malware scan: unverified → pass ▲ security
- 22 Oct 26 53
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 npm/mcp-server-fbc-guard@0.1.0
Provenance No attestation
The registry publishes no build provenance for this version, so there is nothing to verify.
| Result | No attestation |
|---|---|
| Ecosystem | npm |
Background: How many MCP packages publish verified provenance →
Vulnerabilities 1 finding
| ID | CVE | Severity | Vector | Fix available |
|---|---|---|---|---|
| GHSA-mrhx-c7xc-m3w5 | CVE-2023-54404 | high | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | yes |
Background: What a vulnerability scan can and cannot prove →
Dependencies 93 packages
| Packages resolved | 93 |
|---|---|
| Stale | 30 |
| 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 →
check_fbc_code ~490
Statically check HTML or JavaScript that reads `fbclid` from the URL and writes Meta's `_fbc` click ID cookie (and optionally `_fbp`). It catches the mistakes that make Meta Events Manager report a modified fbclid or attribute a conversion to the wrong ad: keeping an old click ID when a visitor arrives from a new ad, decoding, re-casing or truncating the click ID, writing creationTime in seconds instead of milliseconds, and hard-coding subdomainIndex. Rules: FBC-01: A new fbclid must overwrite an older _fbc cookie. FBC-02: Do not URL-decode fbclid a second time. FBC-03: Do not change the case of fbclid. FBC-04: Do not truncate fbclid. FBC-05: _fbc creationTime must be in milliseconds. FBC-06: Check that a hard-coded subdomainIndex matches the cookie domain. FBP-01: _fbp creationTime must be in milliseconds. Returns JSON with `status` ("pass", "fail", "unknown" or "not_applicable"), `failed`, `unknown` and `warnings` (rule IDs), and `rules` (one entry per rule with status "pass", "fail", "unknown" or "warn", evidence, what it protects against, severity, and a link to Meta's documentation). "unknown" means no rule failed but at least one could not decide, for example FBC-01 when it cannot tell which variable holds the fbclid from the URL. "not_applicable" means no `_fbc` appeared in the content, so nothing was judged. Neither is a pass. "warn" comes from a warning-level rule (FBC-06) and never changes the overall status. This is static analysis of source text, not execution: minified, bundled or obfuscated code can hide a mistake, so a pass is not proof of correctness.
| Name | Type | Req | Description |
|---|---|---|---|
| code | string | yes | HTML or JavaScript source to check. Include every file that touches fbclid, _fbc or _fbp, concatenated. |
| kind | string | – | How to read `code`. "html": analyse the inline <script> bodies. "js": analyse it as JavaScript. "auto": HTML if it starts with "<", JavaScript otherwise. |
No output schema declared.
No examples provided.
check_fbc_url ~338
Fetch a landing page and run the same checks as check_fbc_code on its HTML plus every same-origin <script src> it loads, so tracking code kept in an external file is included. Cross-origin scripts (tag managers, the Meta Pixel, analytics SDKs) are never fetched and are listed under skipped_scripts. Limits: 30 s timeout per request, at most 20 scripts, 2 MB per file. Uses a mobile Safari user agent. Only public hosts are fetched: URLs that resolve to loopback, private, link-local or other internal addresses are refused, on every redirect hop too (start the server with FBC_GUARD_ALLOW_PRIVATE=1 to check local pages). Returns JSON with `status` ("pass", "fail", "unknown" or "not_applicable"), `failed`, `unknown` and `warnings` (rule IDs), and `rules` (one entry per rule with status "pass", "fail", "unknown" or "warn", evidence, what it protects against, severity, and a link to Meta's documentation). "unknown" means no rule failed but at least one could not decide, for example FBC-01 when it cannot tell which variable holds the fbclid from the URL. "not_applicable" means no `_fbc` appeared in the content, so nothing was judged. Neither is a pass. "warn" comes from a warning-level rule (FBC-06) and never changes the overall status. Also returns final_url (after redirects), scanned_scripts and skipped_scripts.
| Name | Type | Req | Description |
|---|---|---|---|
| url | string | yes | http or https URL of the landing page. |
No output schema declared.
No examples provided.
How do I install the io.github.adsandcode/fbc-guard MCP server?
io.github.adsandcode/fbc-guard runs locally as an npm package, launched with npx -y mcp-server-fbc-guard. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
npm · mcp-server-fbc-guard
claude mcp add adsandcode-fbc-guard -- npx -y mcp-server-fbc-guard
What is the io.github.adsandcode/fbc-guard MCP server?
io.github.adsandcode/fbc-guard is an MCP server listed in the public MCP registry as io.github.adsandcode/fbc-guard. Static checks for Meta _fbc, _fbp and fbclid code that cause modified click ID warnings. This page covers its npm package (mcp-server-fbc-guard).
Is the io.github.adsandcode/fbc-guard MCP server safe to use?
io.github.adsandcode/fbc-guard scores 63 out of 100 on VerifyMCP. We recorded 1 known advisory against it as of 5 November 2026. It declares no install or post-install scripts. 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 io.github.adsandcode/fbc-guard MCP server expose?
io.github.adsandcode/fbc-guard exposes 2 tools: check_fbc_code, check_fbc_url. Their descriptions and schemas cost roughly 828 tokens of context every time the server is loaded.
Is the io.github.adsandcode/fbc-guard MCP server still maintained?
io.github.adsandcode/fbc-guard 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 io.github.adsandcode/fbc-guard MCP server under?
io.github.adsandcode/fbc-guard declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.