# 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. - Trust score: 63/100 (medium) - Change this week: 0 - Registry status: active - Liveness: live - Owner verified: no - Last scored: 2026-11-05 ## Components - npm · `mcp-server-fbc-guard`: 63/100 (this document), [markdown](https://verifymcp.io/servers/adsandcode-fbc-guard/mcp-server-fbc-guard.md), [page](https://verifymcp.io/servers/adsandcode-fbc-guard/mcp-server-fbc-guard) ## Channel facts - Registry: `npm` - Package: `mcp-server-fbc-guard` - Version: `0.1.0` - 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**: 81/100 - No malware found by supply-chain analysis. - CVE check failed: a known high-severity CVE affects zod 3.25.76, a direct dependency. A fixed version is available. - No install/post-install scripts declared. - 30 of 93 dependencies flagged as unhealthy. - **Provenance & Transparency**: 45/100 - Source repository is publicly reachable at the declared URL. - Provenance check failed: no build-provenance attestation is published. - Clear OSI-approved license (MIT). - Actively maintained (last published 13 days ago). - Disclosure check failed: no security disclosure policy was found in the source repository. - **Schema Quality & AI Usability**: 66/100 - AI-judged instruction clarity (excellent). - 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. - Usage-examples check failed: none of the tools include examples. - **Stability & Change Management**: 0/100 - Stability not yet verified: not enough scan history yet (needs a 30-day window). - **Tool Coverage**: 100/100 - 100% of tools have a non-trivial description (not blank, and not just the tool's name). - 100% of tool parameters carry a description. - **Tool Safety**: 100/100 - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured. - We read all 2 captured tool definition(s), and no name or description among them implies an irreversible operation. - An AI judge read all 2 captured unit(s) of tool text and found none that tries to manipulate the model reading it. - **Capabilities**: 100/100 - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28. **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. ## Install ### 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. ### Claude ```bash claude mcp add adsandcode-fbc-guard -- npx -y mcp-server-fbc-guard ``` ### Cursor ```json { "mcpServers": { "adsandcode-fbc-guard": { "command": "npx", "args": [ "-y", "mcp-server-fbc-guard" ] } } } ``` ### VS Code ```json { "servers": { "adsandcode-fbc-guard": { "command": "npx", "args": [ "-y", "mcp-server-fbc-guard" ] } } } ``` ### Codex ```bash codex mcp add adsandcode-fbc-guard -- npx -y mcp-server-fbc-guard ``` ### opencode ```json { "$schema": "https://opencode.ai/config.json", "mcp": { "adsandcode-fbc-guard": { "type": "local", "command": [ "npx", "-y", "mcp-server-fbc-guard" ], "enabled": true } } } ``` ### OpenClaw ```bash openclaw mcp add adsandcode-fbc-guard --command npx --arg -y --arg mcp-server-fbc-guard ``` ### Hermes ```yaml mcp_servers: adsandcode-fbc-guard: command: "npx" args: ["-y", "mcp-server-fbc-guard"] ``` ### Netclaw ```json { "McpServers": { "adsandcode-fbc-guard": { "Transport": "stdio", "Command": "npx", "Arguments": [ "-y", "mcp-server-fbc-guard" ] } } } ``` ### Vellum ```bash assistant mcp add adsandcode-fbc-guard -t stdio -c npx -a -y mcp-server-fbc-guard ``` ### Other ```json { "mcpServers": { "adsandcode-fbc-guard": { "command": "npx", "args": [ "-y", "mcp-server-fbc-guard" ] } } } ``` ## 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. ### 2026-10-24 (score 63, −5) - [security regression] CVE-2023-54404 affects this package: high - [security regression] Known CVEs: pass → fail ### 2026-10-23 (score 68, +15) - [security improvement] Malware scan: unverified → pass ### 2026-10-22 (score 53) First indexed and scored. ## MCP tools (2) ### `check_fbc_code` (~490 tokens) 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. Input parameters: - `code` (string, required): 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