Server data from the Official MCP Registry
13 deterministic agent utilities: timezone, cron, RRULE, currency, regex, diff, hashing & more.
About
13 deterministic agent utilities: timezone, cron, RRULE, currency, regex, diff, hashing & more.
Remote endpoints: streamable-http: https://belt.fabtally.com/mcp
Security Report
This is a well-designed MCP server with solid security practices. It fronts a remote payment-gated API (x402/USDC), validates all inputs via Zod schemas, has no hardcoded secrets or malicious patterns, and properly separates paid/free tools. Minor code quality observations exist but do not raise security concerns; permissions (network_http, env_vars) are appropriate for a utility service that calls remote APIs and accepts configuration. Supply chain analysis found 3 known vulnerabilities in dependencies (0 critical, 3 high severity).
5 files analyzed · 7 issues found
Security scores are indicators to help you make informed decisions, not guarantees. Always review permissions before connecting any MCP server.
Permissions Required
This plugin requests these system permissions. Most are normal for its category.
How to Install & Connect
Available as Local & Remote
This plugin can run on your machine or connect to a hosted endpoint. during install.
Documentation
View on GitHubFrom the project's GitHub README.
FabTally Utility Belt — MCP server
The deterministic micro-utilities AI agents call constantly, as an MCP server (stdio + streamable-HTTP) and a pay-per-call HTTP API. One reliable bundle instead of thirteen flaky npm deps.
- Free tools return real results with no wallet:
convert,text,hash,encode,id,regex. - Paid tools ($0.001/call, x402 · USDC on Base):
timezone,cron,rrule,currency,diff,jsonschema,datemath. With no payment a paid tool returns the decoded x402 402 challenge (price / network / asset / payTo) so an agent can pay and retry withx_payment. Humans can instead prepay by card and use anX-FabTally-Keycredit key against the HTTP API.
This server holds no private key. It fronts https://belt.fabtally.com. Every utility is a pure,
deterministic function with strict input validation; bad input → 400, never charged; nothing is stored.
Tools
| Tool | Tier | What it does |
|---|---|---|
convert | free | Unit conversion (length/mass/temperature/volume/data/time/area/speed/angle/pressure/energy). |
text | free | slugify · case-convert (camel/pascal/snake/kebab/constant/…) · {{template}} fill. |
hash | free | sha256/sha512/sha384/sha1/md5/sha3-256/keccak256/ripemd160, optional HMAC, hex/base64 out. |
encode | free | base64 / base64url / hex / url / html encode & decode. |
id | free | uuid v4/v7, ULID, nanoid, random hex/base64url/int (count up to 1000). |
regex | free | test/match/extract/replace with catastrophic-backtracking protection (killable worker + timeout). |
timezone | $0.001 | Instant → IANA zone with historically-correct DST; offsets, abbreviations, DST flags. |
cron | $0.001 | Cron expression → next N run times + plain-English description. |
rrule | $0.001 | iCal RRULE (RFC 5545) → next N occurrences. |
currency | $0.001 | Live currency conversion at reference/mid-market rates (keyless ECB feed, cached). |
diff | $0.001 | Text diff: unified patch + structured op-list + add/remove/hunk stats. |
jsonschema | $0.001 | Validate against JSON Schema (draft 2020-12) and explain every error in plain English. |
datemath | $0.001 | Add/subtract ISO-8601 durations, diff into chosen units, business-day add/diff. |
Install / run
stdio (Claude Desktop, Cursor, any MCP client)
// claude_desktop_config.json
{
"mcpServers": {
"fabtally-belt": { "command": "npx", "args": ["-y", "fabtally-belt-mcp"] }
}
}
Or clone and run: node index.js (speaks MCP over stdio).
streamable-HTTP (remote)
Hosted: https://belt.fabtally.com/mcp. Or self-host: MCP_HTTP_PORT=8108 node http.js.
Config
FABTALLY_BELT_BASE— API base (defaulthttps://belt.fabtally.com).
Paying for paid tools
A paid tool with no x_payment returns:
{ "payment_required": true, "http_status": 402,
"challenge": { "x402Version": 2, "accepts": [ { "scheme": "exact", "network": "eip155:8453",
"amount": "1000", "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913", "payTo": "0x…" } ] } }
Build an x402 payment authorization (EIP-3009 transferWithAuthorization to payTo) for the accepts
entry and call the tool again with the token in x_payment. amount is atomic USDC (1000 = $0.001).
Guarantees
Deterministic. Stateless — no PII or request data stored. Receive-only wallet (no custody). Currency figures are reference/mid-market rates for informational use, not a dealable quote. MIT licensed.
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