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FabTally Utility Belt

REMOTE · BELT.FABTALLY.COM · SCANNED SEP 20

13 deterministic agent utilities: timezone, cron, RRULE, currency, regex, diff, hashing & more.

0 this week 77 Trust /100
Trust breakdown (7 categories)

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →

Endpoint Security57
Transport & Reachability100
Schema Quality & AI Usability67
  • AI-judged instruction clarity (excellent).Pass
  • Context-footprint check failed: tool/resource definitions use about 2618 tokens (~201/item across 13 items; 13 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 Management100
  • No destabilizing schema changes in the last 30 days.Pass
Tool Coverage99
  • 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
  • 97% of tool parameters carry a description.Partial
Tool Safety100
  • No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
  • We read all 13 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 supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Install

How do I install the FabTally Utility Belt MCP server?

FabTally Utility Belt is a hosted endpoint at https://belt.fabtally.com/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

remote · belt.fabtally.com

# add to Claude Code
claude mcp add --transport http zvmzaretsky-utility-belt 'https://belt.fabtally.com/mcp'
// .cursor/mcp.json
{
  "mcpServers": {
    "zvmzaretsky-utility-belt": {
      "url": "https://belt.fabtally.com/mcp"
    }
  }
}
// .vscode/mcp.json
{
  "servers": {
    "zvmzaretsky-utility-belt": {
      "type": "http",
      "url": "https://belt.fabtally.com/mcp"
    }
  }
}
# ~/.codex/config.toml
[mcp_servers.zvmzaretsky-utility-belt]
url = "https://belt.fabtally.com/mcp"
// opencode.json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "zvmzaretsky-utility-belt": {
      "type": "remote",
      "url": "https://belt.fabtally.com/mcp",
      "enabled": true
    }
  }
}
# add to OpenClaw
openclaw mcp add zvmzaretsky-utility-belt --url 'https://belt.fabtally.com/mcp' --transport streamable-http
# ~/.hermes/config.yaml
mcp_servers:
  zvmzaretsky-utility-belt:
    url: "https://belt.fabtally.com/mcp"
// ~/.netclaw/config/netclaw.json
{
  "McpServers": {
    "zvmzaretsky-utility-belt": {
      "Transport": "http",
      "Url": "https://belt.fabtally.com/mcp"
    }
  }
}
# add to Vellum
assistant mcp add zvmzaretsky-utility-belt -t streamable-http -u 'https://belt.fabtally.com/mcp'
// mcp.json
{
  "mcpServers": {
    "zvmzaretsky-utility-belt": {
      "type": "http",
      "url": "https://belt.fabtally.com/mcp"
    }
  }
}

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

Changelog

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.

  • 31 Aug 26 +1
    • Stability: 0.97 → pass security
  • 29 Aug 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.

  • 27 Aug 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 83 to 87. That category is still filling its 30-day observation window: 25 days of observed history at the previous scan, 26 at this one. The score rises as the window fills, whether or not the server changes.

  • 26 Aug 26 +1
    • We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
  • 24 Aug 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 73 to 77. That category is still filling its 30-day observation window: 22 days of observed history at the previous scan, 23 at this one. The score rises as the window fills, whether or not the server changes.

  • 11 Aug 26 0
    • We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
  • 2 Aug 26 0
    • Stability: unverified → 0.03 functional
  • 1 Aug 26 0

    First indexed and scored.

Diagnostics

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 20 Sept 2026 · Probed https://belt.fabtally.com/mcp

TLS valid

Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .

Subject Issuer Valid from Valid until Key Signature Serial
CN=belt.fabtally.com CN=YR1,O=Let's Encrypt,C=US 31 Jul 2026 29 Oct 2026 RSA 2048 SHA256-RSA 5505e9586deeff102cf9794aef99ce6bfe5
SANs: belt.fabtally.com
CN=YR1,O=Let's Encrypt,C=US (CA) CN=Root YR,O=ISRG,C=US 3 Sept 2025 2 Sept 2028 RSA 2048 SHA256-RSA a20253f15f2691c05dc1ce13b9bcca4e
CN=Root YR,O=ISRG,C=US (CA) CN=ISRG Root X1,O=Internet Security Research Group,C=US 13 May 2026 2 Sept 2032 RSA 4096 SHA256-RSA f24b6d17f9d9ad7cb1c9fea78782699f

Background: What to check on a remote MCP endpoint →

DNSSEC insecure

Validation of belt.fabtally.com. Not signed

Zone DS Keys Algorithms Outcome
. trust_anchor 20326, 38696 8, 8 Verified
com. present 19718 13 Verified
fabtally.com. absent Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation
Authentication No authorisation required

The endpoint answered without asking for a token. Anyone who knows the URL can reach it.

Result No authorisation required
HTTP status 200

Background: How OAuth 2.1 works in the 2026 MCP spec →

Transports 2 probes
Transport URL Outcome Status Location
streamable-http https://belt.fabtally.com/mcp Verified 200
http (plaintext) http://belt.fabtally.com/mcp HTTPS enforced 301 https://belt.fabtally.com/mcp
MCP tools · 13 exposed · ~2,618 tokens

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 →

Tool Tokens
convert ~145

FREE. Convert a value between units in the same dimension: length, mass, temperature, volume, data, time, area, speed, angle, pressure, energy. Deterministic. Args: value (number), from (unit), to (unit). e.g. {value:100, from:'c', to:'f'} or {value:1, from:'GiB', to:'MB'}. Different-dimension conversions 400.

NameTypeReqDescription
fromstringyesSource unit, e.g. c, km, GiB, gal, kg.
tostringyesTarget unit in the same dimension.
valuenumberyesNumeric value to convert.

No output schema declared.

No examples provided.

cron ~209

PAID $0.001. Parse a 5- or 6-field cron expression and return the next N run times plus a plain-English description. Args: expression, timezone (IANA, default UTC), count (default 5), from (ISO, optional). Without payment returns the x402 challenge; pass x_payment to settle.

NameTypeReqDescription
countintegerHow many upcoming runs (1-100, default 5).
expressionstringyesCron expression, e.g. '0 9 * * 1-5'.
fromstringCompute runs after this ISO datetime (default now).
timezonestringIANA timezone (default UTC).
x_paymentstringx402 payment payload (base64) for this PAID tool. If supplied it is forwarded as the X-PAYMENT header to settle the $0.001 call and return the real result instead of a 402 challenge. Omit to get the…

No output schema declared.

No examples provided.

currency ~194

PAID $0.001. Convert an amount between currencies at reference/mid-market rates from a keyless public central-bank feed (ECB), cached. Informational, not a dealable quote. Args: amount, from, to (ISO-4217, e.g. USD, EUR, JPY). Without payment returns the x402 challenge; pass x_payment to settle.

NameTypeReqDescription
amountnumberyesAmount in the source currency.
fromstringyesSource ISO-4217 code, e.g. USD.
tostringyesTarget ISO-4217 code, e.g. EUR.
x_paymentstringx402 payment payload (base64) for this PAID tool. If supplied it is forwarded as the X-PAYMENT header to settle the $0.001 call and return the real result instead of a 402 challenge. Omit to get the…

No output schema declared.

No examples provided.

datemath ~333

PAID $0.001. Calendar date math. op='add'/'subtract' an ISO-8601 duration (P1Y2M10DT2H30M) to a date; op='diff' two datetimes into chosen units; op='business-add' add business days (configurable weekend + holidays); op='business-diff' count business days between two dates. Without payment returns the x402 challenge; pass x_payment to settle.

NameTypeReqDescription
datestringBase date for add/subtract/business-add (ISO 8601).
daysintegerBusiness days to add (business-add; may be negative).
durationISO-8601 duration string or object for add/subtract.
fromstringStart datetime for diff/business-diff.
holidaysarrayISO dates to skip as holidays.
opstringyesadd | subtract | diff | business-add | business-diff
timezonestringIANA zone for parsing/rendering.
tostringEnd datetime for diff/business-diff.
unitsdiff units, e.g. ['days','hours'].
weekendarrayWeekend weekdays (1=Mon..7=Sun; default [6,7]).
x_paymentstringx402 payment payload (base64) for this PAID tool. If supplied it is forwarded as the X-PAYMENT header to settle the $0.001 call and return the real result instead of a 402 challenge. Omit to get the…

No output schema declared.

No examples provided.

diff ~209

PAID $0.001. Diff two texts: a unified patch, a structured op-list (add/remove/equal), and add/remove/hunk stats. Args: a, b, mode (lines|words|chars, default lines), context (default 3), label_a, label_b. Without payment returns the x402 challenge; pass x_payment to settle.

NameTypeReqDescription
astringyesOriginal text.
bstringyesChanged text.
contextintegerUnified-diff context lines (default 3).
label_astring
label_bstring
modestringlines (default) | words | chars.
x_paymentstringx402 payment payload (base64) for this PAID tool. If supplied it is forwarded as the X-PAYMENT header to settle the $0.001 call and return the real result instead of a 402 challenge. Omit to get the…

No output schema declared.

No examples provided.

encode ~134

FREE. Encode or decode text. op is one of base64-encode|base64-decode|base64url-encode|base64url-decode|hex-encode|hex-decode|url-encode|url-decode|html-encode|html-decode. Args: op, text.

NameTypeReqDescription
opstringyesbase64-encode|base64-decode|base64url-encode|base64url-decode|hex-encode|hex-decode|url-encode|url-decode|html-encode|html-decode
textstringyesText to encode/decode.

No output schema declared.

No examples provided.

hash ~227

FREE. Compute a cryptographic digest: sha256, sha512, sha384, sha1, md5, sha3-256, keccak256, ripemd160. Optional HMAC via hmac_key. Output hex (default), base64, or base64url. keccak256 also returns a 0x-form (handy for Ethereum). Args: algorithm, text (+ input_encoding utf8|hex|base64, output_encoding, hmac_key).

NameTypeReqDescription
algorithmstringyessha256 | sha512 | sha384 | sha1 | md5 | sha3-256 | keccak256 | ripemd160
hmac_keystringIf set, compute HMAC with this key (not for keccak256/sha3-256).
input_encodingstringHow `text` is encoded: utf8 (default) | hex | base64 | base64url.
output_encodingstringDigest encoding: hex (default) | base64 | base64url.
textstringyesInput to hash.

No output schema declared.

No examples provided.

id ~154

FREE. Generate identifiers. kind is one of uuidv4|uuidv7|ulid|nanoid|hex|base64url|int. count up to 1000. nanoid takes `size`; hex/base64url take `bytes`. Uses a CSPRNG. Args: kind, count.

NameTypeReqDescription
bytesintegerhex/base64url random byte length (default 16).
countintegerHow many to generate (1-1000, default 1).
kindstringuuidv4 (default) | uuidv7 | ulid | nanoid | hex | base64url | int
sizeintegernanoid length (default 21).

No output schema declared.

No examples provided.

jsonschema ~165

PAID $0.001. Validate a value against a JSON Schema (draft 2020-12) and explain every error in plain English (which property, what was wrong, allowed values). Args: schema (object), data (any). Without payment returns the x402 challenge; pass x_payment to settle.

NameTypeReqDescription
dataThe value to validate against the schema.
schemaobjectyesA JSON Schema (draft 2020-12) object.
x_paymentstringx402 payment payload (base64) for this PAID tool. If supplied it is forwarded as the X-PAYMENT header to settle the $0.001 call and return the real result instead of a 402 challenge. Omit to get the…

No output schema declared.

No examples provided.

regex ~182

FREE. Run a regular expression against input with catastrophic-backtracking protection (it runs in a killable worker with a hard timeout, so a pathological pattern returns a 400 instead of hanging). op is test|match|extract|replace. Args: pattern, input, flags (gimsuy), op, replacement (for replace).

NameTypeReqDescription
flagsstringAny of g,i,m,s,u,y.
inputstringyesThe text to run it against (max 200k chars).
limitintegerMax matches for global ops (default 1000).
opstringtest | match | extract (capture groups) | replace. Default match.
patternstringyesThe regular expression source (max 2000 chars).
replacementstringReplacement string for op='replace' (supports $1 etc.).

No output schema declared.

No examples provided.

rrule ~222

PAID $0.001. Expand an iCal RRULE (RFC 5545) recurrence into its next N occurrences. Args: rrule (e.g. 'FREQ=WEEKLY;BYDAY=MO,WE;COUNT=10'), after (ISO, default now), count (default 5), timezone. Tip: include DTSTART for anchored series. Without payment returns the x402 challenge; pass x_payment.

NameTypeReqDescription
afterstringReturn occurrences after this ISO datetime (default now).
countintegerHow many occurrences (1-366, default 5).
rrulestringyesRRULE string, optionally with a DTSTART line.
timezonestringRender occurrences in this IANA zone.
x_paymentstringx402 payment payload (base64) for this PAID tool. If supplied it is forwarded as the X-PAYMENT header to settle the $0.001 call and return the real result instead of a 402 challenge. Omit to get the…

No output schema declared.

No examples provided.

text ~194

FREE. Text transforms. op='slugify' -> URL slug; op is one of camel|pascal|snake|kebab|constant|dot|path|title|sentence|upper|lower for case conversion; op='template' fills {{placeholders}} from `data`. Args: op, text (for slugify/case), or template + data (for template).

NameTypeReqDescription
dataobjectObject of values for op='template'.
opstringyesslugify | template | camel | pascal | snake | kebab | constant | dot | path | title | sentence | upper | lower
separatorstringSlug separator (default '-').
strictbooleantemplate: throw on missing keys.
templatestringTemplate string for op='template', with {{key}} placeholders.
textstringInput text for slugify/case ops.

No output schema declared.

No examples provided.

timezone ~250

PAID $0.001 (x402, USDC on Base). Convert an instant between IANA time zones with historically-correct DST. Returns converted datetime, UTC offsets, tz abbreviations, DST flags, and the offset difference. Args: datetime (ISO 8601 or epoch), from_zone, to_zone. Without payment returns the x402 challenge; pass x_payment to settle. Free teaser exists on the HTTP API at /v1/timezone/free.

NameTypeReqDescription
datetimestring|numberyesInstant to convert: ISO 8601 (e.g. 2021-03-14T01:30:00) or epoch seconds/millis.
from_zonestringSource IANA zone (default UTC), e.g. America/New_York.
to_zonestringyesTarget IANA zone, e.g. Europe/London, Asia/Tokyo.
x_paymentstringx402 payment payload (base64) for this PAID tool. If supplied it is forwarded as the X-PAYMENT header to settle the $0.001 call and return the real result instead of a 402 challenge. Omit to get the…

No output schema declared.

No examples provided.

Common questions

What is the FabTally Utility Belt MCP server?

FabTally Utility Belt is an MCP server listed in the public MCP registry as io.github.zvmzaretsky/utility-belt. 13 deterministic agent utilities: timezone, cron, RRULE, currency, regex, diff, hashing & more. This page covers its hosted endpoint (https://belt.fabtally.com/mcp).

Is the FabTally Utility Belt MCP server safe to use?

FabTally Utility Belt scores 77 out of 100 on VerifyMCP. 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 FabTally Utility Belt MCP server expose?

FabTally Utility Belt exposes 13 tools: convert, text, hash, encode, id, and 8 more. Their descriptions and schemas cost roughly 2,618 tokens of context every time the server is loaded.

Does the FabTally Utility Belt MCP server require authentication?

No. We connected to FabTally Utility Belt without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

Is the FabTally Utility Belt MCP server still maintained?

FabTally Utility Belt is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.