FabTally Utility Belt

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

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

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{
  "mcpServers": {
    "FabTally Utility Belt": {
      "url": "https://belt.fabtally.com/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (13)

• convert

  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.

  Parameters:

  • value (required) — number — Numeric value to convert.
  • from (required) — string — Source unit, e.g. c, km, GiB, gal, kg.
  • to (required) — string — Target unit in the same dimension.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• text

  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).

  Parameters:

  • op (required) — string — slugify | template | camel | pascal | snake | kebab | constant | dot | path | title | sentence | upper | lower
  • data — object — Object of values for op='template'.
  • text — string — Input text for slugify/case ops.
  • strict — boolean — template: throw on missing keys.
  • template — string — Template string for op='template', with {{key}} placeholders.
  • separator — string — Slug separator (default '-').

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• hash

  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).

  Parameters:

  • algorithm (required) — string — sha256 | sha512 | sha384 | sha1 | md5 | sha3-256 | keccak256 | ripemd160
  • text (required) — string — Input to hash.
  • hmac_key — string — If set, compute HMAC with this key (not for keccak256/sha3-256).
  • input_encoding — string — How `text` is encoded: utf8 (default) | hex | base64 | base64url.
  • output_encoding — string — Digest encoding: hex (default) | base64 | base64url.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• encode

  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.

  Parameters:

  • op (required) — string — base64-encode|base64-decode|base64url-encode|base64url-decode|hex-encode|hex-decode|url-encode|url-decode|html-encode|html-decode
  • text (required) — string — Text to encode/decode.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• id

  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.

  Parameters:

  • kind — string — uuidv4 (default) | uuidv7 | ulid | nanoid | hex | base64url | int
  • size — integer — nanoid length (default 21).
  • bytes — integer — hex/base64url random byte length (default 16).
  • count — integer — How many to generate (1-1000, default 1).

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• regex

  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).

  Parameters:

  • pattern (required) — string — The regular expression source (max 2000 chars).
  • input (required) — string — The text to run it against (max 200k chars).
  • op — string — test | match | extract (capture groups) | replace. Default match.
  • flags — string — Any of g,i,m,s,u,y.
  • limit — integer — Max matches for global ops (default 1000).
  • replacement — string — Replacement string for op='replace' (supports $1 etc.).

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• timezone

  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.

  Parameters:

  • datetime (required) — ['string', 'number'] — Instant to convert: ISO 8601 (e.g. 2021-03-14T01:30:00) or epoch seconds/millis.
  • to_zone (required) — string — Target IANA zone, e.g. Europe/London, Asia/Tokyo.
  • from_zone — string — Source IANA zone (default UTC), e.g. America/New_York.
  • x_payment — string — x402 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 price challenge first.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• cron

  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.

  Parameters:

  • expression (required) — string — Cron expression, e.g. '0 9 * * 1-5'.
  • from — string — Compute runs after this ISO datetime (default now).
  • count — integer — How many upcoming runs (1-100, default 5).
  • timezone — string — IANA timezone (default UTC).
  • x_payment — string — x402 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 price challenge first.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• rrule

  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.

  Parameters:

  • rrule (required) — string — RRULE string, optionally with a DTSTART line.
  • after — string — Return occurrences after this ISO datetime (default now).
  • count — integer — How many occurrences (1-366, default 5).
  • timezone — string — Render occurrences in this IANA zone.
  • x_payment — string — x402 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 price challenge first.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• currency

  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.

  Parameters:

  • amount (required) — number — Amount in the source currency.
  • from (required) — string — Source ISO-4217 code, e.g. USD.
  • to (required) — string — Target ISO-4217 code, e.g. EUR.
  • x_payment — string — x402 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 price challenge first.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• diff

  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.

  Parameters:

  • a (required) — string — Original text.
  • b (required) — string — Changed text.
  • mode — string — lines (default) | words | chars.
  • context — integer — Unified-diff context lines (default 3).
  • label_a — string
  • label_b — string
  • x_payment — string — x402 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 price challenge first.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• jsonschema

  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.

  Parameters:

  • schema (required) — object — A JSON Schema (draft 2020-12) object.
  • data — The value to validate against the schema.
  • x_payment — string — x402 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 price challenge first.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• datemath

  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.

  Parameters:

  • op (required) — string — add | subtract | diff | business-add | business-diff
  • to — string — End datetime for diff/business-diff.
  • date — string — Base date for add/subtract/business-add (ISO 8601).
  • days — integer — Business days to add (business-add; may be negative).
  • from — string — Start datetime for diff/business-diff.
  • units — diff units, e.g. ['days','hours'].
  • weekend — array — Weekend weekdays (1=Mon..7=Sun; default [6,7]).
  • duration — ISO-8601 duration string or object for add/subtract.
  • holidays — array — ISO dates to skip as holidays.
  • timezone — string — IANA zone for parsing/rendering.
  • x_payment — string — x402 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 price challenge first.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

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