Duo Data Utilities: IBAN, ISIN, VAT and Tax ID, Barcode, Timezone, Geo APIs

At a glance

Runs where

On their server. What you send to it goes to them.

What you need

Nothing: it answered without a login

Tools

33 tools

Its own safety labels

33 read-only

Memory it takes

About 11,700 tokens of your AI's memory, just for its tool descriptions

Speed

Average answer in our test: 35 ms

Tokens are an estimate: the characters in its tool names, descriptions and inputs, divided by 4. The exact number depends on your AI model. Safety labels are what the server says about itself. From our latest test, 7 Nov 2026.

Is Duo Data Utilities: IBAN, ISIN, VAT and Tax ID, Barcode, Timezone, Geo APIs MCP server safe?

• None of the hidden-instruction wordings we know were found in its 33 tool descriptions.
• Its error messages showed no secrets or internal details.
• All 33 of its tools are labeled read-only.
• Overall it scored 95/100 on 7 Nov 2026.

A test can only see what the server shows from outside, not what it does with your data behind the scenes. Connect servers from makers you trust.

What this test does not check

• Its source code and packages.
• What a tool quietly does behind the scenes, such as writing a file or calling another service.
• Instructions hidden inside live tool answers. We only look for those in tool descriptions.
• Hidden instructions worded in a way our list doesn't know yet.
• Tools that could change something. Those are read, never run.

What QAmcp can and can't see · How to tell if an MCP server is safe · Hidden instructions · Prompt injection

Known security advisories

Not looked up yet. QAmcp tests how a server behaves. It does not scan source code.

What it can do

33 tools, in the server's own words.

and 9 more

Test results

Safe mode: only tools labeled read-only were run. How the test works

• !
  Ready for the newest MCP version

  1 warning

  • !Uses an older MCP version (2025-11-25). It works today, but it isn't on the July 2026 version (2026-07-28) yet.
  note
• !
  Follows MCP best practices (not scored yet)

  1 tip (not scored)

  • !The tool list is about 51 KB (roughly 13k tokens). AI apps send it with every message, so it takes that much of the AI's memory before any work starts.
  note
• ✓
  ConnectsConnected in 570 ms
  pass
• ✓
  Lists its toolsFound 33 tools
  pass
• ✓
  Every tool is describedAll 33 tools and their inputs are described
  pass
• ✓
  Tools are labeled safe or dangerousEvery tool has a safety label
  pass
• ✓
  No known hidden instructionsNone of the hidden-instruction wordings we know were found in tool descriptions. New wordings can get past this check.
  pass
• ✓
  Tools work with good inputs

  All good

  • ✓vat_tax_id_validate: Answered with an error, probably because of our sample input: {"ok":false,"route":"/v1/id/national","version":"1.0.0","error":{"code":"UNSUPPORTED_VALUE","param":"country","message":"Query parameter 'c…
  • ✓gtin_barcode_validate: Answered with an error, probably because of our sample input: {"ok":false,"route":"/v1/id/gs1","version":"1.0.0","error":{"code":"INVALID_PARAM","param":"value","message":"Query parameter 'value' is no…
  • ✓isin_cusip_sedol_validate: Answered with an error, probably because of our sample input: {"ok":false,"route":"/v1/id/security","version":"1.0.0","error":{"code":"MISSING_PARAM","param":"value","message":"Required query parameter…
  • ✓iban_validate: Answered with an error, probably because of our sample input: {"x402Version":2,"error":"Payment required to access this tool","resource":{"url":"mcp://tool/iban_validate","description":"IBAN validator:…
  • ✓iban_generate: Answered with an error, probably because of our sample input: {"ok":false,"route":"/v1/id/iban-build","version":"1.0.0","error":{"code":"UNSUPPORTED_VALUE","param":"country","message":"Query parameter …
  • ✓timezone_convert: Answered with an error, probably because of our sample input: {"ok":false,"route":"/v1/time/zone","version":"1.0.0","error":{"code":"UNSUPPORTED_VALUE","param":"zone","message":"'test' is not a time zo…
  • ✓dst_transitions: Answered with an error, probably because of our sample input: {"ok":false,"route":"/v1/time/dst","version":"1.0.0","error":{"code":"UNSUPPORTED_VALUE","param":"zone","message":"'test' is not a time zon…
  • ✓business_days_calculate: Answered with an error, probably because of our sample input: {"ok":false,"route":"/v1/time/business-days","version":"1.0.0","error":{"code":"INVALID_PARAM","param":"from","message":"Query parameter 'f…
  • and 25 more
  pass
• ✓
  Bad inputs give a clean error

  All good

  • ✓vat_tax_id_validate: Refused missing required input "country" with a clear error
  • ✓vat_tax_id_validate: Refused wrong type for "country" with a clear error
  • ✓gtin_barcode_validate: Refused missing required input "value" with a clear error
  • ✓gtin_barcode_validate: Refused wrong type for "value" with a clear error
  • ✓isin_cusip_sedol_validate: Refused wrong type for "op" with a clear error
  • ✓iban_validate: Refused missing required input "iban" with a clear error
  • ✓iban_validate: Refused wrong type for "iban" with a clear error
  • ✓iban_generate: Refused missing required input "country" with a clear error
  • and 32 more
  pass
• ✓
  Fast enough

  All good

  • ✓Connecting took 570 ms
  • ✓Listing tools took 72 ms
  • ✓Average tool answer: 35 ms
  • ✓iban_validate: Slowest tool: iban_validate (163 ms)
  pass
• ✓
  No secrets leakedChecked 85 error messages: no secrets or internal details
  pass
• –
  Tools work togetherNo safe tool returned data to start a chain from, so chains were not tested (not counted either way)
  not tested

Test it yourself

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Score over time

• 7 Nov 202695

One test so far. New tests will show here.

Reviews

Coming soon: reviews from people who use Duo Data Utilities: IBAN, ISIN, VAT and Tax ID, Barcode, Timezone, Geo APIs, signed in with GitHub, one per person. Reviews never change the score.