CheckDigit
REMOTE · CHECKDIGIT.MIKE-TUSA.WORKERS.DEV
Offline check-digit validation for IBAN, BIC, EU VAT, GTIN/EAN/UPC and ISBN. Format check only.
Available components
Last scanned (6 minutes ago)
Scores higher than 62% of remote servers
Reachable. Last reached 24 Oct 2026.
Category Finance and Payments
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 Security69
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one. See how to fix → View diagnostics → Partial
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- The HSTS (Strict-Transport-Security) header is present. View diagnostics → Pass
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability68
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 501 tokens (~250/item across 2 items; 2 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 Management30
- Stability observed for 9 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 2 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 3 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a current MCP spec version (2026-07-28).Pass
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.
- 23 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.
- 21 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.
- 19 Oct 26 +1
- Server version: 0.2.2 → 0.2.3 functional
- 17 Oct 26 +1
- Server version: 0.2.1 → 0.2.2 functional
- 16 Oct 26 0
- Stability: unverified → 0.03 ▲ functional
- 15 Oct 26 68
First indexed and scored.
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 24 Oct 2026 · Probed https://checkdigit.mike-tusa.workers.dev/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=mike-tusa.workers.dev | CN=WE1,O=Google Trust Services,C=US | 12 Oct 2026 | 10 Jan 2027 | ECDSA 256 | ECDSA-SHA256 | f05aa95d8943eeed0e4e86dd1f6f1e02 |
| SANs: mike-tusa.workers.dev, *.mike-tusa.workers.dev | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of checkdigit.mike-tusa.workers.dev. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| dev. | present | 60074 | 8 | Verified |
| workers.dev. | 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 |
| Header | Value |
|---|---|
| strict-transport-security | max-age=31536000 |
| x-content-type-options | nosniff |
| x-frame-options | DENY |
| referrer-policy | no-referrer |
| permissions-policy | camera=(), microphone=(), geolocation=() |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://checkdigit.mike-tusa.workers.dev/mcp | Verified | 200 | |
| http (plaintext) | http://checkdigit.mike-tusa.workers.dev/mcp | Inconclusive | 405 |
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 →
get_meta Service version, supported formats and limits ~52
Return the service version and build, supported IBAN and VAT countries, GTIN formats, the disclaimer and the current limits. Does not count as a check. Read-only. Same data as GET /v1/meta.
Input schema present but exposes no named parameters.
| Name | Type | Req | Description |
|---|---|---|---|
| bic | object | – | – |
| build | string | – | – |
| disclaimer | string | – | – |
| endpoints | array | – | – |
| gtin | object | – | – |
| iban | object | – | – |
| limits | object | – | – |
| privacy | string | – | – |
| service | string | yes | – |
| vat | object | – | – |
| version | string | yes | – |
No examples provided.
validate_code Validate an IBAN, BIC, EU VAT number, GTIN/EAN/UPC or ISBN ~272
Check the format and check digits of one identifier: IBAN (ISO 13616, per-country length and layout), BIC/SWIFT (ISO 9362 format and country), EU VAT number (offline checksum, VIES not queried), GTIN/EAN-8/UPC-A/EAN-13/GTIN-14 (GS1 mod 10) or ISBN-10/13. type "auto" (default) detects the type from the shape. Returns valid, a reason when invalid (e.g. the expected check digit), and normalized/formatted forms. Format check, not a compliance check: valid does not mean the account, registration or product exists. The code is sent in a POST body and not stored or logged. Read-only. Same engine, keys and limits as POST /v1/{type}.
| Name | Type | Req | Description |
|---|---|---|---|
| code | string | yes | The identifier to check, e.g. "DE89 3704 0044 0532 0130 00", "ATU13585627", "4006381333931" or "978-0-306-40615-7". Spaces, hyphens and dots are ignored. Max 64 characters. |
| type | string | – | auto (default), iban, bic, vat, gtin or isbn. |
| Name | Type | Req | Description |
|---|---|---|---|
| bank_code | string | – | – |
| bban | string | – | – |
| candidates | array | – | – |
| check_digit | string | – | – |
| check_digits | string | – | – |
| checksum | string | – | – |
| country | string | – | – |
| country_name | string | – | – |
| detected_as | string | – | – |
| ean13 | string | – | – |
| expected_check_digit | string | – | – |
| format | string | – | – |
| formatted | string | – | – |
| input | string | yes | – |
| isbn10 | string | – | – |
| isbn13 | string | – | – |
| normalized | string | – | – |
| number | string | – | – |
| reason | string | – | – |
| sepa | boolean | – | – |
| type | string | – | – |
| valid | boolean | yes | – |
| vies_checked | boolean | – | – |
No examples provided.
How do I install the CheckDigit MCP server?
CheckDigit is a hosted endpoint at https://checkdigit.mike-tusa.workers.dev/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 · checkdigit.mike-tusa.workers.dev
claude mcp add --transport http dev-workers-mike-tusa-checkdigit-checkdigit 'https://checkdigit.mike-tusa.workers.dev/mcp'
What is the CheckDigit MCP server?
CheckDigit is an MCP server listed in the public MCP registry as dev.workers.mike-tusa.checkdigit/checkdigit. Offline check-digit validation for IBAN, BIC, EU VAT, GTIN/EAN/UPC and ISBN. Format check only. This page covers its hosted endpoint (https://checkdigit.mike-tusa.workers.dev/mcp).
Is the CheckDigit MCP server safe to use?
CheckDigit scores 72 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 CheckDigit MCP server expose?
CheckDigit exposes 2 tools: validate_code, get_meta. Their descriptions and schemas cost roughly 324 tokens of context every time the server is loaded.
Does the CheckDigit MCP server require authentication?
No. We connected to CheckDigit without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the CheckDigit MCP server still maintained?
CheckDigit is still listed as active in the MCP registry. We last reached this channel on 24 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.