Check Digit Validator
com.gumballtools/check-digit
MCP Bill of Materials
A machine-readable inventory of what this server exposes and depends on: tools with their effects, transports, packages, findings and provenance (schema version 1.0). Third-party text in it is escaped. Also available from the REST API at /api/v1/servers/0b8afd6b-e961-4e3a-89a5-dedba5ad6bff/mcbom.
MCP Bill of Materials
root{21}
schema_version: "1.0"
bom_format: "squatch-mcbom"
generator{3}
name: "squatch-mcp"
classifier_version: "rules_v1@2026-10-11.1"
unicode_version: "18.0.0"
server{7}
name: "com.gumballtools/check-digit"
title: "Check Digit Validator"
description: "Validates IBAN/ISBN/EAN/Luhn checksums and finds the one wrong digit"
version: "0.1.0"
homepage_url: "https://check-digit.gumballtools.com"
source: "official_registry"
upstream_status: "active"
publisher{4}
namespace: "com.gumballtools"
display_name: "com.gumballtools"
type: "registry_namespace"
status: "unclaimed"
organization: null
repository{5}
url: "https://github.com/bwalvoord/gumball"
provider: "github"
owner: "bwalvoord"
name: "gumball"
verified: false
packages[0]
transports[1]
0{5}
kind: "remote"
type: "streamable-http"
endpoint_url: "https://check-digit.gumballtools.com/api/mcp"
endpoint_host: "check-digit.gumballtools.com"
auth_type: "none"
auth{3}
type: "none"
authorization_servers[0]
scopes[0]
protocol{4}
era: "modern"
negotiated_version: "2026-07-28"
supported_versions[0]
transport_type: "streamable-http"
tools[1]
0{9}
name: "run"
title: "Check Digit Validator"
effect: "EXECUTE"
effect_confidence: 0.9
capabilities[0]
risk_severity: "HIGH"
fingerprint: "c079f300e3b78af6dfa9188e6c243c48b278b339cb15a8a20236be63ba74f1e1"
input_schema_fingerprint: "87bdb39a1bd81a52a90a8c69a96b9411e826d6c51d5b2edee8e42aec395980e3"
annotations{5}
title: null
readOnlyHint: true
destructiveHint: null
idempotentHint: null
openWorldHint: false
resources[0]
prompts[0]
extensions[0]
data{6}
privacy_completeness: "not_provided"
data_categories[0]
ai_training: null
retention_policy: null
processing_regions[0]
subprocessors[0]
external_integrations[1]
0{3}
host: "check-digit.gumballtools.com"
registrable_domain: "gumballtools.com"
source: "transport"
findings[4]
0{6}
check_id: "SQ-SERVER-AUTH-NONE-WRITE"
category: "authentication"
severity: "MEDIUM"
title: "State-changing tools available without authentication"
subject_type: "server"
subject_name: null
1{6}
check_id: "SQ-TOOL-ANNOTATION-UNDERCLAIM"
category: "annotations"
severity: "HIGH"
title: "Annotations understate what the tool does"
subject_type: "tool"
subject_name: "run"
2{6}
check_id: "SQ-TOOL-CONCEALMENT"
category: "prompt_injection"
severity: "HIGH"
title: "Text asks the AI model to hide actions from the user"
subject_type: "tool"
subject_name: "run"
3{6}
check_id: "SQ-TOOL-TITLE-EFFECT-MISMATCH"
category: "deceptive_metadata"
severity: "HIGH"
title: "Display title describes a lower-impact action than the name"
subject_type: "tool"
subject_name: "run"
trust{9}
registry_namespace: "verified_upstream"
publisher_identity: "unverified"
organization: "unverified"
domain: "unverified"
repository: "unverified"
source_provenance: "unknown"
security_scan: "findings_detected"
privacy_transparency: "not_provided"
monitoring: "active"
provenance{4}
registry_name: "com.gumballtools/check-digit"
registry_content_sha256: "28e031f28ad0e5414749aab1c58c9a3e43d6e0d3a8470c999713d8a22263d4c6"
scan_snapshot_fingerprint: "38417aacf1766208d23d973aa0145273467f56b3d6a4cbb7f1935eae9fe9deaa"
scanner_version: "1.0.0"
timestamps{4}
generated_at: "2026-11-15T05:47:27.207Z"
observed_at: "2026-11-14T06:21:44.864+00:00"
registry_published_at: "2026-09-05T20:40:45.802265+00:00"
registry_updated_at: null