# Stanza Developer Tools & Edge Micro-APIs
> High-performance pure-compute developer microservices and regulatory compliance engines running on Cloudflare Workers edge isolates. Zero cold starts, sub-5ms latency, and 100% deterministic pure mathematical outputs.

## Core Micro-API Standards & Specifications

### 1. Healthcare EDI ANSI X12 Parser API
- Category: Healthcare & B2B EDI
- Endpoint: https://stanzaapi.com/tools/x12-parser/
- Edge Host: api.stanzaapi.com/x12-parser
- Supported Standards & Formats: [EDI X12 837P Professional Health Care Claim Parser & Validator](https://stanzaapi.com/tools/x12-parser/transaction/837p-professional-claim), [EDI X12 837I Institutional Claim Parser & Free Validator](https://stanzaapi.com/tools/x12-parser/transaction/837i-institutional-claim), [EDI 835 Remittance Advice (ERA) Parser, Viewer & Format Guide](https://stanzaapi.com/tools/x12-parser/transaction/835-remittance-advice), [EDI X12 270 Eligibility Inquiry Parser & Validator](https://stanzaapi.com/tools/x12-parser/transaction/270-eligibility-inquiry), [EDI X12 271 Eligibility & Benefit Response Parser](https://stanzaapi.com/tools/x12-parser/transaction/271-eligibility-response), [EDI X12 834 Benefit Enrollment and Maintenance Parser](https://stanzaapi.com/tools/x12-parser/transaction/834-benefit-enrollment), [EDI X12 850 Purchase Order Parser & JSON Converter](https://stanzaapi.com/tools/x12-parser/transaction/850-purchase-order), [EDI X12 810 Electronic Commercial Invoice Parser](https://stanzaapi.com/tools/x12-parser/transaction/810-invoice)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/x12-parser`
  - Python (PyPI): `pip install stanzaapi-x12-parser`
  - C# (NuGet): `dotnet add package StanzaApi.X12Parser`
  - Rust (crates.io): `cargo add stanzaapi-x12-parser`
- Key Capabilities: Native parsing for 837P, 837I, 835, 270, 271, 834, 850, 810, 276, and 277 EDI transaction sets Automatic ISA 106-character delimiter autodetection (element, component, segment separators)

### 2. ISO 20022 Financial Message Parser & Validator API
- Category: Fintech & Banking
- Endpoint: https://stanzaapi.com/tools/iso20022-parser/
- Edge Host: api.stanzaapi.com/iso20022-parser
- Supported Standards & Formats: [ISO 20022 pacs.008 Credit Transfer Parser & Schema Validator](https://stanzaapi.com/tools/iso20022-parser/messages/pacs-008-credit-transfer), [ISO 20022 pacs.002 Payment Status Parser & Schema Validator](https://stanzaapi.com/tools/iso20022-parser/messages/pacs-002-payment-status), [ISO 20022 pain.001 Customer Credit Transfer Initiation Parser](https://stanzaapi.com/tools/iso20022-parser/messages/pain-001-customer-credit-transfer), [ISO 20022 pain.002 Customer Payment Status Report Parser](https://stanzaapi.com/tools/iso20022-parser/messages/pain-002-payment-status-report), [ISO 20022 camt.053 Bank-to-Customer Account Statement Parser](https://stanzaapi.com/tools/iso20022-parser/messages/camt-053-bank-statement), [ISO 20022 camt.054 Bank-to-Customer Debit/Credit Notification Parser](https://stanzaapi.com/tools/iso20022-parser/messages/camt-054-debit-credit-notification), [Free Online ISO 20022 XML to JSON Converter & SWIFT MX Inspector](https://stanzaapi.com/tools/iso20022-parser/converter/iso20022-to-json), [Free camt.053 Bank Statement XML to CSV & Excel Converter](https://stanzaapi.com/tools/iso20022-parser/converter/camt-053-to-csv)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/iso20022-parser`
  - Python (PyPI): `pip install stanzaapi-iso20022-parser`
  - C# (NuGet): `dotnet add package StanzaApi.Iso20022Parser`
  - Rust (crates.io): `cargo add stanzaapi-iso20022-parser`
- Key Capabilities: Native parsing for pacs.008, pacs.002, pain.001, pain.002, camt.053, and camt.054 financial XML schemas Automatic Business Application Header (head.001 / BAH) extraction and routing reconciliation

### 3. FDA DSCSA & EU FMD Prescription Drug Serialization API
- Category: Pharmaceutical & Healthcare Compliance
- Endpoint: https://stanzaapi.com/tools/pharma-dscsa/
- Edge Host: api.stanzaapi.com/pharma-dscsa
- Supported Standards & Formats: [GS1 Verification Router Service (VRS) Lightweight Messaging Spec](https://stanzaapi.com/tools/pharma-dscsa/compliance/vrs-verification-router-service), [EPCIS 1.2 XML Event Parser & Schema Validator (FDA DSCSA)](https://stanzaapi.com/tools/pharma-dscsa/compliance/epcis-1-2-xml), [EPCIS 2.0 JSON-LD Supply Chain Event Parser & Validator](https://stanzaapi.com/tools/pharma-dscsa/compliance/epcis-2-0-json-ld), [FDA 21 CFR 201.25 Barcode Requirement & 2D DataMatrix Spec](https://stanzaapi.com/tools/pharma-dscsa/compliance/fda-21-cfr-201-barcode), [DSCSA 4-Element 2D DataMatrix Barcode & Matrix Specification](https://stanzaapi.com/tools/pharma-dscsa/compliance/gtin-serial-lot-exp-matrix), [DSCSA Section 582 Suspect Product Quarantine & Verification Rules](https://stanzaapi.com/tools/pharma-dscsa/compliance/suspect-product-verification)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/pharma-dscsa`
  - Python (PyPI): `pip install stanzaapi-pharma-dscsa`
  - C# (NuGet): `dotnet add package StanzaApi.PharmaDscsa`
  - Rust (crates.io): `cargo add stanzaapi-pharma-dscsa`
- Key Capabilities: Instant validation of FDA DSCSA 4-element 2D DataMatrix barcodes (AI 01, AI 21, AI 17, AI 10) Deterministic NDC-to-GTIN (5-4-2, 5-3-2, 4-4-2) and GTIN-to-NDC bidirectional converters

### 4. Global IBAN, BIC/SWIFT & Bank Routing Validator API
- Category: Fintech & Banking
- Endpoint: https://stanzaapi.com/tools/iban-validator/
- Edge Host: api.stanzaapi.com/iban-validator
- Supported Standards & Formats: [Andorra (AD) IBAN & Bank Routing Validator](https://stanzaapi.com/tools/iban-validator/country/andorra-ad), [UAE IBAN Number (AE) Validator, Format & Bank Codes](https://stanzaapi.com/tools/iban-validator/country/united-arab-emirates-ae), [Albania (AL) IBAN & Bank Routing Validator](https://stanzaapi.com/tools/iban-validator/country/albania-al), [Austria (AT) IBAN & Bank Routing Validator](https://stanzaapi.com/tools/iban-validator/country/austria-at), [Azerbaijan (AZ) IBAN & Bank Routing Validator](https://stanzaapi.com/tools/iban-validator/country/azerbaijan-az), [Bosnia and Herzegovina (BA) IBAN & Bank Routing Validator](https://stanzaapi.com/tools/iban-validator/country/bosnia-and-herzegovina-ba), [Belgium (BE) IBAN & Bank Routing Validator](https://stanzaapi.com/tools/iban-validator/country/belgium-be), [Bulgaria (BG) IBAN & Bank Routing Validator](https://stanzaapi.com/tools/iban-validator/country/bulgaria-bg)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/iban-validator`
  - Python (PyPI): `pip install stanzaapi-iban-validator`
  - C# (NuGet): `dotnet add package StanzaApi.IbanValidator`
  - Rust (crates.io): `cargo add stanzaapi-iban-validator`
- Key Capabilities: Complete ISO 13616 registry covering all 87 official IBAN countries High-speed integer Modulo-97 arithmetic fold without heavy BigInt allocations

### 5. EU & UK VAT Validator & Rate Engine API
- Category: Tax & E-commerce
- Endpoint: https://stanzaapi.com/tools/vat-validator/
- Edge Host: api.stanzaapi.com/vat-validator
- Supported Standards & Formats: [EU VAT Rates 2026: Standard & Reduced Rates for All 28 Countries](https://stanzaapi.com/tools/vat-validator/rates/eu-vat-rates-2026), [Austrian VAT Number (UID) Validator & VIES Check](https://stanzaapi.com/tools/vat-validator/vies/austria-at), [Belgian VAT Number (BTW/TVA) Validator & VIES Check](https://stanzaapi.com/tools/vat-validator/vies/belgium-be), [Bulgarian VAT Number (ДДС / ЕИК) Check, Format & Rates 2026](https://stanzaapi.com/tools/vat-validator/vies/bulgaria-bg), [Cyprus (CY) VAT Validator & VIES Check](https://stanzaapi.com/tools/vat-validator/vies/cyprus-cy), [Czechia (CZ) VAT Validator & VIES Check](https://stanzaapi.com/tools/vat-validator/vies/czechia-cz), [German VAT Number (USt-IdNr) Validator & Free VIES Check](https://stanzaapi.com/tools/vat-validator/vies/germany-de), [Danish VAT Number (CVR) Check, Format & VIES Validator 2026](https://stanzaapi.com/tools/vat-validator/vies/denmark-dk)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/vat-validator`
  - Python (PyPI): `pip install stanzaapi-vat-validator`
  - C# (NuGet): `dotnet add package StanzaApi.VatValidator`
  - Rust (crates.io): `cargo add stanzaapi-vat-validator`
- Key Capabilities: Full coverage for all 27 EU member states and the United Kingdom Deterministic offline MOD-97, MOD-11, Luhn, and weighted check digit validation

### 6. Medical Device UDI Barcode & AIDC Engine
- Category: Medical Devices & Healthcare Regulation
- Endpoint: https://stanzaapi.com/tools/udi-decoder/
- Edge Host: api.stanzaapi.com/udi-decoder
- Supported Standards & Formats: [GS1 UDI Barcode Format & AI Parser Guide (GS1-128 & DataMatrix)](https://stanzaapi.com/tools/udi-decoder/standard/gs1-udi-format), [HIBCC Medical Device Barcode Decoder & Modulo-43 Checksum Spec](https://stanzaapi.com/tools/udi-decoder/standard/hibcc-udi-format), [ICCBBA ISBT 128 Medical Device & Cellular Therapy UDI Spec](https://stanzaapi.com/tools/udi-decoder/standard/iccbba-udi-format), [FDA Global UDI Database (GUDID) Submission & Compliance Spec](https://stanzaapi.com/tools/udi-decoder/standard/fda-gudid-spec), [EU Medical Device Regulation (MDR 2017/745) EUDAMED UDI Spec](https://stanzaapi.com/tools/udi-decoder/standard/eu-mdr-eudamed-spec), [FDA AccessGUDID Device Identifier (DI) Lookup & Record Verification](https://stanzaapi.com/tools/udi-decoder/standard/accessgudid-di-lookup), [Medical Device Barcode Decoder — 2D DataMatrix, GS1-128 & Hospital Scanners](https://stanzaapi.com/tools/udi-decoder/standard/medical-device-barcode-decoder), [EU EUDAMED Basic UDI-DI & UDI-DI Validation Architecture](https://stanzaapi.com/tools/udi-decoder/standard/eudamed-basic-udi-di-lookup)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/udi-decoder`
  - Python (PyPI): `pip install stanzaapi-udi-decoder`
  - C# (NuGet): `dotnet add package StanzaApi.UdiDecoder`
  - Rust (crates.io): `cargo add stanzaapi-udi-decoder`
- Key Capabilities: Universal support for GS1-128 / GS1 DataMatrix, HIBCC (Health Industry Bar Code), and ICCBBA ISBT 128 Automated Device Identifier (DI) and Production Identifier (PI) separation (Lot, Serial, Expiration, Manufacturing Date)

### 7. GS1 Barcode & Digital Link Decoder (Sunrise 2027) API
- Category: Retail & Supply Chain
- Endpoint: https://stanzaapi.com/tools/gs1-decoder/
- Edge Host: api.stanzaapi.com/gs1-decoder
- Supported Standards & Formats: [GS1 AI (01) Global Trade Item Number (GTIN) & Mod-10 Checksum](https://stanzaapi.com/tools/gs1-decoder/ai/01-gtin), [GS1 AI (10) Batch / Lot Number Specification & FNC1 Rules](https://stanzaapi.com/tools/gs1-decoder/ai/10-batch-lot), [GS1 AI (17) Expiration Date Specification (YYMMDD & YYMM00)](https://stanzaapi.com/tools/gs1-decoder/ai/17-expiration-date), [GS1 AI (21) Individual Serial Number Specification](https://stanzaapi.com/tools/gs1-decoder/ai/21-serial-number), [GS1 AI (00) Serial Shipping Container Code (SSCC-18) Spec](https://stanzaapi.com/tools/gs1-decoder/ai/00-sscc), [GS1 Digital Link URI Standard & QR Web Transition (Sunrise 2027)](https://stanzaapi.com/tools/gs1-decoder/ai/gs1-digital-link-uri), [GS1 AI (02) CONTENT Global Trade Item Number Specification](https://stanzaapi.com/tools/gs1-decoder/ai/02-content), [GS1 AI (37) COUNT of Trade Items Specification](https://stanzaapi.com/tools/gs1-decoder/ai/37-count)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/gs1-decoder`
  - Python (PyPI): `pip install stanzaapi-gs1-decoder`
  - C# (NuGet): `dotnet add package StanzaApi.Gs1Decoder`
  - Rust (crates.io): `cargo add stanzaapi-gs1-decoder`
- Key Capabilities: Full support for GS1 Application Identifiers with variable-length FNC1 separation Bi-directional GS1 Digital Link URI encoder and decoder (Web URI <-> Raw Barcode)

### 8. IATA Air Cargo AWB & Aviation Validator API
- Category: Aviation & Freight Logistics
- Endpoint: https://stanzaapi.com/tools/iata-validator/
- Edge Host: api.stanzaapi.com/iata-validator
- Supported Standards & Formats: [IATA Resolution 600a Air Waybill (AWB) 11-Digit MOD-7 Spec](https://stanzaapi.com/tools/iata-validator/standard/air-waybill-awb-mod7), [IATA 3-Digit Airline Accounting Prefix Directory & Resolver](https://stanzaapi.com/tools/iata-validator/standard/airline-prefix-directory), [IATA 13-Digit E-Ticket Validator & Resolution 722e Check Digit](https://stanzaapi.com/tools/iata-validator/standard/iata-e-ticket-13-digit), [IATA 3-Letter Airport Code & Metropolitan Area Standard](https://stanzaapi.com/tools/iata-validator/standard/iata-airport-codes)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/iata-validator`
  - Python (PyPI): `pip install stanzaapi-iata-validator`
  - C# (NuGet): `dotnet add package StanzaApi.IataValidator`
  - Rust (crates.io): `cargo add stanzaapi-iata-validator`
- Key Capabilities: IATA Resolution 600a 11-digit Air Waybill MOD-7 check digit calculation Built-in directory of 500+ official 3-digit IATA airline accounting prefixes

### 9. ISO 6346 Container & Chassis Check-Digit Validator API
- Category: Maritime & Intermodal Freight
- Endpoint: https://stanzaapi.com/tools/container-validator/
- Edge Host: api.stanzaapi.com/container-validator
- Supported Standards & Formats: [BIC Bureau International des Conteneurs 3-Letter Owner Prefix Spec](https://stanzaapi.com/tools/container-validator/iso-6346/bic-owner-code-format), [ISO 6346 Modulo-11 Shipping Container Check Digit Formula & Step-by-Step](https://stanzaapi.com/tools/container-validator/iso-6346/iso-6346-check-digit-calculation), [ISO 6346 4-Character Container Size and Type Code Directory](https://stanzaapi.com/tools/container-validator/iso-6346/container-size-type-codes), [ISO 6346 Equipment Category Identifiers (U, J, Z)](https://stanzaapi.com/tools/container-validator/iso-6346/equipment-category-identifiers)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/container-validator`
  - Python (PyPI): `pip install stanzaapi-container-validator`
  - C# (NuGet): `dotnet add package StanzaApi.ContainerValidator`
  - Rust (crates.io): `cargo add stanzaapi-container-validator`
- Key Capabilities: Complete ISO 6346 Modulo-11 check digit verification and calculation Automated extraction of 3-letter BIC Owner Code, Equipment Identifier (U, J, Z), and Serial Number

### 10. Global LEI & Corporate Tax ID Validator API
- Category: Entity Identification & Compliance
- Endpoint: https://stanzaapi.com/tools/lei-validator/
- Edge Host: api.stanzaapi.com/lei-validator
- Supported Standards & Formats: [LEI Number Format Rules & ISO 17442 Check Digit Validator](https://stanzaapi.com/tools/lei-validator/gleif/iso-17442-format-rules), [SWIFT BIC to GLEIF LEI Mapping Standard & Cross-Referencing](https://stanzaapi.com/tools/lei-validator/gleif/bic-to-lei-mapping), [ISO 20275 Entity Legal Form (ELF) Code Directory & Resolver](https://stanzaapi.com/tools/lei-validator/gleif/elf-entity-legal-form-codes), [GLEIF Level 2 Relationship Data (Who Owns Whom) Model](https://stanzaapi.com/tools/lei-validator/gleif/gleif-level-2-relationship-data)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/lei-validator`
  - Python (PyPI): `pip install stanzaapi-lei-validator`
  - C# (NuGet): `dotnet add package StanzaApi.LeiValidator`
  - Rust (crates.io): `cargo add stanzaapi-lei-validator`
- Key Capabilities: ISO 17442 20-character LEI Modulo 97-10 check digit verification Extraction of 4-character Local Operating Unit (LOU) prefix and 14-character entity code

### 11. EU CBAM & Carbon Tax Calculation Engine
- Category: Carbon Border Tax & Regulatory Compliance
- Endpoint: https://stanzaapi.com/tools/cbam-carbon/
- Edge Host: api.stanzaapi.com/cbam-carbon
- Supported Standards & Formats: [EU CBAM Iron & Steel Emissions Calculator [CN 7201-7326 Benchmark API]](https://stanzaapi.com/tools/cbam-carbon/compliance/iron-steel-emissions), [Aluminum CBAM Embedded Carbon Calculator (CN Chapter 76)](https://stanzaapi.com/tools/cbam-carbon/compliance/aluminum-factors), [Cement & Clinker CBAM Carbon Tax Calculator (CN 2523)](https://stanzaapi.com/tools/cbam-carbon/compliance/cement-clinker-calc), [Country Electricity Grid Carbon Intensity Directory (2026 Scope 2 Factors)](https://stanzaapi.com/tools/cbam-carbon/compliance/grid-intensity-factors), [European Commission CBAM Registry XML Declaration Guide](https://stanzaapi.com/tools/cbam-carbon/compliance/quarterly-declaration-guide)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/cbam-carbon`
  - Python (PyPI): `pip install stanzaapi-cbam-carbon`
  - C# (NuGet): `dotnet add package StanzaApi.CbamCarbon`
  - Rust (crates.io): `cargo add stanzaapi-cbam-carbon`
- Key Capabilities: Continuous Statutory Sync™ with European Commission Implementing Regulation (EU) 2023/1773 & EU ETS EEX auction benchmarks Automated 6-hour Continuous Edge Reconciliation guaranteeing zero-drift regulatory currency

### 12. Peppol BIS Billing 3.0 & EN 16931 E-Invoice Engine
- Category: Electronic Invoicing & Tax Compliance
- Endpoint: https://stanzaapi.com/tools/peppol-validator/
- Edge Host: api.stanzaapi.com/peppol-validator
- Supported Standards & Formats: [Peppol BIS Billing 3.0 UBL 2.1 E-Invoice Validator & Parser](https://stanzaapi.com/tools/peppol-validator/standards/peppol-bis-billing-3-0), [Factur-X / ZUGFeRD 2.2 UN/CEFACT CII E-Invoice Parser & Validator](https://stanzaapi.com/tools/peppol-validator/standards/factur-x-zugferd-2-2), [ISO 6523 Electronic Address Scheme (EAS) Participant Registry](https://stanzaapi.com/tools/peppol-validator/registries/iso-6523-eas-schemes)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/peppol-validator`
  - Python (PyPI): `pip install stanzaapi-peppol-validator`
  - C# (NuGet): `dotnet add package StanzaApi.PeppolValidator`
  - Rust (crates.io): `cargo add stanzaapi-peppol-validator`
- Key Capabilities: Complete support for both EN 16931 syntaxes: OASIS UBL 2.1 (Invoice & CreditNote) and UN/CEFACT CII (Factur-X / ZUGFeRD 2.2) 100% deterministic business rules engine evaluating BR-01..BR-65, BR-CO-01..BR-CO-26, and PEPPOL-EN16931-R* rules

### 13. Factur-X & ZUGFeRD 2.3 E-Invoice Validation Engine
- Category: Electronic Invoicing & Tax Compliance
- Endpoint: https://stanzaapi.com/tools/factur-x-validator/
- Edge Host: api.stanzaapi.com/factur-x-validator
- Supported Standards & Formats: [Factur-X PDF/A-3 Attachment Extraction & Validation API](https://stanzaapi.com/tools/factur-x-validator/standards/pdf-a-3-factur-x-extraction), [ZUGFeRD 2.3 CII E-Invoice Validator & Parser](https://stanzaapi.com/tools/factur-x-validator/standards/zugferd-2-3), [XRechnung CII Validator API (EN 16931)](https://stanzaapi.com/tools/factur-x-validator/standards/xrechnung-cii), [Factur-X Profile Detection (BT-24) & EN 16931 Rule Scoping](https://stanzaapi.com/tools/factur-x-validator/profiles/en16931-profile-detection)
- SDKs:
  - TypeScript (NPM): `npm install @stanzaapi/factur-x-validator`
  - Python (PyPI): `pip install stanzaapi-factur-x-validator`
  - C# (NuGet): `dotnet add package StanzaApi.FacturXValidator`
  - Rust (crates.io): `cargo add stanzaapi-factur-x-validator`
- Key Capabilities: PDF/A-3 attachment extraction: reads factur-x.xml and zugferd-invoice.xml from hybrid invoice PDFs UN/CEFACT CII validation for Factur-X 1.0.x, ZUGFeRD 2.x and XRechnung documents

## Free Browser Tools (Client-Side, No API Key)
- [Developer Toolbox](https://stanzaapi.com/toolbox): every free client-side tool on one page.
- [Sample Files](https://stanzaapi.com/samples): engine-validated X12 and ISO 20022 test payloads.

- [IBAN Checker: Validate IBAN Numbers and MOD-97 Checksum](https://stanzaapi.com/tools/iban-validator/checker): An IBAN checker validates an International Bank Account Number against the length and structure rules for its country and the ISO 7064 MOD-97-10 checksum, then breaks the number into its country, check-digit, bank, branch, and account parts.
- [IBAN Generator: Create Valid Test IBANs for Any Country](https://stanzaapi.com/tools/iban-validator/generator): An IBAN generator creates structurally valid, checksum-correct bank account numbers for software testing. Each value matches the ISO 13616 country format and passes the ISO 7064 MOD-97 check, but it is not tied to a real account and cannot receive payments.
- [Container Check Digit Calculator (ISO 6346)](https://stanzaapi.com/tools/container-validator/check-digit-calculator): A container check digit calculator computes the 11th character of an ISO 6346 container number from the three-letter owner code, the equipment category letter, and the six-digit serial number.
- [Air Waybill Validator: Check an 11-Digit AWB Number](https://stanzaapi.com/tools/iata-validator/air-waybill-validator): An air waybill validator checks the structure of an 11-digit IATA air waybill number and verifies that its final digit equals the seven-digit serial number modulo 7.
- [GTIN Check Digit Calculator (GTIN-8, GTIN-12, GTIN-13, GTIN-14)](https://stanzaapi.com/tools/gs1-decoder/gtin-check-digit-calculator): A GTIN check digit calculator computes the final digit of a GTIN-8, GTIN-12, GTIN-13, or GTIN-14 by applying the GS1 modulo-10 algorithm to the preceding digits.

## Platform Architecture, Trust & Governance
- Developer Documentation & Master API Reference Hub: https://stanzaapi.com/docs
- Live Edge Telemetry & System Status (99.99% Uptime, Sub-5ms P95): https://stanzaapi.com/status
- Trust & Compliance Center (HIPAA program in progress — no live PHI, Zero-Retention Isolates, GDPR Article 28 DPA): https://stanzaapi.com/compliance
- Pricing & 99.9% Uptime SLA Plans: https://stanzaapi.com/pricing
- Enterprise Contact & Custom Solutions (>1M Quotas, Dedicated Workers): https://stanzaapi.com/contact
- Full Detailed Knowledge Base & All Specs: https://stanzaapi.com/tools/llms-full.txt