wsystem-dev

W System provides a comprehensive e‑invoicing API suite for software teams, supporting European standards such as EN 16931, Peppol, and XRechnung. The platform offers invoice validation, generation of UBL documents, buyer identifier lookup, and sandbox testing with signed receipts. It targets developers needing to integrate invoicing, ERP, or shop software to meet upcoming regulatory deadlines across Belgium, France, Germany, the UK and other EU markets.

wsystem-dev publishes 8 API contracts indexed on the APIs.io network, including Billing API, Company API, E Invoice API, and 5 more. Tagged areas include Company, E-Invoicing, European, and Compliance.

The wsystem-dev catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

wsystem-dev’s developer surface includes authentication, documentation, API reference, engineering blog, pricing, and 25 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

49.2/100 developing ▬ flat Agent 29/100 agent ready Full breakdown ↓
scored 2026-11-02 · rubric v0.26.0 · Show this score on your site →

AccessFreemiumSelf serve⚡ Free to try

1 published contract 1 MCP Servers 3 Agent Skills

Company E-Invoicing European Compliance

Kin Score

Kin Score How this is scored →
scored 2026-11-02 · rubric v0.26.0

Composite quality — 49.2/100 · developing

Contract Quality 13.0 / 21

Developer Ergonomics 5.6 / 17

Access Clarity 10.7 / 17

Operational Transparency 3.5 / 11

Contract Governance 2.2 / 10

Discoverability 4.8 / 9

Regulatory Posture 4.6 / 15

Agent readiness — 29/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document
Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented)

7 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Developer Ergonomics scores 32.7 — up to +13.5 composite points
Contract Quality scores 61.2 — up to +9.7 composite points
Contract Governance scores 22.0 — up to +9.4 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/wsystem-dev/apis.yml: open an issue on github.com/api-evangelist/wsystem-dev to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 2

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

Model Context Protocol (MCP)

measured — observed by APIs.io (documented)

OpenAPI

measured — observed by APIs.io (published)

APIs 8

Individual APIs this provider publishes, each with its own machine-readable definition.

wsystem-dev Billing API

The Billing API from wsystem-dev — 3 operation(s) for billing.

wsystem-dev Company API

Official business-register lookup (FR, NO, FI, CZ, PL, EE; others via GLEIF LEI)

wsystem-dev E Invoice API

EU e-invoice validation (EN 16931, XRechnung; UBL, CII, ZUGFeRD/Factur-X PDF) and creation (JSON -> UBL)

wsystem-dev EORI API

EU EORI customs number validation via the EC EOS service

wsystem-dev Health API

The Health API from wsystem-dev — 1 operation(s) for health.

wsystem-dev KYB API

VAT + registry + sanctions in one call with a pass/review/fail verdict

wsystem-dev Sanctions API

Name screening against EU, UN, OFAC SDN and UK sanctions lists (refreshed daily)

wsystem-dev VAT API

EU VAT number validation via VIES (27 EU states + XI Northern Ireland)

Scroll for all 8

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

wsystem-dev MCP Server

Remote MCP server at api.wsystem.dev.

MCP SERVER

Agent Skills 3

Packaged agent skills for driving this provider's APIs from an AI assistant.

wsystem-dev-billing-subscribe

AGENT SKILL

wsystem-dev-lookup-company

AGENT SKILL

wsystem-dev-send-e-invoice

AGENT SKILL

Pricing Plans 1

Published pricing tiers and plan structures.

Wsystem Dev Plans Pricing

6 plans

PLANS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Wsystem Dev Context

10 classes · 37 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

wsystem-dev API Rules

14 rules · 11 errors 2 warnings 1 info

SPECTRAL

JSON Schema 6

Standalone JSON Schema definitions for this provider's data models.

CheckoutReq

11 properties

JSON SCHEMA

CompanyBatch

2 properties

JSON SCHEMA

DDReport

3 properties

JSON SCHEMA

KybCheck

3 properties

JSON SCHEMA

MandateIn

12 properties

JSON SCHEMA

SanctionsBatch

2 properties

JSON SCHEMA

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Wsystem Dev Authentication

1 scheme

SECURITY

Wsystem Dev Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Wsystem Dev Vulnerability Disclosure

security.txt · contact published

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Wsystem Dev Agentic Access

28 operations · 12 acting · 1 human-in-the-loop

28 operations · 12 acting

AGENTIC

Resources

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 5

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgentSkill

LLMsTxt

MCPServer

WellKnown

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Spectral

JSONLD

Vocabulary

DataModel

ErrorCatalog

Conformance

Build 2

SDKs, sample code, and the tooling you integrate with

ToolCrosswalk

ToolCrosswalk

GitHubOrganization

GitHubOrganization

Access & Security 6

Authentication, authorization, and security posture

Authentication

SecurityTxt

SecurityTxt

Security

VulnerabilityDisclosure

VulnerabilityDisclosure

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

StatusPage

StatusPage

Commercial 4

Pricing, plans, and the legal terms of use

Plans

Pricing

TermsOfService

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 2

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: wsystem-dev
name: wsystem-dev
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  gated: none
  gated_source:
  - onboarding
  label: Freemium · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-11-02'
  method: derived
image: https://wsystem.dev/og.png
description: W System provides a comprehensive e‑invoicing API suite for software teams, supporting European standards such
  as EN 16931, Peppol, and XRechnung. The platform offers invoice validation, generation of UBL documents, buyer identifier
  lookup, and sandbox testing with signed receipts. It targets developers needing to integrate invoicing, ERP, or shop software
  to meet upcoming regulatory deadlines across Belgium, France, Germany, the UK and other EU markets.
url: https://artifacts.apis.io/wsystem-dev/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-31 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-10-31'
modified: '2026-10-31'
tags:
- Company
- E-Invoicing
- European
- Compliance
tags_raw:
- Company
- E-invoicing
- API
- European
- Compliance
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: AgenticAccess
  url: agentic-access/wsystem-dev-agentic-access.yml
- type: Plans
  url: plans/wsystem-dev-plans-pricing.yml
- type: Spectral
  url: rules/wsystem-dev-rules.yml
- type: JSONLD
  url: json-ld/wsystem-dev-context.jsonld
- type: Vocabulary
  url: vocabulary/wsystem-dev-vocabulary.yml
- type: AgentSkill
  url: skills/_index.yml
- type: DataModel
  url: data-model/wsystem-dev-data-model.yml
- type: Authentication
  url: authentication/wsystem-dev-authentication.yml
- type: ErrorCatalog
  url: errors/wsystem-dev-problem-types.yml
- type: Conformance
  url: conformance/wsystem-dev-conformance.yml
- type: LLMsTxt
  url: llms/wsystem-dev-llms.txt
- type: ToolCrosswalk
  url: mcp/wsystem-dev-tool-crosswalk.yml
- type: MCPServer
  url: mcp/wsystem-dev-mcp.yml
- type: SecurityTxt
  url: well-known/wsystem-dev-security.txt
- type: SecurityTxt
  url: well-known/wsystem-dev-api-security.txt
- type: WellKnown
  url: well-known/wsystem-dev-well-known.yml
- type: Hosts
  url: hosts/wsystem-dev-hosts.yml
- type: Vendors
  url: vendors/wsystem-dev-vendors.yml
- type: StatusPage
  url: https://wsystem.dev/status
- type: Security
  url: https://wsystem.dev/security
- type: GitHubOrganization
  url: https://github.com/wsystemdev
- type: VulnerabilityDisclosure
  url: security/wsystem-dev-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/wsystem-dev-domain-security.yml
- type: Website
  url: https://wsystem.dev/
- type: Documentation
  url: https://wsystem.dev/docs
- type: APIReference
  url: https://api.wsystem.dev/docs
- type: Blog
  url: https://wsystem.dev/blog
- type: Pricing
  url: https://api.wsystem.dev/billing/plans
- type: TermsOfService
  url: https://wsystem.dev/terms
- type: PrivacyPolicy
  url: https://wsystem.dev/legal/peppol-mandate-terms
apis:
- aid: wsystem-dev:wsystem-dev-billing-api
  name: wsystem-dev Billing API
  description: The Billing API from wsystem-dev — 3 operation(s) for billing.
  humanURL: https://api.wsystem.dev/docs
  baseURL: https://api.wsystem.dev
  tags:
  - Billing
  properties:
  - type: OpenAPI
    url: openapi/wsystem-dev-billing-api-openapi.yml
  - type: JSONSchema
    url: json-schema/wsystem-dev-mandate-in-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-checkout-req-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-kyb-check-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-ddreport-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-company-batch-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-sanctions-batch-schema.json
- aid: wsystem-dev:wsystem-dev-company-api
  name: wsystem-dev Company API
  description: Official business-register lookup (FR, NO, FI, CZ, PL, EE; others via GLEIF LEI)
  humanURL: https://api.wsystem.dev/docs
  baseURL: https://api.wsystem.dev
  tags:
  - Company
  properties:
  - type: OpenAPI
    url: openapi/wsystem-dev-company-api-openapi.yml
  - type: JSONSchema
    url: json-schema/wsystem-dev-mandate-in-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-checkout-req-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-kyb-check-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-ddreport-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-company-batch-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-sanctions-batch-schema.json
- aid: wsystem-dev:wsystem-dev-e-invoice-api
  name: wsystem-dev E Invoice API
  description: EU e-invoice validation (EN 16931, XRechnung; UBL, CII, ZUGFeRD/Factur-X PDF) and creation (JSON -> UBL)
  humanURL: https://api.wsystem.dev/docs
  baseURL: https://api.wsystem.dev
  tags:
  - E-invoice
  properties:
  - type: OpenAPI
    url: openapi/wsystem-dev-e-invoice-api-openapi.yml
  - type: JSONSchema
    url: json-schema/wsystem-dev-mandate-in-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-checkout-req-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-kyb-check-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-ddreport-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-company-batch-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-sanctions-batch-schema.json
- aid: wsystem-dev:wsystem-dev-eori-api
  name: wsystem-dev EORI API
  description: EU EORI customs number validation via the EC EOS service
  humanURL: https://api.wsystem.dev/docs
  baseURL: https://api.wsystem.dev
  tags:
  - EORI
  properties:
  - type: OpenAPI
    url: openapi/wsystem-dev-eori-api-openapi.yml
  - type: JSONSchema
    url: json-schema/wsystem-dev-mandate-in-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-checkout-req-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-kyb-check-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-ddreport-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-company-batch-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-sanctions-batch-schema.json
- aid: wsystem-dev:wsystem-dev-health-api
  name: wsystem-dev Health API
  description: The Health API from wsystem-dev — 1 operation(s) for health.
  humanURL: https://api.wsystem.dev/docs
  baseURL: https://api.wsystem.dev
  tags:
  - Health
  properties:
  - type: OpenAPI
    url: openapi/wsystem-dev-health-api-openapi.yml
  - type: JSONSchema
    url: json-schema/wsystem-dev-mandate-in-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-checkout-req-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-kyb-check-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-ddreport-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-company-batch-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-sanctions-batch-schema.json
- aid: wsystem-dev:wsystem-dev-kyb-api
  name: wsystem-dev KYB API
  description: VAT + registry + sanctions in one call with a pass/review/fail verdict
  humanURL: https://api.wsystem.dev/docs
  baseURL: https://api.wsystem.dev
  tags:
  - KYB
  properties:
  - type: OpenAPI
    url: openapi/wsystem-dev-kyb-api-openapi.yml
  - type: JSONSchema
    url: json-schema/wsystem-dev-mandate-in-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-checkout-req-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-kyb-check-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-ddreport-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-company-batch-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-sanctions-batch-schema.json
- aid: wsystem-dev:wsystem-dev-sanctions-api
  name: wsystem-dev Sanctions API
  description: Name screening against EU, UN, OFAC SDN and UK sanctions lists (refreshed daily)
  humanURL: https://api.wsystem.dev/docs
  baseURL: https://api.wsystem.dev
  tags:
  - Sanctions
  properties:
  - type: OpenAPI
    url: openapi/wsystem-dev-sanctions-api-openapi.yml
  - type: JSONSchema
    url: json-schema/wsystem-dev-mandate-in-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-checkout-req-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-kyb-check-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-ddreport-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-company-batch-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-sanctions-batch-schema.json
- aid: wsystem-dev:wsystem-dev-vat-api
  name: wsystem-dev VAT API
  description: EU VAT number validation via VIES (27 EU states + XI Northern Ireland)
  humanURL: https://api.wsystem.dev/docs
  baseURL: https://api.wsystem.dev
  tags:
  - VAT
  properties:
  - type: OpenAPI
    url: openapi/wsystem-dev-vat-api-openapi.yml
  - type: JSONSchema
    url: json-schema/wsystem-dev-mandate-in-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-checkout-req-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-kyb-check-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-ddreport-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-company-batch-schema.json
  - type: JSONSchema
    url: json-schema/wsystem-dev-sanctions-batch-schema.json
x-enrichment:
  date: '2026-10-31'
  status: enriched
  artifacts_added: 31
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

wsystem-dev API — frequently asked questions

Does wsystem-dev have an API?

Yes. APIs.io lists 8 APIs from wsystem-dev, including wsystem-dev Billing API, wsystem-dev Company API and wsystem-dev E Invoice API, and 5 more.

Is there an OpenAPI specification for the wsystem-dev API?

Yes. APIs.io indexes 8 OpenAPI specifications for wsystem-dev, each linked for download from this page.

How do I authenticate with the wsystem-dev API?

wsystem-dev uses bearer-token authentication (1 scheme). The details are profiled on APIs.io as Wsystem Dev Authentication.

How much does the wsystem-dev API cost?

APIs.io lists 6 pricing plans for wsystem-dev, with each plan's price, limits and inclusions under Pricing Plans on this page.

Does wsystem-dev have an MCP server?

Yes. APIs.io lists 1 MCP server for wsystem-dev: Remote MCP server at api.wsystem.dev.

Is the wsystem-dev API ready for AI agents?

wsystem-dev has a Kin Score of 49.2 out of 100 (developing) and an Agent Readiness score of 28.9 (agent-ready), scored by API Evangelist on 2026-11-02.

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