SDK & client generation

Generate a strongly-typed client for the messpunkt.io Partner API from the OpenAPI 3.1 spec. One command, any language your stack speaks — C#, Java, TypeScript, Python, Go, PHP, Ruby. First-party SDK packages on NuGet/npm/PyPI arrive with GA in Q2 2026.

Why generate instead of wait for us? Every generated client tracks the exact field names, types and enum values from the spec you see on this site. When we add a field, you regenerate — the compiler tells you where the new field is available. There is no drift between docs and client.

Recommended: OpenAPI Generator

One CLI, dozens of target languages, maintained by the OpenAPI community. Install once, target anything.

# macOS / Linux
brew install openapi-generator
# or via npm (any OS)
npm install -g @openapitools/openapi-generator-cli

C# / .NET HttpClient · System.Text.Json

Produces a NuGet-ready project with async methods, typed DTOs, and built-in OAuth support.

openapi-generator-cli generate \
  -i https://developer.messpunkt.io/erp-api-openapi.yaml \
  -g csharp \
  --additional-properties=targetFramework=net9.0,library=httpclient \
  -o ./MesspunktPartnerApi

TypeScript fetch · strict types

Types and runtime in one package. Works in Node, Deno, Bun and the browser.

openapi-generator-cli generate \
  -i https://developer.messpunkt.io/erp-api-openapi.yaml \
  -g typescript-fetch \
  -o ./messpunkt-partner-api

Python urllib3 · pydantic

Type hints throughout, pydantic models for every schema, pytest-friendly.

openapi-generator-cli generate \
  -i https://developer.messpunkt.io/erp-api-openapi.yaml \
  -g python \
  -o ./messpunkt_partner_api

Java OkHttp · Jackson

Maven-ready, Java 17+. Spring-Boot-friendly variants available via -g spring.

openapi-generator-cli generate \
  -i https://developer.messpunkt.io/erp-api-openapi.yaml \
  -g java \
  --additional-properties=library=okhttp-gson,dateLibrary=java8 \
  -o ./messpunkt-partner-api

Go net/http · Go modules

Module-aware, context-aware, zero-dependency runtime beyond the standard library.

openapi-generator-cli generate \
  -i https://developer.messpunkt.io/erp-api-openapi.yaml \
  -g go \
  -o ./messpunkt-partner-api

PHP Guzzle · PSR-7

Composer-ready, PSR-4 autoloading, typed properties. PHP 8.1+.

openapi-generator-cli generate \
  -i https://developer.messpunkt.io/erp-api-openapi.yaml \
  -g php \
  -o ./messpunkt-partner-api

Alternative for .NET shops: NSwag

If you prefer NSwag's code-generation style (inline in your build, no Java dependency), it's equally supported. Install as a dotnet tool or NuGet reference:

dotnet tool install -g NSwag.ConsoleCore
nswag openapi2csclient \
  /input:https://developer.messpunkt.io/erp-api-openapi.yaml \
  /classname:MesspunktClient \
  /namespace:YourErp.Integrations.Messpunkt \
  /output:MesspunktClient.cs

Single-file output, no project scaffolding, easy to drop into an existing solution.

Spec URLs you'll want

URL	When to use
`https://developer.messpunkt.io/erp-api-openapi.yaml`	The canonical spec. Version field in the document tracks `1.0.0-rc.2`.
`https://api.sandbox.messpunkt.io/v1`	The sandbox base URL — what your generated client calls during integration testing.
`https://auth.sandbox.messpunkt.io`	The sandbox authorization server — OAuth flows here, not against the resource API.

OAuth setup after generation

Generators emit the HTTP layer, not the OAuth layer. You handle the token exchange once and inject the resulting access token into the generated client's default headers. See the Quickstart for the PKCE flow and the DPoP guide when you move to production (production will require sender-constrained tokens; the sandbox accepts plain Bearer).

Token refresh is your client's responsibility. Access tokens last 1 h; wrap your generated client with a thin interceptor that refreshes before calls and retries 401 once. See the Error-handling guide for the exact action matrix.

Coming with GA

For Q2 2026 we plan to publish first-party SDK packages on:

NuGet — Messpunkt.PartnerApi
npm — @messpunkt/partner-api
PyPI — messpunkt-partner-api

They will be thin wrappers on top of the OpenAPI-generated core, adding opinionated OAuth 2.1 helpers, automatic refresh handling, DPoP-proof generation, and typed error handling. Pilot partners can get pre-release builds by email.