The comparison tool
Compare SDKs head to head
Set the two sides and the criteria. The page address updates as you go, so the link you copy opens exactly this matchup for anyone on your team.
Verdict
OpenAPI Generator wins, 10 to 8, narrowly, over Hand-written SDK.
Hand-written SDK 8/18 OpenAPI Generator 10/18
Hand-written SDK takes auth handling and pagination. OpenAPI Generator takes language support and maintenance. Even on typing and retries.
| Criterion | Hand-written SDK | OpenAPI Generator |
|---|---|---|
| Language supportEdge: OpenAPI Generator | Partial Each language is a separate codebase someone has to write and staff, so coverage is usually limited to the few languages the team knows best. | Strong It ships client generators for dozens of languages and frameworks. Quality and completeness vary by generator, so check the one you need. Check: OpenAPI Generator: generators list |
| TypingEven | Solid Types can be as idiomatic as the authors make them, but they are written by hand and can drift from the API as it changes. | Solid Typed models come from the schemas in your description. How well unions (oneOf), enums and nullables come through depends on the language's generator. Check: OpenAPI Generator: generators list |
| Auth handlingEdge: Hand-written SDK | Strong Full control: any flow, including OAuth token refresh and custom signing, can be built exactly as the API needs it. | Solid Security schemes in the description (API key, basic, bearer, OAuth) become configuration on the client. Token refresh is usually yours to build. Check: OpenAPI Generator: generators list |
| RetriesEven | Partial Retries exist only if someone built them, language by language. Check each SDK's source; behaviour often differs between languages. | Partial Retry behaviour mostly comes from the HTTP library the generated client uses; you configure it, and it differs by generator. Check: OpenAPI Generator: generators list |
| PaginationEdge: Hand-written SDK | Partial Paging helpers are possible and often nice, but each one is written by hand for each language and each list endpoint. | Weak OpenAPI has no standard pagination keyword, so generated clients return one page per call and callers write the loop. |
| MaintenanceEdge: OpenAPI Generator | Weak Every new endpoint, field and deprecation is hand work in every language, and the SDKs drift from the API when that work slips. | Solid Regenerate from the description when the API changes. Custom templates and patches have to be carried forward across generator upgrades. |
What you can compare
Every option is judged on the same criteria. For anything not listed, choose “Your own SDK” and rate it yourself.
Approach
Hand-written SDK
An SDK your team writes and maintains by hand, one codebase per language.
Generator
OpenAPI Generator
The open-source, community-maintained generator that turns an OpenAPI description into clients from templates.
openapi-generator.techGenerator
Microsoft Kiota
Microsoft's open-source command-line generator for API clients from OpenAPI descriptions, built on shared core libraries.
Kiota on Microsoft LearnGenerator
Speakeasy
A commercial generator that builds SDKs, Terraform providers, CLIs and MCP servers from an OpenAPI description.
speakeasy.comApproach
No SDK (raw HTTP)
Callers use their language's HTTP client (fetch, requests, net/http) against your API docs.
Agent interface
MCP server over your API
An MCP server that exposes your API's operations as tools AI agents can discover and call.
modelcontextprotocol.io