sdk-generator — launch kit

1-liner

OpenAPI → polished multi-language SDKs (Python, TypeScript, Go, Ruby, Java, C#). $1.5-5K per language.

Tweet hook

openapi-generator-cli emits stubs. The READMEs + auth-walkthrough samples are weak.

Built a wrapper: stubs from generator-cli + Qwen polishes the README + auth flow.

$1.5-5K per language. Recurring on spec changes 🧵

Reddit

• r/programming: "Better SDK generation — beyond openapi-generator-cli"
• r/SaaS: "Why API companies don't have SDKs and how to fix"

Cold-email ICP

• Mid-market API companies without official SDKs (look at their docs page)
• Stripe-style API products in growth phase

Cold-email template

Subject: official Python + TS SDK in a week

Hi {first} — caught {their API} on {Hacker News / launch}.

You ship REST docs. Devs want native SDKs (typed, documented, idiomatic).
Most teams don't have time for 6 weeks of SDK work × 4 languages.

I do it: $1.5K per language, $5K bundle for 4. Includes polished README +
auth setup samples. CI included for spec-change regen.

Free POC on one endpoint. Reply for setup.

SEO content

1. "OpenAPI to multi-language SDKs 2026"
2. "Why your API needs native SDKs (vs docs-only)"
3. "Stripe-style SDK quality bar — what good looks like"

sdk-generator

Generate language-specific SDKs (Python / TypeScript / Go / Ruby / Java / C#) from an OpenAPI spec. Sells to API companies that haven't built SDKs yet.

Pricing

• One-shot generation $1,499 per language for one API
• Multi-language bundle $4,999 for Python + TS + Go + Ruby
• Maintenance retainer $499/mo per API to regenerate on spec changes
• DIY $0 (open code; you run it on your own spec)

Why this works

• API companies want SDKs; building good ones is 1-3 weeks of dev time per language. Half don't have any.
• openapi-generator-cli emits stubs but the READMEs and auth-flow walkthroughs are weak — that's where Qwen adds value.
• Recurring revenue from spec-change maintenance.

Architecture

OpenAPI spec
   │
   ▼
generate_stubs()        openapi-generator-cli → typed client stubs
   │
   ▼
write_readme()          Qwen → polished README + auth + samples
   │
   ▼
out/<lang>/             ready to publish to PyPI / npm / pkg.go.dev / RubyGems

Run

cd C:\openclaw-products\sdk-generator
python -m venv .venv
.\.venv\Scripts\activate
pip install -e .

# Need openapi-generator-cli on PATH (npm install -g @openapitools/openapi-generator-cli)

sdkgen build \
   --spec specs/acme-api.yaml \
   --language python \
   --package acme_client \
   --api-name "Acme API" \
   --out generated/python

Roadmap

• Drop the openapi-generator-cli dep; emit stubs natively for the top 3 languages
• Diff-aware regeneration (only touch changed paths)
• CHANGELOG.md generation across versions
• Auto-publish to PyPI / npm via CI integration
• Test-suite stub for each language