Comparison

SDK Factory vs OpenAPI Generator

Open-source, self-hosted, 50+ language generators — and how that lines up against a TypeScript-only, zero-touch generator that auto-rebuilds on every schema change.

Last reviewed: April 23, 2026

TL;DR

  • OpenAPI Generator is the OSS baseline: a CLI that turns a spec into source code for 50+ targets. Free, battle-tested, completely self-managed.
  • SDK Factory is the hosted counterpart: we run the generator, poll your schema, and publish the result automatically. You pay for the pipeline, not the code.
  • Pick OpenAPI Generator if you want full control and a generation catalog. Pick SDK Factory if you want to stop thinking about the pipeline entirely.

OpenAPI Generator is the canonical open-source tool in this space. Forked from swagger-codegen years ago, it now ships generators for more than 50 languages and frameworks under the Apache 2.0 license. The pattern is well-worn: install the CLI, point it at your OpenAPI document, pick a generator (`typescript-axios`, `typescript-fetch`, `typescript-node`, etc.), get source code in an output directory. From there, building, versioning and publishing are entirely your problem.

That "entirely your problem" is the real axis of comparison. OpenAPI Generator is a generator — it does not poll your schema, it does not publish to a registry, it does not track build history, it does not warn you when the generated code diffs sharply against a previous version. Those are things your CI pipeline, your internal tooling and your engineers maintain around it.

SDK Factory is the opposite end: the generator is one step in a hosted pipeline that also polls, hashes, builds, publishes, audits, and (on paid tiers) rolls back. You don't see the generator; you see the published package. If what you actually want is "every time our schema changes, a new tarball shows up on our registry", the open-source route requires real engineering work to glue together. Our job is to have that work already done.

Feature by feature

Capability
OpenAPI Generator
SDK Factory
Operating model
Self-hosted. You run the CLI locally or in CI, commit or publish the output, maintain the glue code.
Fully hosted. We poll, generate, build, publish and retain artifacts. You don't run anything.
Language catalog
50+ generators spanning every major runtime. Quality varies — a few are actively maintained, many are community-contributed and may lag.
TypeScript only — one generator, heavily opinionated, with ESM + CJS + bundled types and Zod runtime validation.
Build / publish pipeline
None. You wire it into your CI: install CLI, run generator, `npm install` output, build, version-bump, `npm publish`.
Included. Each schema change triggers a build, artifact goes to S3, tarball is published to the registry you configured.
Response to schema changes
Manual. You re-run the CLI when you remember, or write a cron/Action that does. Most teams drift.
Automatic. We poll every few minutes, hash the canonicalised document, and rebuild + republish the moment the hash changes.
Artifact audit trail
Whatever your CI + registry retain. No built-in "which tarball was published on which day from which schema hash".
Every tarball persisted to S3 keyed by deployment ID with package name, version and SHA-256 manifest.
Rollback story
Republish a prior commit from source. Tarball reproducibility depends on you pinning the generator version and every transitive dep.
One click. We re-upload the already-stored tarball from S3, flip `dist-tag` latest, done — no rebuild, no version drift.
Cost
$0 in license. The actual cost is the CI minutes + engineer time maintaining the pipeline + the incidents when it breaks.
$0 Free (1 app), $10/mo Premium (5 apps), $30/mo Pro (unlimited + rollback). Includes the pipeline entirely.

Compiled from OpenAPI Generator’s public documentation at the time of the last review date above.

What day-one setup looks like

The concrete shape of the integration — a file that lives in your repo vs a URL pasted into a dashboard. Same outcome, very different footprint.

OpenAPI Generatoryour repo + CI
# 1. Install the CLI (per repo or globally)
npm install -D @openapitools/openapi-generator-cli

# 2. Generate source into a directory
npx @openapitools/openapi-generator-cli generate \
  -i ./openapi.yaml \
  -g typescript-axios \
  -o ./generated \
  --additional-properties=npmName=@acme/api-client

# 3. Build, version, publish — your problem now
cd generated
npm install
npm run build
npm version patch
npm publish --access public

# 4. Re-run every time the schema changes. Cron? Action? Human?
#    Your call. Not included.
SDK Factorydashboard
sdk.mapree.dev / apps / createCreate appPoint us at your OpenAPI URL — we take it from there.Schema URLhttps://api.example.com/openapi.yamlRegistrynpm (public)Package@acme/api-clientCreate & publishPublishing…Publishedv1.0.0 · shippedNothing added to your API repo. Auto-rebuild on every schema change.

How each one handles the real moments

Past the pitch — what actually happens on day one, when the schema drifts, and when the upstream breaks.

Day one — first publish

OpenAPI Generator

Install the CLI, pick a generator (`typescript-axios`? `typescript-fetch`? opinions vary), write the config file, write a CI step that runs the generator, write a second step that builds the output, write a third that versions + publishes. Review the output. Publish. Expect a half-day to a full day.

SDK Factory

Dashboard, paste URL, pick registry, click publish. Out in minutes. The decision tree is smaller because the generator is chosen for you.

Schema changes mid-sprint

OpenAPI Generator

Depends on what you wired up. Some teams: re-run CLI on a cron, open a PR with the diff, review, merge, publish. Many teams: notice weeks later that the SDK is stale, manually regenerate, ship a batched bump. Drift is the default unless you invest.

SDK Factory

Detected within a few minutes of the schema URL returning a new hash. New version published automatically, consumers see it on next install.

Something upstream breaks

OpenAPI Generator

CLI exits non-zero. Your CI goes red. You read the logs and decide whether it's a generator bug, a spec issue, or a transitive-dep problem. You own the recovery.

SDK Factory

We mark the app REQUIRE_ACTION, stop the pipeline, surface the upstream fetch or generation error in the dashboard, and leave the last good published version in place.

Pick OpenAPI Generator if…

  • You have a strong preference for open-source, self-hosted tools — no third-party data plane in the SDK supply chain.
  • You need SDKs in multiple languages, especially ones outside the TypeScript ecosystem.
  • You have engineers who enjoy owning the generation pipeline and want that level of control.
  • Compliance or security rules forbid sending your OpenAPI document to an external hosted service.
  • Budget is zero and the engineer time to maintain the pipeline is already allocated elsewhere.

Pick SDK Factory if…

  • You want the output (published SDK) without building the pipeline (poll + generate + build + publish + audit).
  • TypeScript is the one language you ship, and you'd rather have one great generator than fifty okay ones.
  • Schema drift is a real problem and you want "new schema → new package" to happen without anyone thinking about it.
  • You want artifact-level audit (every tarball stored, content-hashed, keyed by deployment) without implementing it yourself.
  • Spending $10–$30/month to delete a class of CI maintenance is a trade you'd make.

Pricing at a glance

OpenAPI Generator

Free and open source (Apache 2.0). You host, you run, you maintain — no tier system, no vendor.

SDK Factory

Free (1 app). $10/mo Premium (5 apps). $30/mo Pro (unlimited apps + rollback). Published publicly, no sales call.

View our pricing

Migrating from OpenAPI Generator to SDK Factory

  1. 1

    Expose your OpenAPI document at a stable URL

    If your current pipeline reads a file from disk or from a generated artifact, publish the same OpenAPI file at a stable HTTPS URL (static host, an API endpoint, or a GitHub raw link). We poll — no webhooks required — so the URL just needs to return the current spec.

  2. 2

    Publish the SDK Factory SDK under a separate package name

    Don't collide with your existing output. Create an SDK Factory app that publishes `@acme/api-client-v2` (or a scope/name of your choice) so both SDKs live side-by-side in your registry during the migration.

  3. 3

    Diff the generated TS against your current OpenAPI Generator output

    The two generators aren't symbol-compatible. Our output is hand-tuned TypeScript (Zod-validated, typed errors, retry config) while `typescript-axios` / `typescript-fetch` ship thinner stubs. Budget a review: expect function-name differences and a few shape changes. Pilot on one consumer first.

  4. 4

    Migrate consumers incrementally

    Ship a `@acme/api-client-v2` PR per consumer that swaps the import and adjusts call sites. There's no deadline — both SDKs can coexist in your registry indefinitely. Move on each consumer's own schedule.

  5. 5

    Tear down the old generator pipeline

    Once every consumer is on the new SDK, delete the `openapitools.json` (or equivalent config), drop the CI steps that invoked the CLI, and remove the `@openapitools/openapi-generator-cli` dev dependency. Revoke any npm tokens that the CI step held. Optional: take over the original package name by deprecating the old versions and publishing fresh under it.

FAQ

Does SDK Factory use OpenAPI Generator under the hood?

No. We wrote our own TypeScript generator tailored to the runtime we ship (Zod validation, typed errors, retries/timeouts, interceptors, ESM + CJS + bundled types). We reviewed OpenAPI Generator's output early on and chose a different approach for the TypeScript story. If you need multi-language generation, OpenAPI Generator remains the broader tool.

Can I self-host SDK Factory?

Not today. SDK Factory is hosted only. If self-hosting is a hard requirement (compliance, air-gapped environments, data residency), OpenAPI Generator is the better match. We may revisit a self-hosted tier later, but it is not on the near-term roadmap.

What does SDK Factory's TypeScript output look like compared to typescript-axios or typescript-fetch?

Meaningfully different. We ship ESM + CJS + a single bundled .d.ts per entry, Zod schemas validate requests and responses at the runtime boundary, errors are typed per operation (so `catch` blocks get a narrow union, not a generic AxiosError), and retries/timeouts are configurable per call. The API surface is smaller and more opinionated than the OpenAPI Generator TS presets, which aim to be generic across many possible use cases.

Can I get the generated source code if I use SDK Factory?

The published npm tarball ships the built artifacts (ESM, CJS, .d.ts). If you need the pre-build TypeScript, that's not part of the product today — the hosted build lives in our infrastructure. OpenAPI Generator is the right choice if "the generated source code must live in our repo" is the requirement.

Why would I pay for SDK Factory when OpenAPI Generator is free?

You're not paying for the generator — you're paying for the pipeline. Automated polling, build on every schema change, artifact audit in S3, one-click rollback, registry flexibility and the fact that no one on your team has to maintain any of it. If the CI surface and the on-call incidents cost you more than $30/month in engineer time, the trade is worth making. If they don't, OpenAPI Generator is the honest answer.

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