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APIs · head to head

Stainless vs Zeplo

Stainless logo

Stainless

APIs

Generates client SDKs, API docs, and MCP servers from an OpenAPI spec

From
Free
Rated
-
Full reviewWebsite
Zeplo logo

Zeplo

APIs

Message queue as a URL prefix, adding retries and delays to any HTTP request

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Stainless starter and Pro plan prices are not published and require contacting the company.; Zeplo zeplo sits directly in the execution path of your background work, so an outage at a very small vendor means your jobs do not run at all, and there is no published SLA below Enterprise.
  • They diverge on capability: Stainless covers SDK generation, Zeplo covers URL prefix interface.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Stainless and Zeplo actually diverge.

Attributes where Stainless and Zeplo differ
AttributeStainlessZeplo
Pricing modelfreemiumPer month by request count
Platformsweb, apiWeb, Cloud

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (APIs).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Stainless

  • SDK generation
  • MCP server generation
  • Docs site generation
  • Webhooks and streaming support
  • Automated unit tests
  • Git integration

Only in Zeplo

  • URL prefix interface
  • Retries with backoff
  • Delayed delivery
  • Cron scheduling
  • Concurrency limits
  • Deduplication keys
  • Request logs
  • Team workspaces

What people use each for

The jobs each tool is most often brought in to do.

Stainless

  • Generating typed SDKs for a public APInot Zeplo
  • Producing an MCP server from an existing OpenAPI specnot Zeplo
  • Building an API documentation site alongside client librariesnot Zeplo
  • Giving open-source APIs a free SDK generation pathnot Zeplo

Zeplo

  • A Vercel or Cloudflare Workers application that needs retried background jobs without deploying a separate always-on workernot Stainless
  • A team that wants a webhook receiver protected by a concurrency limit so a burst does not overwhelm a downstream APInot Stainless
  • A small product needing cron jobs against HTTP endpoints without adding a scheduler to its infrastructurenot Stainless
  • A developer adding idempotent retries to an unreliable third-party API call with a one-line URL changenot Stainless

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Stainless

  • Starter and Pro plan prices are not published and require contacting the company.
  • The free plan caps APIs at 25 endpoints, which excludes larger production APIs.
  • Overage charges apply per SDK/endpoint/month once limits are exceeded, which can make costs unpredictable at scale.

Zeplo

  • Zeplo sits directly in the execution path of your background work, so an outage at a very small vendor means your jobs do not run at all, and there is no published SLA below Enterprise.
  • The free Developer tier includes only 500 requests a month and one team member, so it is a demonstration allowance rather than a usable free plan for anything real.
  • Overage on the Developer tier is 20 US dollars per 100,000 requests, two hundred times the marginal rate on the Company tier, so exceeding the free allowance without upgrading is expensive.
  • Team members cost 15 US dollars each beyond the plan allowance, which is an odd charge on an infrastructure product billed by request volume.
  • Log retention is 30 days on both published tiers, so anything requiring longer audit trails on job execution has to be logged separately.

Pricing, plan by plan

Stainless

Free
  • FreeFree
    • Up to 5 generators (SDKs, docs, or MCP servers)
    • 5 seats
    • APIs with 25 or fewer endpoints
  • Starter$undefined/mo
    • Unlimited generators
    • Expanded seats
    • Private SDKs of any size
  • Pro$undefined/mo
    • Custom enterprise features and pricing
  • Enterprise$undefined/mo
    • Dedicated support
    • SOC 2 compliance reports
    • Purchase order/invoicing with negotiable terms

Zeplo

Free
  • DeveloperFree
    • 500 requests a month included
    • $20 per additional 100,000 requests
    • 1 team member
  • Company$39/month
    • 1,000,000 requests a month included
    • $10 per additional million requests
    • Up to 3 team members
  • Enterprise$undefined/month
    • Volume discounts
    • Custom team size
    • Support with SLA

Which should you pick?

Choose Stainless if

  • You need sdk generation.
  • You want to start without paying.
  • You work on web, api.
  • You also want mcp server generation.
Stainless review

Choose Zeplo if

  • You need url prefix interface.
  • You want to start without paying.
  • You work on Web, Cloud.
  • You also want retries with backoff.
Zeplo review

Questions people ask

Is Stainless or Zeplo better?
Neither clearly leads. Stainless starts at Free and Zeplo at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Stainless or Zeplo?
Stainless starts at Free and Zeplo at Free.
Does Stainless or Zeplo run on more platforms?
Stainless runs on web, api. Zeplo runs on Web, Cloud.
Can I use Stainless for free?
Both have a free tier, so you can try either at no cost before committing.
What is Stainless best used for?
Stainless is most often used for generating typed sdks for a public api, producing an mcp server from an existing openapi spec, building an api documentation site alongside client libraries, giving open-source apis a free sdk generation path. Of those, generating typed sdks for a public api and producing an mcp server from an existing openapi spec are not what Zeplo is typically brought in for.
What can Stainless do that Zeplo cannot?
Stainless covers SDK generation, MCP server generation, Docs site generation, Webhooks and streaming support. Zeplo covers URL prefix interface, Retries with backoff, Delayed delivery, Cron scheduling.

Answered from the vendors’ own pages

Stainless: Is there a free plan, and what are its limits?

Yes. The Free plan supports up to 5 generators, 5 seats, APIs with 25 or fewer endpoints, and 100 preview builds per month, with email support.

Source
Zeplo: How does Zeplo work?

You prefix your endpoint URL with zeplo.to and add query parameters for retries, delay, cron or concurrency. No SDK or broker is needed.

Stainless: Who owns the generated SDK code?

The generated SDK code is owned by the customer and published by Stainless under the Apache 2.0 license.

Source
Zeplo: What does it cost?

Free for 500 requests a month; 39 US dollars a month for a million requests, then 10 dollars per additional million.

Stainless: What happens if I exceed my plan's endpoint limit?

Customers exceeding their endpoint limits are billed per SDK, per endpoint, per month for the overage.

Source
Zeplo: Is it suitable for critical jobs?

It is a small vendor in your execution path with no published SLA below Enterprise, so weigh that against the convenience.

Zeplo: Does it work with serverless platforms?

Yes, that is its main use, covering Vercel, Cloudflare Workers, Netlify and similar environments that lack long-running workers.

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