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APIs · head to head

Asyncapi vs Trustly

Asyncapi logo

Asyncapi

APIs

Specification and tools for defining asynchronous APIs

From
Free
Rated
-
Full reviewWebsite
Trustly logo

Trustly

APIs

Pay-by-bank payments network, majority-owned by private equity firm Nordic Capital

From
On request
Rated
-
Full reviewWebsite

The short version

  • Only Asyncapi has a free tier, so it costs nothing to try first.
  • Each has a real cost: Asyncapi complex to implement and debug asynchronous operations due to their non-linear and concurrent nature; Trustly it is majority-owned by Nordic Capital, a private equity firm, so its long-term roadmap is ultimately oriented toward an eventual sale or IPO rather than indefinite independent operation.
  • They diverge on capability: Asyncapi covers API Specification, Trustly covers Pay by bank checkout.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Asyncapi and Trustly actually diverge.

Attributes where Asyncapi and Trustly differ
AttributeAsyncapiTrustly
Starting priceFreeOn request
Pricing modelopen-sourcequote
Free tierYesNo
PlatformsWeb, CLI, IDE ExtensionsWeb, API
Founded2019Unknown

Identical on both: 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 Asyncapi

  • API Specification
  • Code generation
  • Documentation
  • Multiple messaging protocols
  • Code generators
  • Specification support
  • Tools support
  • CLI support

Only in Trustly

  • Pay by bank checkout
  • Instant refunds
  • Verified payouts
  • Multi-market bank connectivity
  • Merchant dashboard and reconciliation
  • Fraud and risk tooling

What people use each for

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

Asyncapi

  • API Developmentnot Trustly
  • API Gatewaynot Trustly
  • API Testingnot Trustly
  • API Documentationnot Trustly
  • Microservicesnot Trustly

Trustly

  • An e-commerce merchant wanting a lower-cost alternative or complement to card payment acceptancenot Asyncapi
  • A gaming or gambling operator needing verified, instant payouts to players' bank accountsnot Asyncapi
  • A merchant wanting instant refunds processed directly to a customer's bank account rather than card reversal delaysnot Asyncapi
  • A business in a market with strong open banking adoption wanting pay-by-bank as a checkout optionnot Asyncapi

Where each one falls short

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

Asyncapi

  • Complex to implement and debug asynchronous operations due to their non-linear and concurrent nature
  • Keeping AsyncAPI documents up to date is challenging as systems evolve
  • Tracing and debugging asynchronous operations is more difficult than synchronous request-response patterns

Trustly

  • It is majority-owned by Nordic Capital, a private equity firm, so its long-term roadmap is ultimately oriented toward an eventual sale or IPO rather than indefinite independent operation.
  • Consumer familiarity with paying by bank transfer still lags card payments in most markets, so merchants typically see it used as a secondary option rather than a full card replacement.
  • The 1.15 to 3.15% merchant fee range is not a single published rate, so a merchant cannot know its actual cost without a sales negotiation.
  • As with all open banking-dependent payment methods, reliability depends on the consistency of the underlying banks' own APIs, which Trustly does not control.
  • Its verified payout functionality is heavily used in gaming and gambling, a sector with additional regulatory scrutiny, which is worth factoring in when evaluating vendor risk exposure by association.

Pricing, plan by plan

Asyncapi

Free
  • Open SourceFree
    • AsyncAPI specification
    • Tools
    • Community support

Trustly

On request
  • Trustly$undefined/month
    • Typical merchant cost of 1.15% to 3.15% depending on volume and market
    • Exact rate negotiated per merchant, not published as a flat card

Which should you pick?

Choose Asyncapi if

  • You need api specification.
  • You want to start without paying.
  • You work on Web, CLI, IDE Extensions.
  • You also want code generation.
Asyncapi review

Choose Trustly if

  • You need pay by bank checkout.
  • You work on Web, API.
  • You also want instant refunds.
Trustly review

Questions people ask

Is Asyncapi or Trustly better?
Neither clearly leads. Asyncapi starts at Free and Trustly at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Asyncapi or Trustly?
Asyncapi has a free tier; the other does not. Paid plans start at Free for Asyncapi and On request for Trustly.
Does Asyncapi or Trustly run on more platforms?
Asyncapi runs on Web, CLI, IDE Extensions. Trustly runs on Web, API.
Can I use Asyncapi for free?
Yes. Asyncapi has a free tier, so you can try it without paying. Trustly starts at On request.
What is Asyncapi best used for?
Asyncapi is most often used for api development, api gateway, api testing, api documentation. Of those, api development and api gateway are not what Trustly is typically brought in for.
What can Asyncapi do that Trustly cannot?
Asyncapi covers API Specification, Code generation, Documentation, Multiple messaging protocols. Trustly covers Pay by bank checkout, Instant refunds, Verified payouts, Multi-market bank connectivity.

Answered from the vendors’ own pages

Asyncapi: What is AsyncAPI used for?

AsyncAPI is an open-source specification for defining and documenting asynchronous APIs, message-driven systems, and event-driven architectures. It serves the same purpose for async APIs as OpenAPI does for REST APIs, providing standardized documentation, code generation, and tooling.

Source
Trustly: Who owns Trustly?

Nordic Capital, a private equity firm, holds a 51.1% majority stake; Alfven & Didrikson and BlackRock hold smaller stakes.

Asyncapi: Is AsyncAPI free to use?

Yes, AsyncAPI is completely free and open-source. It is hosted by the Linux Foundation and supported by community contributions and sponsorships from companies like Postman, IBM, IQVIA Technology, and Solace.

Source
Trustly: Is Trustly going public?

It has discussed an IPO but as of its most recent comments said one remained at least a year away.

Asyncapi: What protocols and technologies does AsyncAPI support?

AsyncAPI supports multiple protocols and technologies including Kafka, RabbitMQ, MQTT, Socket.IO, AWS EventBridge, and others. It provides language support for JavaScript/TypeScript, Python, Java, Go, C#/.NET, Kotlin, and PHP.

Source
Trustly: What does it typically cost a merchant?

Roughly 1.15% to 3.15% of transaction value depending on volume and market, negotiated per merchant.

Asyncapi: Does AsyncAPI have IDE support?

Yes, AsyncAPI has IDE extensions available for VSCode and IntelliJ, along with CLI utilities and GitHub Actions integration for developers.

Source
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