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APIs · head to head

Asyncapi vs Infracost

Asyncapi logo

Asyncapi

APIs

Specification and tools for defining asynchronous APIs

From
Free
Rated
-
Full reviewWebsite
Infracost logo

Infracost

Cloud

Cloud cost estimates in pull requests, with governance in the paid tier

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Asyncapi complex to implement and debug asynchronous operations due to their non-linear and concurrent nature; Infracost usage-based resources such as object storage, serverless functions and data transfer have no cost without monthly usage figures supplied by hand, and the documentation warns plainly that engineers otherwise read them as free.
  • They diverge on capability: Asyncapi covers API Specification, Infracost covers Pull request cost diffs.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Asyncapi and Infracost actually diverge.

Attributes where Asyncapi and Infracost differ
AttributeAsyncapiInfracost
Pricing modelopen-sourceFree open source tool, then per month by run volume
PlatformsWeb, CLI, IDE ExtensionsWeb, macOS, Linux, Windows, Docker
CategoryAPIsCloud
Founded2019Unknown

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

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 Infracost

  • Pull request cost diffs
  • Multi-format parsing
  • Apache-2.0 CLI
  • FinOps policies
  • Automated remediation
  • IDE integration

What people use each for

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

Asyncapi

  • API Developmentnot Infracost
  • API Gatewaynot Infracost
  • API Testingnot Infracost
  • API Documentationnot Infracost
  • Microservicesnot Infracost

Infracost

  • Teams that want an expensive infrastructure change questioned at review rather than discovered on an invoicenot Asyncapi
  • Platform groups enforcing tagging so cloud spend can be attributed to a team at allnot Asyncapi
  • Organisations adopting FinOps practice without buying a full cloud management platformnot Asyncapi
  • Engineers who want a cost figure in the editor while writing the Terraformnot 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

Infracost

  • Usage-based resources such as object storage, serverless functions and data transfer have no cost without monthly usage figures supplied by hand, and the documentation warns plainly that engineers otherwise read them as free.
  • Splitting production from non-production usage assumptions is not supported in the free usage file, which the docs attribute to a missing project filter, so that separation requires the paid product.
  • The step from 250 to 1,000 dollars a month is large and the Cloud tier includes only ten admin seats, with developer seats charged at a figure that is not published, so the cost for a large organisation cannot be computed from the pricing page.
  • Estimates are list price. Negotiated agreements, committed use discounts and reserved instance economics require SKU-level overrides available only on Enterprise, so the number in the pull request is not the number on the bill.
  • The share of the product covered by the Apache-2.0 licence is shrinking. Checks, automated fixes, policies and agent integrations are all hosted-only, so the permissive licence increasingly protects the estimation engine rather than the product.

Pricing, plan by plan

Asyncapi

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

Infracost

Free
  • FreeFree
    • 1,000 runs a month
    • Terraform, CloudFormation and CDK estimates
    • Community support
  • Starter$250/month
    • 10,000 runs a month
    • Email support
  • Cloud$1000/month
    • Ten admin seats, developer seats charged separately
    • FinOps policies and cost guardrails
    • Dashboards and audit trails
  • Enterprise$undefined/year
    • SKU-level price overrides for negotiated rates
    • Business unit reporting
    • SSO with SAML group mapping

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 Infracost if

  • You need pull request cost diffs.
  • You want to start without paying.
  • You work on Web, macOS, Linux, Windows, Docker.
  • You also want multi-format parsing.
Infracost review

Questions people ask

Is Asyncapi or Infracost better?
Neither clearly leads. Asyncapi starts at Free and Infracost at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Asyncapi or Infracost?
Asyncapi starts at Free and Infracost at Free.
Does Asyncapi or Infracost run on more platforms?
Asyncapi runs on Web, CLI, IDE Extensions. Infracost runs on Web, macOS, Linux, Windows, Docker.
Can I use Asyncapi for free?
Both have a free tier, so you can try either at no cost before committing.
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 Infracost is typically brought in for.
What can Asyncapi do that Infracost cannot?
Asyncapi covers API Specification, Code generation, Documentation, Multiple messaging protocols. Infracost covers Pull request cost diffs, Multi-format parsing, Apache-2.0 CLI, FinOps policies.

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
Infracost: Is the open source version genuinely useful on its own?

Yes, for estimation. It parses your definitions and produces breakdowns and diffs locally. What it does not do is comment on pull requests, enforce policy or report across an organisation, all of which are hosted-only.

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
Infracost: Will the estimate match my cloud bill?

No. It is list price. Committed use discounts, enterprise agreements and reserved instances need SKU-level overrides that sit in the Enterprise tier.

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
Infracost: Why do my S3 and Lambda resources show no cost?

Usage-based resources need monthly usage values supplied in a usage file or defined centrally. Without them they estimate at zero, which is the documented behaviour and the most common way the tool misleads.

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
Infracost: Has the licence ever changed?

No. The command line tool has been Apache 2.0 throughout, with no Business Source or AGPL episode, which is unusual in this category.

Infracost: What is a run?

Not defined on the public pricing page, and the run allowance is what separates the free and Starter tiers, so establish the definition before choosing between them.

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