Hoverfly

Hoverfly is an open source API simulation tool for creating realistic mock services and capturing-replaying HTTP traffic for testing.

Hoverfly publishes 10 API contracts indexed on the APIs.io network, including Cache API, Diff API, and 8 more. Tagged areas include Mocking and Testing.

The Hoverfly catalog on APIs.io includes 1 Spectral governance ruleset.

Hoverfly’s developer surface includes engineering blog, documentation, and 13 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

27.1/100 thin ▬ flat Agent 17/100 agent aware Front door AI 3/6 light Heartbeat 22/100 dormant self hosted · Apache-2.0 Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreemium

1 published contract

Mocking Testing

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 27.1/100 · thin

Contract Quality 6.3 / 16

Developer Ergonomics 2.5 / 13

Access Clarity 1.0 / 13

Operational Transparency 2.4 / 8

Contract Governance 1.1 / 8

Discoverability 2.6 / 7

Regulatory Posture 0.9 / 15

Open Source Surface 5.0 / 10

Create-or-Update Ergonomics 2.2 / 10

Agent readiness — 17/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 0 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Open Source Surface applies to this provider. This product is open source and we read its repository directly, so Open Source Surface carries 10 points of the composite. It is scored from what the repository actually publishes — a security policy, a contribution guide, a release history, a code of conduct — read live from the provider rather than inferred from our own catalog pointers. This facet adds; nothing was taken away to make room for it. An open-source project is not excused from the commercial facets, because exemption would strip it of the points it does earn. If we have the wrong repository, or this product is not open source, say so on your provider repo and we will drop the facet rather than have you publish against it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 65 points between them, because both conditional facets apply and carry 35 points together. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 65% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link

11 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Access Clarity scores 7.9 — up to +18.4 composite points
Developer Ergonomics scores 19.0 — up to +16.2 composite points
Contract Quality scores 38.7 — up to +15.3 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/hoverfly/apis.yml: open an issue on github.com/api-evangelist/hoverfly to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 1

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

OpenAPI

measured — observed by APIs.io (published)

APIs 10

Individual APIs this provider publishes, each with its own machine-readable definition.

Hoverfly Cache API

Inspect and clear the cache of matched request-response pairs.

Hoverfly Diff API

Inspect and clear response difference reports.

Hoverfly API

Manage Hoverfly runtime configuration.

Hoverfly Journal API

Inspect and filter the journal of intercepted requests.

Hoverfly Logs API

Retrieve runtime logs.

Hoverfly Post-Serve Actions API

Manage post-serve actions executed after responses are served.

Hoverfly Simulation API

Manage simulation request-response pairs and metadata.

Hoverfly State API

Manage stateful keys used during simulation.

Hoverfly System API

System-level controls.

Hoverfly Templating Data API

Manage CSV-based templating data sources.

Scroll for all 10

Open Collections 11

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Hoverfly Admin Cache API

OPEN COLLECTION

Hoverfly Admin Cache Diff API

OPEN COLLECTION

Admin Cache Hoverfly API

OPEN COLLECTION

Hoverfly Admin Cache Journal API

OPEN COLLECTION

Hoverfly Admin Cache Logs API

OPEN COLLECTION

Hoverfly Admin Cache Post-Serve Actions API

OPEN COLLECTION

Hoverfly Admin Cache Simulation API

OPEN COLLECTION

Hoverfly Admin Cache State API

OPEN COLLECTION

Hoverfly Admin Cache System API

OPEN COLLECTION

Hoverfly Admin Cache Templating Data API

OPEN COLLECTION

Hoverfly Admin API

OPEN COLLECTION

Scroll for all 11

Hoverfly API pricing

Not yet checked against Hoverfly's own pricing page. Compiled by API Evangelist on 2026-05-04; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Free freemium	Free
Professional paid	Free
Enterprise enterprise	—

Plan details, limits and sources →

Rate limits

Free Tier Default: 10 requests per minute
Free Tier Monthly Quota: 1000 requests per month
Professional Tier Default: 100 requests per minute

Compiled by API Evangelist, not yet checked against Hoverfly's documentation. All 5 limits →

Pricing Plans 1

Published pricing tiers and plan structures.

Hoverfly Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Hoverfly Rate Limits

5 limits

RATE LIMITS

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

Hoverfly

SLA

FinOps 1

Cost, billing, and metering signals for API financial operations.

Hoverfly Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Hoverfly API Rules

53 rules · 50 errors 2 warnings 1 info

SPECTRAL

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Hoverfly Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Hoverfly Agentic Access

42 operations · 23 acting · 1 human-in-the-loop

42 operations · 23 acting

AGENTIC

Resources

Documentation 2

Reference material describing how the API behaves

ContributionGuide

ContributionGuide

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

SourceCode

SourceCode

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 3

Status, limits, changes, and where to get help

RateLimits

RateLimits

IssueTracker

IssueTracker

Releases

Releases

Commercial 3

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

License

License

Company 4

The organization behind the API

Blog

Blog

BlogRSS

BlogRSS

LinkedIn

Website

Website

Source (apis.yml)

aid: hoverfly
name: Hoverfly
description: Hoverfly is an open source API simulation tool for creating realistic mock services and capturing-replaying HTTP
  traffic for testing.
type: Index
deliveryModel:
  model: self-hosted
  license: Apache-2.0
  open_source: true
  commercial: false
  callable_host: false
  label: Self-hosted open source · you run it yourself
  confidence: high
  source:
  - license
  - openapi
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: low
  try_now_blocked_by: loopback
  source:
  - plans
  - security
  generated: '2026-11-06'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/hoverfly.png
x-docs-platform: readthedocs
x-docs-platform-confidence: high
x-docs-platform-checked: 2026-10-03
tags:
- Mocking
- Testing
url: https://raw.githubusercontent.com/api-evangelist/hoverfly/refs/heads/main/apis.yml
created: '2026-03-25'
modified: '2026-10-06'
specificationVersion: '0.23'
apis:
- aid: hoverfly:hoverfly-cache-api
  name: Hoverfly Cache API
  description: Inspect and clear the cache of matched request-response pairs.
  humanURL: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  baseURL: http://localhost:8888
  tags:
  - Cache
  properties:
  - type: OpenAPI
    url: openapi/hoverfly-cache-api-openapi.yml
  - type: Documentation
    url: https://docs.hoverfly.io
  - type: APIReference
    url: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  - type: SourceCode
    url: https://github.com/SpectoLabs/hoverfly
- aid: hoverfly:hoverfly-diff-api
  name: Hoverfly Diff API
  description: Inspect and clear response difference reports.
  humanURL: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  baseURL: http://localhost:8888
  tags:
  - Diff
  properties:
  - type: OpenAPI
    url: openapi/hoverfly-diff-api-openapi.yml
  - type: Documentation
    url: https://docs.hoverfly.io
  - type: APIReference
    url: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  - type: SourceCode
    url: https://github.com/SpectoLabs/hoverfly
- aid: hoverfly:hoverfly-hoverfly-api
  name: Hoverfly API
  description: Manage Hoverfly runtime configuration.
  humanURL: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  baseURL: http://localhost:8888
  tags:
  - Hoverfly
  properties:
  - type: OpenAPI
    url: openapi/hoverfly-hoverfly-api-openapi.yml
  - type: Documentation
    url: https://docs.hoverfly.io
  - type: APIReference
    url: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  - type: SourceCode
    url: https://github.com/SpectoLabs/hoverfly
- aid: hoverfly:hoverfly-journal-api
  name: Hoverfly Journal API
  description: Inspect and filter the journal of intercepted requests.
  humanURL: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  baseURL: http://localhost:8888
  tags:
  - Journals
  tags_raw:
  - Journal
  properties:
  - type: OpenAPI
    url: openapi/hoverfly-journal-api-openapi.yml
  - type: Documentation
    url: https://docs.hoverfly.io
  - type: APIReference
    url: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  - type: SourceCode
    url: https://github.com/SpectoLabs/hoverfly
- aid: hoverfly:hoverfly-logs-api
  name: Hoverfly Logs API
  description: Retrieve runtime logs.
  humanURL: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  baseURL: http://localhost:8888
  tags:
  - Logs
  properties:
  - type: OpenAPI
    url: openapi/hoverfly-logs-api-openapi.yml
  - type: Documentation
    url: https://docs.hoverfly.io
  - type: APIReference
    url: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  - type: SourceCode
    url: https://github.com/SpectoLabs/hoverfly
- aid: hoverfly:hoverfly-post-serve-actions-api
  name: Hoverfly Post-Serve Actions API
  description: Manage post-serve actions executed after responses are served.
  humanURL: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  baseURL: http://localhost:8888
  tags:
  - Post-Serve Actions
  properties:
  - type: OpenAPI
    url: openapi/hoverfly-post-serve-actions-api-openapi.yml
  - type: Documentation
    url: https://docs.hoverfly.io
  - type: APIReference
    url: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  - type: SourceCode
    url: https://github.com/SpectoLabs/hoverfly
- aid: hoverfly:hoverfly-simulation-api
  name: Hoverfly Simulation API
  description: Manage simulation request-response pairs and metadata.
  humanURL: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  baseURL: http://localhost:8888
  tags:
  - Simulation
  properties:
  - type: OpenAPI
    url: openapi/hoverfly-simulation-api-openapi.yml
  - type: Documentation
    url: https://docs.hoverfly.io
  - type: APIReference
    url: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  - type: SourceCode
    url: https://github.com/SpectoLabs/hoverfly
- aid: hoverfly:hoverfly-state-api
  name: Hoverfly State API
  description: Manage stateful keys used during simulation.
  humanURL: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  baseURL: http://localhost:8888
  tags:
  - States
  tags_raw:
  - State
  properties:
  - type: OpenAPI
    url: openapi/hoverfly-state-api-openapi.yml
  - type: Documentation
    url: https://docs.hoverfly.io
  - type: APIReference
    url: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  - type: SourceCode
    url: https://github.com/SpectoLabs/hoverfly
- aid: hoverfly:hoverfly-system-api
  name: Hoverfly System API
  description: System-level controls.
  humanURL: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  baseURL: http://localhost:8888
  tags:
  - System
  properties:
  - type: OpenAPI
    url: openapi/hoverfly-system-api-openapi.yml
  - type: Documentation
    url: https://docs.hoverfly.io
  - type: APIReference
    url: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  - type: SourceCode
    url: https://github.com/SpectoLabs/hoverfly
- aid: hoverfly:hoverfly-templating-data-api
  name: Hoverfly Templating Data API
  description: Manage CSV-based templating data sources.
  humanURL: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  baseURL: http://localhost:8888
  tags:
  - Templating Data
  properties:
  - type: OpenAPI
    url: openapi/hoverfly-templating-data-api-openapi.yml
  - type: Documentation
    url: https://docs.hoverfly.io
  - type: APIReference
    url: https://docs.hoverfly.io/en/latest/pages/reference/api/api.html
  - type: SourceCode
    url: https://github.com/SpectoLabs/hoverfly
common:
- type: Plans
  url: plans/hoverfly-plans-pricing.yml
- type: RateLimits
  url: rate-limits/hoverfly-rate-limits.yml
- type: FinOps
  url: finops/hoverfly-finops.yml
- url: https://hoverfly.io/blog
  type: Blog
- url: https://hoverfly.io/blog/rss.xml
  type: BlogRSS
- type: IssueTracker
  url: https://github.com/SpectoLabs/hoverfly/issues
- type: Releases
  url: https://github.com/SpectoLabs/hoverfly/releases
- type: ContributionGuide
  url: https://github.com/SpectoLabs/hoverfly/blob/master/CONTRIBUTING.md
- type: License
  name: Apache-2.0
  url: https://github.com/SpectoLabs/hoverfly/blob/master/LICENSE
- type: AgenticAccess
  url: agentic-access/hoverfly-agentic-access.yml
- type: DomainSecurity
  url: security/hoverfly-domain-security.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/hoverfly
- type: Website
  url: https://hoverfly.io
- type: Documentation
  url: https://docs.hoverfly.io
- type: SourceCode
  url: https://github.com/SpectoLabs/hoverfly
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

Hoverfly API — frequently asked questions

Does Hoverfly have an API?

Yes. APIs.io lists 10 APIs from Hoverfly, including Hoverfly Cache API, Hoverfly Diff API and Hoverfly API, and 7 more.

Is there an OpenAPI specification for the Hoverfly API?

Yes. APIs.io indexes 10 OpenAPI specifications for Hoverfly, each linked for download from this page.

How much does the Hoverfly API cost?

APIs.io lists 3 pricing plans for Hoverfly, with each plan's price, limits and inclusions under Pricing on this page.

Is the Hoverfly API ready for AI agents?

Hoverfly has a Kin Score of 27.1 out of 100 (thin) and an Agent Readiness score of 16.6 (agent-aware), scored by API Evangelist on 2026-11-06.

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

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Tools for providers

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find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

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