API Testing
Providers using this tag (52)
Ranked by API Evangelist rating — Exemplar and Strong are expanded by default.
Exemplar 1 Complete, well-documented, and agent-ready
Developing 13 Usable, with meaningful gaps to close
Thin 14 Limited public surface area
Emerging 17 Early or largely undocumented
Minimal 2 Almost no public developer surface
Unrated 3 Not yet scored
APIs with this tag (40)
Ranked by the provider's API Evangelist rating — the Kin Score is scored per provider, not per API, so every API of a provider shares its band. How the rating works →
Exemplar 1 Complete, well-documented, and agent-ready
Strong 1 Solid coverage with minor gaps
Developing 10 Usable, with meaningful gaps to close
Bruno API ClientBruno is an open-source API client for exploring and testing REST, GraphQL, and gRPC APIs. Collections are ...Bruno API ClientThe core open-source, git-native desktop API client (a lightweight Postman/Insomnia alternative). Compose a...Bruno CLI (bru)The @usebruno/cli command-line runner (invoked as bru, installed via npm install -g @usebruno/cli) executes...Spec Scoring APIPublic, no-auth REST API for scoring OpenAPI documents. GET /api/review/checks returns the full set of chec...Assertible APIAssertible's public programmatic surface, used to drive test runs from a CI/CD pipeline. It consists of two...Fiddler EverywhereFiddler Everywhere is a cross-platform web debugging proxy for macOS, Windows, and Linux. It captures HTTP ...Testkit (YAML API Testing DSL)MIT-licensed Rust testing tool by the APItoolkit/Monoscope team that uses a simplified YAML DSL for definin...PactFlowPactFlow is SmartBear's contract testing platform that ensures API changes do not break consumer applicatio...ReadyAPIReadyAPI is SmartBear's API quality platform for functional, security, and performance testing. It supports...HoppscotchHoppscotch is a lightweight open-source browser-based API client supporting REST, GraphQL, WebSockets, SSE,...
Thin 9 Limited public surface area
Traceable API Security PlatformTraceable provides an intelligent API security platform offering API discovery, threat detection and protec...Speedscale PlatformSpeedscale captures production API traffic and replays it in lower environments for load testing, regressio...Postman APIPostman hosts the platform collections and their runs. 92 paths, 152 operations.SchemathesisSchemathesis is a property-based API testing tool that automatically generates test cases from OpenAPI and ...REST AssuredREST Assured is a Java DSL library for testing and validating RESTful APIs using a fluent, BDD-style syntax...GoReplayGoReplay captures live HTTP traffic with libpcap and replays it against a test target, letting teams valida...REST ClientREST Client is a Visual Studio Code extension for sending HTTP requests and viewing responses directly with...Thunder ClientThunder Client is the flagship VS Code REST API client extension offering a lightweight GUI for sending HTT...Thunder Client CLIThe Thunder Client CLI (@thunderclient/cli) is a Node.js command-line tool for running Thunder Client reque...
Emerging 14 Early or largely undocumented
KarateKarate is a modern open-source BDD framework that unifies API testing, UI automation, performance testing, ...RestfoxRestfox is a lightweight, offline-first web HTTP client for testing REST APIs, similar to Postman but brows...Testim API TestingAuthoring and execution surface for HTTP API tests inside Testim. Lets teams compose, chain, assert, and ru...SuperTestSuperTest is a Node.js library for testing HTTP servers by providing a high-level abstraction for HTTP asse...Broadcom BlazeMeterContinuous testing platform for API, web, mobile, and performance testing. Exposes a REST API for orchestra...cURL Command Line ToolThe curl command-line tool transfers data to or from a server using URL syntax, supporting protocols includ...DreddDredd is a language-agnostic command-line tool for validating an API description document against a backend...Runscope API Monitoring APIREST API for the Runscope (now BlazeMeter API Monitoring) platform. Manages buckets, API tests, environment...Step CIStep CI is an open source API Quality Assurance framework that is language-agnostic and configured using YA...Mitmproxymitmproxy is a free and open source interactive HTTPS proxy for intercepting, inspecting, modifying, and re...Arga APIPublic REST API for Arga's testing infrastructure — provision digital twins, deploy branches/PRs into sandb...Noname Active TestingNoname Active Testing enables organizations to test APIs for vulnerabilities and misconfigurations before t...Noname API Security PlatformThe Noname API Security Platform provides comprehensive API security through discovery, posture management,...PawPaw (now RapidAPI for Mac) is a full-featured HTTP client that lets you test and describe the APIs you buil...
Unrated 5 Not yet scored
BrunoBruno is an open-source API client and test suite manager that stores API collections as plain files alongs...Dredd APICommand-line HTTP API testing framework that validates API implementations against API Blueprint or OpenAPI...HurlHurl is a command-line tool that runs HTTP requests defined in a simple plain-text format, enabling lightwe...Karate API Testing FrameworkKarate is an open-source framework that combines API test automation, mocks, performance testing, and UI au...Postman APIAPI for managing Postman collections, environments, monitors, mock servers, and test runs programmatically....
Companies reaching this through an API (9)
These companies publish an API, specification or operation carrying “API Testing” but do not classify their business under it. Listed unranked and kept out of the count above, because one tagged operation is not a statement about what a company does.
APIs.io Engineering Platform
BDD (Behavior-Driven Development)
CA Technologies (Broadcom)
cURL
Fiddler
Stoplight
Test First
Test Scripts
Testim
Score breakdown
Frequency
52.6
log-scaled weighted occurrences
Breadth
1.4
spread across providers
Quality lift
35.8
mean composite of providers using it
Cohesion
10.5
strength of nearest seed neighbor
Where this tag sits
Related tags
Performance Testing 9 co-occurrences
API Client 8 co-occurrences
API Design 11 co-occurrences
Contract Testing 7 co-occurrences
API Monitoring 6 co-occurrences
CI/CD 19 co-occurrences
Quality Assurance 11 co-occurrences
Functional Testing 5 co-occurrences
Where this tag comes from
Provider tag52
Api tag40
Cohort brief
Auto-generatedThe 48 providers in the APIs.io catalog tagged API Testing, scored on the Kin Score. Every figure below is computed from the catalog — nothing here is written.
Providers
48
all scored
Mean Kin Score
32
+8 vs catalog 24
Mean Agent Readiness
15.6
+3.2 vs catalog 12.4
Spread
7.7–72.4
median 30.9 · σ 14.7
How the 48 split by band
Exemplar 1Strong 2Developing 13Thin 14Emerging 17Minimal 1
Facet averages, against the whole catalog
| Facet | This cohort | Catalog | Difference | Scored |
|---|---|---|---|---|
| Developer Ergonomics | 33.9 | 23.4 | +10.5 | 48 |
| Contract Quality | 29.3 | 20.1 | +9.2 | 48 |
| Operational Transparency | 22.9 | 14 | +8.9 | 48 |
| Contract Governance | 13.5 | 6.5 | +7 | 48 |
| Access Clarity | 32.3 | 26.5 | +5.8 | 48 |
| Discoverability | 64.6 | 61 | +3.6 | 48 |
A facet is averaged over the members that carry it, not over the whole cohort — the “Scored” column is that count. Averaging an absent facet as zero would score our own coverage gaps as the providers’ posture.
What this cohort publishes
| Artifact | This cohort | Catalog | Difference |
|---|---|---|---|
| MCP server (any) | 24% | 10% | +14 |
| MCP server (first-party) | 16% | 13% | +3 |
| Agent Skills | 0% | 0% | 0 |
| OAuth scopes | 6% | 11% | -5 |
| Security | 98% | 96% | +2 |
| Arazzo workflows | 6% | 2% | +4 |
| Governance rules | 45% | 13% | +32 |
mcp_pct counts any mcp/ artifact including ones API Evangelist derived from the provider OpenAPI; mcp_first_party_pct counts only servers the provider publishes. Prefer the latter.
Top by Kin Score
- 1 Postman 72.4
- 2 Routebase 62.1
- 3 Keploy 57
- 4 Apidog 52.5
- 5 Pynt 51.2
- 6 Bruno 49.9
- 7 Elva 49.5
- 8 Assertible 48.5
- 9 Testmail 44.6
- 10 APIToolkit (Monoscope) 44.5
Top by Agent Readiness
- 1 Postman 57.6
- 2 Routebase 52.9
- 3 Elva 44.8
- 4 Assertible 34.7
- 5 Keploy 34.6
- 6 Archal 31
- 7 Testmail 30.6
- 8 Agent Diff 30.6
- 9 Ressl 29.9
- 10 Traceable 29
All 52 members of this roster resolve to a scored provider in
the catalog.Generated from the catalog build of
20 September 2026, across 27620
providers, using the same computation served by the
APIs.io cohort API. Briefs are published for rosters of
5 or more scored providers; below that a distribution is not meaningful.
Work with this as data
Every tag here is available over the APIs.io API and to AI agents over MCP.