API Development & Testing Tools covers a mixed set of API clients, gateways, proxies, contract-testing tools, developer portals, local emulators, and related infrastructure. The May 2026 ToolVitals data compares 27 open-source tools using the supplied health score, shipping score, GitHub stars, ToolVitals score, and status for each project.
The ranking is sorted by ToolVitals score first, with GitHub stars used as a secondary popularity signal when scores are tied. That puts tools with strong health and shipping signals ahead of larger but less active projects, while still using stars to break close groups in a transparent way.
Rankings
| Rank | Tool | Health | Shipping | GitHub Stars | Score | Status |
|---|---|---|---|---|---|---|
| 1 | Strapi | 100 | 100 | 72134 | 94 | 🟢 Excellent |
| 2 | Traefik | 100 | 100 | 63111 | 94 | 🟢 Excellent |
| 3 | Scalar | 100 | 100 | 14990 | 94 | 🟢 Excellent |
| 4 | kgateway | 91 | 100 | 5506 | 94 | 🟢 Excellent |
| 5 | Ministack | 91 | 100 | 2716 | 94 | 🟢 Excellent |
| 6 | Kumo | 97 | 100 | 1267 | 94 | 🟢 Excellent |
| 7 | Requesto | 89 | 100 | 5 | 94 | 🟢 Excellent |
| 8 | remote-store | 89 | 100 | 4 | 94 | 🟢 Excellent |
| 9 | Specmatic | 88 | 100 | 374 | 93 | 🟢 Excellent |
| 10 | new-api | 95 | 100 | 32247 | 90 | 🟢 Excellent |
| 11 | Previa | 67 | 100 | 2 | 78 | 🟢 Good |
| 12 | Higress | 82 | 62 | 8352 | 73 | 🟢 Good |
| 13 | mitmproxy | 84 | 56 | 43478 | 71 | 🟢 Good |
| 14 | Apache APISIX | 87 | 47 | 16577 | 69 | 🟢 Good |
| 15 | Easegress | 78 | 47 | 5870 | 64 | 🟢 Good |
| 16 | Tyk | 79 | 38 | 10713 | 61 | 🟢 Good |
| 17 | AI Gateway | 73 | 30 | 31 | 54 | 🟡 Fair |
| 18 | Yasumu | 65 | 30 | 44 | 49 | 🟡 Fair |
| 19 | APIPark | 73 | 0 | 1705 | 40 | 🟡 Fair |
| 20 | Lura | 61 | 0 | 6772 | 34 | 🔴 Needs Attention |
| 21 | LegalContext | 61 | 0 | 25 | 34 | 🔴 Needs Attention |
| 22 | API Dash | 58 | 0 | 2813 | 32 | 🔴 Needs Attention |
| 23 | FlyGasal | 58 | 0 | 0 | 32 | 🔴 Needs Attention |
| 24 | Kong | 57 | 0 | 43355 | 31 | 🔴 Needs Attention |
| 25 | Sitecore Developer Portal | 55 | 0 | 35 | 30 | 🔴 Needs Attention |
| 26 | Moesif Developer Portal | 52 | 0 | 39 | 29 | 🔴 Needs Attention |
| 27 | API 200 | 13 | 0 | 255 | 7 | 🔴 Needs Attention |
Top 3 Highlights
Strapi ranks first with a ToolVitals score of 94, health score of 100, shipping score of 100, and 72,134 GitHub stars. It is described as an open-source headless CMS built with JavaScript and TypeScript, and it leads a crowded top tier because it combines perfect health and shipping scores with the largest star count among tools tied at 94.
Traefik ranks second with the same 94 ToolVitals score, 100 health score, and 100 shipping score as Strapi, backed by 63,111 GitHub stars. Its description is narrower and infrastructure-focused: a cloud-native application proxy. Among the top-scoring tools, it has the second-highest GitHub star count, which places it ahead of the other 94-score projects.
Scalar ranks third with a ToolVitals score of 94, perfect 100 health and shipping scores, and 14,990 GitHub stars. It stands out as a purpose-built API platform in this group, with the supplied description highlighting a modern REST API client, API references, and first-class OpenAPI and Swagger support.
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