For June 2026, the API Development & Testing Tools set covers tools used around API clients, gateways, proxies, code generation, contract testing, local service emulation, and related developer workflows. The ToolVitals data compares each tool by health score, shipping score, openness_label, license_label, GitHub stars, ToolVitals score, and status.
This ranking includes open/source-visible tools only and sorts first by ToolVitals score, with GitHub stars used only as a secondary popularity signal when scores are tied. The result favors actively maintained and consistently shipping projects over name recognition alone.
Rankings
| Rank | Tool | Openness | License | Health | Shipping | GitHub Stars | Score | Status |
|---|---|---|---|---|---|---|---|---|
| 1 | Strapi | OSI-approved OSS | MIT | 100 | 100 | 72348 | 100 | 🟢 Excellent |
| 2 | Scalar | OSI-approved OSS | MIT | 100 | 100 | 15239 | 100 | 🟢 Excellent |
| 3 | Traefik | OSI-approved OSS | MIT | 100 | 94 | 63595 | 98 | 🟢 Excellent |
| 4 | new-api | OSI-approved OSS | AGPL-3.0 | 95 | 100 | 38549 | 97 | 🟢 Excellent |
| 5 | Ministack | OSI-approved OSS | MIT | 93 | 100 | 0 | 97 | 🟢 Excellent |
| 6 | kgateway | OSI-approved OSS | Apache-2.0 | 93 | 100 | 5560 | 96 | 🟢 Excellent |
| 7 | Kumo | OSI-approved OSS | MIT | 92 | 98 | 1380 | 96 | 🟢 Excellent |
| 8 | OpenAPI Generator | OSI-approved OSS | Apache-2.0 | 90 | 89 | 26397 | 92 | 🟢 Excellent |
| 9 | MCP Context Forge | OSI-approved OSS | Apache-2.0 | 91 | 89 | 3879 | 92 | 🟢 Excellent |
| 10 | Kuadrant MCP Gateway | OSI-approved OSS | Apache-2.0 | 86 | 95 | 82 | 92 | 🟢 Excellent |
| 11 | Specmatic | OSI-approved OSS | MIT | 80 | 98 | 381 | 91 | 🟢 Excellent |
| 12 | MCP Assert | OSI-approved OSS | MIT | 83 | 93 | 18 | 90 | 🟢 Excellent |
| 13 | Apache APISIX | OSI-approved OSS | Apache-2.0 | 87 | 76 | 16720 | 87 | 🟢 Excellent |
| 14 | Requesto | OSI-approved OSS | MIT | 78 | 83 | 5 | 84 | 🟢 Excellent |
| 15 | mitmproxy | OSI-approved OSS | MIT | 84 | 69 | 43894 | 83 | 🟢 Excellent |
| 16 | Higress | OSI-approved OSS | Apache-2.0 | 81 | 72 | 8636 | 83 | 🟢 Excellent |
| 17 | Stoa | OSI-approved OSS | Apache-2.0 | 68 | 89 | 2 | 83 | 🟢 Excellent |
| 18 | HttpArena | OSI-approved OSS | MIT | 72 | 72 | 0 | 76 | 🟢 Good |
| 19 | testcontainers-go | OSI-approved OSS | MIT | 77 | 57 | 4878 | 75 | 🟢 Good |
| 20 | Previa | OSI-approved OSS | MIT | 55 | 95 | 2 | 75 | 🟢 Good |
| 21 | API Dash | OSI-approved OSS | Apache-2.0 | 76 | 58 | 0 | 73 | 🟢 Good |
| 22 | Kong | OSI-approved OSS | Apache-2.0 | 78 | 42 | 43584 | 72 | 🟢 Good |
| 23 | Tyk | OSI-approved OSS | AGPL-3.0 | 73 | 48 | 10739 | 72 | 🟢 Good |
| 24 | AI Gateway | OSI-approved OSS | Apache-2.0 | 59 | 65 | 55 | 71 | 🟢 Good |
| 25 | Easegress | OSI-approved OSS | Apache-2.0 | 69 | 29 | 5871 | 61 | 🟢 Good |
| 26 | Webhookx | OSI-approved OSS | Apache-2.0 | 60 | 34 | 297 | 60 | 🟢 Good |
| 27 | Yasumu | OSI-approved OSS | AGPL-3.0 | 54 | 34 | 44 | 59 | 🟡 Fair |
| 28 | Lura | OSI-approved OSS | Apache-2.0 | 62 | 21 | 0 | 55 | 🟡 Fair |
| 29 | APIPark | OSI-approved OSS | Apache-2.0 | 49 | 7 | 1754 | 46 | 🟡 Fair |
| 30 | Restfox | OSI-approved OSS | MIT | 46 | 14 | 0 | 44 | 🟡 Fair |
| 31 | Moesif Developer Portal | OSI-approved OSS | Apache-2.0 | 38 | 7 | 42 | 42 | 🟡 Fair |
| 32 | APIMAN | OSI-approved OSS | Apache-2.0 | 28 | 0 | 0 | 32 | 🔴 Needs Attention |
| 33 | OpenTest | OSI-approved OSS | MIT | 28 | 0 | 0 | 30 | 🔴 Needs Attention |
| 34 | Gotcha REST Client | OSI-approved OSS | MIT | 11 | 0 | 206 | 23 | 🔴 Needs Attention |
Top 3 Highlights
Strapi ranks first with a ToolVitals score of 100, health score of 100, and shipping score of 100. It is listed as OSI-approved OSS under MIT, and its 72,348 GitHub stars give it the strongest popularity signal among the tools tied at the top.
Scalar also has a ToolVitals score of 100, with perfect health and shipping scores. It is listed as OSI-approved OSS under MIT, and its positioning is especially relevant to this category because the supplied description calls out a modern REST API client, API references, and first-class OpenAPI/Swagger support.
Traefik ranks third with a ToolVitals score of 98, backed by a health score of 100 and shipping score of 94. It is listed as OSI-approved OSS under MIT, and its 63,595 GitHub stars make it one of the most widely followed projects in the dataset.
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