API Development & Testing Tools cover more than request runners: the July 2026 ToolVitals data includes API platforms, gateways, AI gateways, contract-testing suites, local cloud emulators, mocking tools, code generators, proxies, and load-testing tools. The practical question is which projects show both strong current health and visible shipping activity, rather than just name recognition.
This ranking includes open/source-visible tools only. Tools are ordered by ToolVitals score descending, with GitHub stars used as a secondary popularity signal when scores are tied; openness_label and license_label are reported as supplied so OSI-approved OSS is not mixed up with other source-visible models.
Rankings
| Rank | Tool | Openness | License | Health | Shipping | GitHub Stars | Score | Status |
|---|---|---|---|---|---|---|---|---|
| 1 | Strapi | OSI-approved OSS | MIT | 100 | 100 | 72589 | 100 | 🟢 Excellent |
| 2 | Traefik | OSI-approved OSS | MIT | 100 | 100 | 63849 | 100 | 🟢 Excellent |
| 3 | Scalar | OSI-approved OSS | MIT | 100 | 100 | 15421 | 100 | 🟢 Excellent |
| 4 | Bifrost | OSI-approved OSS | Apache-2.0 | 98 | 100 | 6263 | 99 | 🟢 Excellent |
| 5 | new-api | OSI-approved OSS | AGPL-3.0 | 95 | 100 | 41090 | 97 | 🟢 Excellent |
| 6 | AxonHub | OSI-approved OSS | Apache-2.0 | 98 | 100 | 4549 | 97 | 🟢 Excellent |
| 7 | Ministack | OSI-approved OSS | MIT | 93 | 100 | 3433 | 97 | 🟢 Excellent |
| 8 | kgateway | OSI-approved OSS | Apache-2.0 | 93 | 100 | 5593 | 96 | 🟢 Excellent |
| 9 | MCP Context Forge | OSI-approved OSS | Apache-2.0 | 95 | 95 | 4016 | 95 | 🟢 Excellent |
| 10 | Specmatic | OSI-approved OSS | MIT | 85 | 98 | 386 | 93 | 🟢 Excellent |
| 11 | Apache APISIX | OSI-approved OSS | Apache-2.0 | 91 | 83 | 16812 | 91 | 🟢 Excellent |
| 12 | Inference Gateway | OSI-approved OSS | Apache-2.0 | 85 | 95 | 129 | 91 | 🟢 Excellent |
| 13 | Kumo | OSI-approved OSS | MIT | 83 | 92 | 1406 | 90 | 🟢 Excellent |
| 14 | Kuadrant MCP Gateway | OSI-approved OSS | Apache-2.0 | 81 | 95 | 89 | 90 | 🟢 Excellent |
| 15 | MCP Assert | OSI-approved OSS | MIT | 83 | 93 | 21 | 90 | 🟢 Excellent |
| 16 | OpenAPI Generator | OSI-approved OSS | Apache-2.0 | 86 | 83 | 26477 | 89 | 🟢 Excellent |
| 17 | FakeCloud | OSI-approved OSS | AGPL-3.0 | 80 | 93 | 461 | 89 | 🟢 Excellent |
| 18 | Karate | OSI-approved OSS | MIT | 77 | 90 | 8892 | 87 | 🟢 Excellent |
| 19 | Higress | OSI-approved OSS | Apache-2.0 | 87 | 78 | 8780 | 87 | 🟢 Excellent |
| 20 | Membrane API Gateway | OSI-approved OSS | Apache-2.0 | 83 | 80 | 618 | 85 | 🟢 Excellent |
| 21 | Tyk | OSI-approved OSS | AGPL-3.0 | 84 | 72 | 10757 | 84 | 🟢 Excellent |
| 22 | Microcks | OSI-approved OSS | Apache-2.0 | 81 | 72 | 1975 | 83 | 🟢 Excellent |
| 23 | testcontainers-go | OSI-approved OSS | MIT | 81 | 70 | 4905 | 81 | 🟢 Excellent |
| 24 | mitmproxy | OSI-approved OSS | MIT | 81 | 63 | 44164 | 80 | 🟢 Excellent |
| 25 | Requesto | OSI-approved OSS | MIT | 76 | 69 | 5 | 79 | 🟢 Good |
| 26 | Gravitee | OSI-approved OSS | Apache-2.0 | 74 | 72 | 426 | 78 | 🟢 Good |
| 27 | HttpArena | OSI-approved OSS | MIT | 72 | 72 | 83 | 76 | 🟢 Good |
| 28 | Stoa | OSI-approved OSS | Apache-2.0 | 73 | 59 | 2 | 76 | 🟢 Good |
| 29 | API Dash | OSI-approved OSS | Apache-2.0 | 76 | 65 | 2842 | 75 | 🟢 Good |
| 30 | KrakenD | OSI-approved OSS | Apache-2.0 | 79 | 48 | 2647 | 74 | 🟢 Good |
| 31 | Kong | OSI-approved OSS | Apache-2.0 | 78 | 46 | 43723 | 73 | 🟢 Good |
| 32 | AI Gateway | OSI-approved OSS | Apache-2.0 | 62 | 60 | 48 | 71 | 🟢 Good |
| 33 | Emissary | OSI-approved OSS | Apache-2.0 | 74 | 36 | 4510 | 67 | 🟢 Good |
| 34 | digiRunner | OSI-approved OSS | Apache-2.0 | 66 | 40 | 306 | 65 | 🟢 Good |
| 35 | PomeloHook | OSI-approved OSS | MIT | 53 | 59 | 5 | 65 | 🟢 Good |
| 36 | GhostPour | OSI-approved OSS | MIT | 53 | 58 | 2 | 65 | 🟢 Good |
| 37 | Previa | OSI-approved OSS | MIT | 53 | 67 | 2 | 65 | 🟢 Good |
| 38 | Apache JMeter | OSI-approved OSS | Apache-2.0 | 73 | 28 | 9453 | 62 | 🟢 Good |
| 39 | Fusio | OSI-approved OSS | Apache-2.0 | 56 | 39 | 2100 | 62 | 🟢 Good |
| 40 | pREST | OSI-approved OSS | MIT | 61 | 42 | 0 | 62 | 🟢 Good |
| 41 | Lura | OSI-approved OSS | Apache-2.0 | 67 | 21 | 6783 | 57 | 🟡 Fair |
| 42 | Easegress | OSI-approved OSS | Apache-2.0 | 63 | 18 | 5874 | 55 | 🟡 Fair |
| 43 | Webhookx | OSI-approved OSS | Apache-2.0 | 51 | 24 | 295 | 53 | 🟡 Fair |
| 44 | Restfox | OSI-approved OSS | MIT | 65 | 10 | 2724 | 51 | 🟡 Fair |
| 45 | Yasumu | OSI-approved OSS | AGPL-3.0 | 39 | 24 | 44 | 50 | 🟡 Fair |
| 46 | Choreo Connect | OSI-approved OSS | Apache-2.0 | 54 | 0 | 315 | 47 | 🟡 Fair |
| 47 | NyaProxy | OSI-approved OSS | MIT | 36 | 28 | 0 | 47 | 🟡 Fair |
| 48 | APIPark | OSI-approved OSS | Apache-2.0 | 49 | 7 | 1768 | 46 | 🟡 Fair |
| 49 | ATAC | OSI-approved OSS | MIT | 35 | 4 | 3660 | 40 | 🟡 Fair |
| 50 | Moesif Developer Portal | OSI-approved OSS | Apache-2.0 | 36 | 0 | 41 | 39 | 🔴 Needs Attention |
Top 3 Highlights
Strapi ranks #1 with a ToolVitals score of 100, health score of 100, and shipping score of 100. It is labeled OSI-approved OSS under the MIT license_label, with 72,589 GitHub stars, making it the highest-starred tool among the 100-score group in this dataset.
Traefik ranks #2 with a ToolVitals score of 100, health score of 100, and shipping score of 100. Its API infrastructure role is clear from the supplied description, “The Cloud Native Application Proxy,” and it is labeled OSI-approved OSS under the MIT license_label with 63,849 GitHub stars.
Scalar ranks #3 with a ToolVitals score of 100 and perfect health and shipping scores. It stands out as the most directly API-documentation-and-client-focused project in the top three, with the supplied description calling out a modern REST API client, API references, and first-class OpenAPI/Swagger support; it is OSI-approved OSS with the MIT license_label.
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