Open-source license compatibility API

Given a set of SPDX license IDs (e.g. your dependencies'), the resulting obligation level, the license the combined/distributed work must carry, and known incompatibilities (e.g. GPL-2.0 ⊗ Apache-2.0). Deterministic guidance — correctness is the moat; license compat is easy to get subtly wrong. Answers 'are these licenses compatible', 'can I combine MIT and GPL-3.0', 'what license must my project be'.

Price$0.01per request

MethodPOST

Route/v1/dev/license-check

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache3600s public

devlicensespdxcompatibilityopen-sourcecompliancegplcopyleft

API URLhttps://x402.hexl.dev/v1/dev/license-check

Integration docs

Example request

{
  "licenses": [
    "MIT",
    "GPL-2.0",
    "Apache-2.0"
  ]
}

Example response

{
  "licenses": [
    {
      "input": "MIT",
      "spdx": "MIT",
      "kind": "permissive",
      "tier": 1
    },
    {
      "input": "GPL-2.0",
      "spdx": "GPL-2.0",
      "kind": "strong-copyleft",
      "tier": 3
    }
  ],
  "compatible": false,
  "conflicts": [
    "GPL-2.0 is incompatible with Apache-2.0 (patent clause) — only GPL-3.0 is Apache-2.0-compatible."
  ],
  "resultingObligation": "share source of the whole combined work when distributed (strong copyleft)",
  "recommendedLicenseForCombinedWork": "GPL-2.0",
  "disclaimer": "Heuristic guidance, not legal advice."
}

Input schema

{
  "type": "object",
  "required": [
    "licenses"
  ],
  "properties": {
    "licenses": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "examples": [
        [
          "MIT",
          "Apache-2.0",
          "GPL-3.0"
        ]
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}