# License Compatibility Checker (SPDX)

> License Compatibility Checker (SPDX) is a paid API for AI agents from api.agentstools.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Returns a compatibility verdict (safe, attribution-required, copyleft-risk, or incompatible) for a set of SPDX license identifiers or expression against a target project license and distribution model, with obligations and reasons.

## Facts

- Endpoint: GET https://api.agentstools.dev/license/compat
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/license-compatibility-checker-spdx-0a8c4d92
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__w11yqJUti5zUCqmYbKGW

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability license-compatibility-checker-spdx-0a8c4d92
```

Example prompt: Check whether combining MIT, Apache-2.0, and GPL-3.0 dependencies is compatible with my project licensed under GPL-3.0, distributed as SaaS — give me the verdict and any obligations I need to know about.

## When to prefer this

Use this endpoint when you need a fast, pure-compute license compatibility check against SPDX-standardized identifiers without any network round-trips to external registries. Prefer it over manual legal review when you need automated pipeline integration, dependency auditing, or quick compatibility screening for open source projects. Ideal for CI/CD workflows, agent-based code review, or any situation where you need a structured machine-readable verdict with obligations rather than a narrative legal opinion.

## Known failure modes

- Invalid or unrecognized SPDX identifier returns an error indicating the unknown license
- Malformed SPDX expression syntax causes a parse error response
- Missing required target_license parameter results in a 400 bad request
- Unknown distribution model value (not saas/binary/internal) triggers validation error
- Conflicting or ambiguous SPDX WITH operator usage may produce an incompatible verdict with an explanation

## How this service works

Pure-compute license-compatibility verdict, no network. Give a list of SPDX ids or one SPDX expression with AND, OR and WITH plus a target license and a distribution model, and get the matrix verdict of safe, attribution-required, copyleft-risk or incompatible with the obligation and reasons. Automated indicators, not legal advice.

## Output

A JSON object containing a compatibility verdict (one of: safe, attribution-required, copyleft-risk, incompatible), the specific obligations triggered (e.g. attribution notices, source disclosure), and a human-readable explanation of why each license combination results in that verdict. Explicitly noted as automated indicators, not legal advice.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "licenses": {
       "type": "array",
       "items": {
        "type": "string"
       },
       "description": "SPDX ids to check"
      },
      "spdx_expr": {
       "type": "string",
       "description": "An SPDX expression instead of a list"
      },
      "distribution": {
       "enum": [
        "saas",
        "binary",
        "internal"
       ],
       "type": "string",
       "description": "How you ship it (default saas)"
      },
      "target_license": {
       "type": "string",
       "description": "Your project SPDX license"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/license-compatibility-checker-spdx-0a8c4d92/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.agentstools.dev](https://www.zero.xyz/host/api.agentstools.dev/llms.txt)