# POST /license/check: $0.003 per call

Licence compatibility check for coding agents: give your project's licence (or proprietary) and how it's used (distributed, SaaS or internal) plus up to 50 dependencies as SPDX ids or packages (npm:express@4.21.2); get ok / conditions / review / incompatible per dependency with the reason (GPL, AGPL, LGPL, MPL, Apache, dual licences...). Not legal advice.

- **Price:** $0.003 in USDC, the same on Base, Solana, Polygon, Arbitrum. Failed calls are never charged.
- **Free trial:** yes, 20 free calls a day from Claude, Cursor or any MCP client ([set-up](/mcp/setup)).
- **Tier:** live
- **Answers cached for:** 1 day(s)
- **Data sources:** Built-in licence compatibility rules; deps.dev licences for packages (free)
- **Lane:** AI coding agents ([OpenAPI](/openapi/coding.json))
- **Live health:** [status page](/status)

## Free sample

See an answer for the demo input first, free (no payment, 10 a minute): [https://aayatai.com/sample/license-check](/sample/license-check). It is a stored real answer when we have one, otherwise an example marked `"kind": "illustrative"`.

```bash
curl "https://aayatai.com/sample/license-check"
```

## 1. See the price (free)

Call it without paying: you get `402 Payment Required` and a `PAYMENT-REQUIRED` header with the exact price and where to pay.

```bash
curl -i -X POST https://aayatai.com/license/check -H "content-type: application/json" -d '{"project":"proprietary","usage":"saas","dependencies":["MIT","AGPL-3.0-only","npm:express@4.21.2"]}'
```

## 2. Pay and call (TypeScript)

```bash
npm install @x402/fetch @x402/evm viem
```

```ts
import { wrapFetchWithPaymentFromConfig } from "@x402/fetch";
import { ExactEvmScheme } from "@x402/evm";
import { privateKeyToAccount } from "viem/accounts";

// A wallet used only by your agent, holding a little USDC on Base.
const account = privateKeyToAccount(process.env.WALLET_PRIVATE_KEY as `0x${string}`);
const pay = wrapFetchWithPaymentFromConfig(fetch, {
  schemes: [{ network: "eip155:8453", client: new ExactEvmScheme(account) }],
});

const res = await pay("https://aayatai.com/license/check", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({"project":"proprietary","usage":"saas","dependencies":["MIT","AGPL-3.0-only","npm:express@4.21.2"]}),
});
console.log(await res.json());
```

## 3. Or as an MCP tool

```ts
// MCP server: https://aayatai.com/mcp (Streamable HTTP). With the x402 MCP client (see /start):
const result = await client.callTool("license-check", {"project":"proprietary","usage":"saas","dependencies":["MIT","AGPL-3.0-only","npm:express@4.21.2"]});
```

## Inputs

- `project` (string; default `proprietary`): Your project's SPDX licence id (e.g. MIT, GPL-3.0-only) or proprietary.
- `usage` (string; one of `distributed`, `saas`, `internal`; default `distributed`): distributed (you ship code or apps), saas (users use it over the network), internal (staff only).
- `dependencies` **(required)** (array): SPDX ids or packages, e.g. ["GPL-3.0-only", "npm:react@19.0.0", "pypi:requests"].

Bad inputs are rejected with HTTP 400 before any payment is asked for.

## Example answer

```json
{
  "project": "proprietary",
  "usage": "saas",
  "verdict": "incompatible",
  "summary": "At least one dependency's licence conflicts with how you plan to use or ship your project.",
  "dependencies": [
    {
      "input": "MIT",
      "licence": "MIT",
      "family": "permissive",
      "status": "ok",
      "reason": "Permissive: keep its copyright and licence notice."
    },
    {
      "input": "AGPL-3.0-only",
      "licence": "AGPL-3.0-only",
      "family": "network-copyleft",
      "status": "incompatible",
      "reason": "AGPL: offering it to users over a network (SaaS)..."
    },
    {
      "input": "npm:express@4.21.2",
      "package": "express",
      "version": "4.21.2",
      "licence": "MIT",
      "family": "permissive",
      "status": "ok",
      "reason": "Permissive."
    }
  ],
  "disclaimer": "Automated guidance from licence texts and common compatibility rules, not legal advice."
}
```

## Related

- [GET /docs/find](/services/docs-find) ($0.003): Find the AI-ready docs for any library or API: checks the project's docs site (from its npm, PyPI, crates or Go metadata) or any company domain (docs., develope
- [GET /docs/lib](/services/docs-lib) ($0.005): Up-to-date docs for any npm, PyPI, crates or Go library, trimmed for a coding agent's context: finds the project's own llms.txt and docs pages (or the latest re
- [POST /docs/answer](/services/docs-answer) ($0.02): Ask a coding question about any npm, PyPI, crates or Go library and get an answer written only from its current docs (project llms.txt, docs pages or latest REA
- [GET /openapi](/services/openapi) ($0.005): Understand any public API fast: give its OpenAPI/Swagger spec URL, its docs or base URL, or a name from the APIs.guru directory (?api=stripe.com); we find the s
- [GET /library/research](/services/library-research) ($0.10): Premium research report on a library or API for coding agents: reads its current docs for your goal, checks version, safety and repository health, gathers what 
- [GET /package/check](/services/package-check) ($0.005): Should a coding agent install this package?
- [GET /dependency/verdict](/services/dependency-verdict) ($0.03): "Should I use this dependency?" in one call for npm, PyPI, crates or Go: full package safety check (vulnerabilities, malware, typosquats, deprecation, licence, 
- [GET /dependency/report](/services/dependency-report) ($0.08): Premium "should I use this dependency?" report: package safety (vulnerabilities, malware, typosquats, deprecation), GitHub repository health, licence compatibil

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