> For the complete documentation index, see [llms.txt](https://minara.ai/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://minara.ai/docs/minara-handbook/ja/qu-yin/agent-api/x402.md).

# x402

x402 はサブスクリプション不要の従量課金 API アクセス方式です。Base、Solana、Polygon 上の USDC などのステーブルコインを使って、各呼び出しごとに直接支払います。

Minara の x402 エンドポイント: `https://x402.minara.ai/.well-known/x402`

すべてのエンドポイントを確認: [x402scan 上の Minara](https://www.x402scan.com/server/66307a3c-aeb9-4508-9531-71eed69bc9b5)

***

## x402 の仕組み

x402 は支払いチャレンジのフローに従います:

1. まず、支払いなしで保護されたエンドポイントにリクエストを送ります。
2. サーバーは `402 Payment Required` と支払い指示（金額、通貨、受取先アドレス、チェーン）を返します。
3. あなたは `x-payment-response` ヘッダーに支払い証明を含めて、リクエストを再試行します。
4. サーバーは証明を検証し、オンチェーンで支払いを処理してから、API レスポンスを返します。

推奨される方法は x402 SDK を使うことです。これがこのフローを自動で処理します。

***

## SDK のはじめ方

### 前提条件

* USDC を保有する暗号資産ウォレット（任意の EVM 互換ウォレット、または Solana ウォレット）
* Node.js / Python / Go
* ウォレットの秘密鍵（支払い署名用）

### インストール

{% tabs %}
{% tab title="Node.js" %}

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

{% endtab %}

{% tab title="Python" %}

```bash
pip install "x402[httpx]"
```

{% endtab %}

{% tab title="Go" %}

```bash
go get github.com/coinbase/x402/go
```

{% endtab %}
{% endtabs %}

### リクエストを送る

SDK は支払いチャレンジを自動で処理します。通常どおりリクエストするだけです。

{% tabs %}
{% tab title="Node.js" %}

```typescript
import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const signer = privateKeyToAccount(process.env.EVM_PRIVATE_KEY as `0x${string}`);
const client = new x402Client();
registerExactEvmScheme(client, { signer });

const fetchWithPayment = wrapFetchWithPayment(fetch, client);

const response = await fetchWithPayment("https://x402.minara.ai/x402/chat", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ userQuery: "BTC の現在価格は？" })
});

const data = await response.json();
console.log(data.content);
```

{% endtab %}

{% tab title="Python" %}

```python
import asyncio, os
from eth_account import Account
from x402 import x402Client
from x402.http.clients import x402HttpxClient
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

async def call_minara():
    client = x402Client()
    account = Account.from_key(os.getenv("EVM_PRIVATE_KEY"))
    register_exact_evm_client(client, EthAccountSigner(account))

    async with x402HttpxClient(client) as http:
        response = await http.post(
            "https://x402.minara.ai/x402/chat",
            json={"userQuery": "BTC の価格は？"}
        )
        await response.aread()
        print(response.json()["content"])

asyncio.run(call_minara())
```

{% endtab %}

{% tab title="Go" %}

```go
evmSigner, _ := evmsigners.NewClientSignerFromPrivateKey(os.Getenv("EVM_PRIVATE_KEY"))
x402Client := x402.Newx402Client().
    Register("eip155:*", evm.NewExactEvmScheme(evmSigner))

httpClient := x402http.WrapHTTPClientWithPayment(
    http.DefaultClient,
    x402http.Newx402HTTPClient(x402Client),
)

req, _ := http.NewRequest("POST", "https://x402.minara.ai/x402/chat",
    strings.NewReader(`{"userQuery":"BTC の価格は？"}`))
req.Header.Set("Content-Type", "application/json")

resp, _ := httpClient.Do(req)
// 支払いは自動的に処理されます
```

{% endtab %}
{% endtabs %}

x402 のクイックスタート全体については、 [x402 ドキュメント](https://docs.x402.org/getting-started/quickstart-for-buyers).

***

## API リファレンス

ベース URL: `https://x402.minara.ai`

すべてのエンドポイントには `x-payment-response` ヘッダーが必要です（SDK により自動処理されます）。

## Chat (Base Chain)

> Ask Minara AI - Intelligent crypto assistant

```json
{"openapi":"3.0.0","info":{"title":"Minara x402 API","version":"1.0"},"servers":[{"url":"https://x402.minara.ai"}],"security":[{"x402Payment":[]}],"components":{"securitySchemes":{"x402Payment":{"type":"apiKey","in":"header","name":"x-payment-response","description":"Payment proof token obtained from x402 payment challenge flow. Required after completing payment."}},"schemas":{"ChatRequest":{"type":"object","required":["userQuery"],"properties":{"userQuery":{"type":"string","description":"Required. User query content."}}},"ChatResponse":{"type":"object","properties":{"content":{"type":"string","description":"AI response content."}}},"BadRequestError":{"type":"object","properties":{"error":{"type":"string"},"message":{"type":"string"}}},"UnauthorizedError":{"type":"object","properties":{"error":{"type":"string"},"message":{"type":"string"}}},"PaymentRequiredError":{"type":"object","properties":{"error":{"type":"string"},"message":{"type":"string"},"paymentInstructions":{"type":"object","properties":{"amount":{"type":"string","description":"Payment amount required."},"currency":{"type":"string","description":"Payment currency (e.g., USDC)."},"recipient":{"type":"string","description":"Payment recipient address."},"chain":{"type":"string","description":"Blockchain for payment."}}}}}}},"paths":{"/x402/chat":{"post":{"summary":"Chat (Base Chain)","description":"Ask Minara AI - Intelligent crypto assistant","operationId":"x402Chat","tags":["AI"],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/ChatRequest"}}}},"responses":{"201":{"description":"Successful response","content":{"application/json":{"schema":{"$ref":"#/components/schemas/ChatResponse"}}}},"400":{"description":"Bad Request - Invalid parameters","content":{"application/json":{"schema":{"$ref":"#/components/schemas/BadRequestError"}}}},"401":{"description":"Unauthorized - Invalid payment response token","content":{"application/json":{"schema":{"$ref":"#/components/schemas/UnauthorizedError"}}}},"402":{"description":"Payment Required","content":{"application/json":{"schema":{"$ref":"#/components/schemas/PaymentRequiredError"}}}}}}}}}
```

## Chat Expert (Base Chain)

> Ask Minara AI - Intelligent crypto assistant

```json
{"openapi":"3.0.0","info":{"title":"Minara x402 API","version":"1.0"},"servers":[{"url":"https://x402.minara.ai"}],"security":[{"x402Payment":[]}],"components":{"securitySchemes":{"x402Payment":{"type":"apiKey","in":"header","name":"x-payment-response","description":"Payment proof token obtained from x402 payment challenge flow. Required after completing payment."}},"schemas":{"ChatRequest":{"type":"object","required":["userQuery"],"properties":{"userQuery":{"type":"string","description":"Required. User query content."}}},"ChatResponse":{"type":"object","properties":{"content":{"type":"string","description":"AI response content."}}},"PaymentRequiredError":{"type":"object","properties":{"error":{"type":"string"},"message":{"type":"string"},"paymentInstructions":{"type":"object","properties":{"amount":{"type":"string","description":"Payment amount required."},"currency":{"type":"string","description":"Payment currency (e.g., USDC)."},"recipient":{"type":"string","description":"Payment recipient address."},"chain":{"type":"string","description":"Blockchain for payment."}}}}}}},"paths":{"/x402/chat/expert":{"post":{"summary":"Chat Expert (Base Chain)","description":"Ask Minara AI - Intelligent crypto assistant","operationId":"x402ChatExpert","tags":["AI"],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/ChatRequest"}}}},"responses":{"201":{"description":"Successful response","content":{"application/json":{"schema":{"$ref":"#/components/schemas/ChatResponse"}}}},"400":{"description":"Bad Request - Invalid parameters"},"401":{"description":"Unauthorized - Invalid payment response token"},"402":{"description":"Payment Required","content":{"application/json":{"schema":{"$ref":"#/components/schemas/PaymentRequiredError"}}}}}}}}}
```

## Perpetual Trading Suggestion

> Get AI-powered perpetual trading suggestions with long/short recommendations, entry price, stop loss, take profit levels, and confidence score.

```json
{"openapi":"3.0.0","info":{"title":"Minara x402 API","version":"1.0"},"servers":[{"url":"https://x402.minara.ai"}],"security":[{"x402Payment":[]}],"components":{"securitySchemes":{"x402Payment":{"type":"apiKey","in":"header","name":"x-payment-response","description":"Payment proof token obtained from x402 payment challenge flow. Required after completing payment."}},"schemas":{"PerpTradingRequest":{"type":"object","required":["symbol"],"properties":{"symbol":{"type":"string","description":"Required. Trading symbol (e.g., 'BTC', 'ETH', 'SOL')."},"style":{"type":"string","enum":["scalping","day-trading","swing-trading"],"default":"scalping","description":"Optional. Trading style: 'scalping', 'day-trading', or 'swing-trading'. Default: 'scalping'."},"marginUSD":{"type":"number","default":1000,"description":"Optional. Margin in USD. Default: 1000."},"leverage":{"type":"number","default":10,"minimum":1,"maximum":40,"description":"Optional. Leverage multiplier (max: 40). Default: 10."},"strategy":{"type":"string","default":"max-profit","description":"Optional. Strategy type. Default: 'max-profit'. More strategies coming soon."}}},"PerpTradingResponse":{"type":"object","properties":{"entryPrice":{"type":"number","description":"Recommended entry price."},"side":{"type":"string","enum":["long","short"],"description":"Trading side recommendation."},"stopLossPrice":{"type":"number","description":"Recommended stop loss price."},"takeProfitPrice":{"type":"number","description":"Recommended take profit price."},"confidence":{"type":"number","minimum":0,"maximum":100,"description":"Confidence score (0-100)."},"reasons":{"type":"array","items":{"type":"string"},"description":"Analysis reasons based on technical indicators."},"risks":{"type":"array","items":{"type":"string"},"description":"Risk factors to consider."}}},"PaymentRequiredError":{"type":"object","properties":{"error":{"type":"string"},"message":{"type":"string"},"paymentInstructions":{"type":"object","properties":{"amount":{"type":"string","description":"Payment amount required."},"currency":{"type":"string","description":"Payment currency (e.g., USDC)."},"recipient":{"type":"string","description":"Payment recipient address."},"chain":{"type":"string","description":"Blockchain for payment."}}}}}}},"paths":{"/x402/perp-trading-suggestion":{"post":{"summary":"Perpetual Trading Suggestion","description":"Get AI-powered perpetual trading suggestions with long/short recommendations, entry price, stop loss, take profit levels, and confidence score.","operationId":"x402PerpTradingSuggestion","tags":["Trading"],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/PerpTradingRequest"}}}},"responses":{"201":{"description":"Successful response","content":{"application/json":{"schema":{"$ref":"#/components/schemas/PerpTradingResponse"}}}},"400":{"description":"Bad Request - Invalid parameters"},"401":{"description":"Unauthorized - Invalid payment response token"},"402":{"description":"Payment Required","content":{"application/json":{"schema":{"$ref":"#/components/schemas/PaymentRequiredError"}}}}}}}}}
```

## Intent to Swap Transaction

> Convert natural language trading intent into an executable swap transaction payload. Compatible with OKX DEX by default.

```json
{"openapi":"3.0.0","info":{"title":"Minara x402 API","version":"1.0"},"servers":[{"url":"https://x402.minara.ai"}],"security":[{"x402Payment":[]}],"components":{"securitySchemes":{"x402Payment":{"type":"apiKey","in":"header","name":"x-payment-response","description":"Payment proof token obtained from x402 payment challenge flow. Required after completing payment."}},"schemas":{"IntentToSwapRequest":{"type":"object","required":["intent","walletAddress"],"properties":{"intent":{"type":"string","description":"Required. Natural language swap intent (e.g., 'swap 0.1 ETH to USDC')."},"walletAddress":{"type":"string","description":"Required. User wallet address (0x...)."},"chain":{"type":"string","description":"Optional. Chain name (e.g., 'base', 'ethereum', 'bsc', 'arbitrum', 'optimism')."}}},"SwapTransactionResponse":{"type":"object","properties":{"transaction":{"type":"object","description":"Swap transaction details","properties":{"chain":{"type":"string","description":"Chain name."},"inputTokenAddress":{"type":"string","description":"Input token contract address."},"inputTokenSymbol":{"type":"string","description":"Input token symbol."},"outputTokenAddress":{"type":"string","description":"Output token contract address."},"outputTokenSymbol":{"type":"string","description":"Output token symbol."},"amount":{"type":"string","description":"Transaction amount."},"amountPercentage":{"type":"number","description":"Amount percentage."},"slippagePercent":{"type":"string","description":"Slippage percentage."}}}}},"PaymentRequiredError":{"type":"object","properties":{"error":{"type":"string"},"message":{"type":"string"},"paymentInstructions":{"type":"object","properties":{"amount":{"type":"string","description":"Payment amount required."},"currency":{"type":"string","description":"Payment currency (e.g., USDC)."},"recipient":{"type":"string","description":"Payment recipient address."},"chain":{"type":"string","description":"Blockchain for payment."}}}}}}},"paths":{"/x402/intent-to-swap-tx":{"post":{"summary":"Intent to Swap Transaction","description":"Convert natural language trading intent into an executable swap transaction payload. Compatible with OKX DEX by default.","operationId":"x402IntentToSwap","tags":["Trading"],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/IntentToSwapRequest"}}}},"responses":{"201":{"description":"Successful response","content":{"application/json":{"schema":{"$ref":"#/components/schemas/SwapTransactionResponse"}}}},"400":{"description":"Bad Request - Invalid parameters"},"401":{"description":"Unauthorized - Invalid payment response token"},"402":{"description":"Payment Required","content":{"application/json":{"schema":{"$ref":"#/components/schemas/PaymentRequiredError"}}}}}}}}}
```

## Prediction Market Analysis (Base Chain)

> AI-powered prediction market analysis. Analyze prediction market events and get probability estimates for each outcome with detailed reasoning.

```json
{"openapi":"3.0.0","info":{"title":"Minara x402 API","version":"1.0"},"servers":[{"url":"https://x402.minara.ai"}],"security":[{"x402Payment":[]}],"components":{"securitySchemes":{"x402Payment":{"type":"apiKey","in":"header","name":"x-payment-response","description":"Payment proof token obtained from x402 payment challenge flow. Required after completing payment."}},"schemas":{"PredictionMarketRequest":{"type":"object","required":["link","mode"],"properties":{"link":{"type":"string","description":"Required. Prediction market page link (e.g., Polymarket event URL)."},"mode":{"type":"string","enum":["fast","expert"],"description":"Required. Chat mode: 'fast' or 'expert'."},"only_result":{"type":"boolean","default":false,"description":"Optional. Only return prediction probabilities without reasoning. Default: false."},"customPrompt":{"type":"string","description":"Optional. Custom instructions to guide the analysis. Use this to specify focus areas, risk preferences, or analysis style."}}},"PredictionMarketResponse":{"type":"object","properties":{"predictions":{"type":"array","description":"Array of prediction outcomes. Each outcome represents an event option with its yes/no probabilities.","items":{"type":"object","properties":{"outcome":{"type":"string","description":"Outcome name (event option, e.g., candidate name, team name)."},"yesProb":{"type":"number","description":"Probability of YES for this outcome (0-1)."},"noProb":{"type":"number","description":"Probability of NO for this outcome (0-1)."}}}},"reasoning":{"type":"string","description":"AI reasoning and analysis (empty if only_result=true)."}}},"BadRequestError":{"type":"object","properties":{"error":{"type":"string"},"message":{"type":"string"}}},"UnauthorizedError":{"type":"object","properties":{"error":{"type":"string"},"message":{"type":"string"}}},"PaymentRequiredError":{"type":"object","properties":{"error":{"type":"string"},"message":{"type":"string"},"paymentInstructions":{"type":"object","properties":{"amount":{"type":"string","description":"Payment amount required."},"currency":{"type":"string","description":"Payment currency (e.g., USDC)."},"recipient":{"type":"string","description":"Payment recipient address."},"chain":{"type":"string","description":"Blockchain for payment."}}}}}}},"paths":{"/x402/prediction-market-ask":{"post":{"summary":"Prediction Market Analysis (Base Chain)","description":"AI-powered prediction market analysis. Analyze prediction market events and get probability estimates for each outcome with detailed reasoning.","operationId":"x402PredictionMarketAsk","tags":["Prediction"],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/PredictionMarketRequest"}}}},"responses":{"201":{"description":"Successful response","content":{"application/json":{"schema":{"$ref":"#/components/schemas/PredictionMarketResponse"}}}},"400":{"description":"Bad Request - Invalid parameters","content":{"application/json":{"schema":{"$ref":"#/components/schemas/BadRequestError"}}}},"401":{"description":"Unauthorized - Invalid payment response token","content":{"application/json":{"schema":{"$ref":"#/components/schemas/UnauthorizedError"}}}},"402":{"description":"Payment Required","content":{"application/json":{"schema":{"$ref":"#/components/schemas/PaymentRequiredError"}}}}}}}}}
```

### マルチチェーンエンドポイント

Solana と Polygon のバリアントは次で利用できます: `/x402/solana/chat`, `/x402/solana/chat/expert`, `/x402/polygon/chat`、および `/x402/polygon/chat/expert` で、リクエスト/レスポンスの形式は同一です。

***

## エラー処理

| コード   | エラー                   | 意味                                                  |
| ----- | --------------------- | --------------------------------------------------- |
| `402` | `payment_required`    | 通常 — SDK が自動的に処理します                                 |
| `401` | `unauthorized`        | 支払い証明が無効、または期限切れ                                    |
| `400` | `bad_request`         | リクエストパラメータが不足、または無効                                 |
| `429` | `rate_limit_exceeded` | AI エンドポイント: 60 req/min; トレーディング エンドポイント: 30 req/min |

***

## リソース

* [x402 プロトコルのドキュメント](https://docs.x402.org)
* [x402 GitHub リポジトリ](https://github.com/coinbase/x402)
* [x402scan 上の Minara](https://www.x402scan.com/server/b9dea1bf-cf70-41d5-96b5-b91c924cfa50)


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://minara.ai/docs/minara-handbook/ja/qu-yin/agent-api/x402.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.