x402

x402 is a pay-per-use API access method that requires no subscription. You pay for each call directly using stablecoins like USDC on Base, Solana, or Polygon.

Minara x402 endpoint: https://x402.minara.ai

Explore all endpoints: Minara on x402scan

How x402 works

x402 follows a payment-challenge flow:

You make a request to a protected endpoint without payment.
The server responds with 402 Payment Required and payment instructions (amount, currency, recipient address, chain).
You include a payment proof in the x-payment-response header and retry the request.
The server verifies the proof, processes the payment on-chain, and returns the API response.

The recommended approach is to use the x402 SDK, which handles this flow automatically.

Getting started with the SDK

Prerequisites

A crypto wallet with USDC (any EVM-compatible wallet, or a Solana wallet)
Node.js / Python / Go
Your wallet's private key (for signing payments)

Install

npm install @x402/fetch @x402/evm

Make a request

The SDK handles payment challenges automatically. Just make requests normally.

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: "What is the current price of BTC?" })
});

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

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": "What is BTC price?"}
        )
        await response.aread()
        print(response.json()["content"])

asyncio.run(call_minara())

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":"What is BTC price?"}`))
req.Header.Set("Content-Type", "application/json")

resp, _ := httpClient.Do(req)
// payment handled automatically

For the full x402 quickstart, see x402 documentation.

API reference

Base URL: https://x402.minara.ai

All endpoints require the x-payment-response header (handled automatically by the SDK).

Chat (Base Chain)

post

Ask Minara AI - Intelligent crypto assistant

Authorizations

x-payment-responsestringRequired

Payment proof token obtained from x402 payment challenge flow. Required after completing payment.

Body

userQuerystringRequired

Required. User query content.

Responses

201

Successful response

application/json

contentstringOptional

AI response content.

400

Bad Request - Invalid parameters

application/json

401

Unauthorized - Invalid payment response token

application/json

402

Payment Required

application/json

post

/x402/chat

POST /x402/chat HTTP/1.1
Host: x402.minara.ai
x-payment-response: YOUR_API_KEY
Content-Type: application/json
Accept: */*
Content-Length: 85

{
  "userQuery": "What is the current price of BTC and what are the key support levels?"
}

{
  "content": "BTC is currently trading at $98,450. Key support levels are at $96,500 and $94,200..."
}

Chat Expert (Base Chain)

post

Ask Minara AI - Intelligent crypto assistant

Authorizations

x-payment-responsestringRequired

Payment proof token obtained from x402 payment challenge flow. Required after completing payment.

Body

userQuerystringRequired

Required. User query content.

Responses

201

Successful response

application/json

contentstringOptional

AI response content.

400

Bad Request - Invalid parameters

401

Unauthorized - Invalid payment response token

402

Payment Required

application/json

post

/x402/chat/expert

POST /x402/chat/expert HTTP/1.1
Host: x402.minara.ai
x-payment-response: YOUR_API_KEY
Content-Type: application/json
Accept: */*
Content-Length: 103

{
  "userQuery": "Provide a comprehensive analysis of ETH including on-chain metrics and trading strategy"
}

{
  "content": "Comprehensive ETH analysis: [Detailed expert analysis content]..."
}

Perpetual Trading Suggestion

post

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

Authorizations

x-payment-responsestringRequired

Payment proof token obtained from x402 payment challenge flow. Required after completing payment.

Body

symbolstringRequired

Required. Trading symbol (e.g., 'BTC', 'ETH', 'SOL').

stylestring · enumOptional

Optional. Trading style: 'scalping', 'day-trading', or 'swing-trading'. Default: 'scalping'.

Default: scalpingPossible values:

marginUSDnumberOptional

Optional. Margin in USD. Default: 1000.

Default: 1000

leveragenumber · min: 1 · max: 40Optional

Optional. Leverage multiplier (max: 40). Default: 10.

Default: 10

strategystringOptional

Optional. Strategy type. Default: 'max-profit'. More strategies coming soon.

Default: max-profit

Responses

201

Successful response

application/json

entryPricenumberOptional

Recommended entry price.

sidestring · enumOptional

Trading side recommendation.

Possible values:

stopLossPricenumberOptional

Recommended stop loss price.

takeProfitPricenumberOptional

Recommended take profit price.

confidencenumber · max: 100Optional

Confidence score (0-100).

reasonsstring[]Optional

Analysis reasons based on technical indicators.

risksstring[]Optional

Risk factors to consider.

400

Bad Request - Invalid parameters

401

Unauthorized - Invalid payment response token

402

Payment Required

application/json

post

/x402/perp-trading-suggestion

POST /x402/perp-trading-suggestion HTTP/1.1
Host: x402.minara.ai
x-payment-response: YOUR_API_KEY
Content-Type: application/json
Accept: */*
Content-Length: 93

{
  "symbol": "BTC",
  "style": "day-trading",
  "marginUSD": 1000,
  "leverage": 10,
  "strategy": "max-profit"
}

{
  "entryPrice": 98450,
  "side": "long",
  "stopLossPrice": 96200,
  "takeProfitPrice": 102800,
  "confidence": 78,
  "reasons": [
    "BTC broke above key resistance at $97,500 with strong volume",
    "RSI at 62 indicates bullish momentum without being overbought",
    "MACD showing bullish crossover"
  ],
  "risks": [
    "Potential pullback at $100,000 psychological resistance",
    "High volatility expected around upcoming Fed meeting"
  ]
}

Intent to Swap Transaction

post

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

Authorizations

x-payment-responsestringRequired

Payment proof token obtained from x402 payment challenge flow. Required after completing payment.

Body

intentstringRequired

Required. Natural language swap intent (e.g., 'swap 0.1 ETH to USDC').

walletAddressstringRequired

Required. User wallet address (0x...).

chainstringOptional

Optional. Chain name (e.g., 'base', 'ethereum', 'bsc', 'arbitrum', 'optimism').

Responses

201

Successful response

application/json

400

Bad Request - Invalid parameters

401

Unauthorized - Invalid payment response token

402

Payment Required

application/json

post

/x402/intent-to-swap-tx

POST /x402/intent-to-swap-tx HTTP/1.1
Host: x402.minara.ai
x-payment-response: YOUR_API_KEY
Content-Type: application/json
Accept: */*
Content-Length: 109

{
  "intent": "swap 0.1 ETH to USDC",
  "chain": "base",
  "walletAddress": "0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb1"
}

{
  "transaction": {
    "chain": "base",
    "inputTokenAddress": "0x4200000000000000000000000000000000000006",
    "inputTokenSymbol": "ETH",
    "outputTokenAddress": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "outputTokenSymbol": "USDC",
    "amount": "0.1",
    "amountPercentage": 100,
    "slippagePercent": "0.5"
  }
}

Prediction Market Analysis (Base Chain)

post

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

Authorizations

x-payment-responsestringRequired

Payment proof token obtained from x402 payment challenge flow. Required after completing payment.

Body

linkstringRequired

Required. Prediction market page link (e.g., Polymarket event URL).

modestring · enumRequired

Required. Chat mode: 'fast' or 'expert'.

Possible values:

only_resultbooleanOptional

Optional. Only return prediction probabilities without reasoning. Default: false.

Default: false

customPromptstringOptional

Optional. Custom instructions to guide the analysis. Use this to specify focus areas, risk preferences, or analysis style.

Responses

201

Successful response

application/json

reasoningstringOptional

AI reasoning and analysis (empty if only_result=true).

400

Bad Request - Invalid parameters

application/json

401

Unauthorized - Invalid payment response token

application/json

402

Payment Required

application/json

post

/x402/prediction-market-ask

POST /x402/prediction-market-ask HTTP/1.1
Host: x402.minara.ai
x-payment-response: YOUR_API_KEY
Content-Type: application/json
Accept: */*
Content-Length: 241

{
  "link": "https://polymarket.com/event/will-there-be-another-us-government-shutdown-by-january-31",
  "mode": "fast",
  "only_result": false,
  "customPrompt": "Focus on recent news and sentiment analysis. Be more conservative in probability estimates."
}

{
  "predictions": [
    {
      "outcome": "Donald Trump",
      "yesProb": 0.65,
      "noProb": 0.35
    },
    {
      "outcome": "Kamala Harris",
      "yesProb": 0.3,
      "noProb": 0.7
    }
  ],
  "reasoning": "Based on recent polling data and historical trends, Trump maintains a slight lead in key swing states. However, the race remains highly competitive with significant uncertainty..."
}

Multi-chain endpoints

Solana and Polygon variants are available at /x402/solana/chat, /x402/solana/chat/expert, /x402/polygon/chat, and /x402/polygon/chat/expert with identical request/response shapes.

Error handling

Code

Error

Meaning

402

payment_required

Normal — SDK handles this automatically

401

unauthorized

Payment proof invalid or expired

400

bad_request

Missing or invalid request parameters

429

rate_limit_exceeded

AI endpoints: 60 req/min; Trading endpoints: 30 req/min

Resources

PreviousAPI Key NextAPI Reference (API Key)

Last updated 1 month ago

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