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Cerebrus Pulse

x402 Payments

x402 Payments

Section titled “x402 Payments”

Cerebrus Pulse uses the x402 protocol for payments — an open standard for HTTP-native micropayments built on the 402 Payment Required status code.

How It Works

Section titled “How It Works”
Client (x402 v2 SDK)              Pulse Gateway                   Facilitator (Coinbase CDP)
  |                                    |                                     |
  |  GET /pulse/BTC                    |                                     |
  |----------------------------------->|                                     |
  |  402 Payment Required              |                                     |
  |  PAYMENT-REQUIRED: terms           |                                     |
  |  (price, Base + Solana, payTo)     |                                     |
  |<-----------------------------------|                                     |
  |                                    |                                     |
  |  Sign a USDC payment authorization |                                     |
  |  (nothing is sent on-chain yet)    |                                     |
  |                                    |                                     |
  |  GET /pulse/BTC                    |                                     |
  |  PAYMENT-SIGNATURE: signed payload |                                     |
  |----------------------------------->|  verify                             |
  |                                    |------------------------------------>|
  |                                    |<------------------------------------|
  |                                    |  run the analysis, then settle      |
  |                                    |------------------------------------>| submits the
  |                                    |<------------------------------------| USDC transfer
  |  200 OK + analysis data            |                                     |
  |  PAYMENT-RESPONSE: receipt         |                                     |
  |<-----------------------------------|                                     |

An x402 v2 client handles everything after the first request: it reads the terms from the base64 PAYMENT-REQUIRED header, signs, and retries with PAYMENT-SIGNATURE. The gateway settles only after it has an answer; a request refused with a 4xx or failing with a 5xx is not charged. From your side it is a normal HTTP request that costs $0.01–$0.06. The 402 offers both Base and Solana; the SDK pays on a network you registered.

The 402 JSON body repeats the Base terms in the older x402 v1 shape for crawlers and directories. It is informational: v1 clients, which pay with an X-PAYMENT header, are not accepted.

Supported Networks

Section titled “Supported Networks”

Cerebrus Pulse accepts USDC payments on two chains. The 402 response includes payment options for both — your x402 SDK picks the right one based on your wallet.

PropertyBase (EVM)Solana
Network IDeip155:8453solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp
CurrencyUSDCUSDC
USDC Address0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v
SchemeExact EVMExact SVM
FacilitatorCoinbase CDPCoinbase CDP
Payer gasNone: you sign an EIP-3009 authorization and the facilitator submits itNone: the facilitator is the fee payer

Payment Details by Endpoint

Section titled “Payment Details by Endpoint”
EndpointPriceDescription
/screener$0.06 USDCMarket-wide scan of 50+ coins
/bundle/{coin}$0.05 USDC/pulse, 24h /funding and /sentiment in one request
/correlation$0.05 USDCBTC-alt correlation matrix
/liquidations/{coin}$0.03 USDCLiquidation heatmap by leverage tier
/pulse/{coin}$0.025 USDCMulti-timeframe technical analysis
/arb$0.02 USDCMarket Stress Index
/basis/{coin}$0.02 USDCHyperliquid vs Chainlink basis
/cex-dex/{token}$0.02 USDCCEX-DEX price divergence
/oi/{coin}$0.015 USDCOpen interest analysis
/spread/{coin}$0.015 USDCSpread & liquidity analysis
/depeg$0.01 USDCUSDC collateral health monitor
/funding/{coin}$0.01 USDCFunding rate analysis
/sentiment$0.01 USDCMarket sentiment labels
/healthFreeGateway status
/coinsFreeList available coins

Why x402?

Section titled “Why x402?”
  • No API keys — Your wallet address is your identity. No registration, no accounts.
  • No subscriptions — Pay only for what you use. One query = one micropayment.
  • Instant settlement — Payments settle on Base (fast, cheap L2) or Solana (sub-second finality).
  • Open standard — x402 is an open protocol. Any x402-compatible client works.
  • Transparent pricing — The 402 response includes exact payment details before you pay.

Wallet Requirements

Section titled “Wallet Requirements”

You need a wallet with USDC on either chain, and nothing else: no ETH and no SOL. The payer only signs; the facilitator submits the transfer and pays its network fee. Use a dedicated wallet holding a few dollars of USDC, not a main wallet.

There is no card or account-based way to pay: every paid call needs a USDC wallet. The free /demo/{coin} endpoint needs none.

Option A: Base (EVM)

Section titled “Option A: Base (EVM)”
  1. USDC on Base: each call costs $0.01–$0.06
  2. No ETH needed: the Base payment is an EIP-3009 transferWithAuthorization that you sign off-chain and the facilitator submits

Getting USDC on Base:

  • Bridge from Ethereum mainnet via the Base Bridge
  • Purchase directly on exchanges that support Base withdrawals (Coinbase, Binance)
  • Use a cross-chain bridge (Across, Stargate)

Option B: Solana

Section titled “Option B: Solana”
  1. USDC on Solana — Same pricing, same endpoints
  2. No SOL needed: the CDP facilitator is the fee payer for the transaction

Getting USDC on Solana:

  • Purchase directly on exchanges that support Solana withdrawals (Coinbase, Phantom, Jupiter)
  • Swap on Jupiter or Raydium

SDK Options

Section titled “SDK Options”

Python

Section titled “Python”
Terminal window
pip install "x402[evm]" httpx eth-account                                        # For Base
pip install "x402[svm]" "solana>=0.36,<0.37" "solders>=0.27,<0.28" httpx         # For Solana

The Solana pins are needed: solana 0.40 removed a module x402’s Solana signer imports. See the Python SDK Guide for full integration details.

TypeScript / Node.js

Section titled “TypeScript / Node.js”
Terminal window
npm install @x402/fetch @x402/evm viem                         # For Base
npm install @x402/fetch @x402/svm @solana/kit @scure/base      # For Solana

These are the x402 v2 packages. The older x402-fetch 1.x pays with an X-PAYMENT header, which this API does not accept. See the TypeScript SDK Guide for full integration details.

Budget Controls

Section titled “Budget Controls”

Both official x402 clients refuse a payment above a per-payment cap, which defaults to $1. Set it lower:

// TypeScript (@x402/fetch)
wrapFetchWithPaymentFromConfig(fetch, { schemes, spendControls: { maxAmountPerPayment: "$0.10" } });
# Python (x402)
x402.set_spend_controls({"max_amount_per_payment": "$0.10"})

Each call costs $0.01–$0.06; set the cap just above the most expensive endpoint you call.

Security

Section titled “Security”
  • Payments use EVM or SVM signatures — your private key never leaves your machine
  • The x402 facilitator (Coinbase CDP) verifies payments on-chain for both Base and Solana
  • Pulse never sees your private key — only the signed payment proof
  • All paid endpoints are rate-limited to prevent abuse
  • The payer never needs gas: no ETH on Base, no SOL on Solana
Section titled “Related”