x402 Payments

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

Client                          Pulse Gateway                    Base Network
  |                                  |                                |
  |  GET /pulse/BTC                  |                                |
  |--------------------------------->|                                |
  |                                  |                                |
  |  402 Payment Required            |                                |
  |  + payment details (x-402-*)     |                                |
  |<---------------------------------|                                |
  |                                  |                                |
  |  Sign USDC payment              |                                |
  |  (x402 SDK handles this)        |                                |
  |--------------------------------------------> USDC transfer        |
  |                                  |                                |
  |  Retry request + payment proof   |                                |
  |--------------------------------->|                                |
  |                                  |  Verify payment via facilitator|
  |                                  |------------------------------->|
  |                                  |<-------------------------------|
  |  200 OK + analysis data          |                                |
  |<---------------------------------|                                |

The x402 SDK in your HTTP client handles steps 2–4 automatically. From your perspective, it’s just a normal HTTP request that costs $0.01–$0.04.

Network Details

Property	Value
Network	Base mainnet (chain ID 8453)
Currency	USDC
Scheme	Exact EVM
Facilitator	Coinbase CDP

Payment Details by Endpoint

Endpoint	Price	Payment Type
/pulse/{coin}	$0.02 USDC	Per request
/sentiment	$0.01 USDC	Per request
/funding/{coin}	$0.01 USDC	Per request
/bundle/{coin}	$0.04 USDC	Per request
/health	Free	No payment
/coins	Free	No payment

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).
• 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

You need a wallet with:

1. USDC on Base — For payments (as little as $1 gets you 50+ pulse queries)
2. A small amount of ETH on Base — For gas fees (typically < $0.001 per transaction)

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)

SDK Options

Python

pip install "x402[evm]" httpx

See the Python SDK Guide for full integration details.

TypeScript / Node.js

npm install x402 viem

See the TypeScript SDK Guide for full integration details.

Budget Controls

The x402 SDKs support budget limits to prevent accidental overspending:

# Python — the SDK supports per-request and global limits
# Configure in your client setup

At Pulse prices ($0.01–$0.04 per query), $10 of USDC gives you 250–1000 API calls.

Security

• Payments use EVM signatures — your private key never leaves your machine
• The x402 facilitator (Coinbase CDP) verifies payments on-chain
• Pulse never sees your private key — only the signed payment proof
• All paid endpoints are rate-limited to prevent abuse