Superhighway
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What is Superhighway?
Superhighway is a web-search API designed specifically for AI agents that can pay for searches on their own using cryptocurrency. The tool operates on the x402 protocol, enabling AI agents to make payments autonomously in USDC on the Base blockchain without any human intervention, signup, or API key required. At $0.001 per search, it provides an extremely affordable micropayment model for agent-native web搜索.
The service works through a simple HTTP flow: when an agent makes a GET request to /search?q=..., it receives a 402 Payment Required response with the price and payment destination. An x402 client then signs a USDC payment and retries automatically, returning clean JSON search results. The entire process requires zero human involvement, making it ideal for autonomous AI agents that need real-time web data.
Superhighway is built on SearXNG for search functionality and x402 for payments. It offers machine-readable specifications via /openapi.json and health checks at /health. The tool is specifically designed for AI agents, developers building agent systems, and anyone creating autonomous AI applications that need web search capabilities without traditional API key management or subscription models.
Superhighway pricing
Pricing model: Freemium
$0.001 per search, paid in USDC on Base blockchain via the x402 protocol. No signup or API key required. A free no-wallet trial is available for testing without needing a wallet. Pay-as-you-go model with no subscriptions or monthly fees. Payment settles in approximately 2 seconds with zero protocol fees and gasless payments for end users.
Superhighway pros
- No signup required to use the API
- No API key needed for authentication
- Zero human intervention in payment flow
- Extremely low cost at $0.001 per search
- Payments in USDC on Base blockchain
- Built on x402 protocol for autonomous payments
- Clean JSON search results output
- Machine-readable OpenAPI spec available
- Health endpoint for monitoring
- Built on SearXNG search engine
- Pay-as-you-go model with no subscriptions
- Free no-wallet trial available for testing
- MCP tool installation is one line
- Payment settles in approximately 2 seconds
- Permissionless access without KYC
- Gasless payments for end users
- No protocol-level fees
- HTTP-native payment integration
Superhighway cons
- Requires USDC wallet on Base blockchain for paid use
- Only one query at a time, no batch searches
- Must implement x402 client for payment flow
- Private key required for agent signing
- No free tier beyond trial for production use
- Limited to web search only, no other API functions
- New protocol may have limited tooling support
- Crypto payment adds complexity for some developers
- Base blockchain dependency limits payment options
- No traditional authentication options available
Frequently asked questions about Superhighway
What is Superhighway?
Superhighway is a web-search API your AI agent can pay for on its own — no signup, no API key, no human in the loop. It costs $0.001 per search, paid in USDC on Base via the x402 protocol, returning clean JSON search results with zero human involvement.
How does the payment flow work?
Your agent GETs /search?q=... and gets back 402 Payment Required with the price and where to pay. An x402 client signs a USDC payment and retries automatically, then receives clean JSON search results. Total human involvement is zero.
Do I need to sign up for an account?
No signup is required. Superhighway operates without any account creation, API keys, or human in the loop. You can start using it immediately with just an x402 client and USDC wallet on Base.
What cryptocurrency do I need to use Superhighway?
You need USDC (USD Coin) on the Base blockchain. Payments are made through the x402 protocol, which enables instant, permissionless payments directly through HTTP requests.
Is there a free tier or trial available?
Yes, there is a free no-wallet trial available if you want to try it out without needing a wallet. This lets you poke at the service and see the 402 payment terms before committing to paid usage.
How do I install the MCP tool?
Installation is straightforward with one line: npx -y superhighway-mcp. This drops in the paid web search tool for AI agents via MCP + x402 with no API key required.
What search engine powers Superhighway?
Superhighway is built on SearXNG for search functionality combined with x402 for payments. SearXNG provides the underlying web search capability that returns clean JSON results.
Can I make batch searches or multiple queries at once?
No, Superhighway supports one query at a time, paid as you go. Each search is a separate GET request to /search?q=... with individual payment for each query.
Where can I find the API documentation?
The machine-readable spec is available at /openapi.json, and you can check the service health at /health. These endpoints provide OpenAPI documentation and status information for the API.
How fast are payments settled?
Payments settle in approximately 2 seconds, enabled by the x402 protocol and Base blockchain's fast finality. This creates a seamless payment experience with minimal delay between payment and receiving search results.