Pay-per-query DuckDuckGo web search agent with LLM-optimized output via x402 micropayments
What it does
This endpoint exposes a DuckDuckGo-based web search agent hosted on Questflow's infrastructure, accessible via the x402 payment protocol. Callers send a POST request with a plain-text query in the `input` field and receive a string response containing search results formatted for consumption by large language models. The agent includes built-in rate limiting protection, error handling with logging, and smart text parsing from web pages.
Payment is handled via x402 on the Base Sepolia testnet using USDC (contract `0x036CbD53842c5426634e7929541eC2318f3dCF7e`). Each request costs up to 0.1 USDC (`maxAmountRequired: 100000` in 6-decimal USDC units). The payment is sent to address `0x98d39e4C3c60e2Db24261DD402c124dB4335B3a7`. The endpoint returns `application/json` with a `response` string field.
Documentation beyond the x402 challenge and the Questflow landing page is not available. There is no OpenAPI spec, no dedicated docs page, and no usage examples from the provider. The endpoint is live and responds with a proper 402 challenge on POST, confirming it is operational on the Base Sepolia testnet.
Capabilities
Use cases
- —AI agents that need real-time web search results to answer user questions
- —Retrieval-augmented generation pipelines requiring fresh web data
- —Autonomous agents performing research tasks across the open web
- —LLM tool-use workflows that call external search as a function
Fit
Best for
- —AI agents needing a simple, pay-per-call web search tool
- —Developers prototyping x402 payment flows on Base Sepolia testnet
- —LLM pipelines that need pre-formatted search results without scraping infrastructure
Not for
- —Production workloads requiring mainnet payment settlement (this uses Base Sepolia testnet)
- —High-volume search applications needing guaranteed SLAs or detailed documentation
- —Users who need structured search result metadata (URLs, snippets, rankings) rather than a single text blob
Quick start
curl -X POST https://api-dev.intra-tls2.dctx.link/x402/agent/qrn:agent:68ee2b6a1d6130e109861f6f \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>" \
-d '{"input": "latest news on Bitcoin ETF approval"}'Example
Request
{
"input": "latest news on Bitcoin ETF approval"
}Response
{
"response": "Here are the latest results regarding Bitcoin ETF approval: ..."
}Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with a clear outputSchema. However, there is no OpenAPI spec, no dedicated documentation, no usage examples, and the response format is only loosely described. The testnet-only payment (Base Sepolia) limits production utility. Most details are inferred from the x402 challenge alone.
Warnings
- —No OpenAPI or dedicated API documentation available from the provider
- —Payment is on Base Sepolia testnet only — not suitable for production/mainnet use
- —Response format is a single string; no structured search result schema is documented
- —Example response is inferred from the outputSchema description, not from an actual call
- —The provider landing page (Questflow) focuses on AI clone trading products, not this search tool specifically
Citations
- —Endpoint returns 402 with x402 challenge on POST, confirming it is livehttps://api-dev.intra-tls2.dctx.link/x402/agent/qrn:agent:68ee2b6a1d6130e109861f6f
- —Payment uses USDC on Base Sepolia with maxAmountRequired of 100000 (0.1 USDC)https://api-dev.intra-tls2.dctx.link/x402/agent/qrn:agent:68ee2b6a1d6130e109861f6f
- —Description states comprehensive web search, smart text parsing, rate limiting, error handling, and LLM-optimized outputhttps://api-dev.intra-tls2.dctx.link/x402/agent/qrn:agent:68ee2b6a1d6130e109861f6f
- —Questflow is the hosting platform behind this agent endpointhttps://api-dev.intra-tls2.dctx.link