Pay-per-call AI sentiment analysis of any news topic via x402 on Base.
What it does
The News Summarizer x402 sentiment endpoint provides AI-powered sentiment analysis for any user-specified news topic. It is part of a small x402-enabled application hosted on Vercel that also offers news summarization. Each call costs $0.005 USDC on the Base network, paid via the x402 payment protocol (exact scheme). The endpoint accepts GET requests and is discoverable.
To use the endpoint, a caller supplies a topic and includes an X-PAYMENT header containing a valid x402 payment proof. Upon successful payment verification, the service returns a sentiment analysis result for the requested topic. The underlying AI model and the exact response schema are not documented, so the structure of the output must be inferred at runtime. No OpenAPI spec, dedicated docs page, or README is available.
The endpoint is live and returns a proper 402 challenge when called without payment. It targets the USDC token contract (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, with payments directed to address 0x19B1614Ee8272178d09CdDC892FAa2c8cCB91268. The maximum payment timeout is 60 seconds.
Capabilities
Use cases
- —Analyze public sentiment around a trending news topic before making decisions
- —Integrate real-time sentiment signals into trading or monitoring pipelines
- —Augment research workflows with automated opinion analysis on any subject
Fit
Best for
- —Agents needing quick, low-cost sentiment reads on arbitrary topics
- —Developers prototyping x402-based AI microservices
- —Lightweight sentiment checks without managing API keys or subscriptions
Not for
- —Bulk or high-volume sentiment analysis (pay-per-call adds up)
- —Use cases requiring a documented, stable response schema with SLA guarantees
Quick start
curl -X GET "http://news-summarizer-x402.vercel.app/sentiment?topic=bitcoin" \
-H "X-PAYMENT: <x402_payment_proof>"Endpoint
Quality
The endpoint is live and returns a valid 402 challenge with clear payment details. However, there is no documentation, no OpenAPI spec, no example responses, and the response schema is entirely unknown. The landing page confirms the service exists and costs $0.005 USDC but provides no further technical detail.
Warnings
- —No OpenAPI or schema documentation available; response format must be discovered empirically.
- —Query parameter name for the topic is inferred (e.g., ?topic=...) and not confirmed by any docs.
- —No rate limits, SLA, or terms of service documented.
- —MIME type and description fields in the x402 challenge are empty.
Citations
- —The service charges $0.005 USDC on Base per call.http://news-summarizer-x402.vercel.app
- —The endpoint returns a 402 challenge with x402Version 1, exact scheme, on Base network using USDC.http://news-summarizer-x402.vercel.app/sentiment
- —The application offers both News Summary and Sentiment Analysis features.http://news-summarizer-x402.vercel.app