Built for agents, from first principles

Why x402 (vs. API keys + scraping)

The flow, end to end

Every step is plain HTTP. No SDK required. The protocol is a 402 status code, a couple of headers, and a JSON body.

GET https://www.supercomputing.news/.well-known/x402.json

GET /api/v1/articles/:slug

HTTP/1.1 402 Payment Required
PAYMENT-REQUIRED: <base64 requirements>

{
  "scheme": "exact",
  "network": "eip155:8453",
  "price": "$0.03",
  "payTo": "0x7E88…65B4",
  "resource": "https://www.supercomputing.news/api/v1/articles/:slug"
}

GET /api/v1/articles/:slug
X-PAYMENT: <base64-encoded signed payload>

HTTP/1.1 200 OK
PAYMENT-RESPONSE: <tx-hash + metadata>

{
  "slug": "…",
  "title": "…",
  "content": { … },
  "provenance": {
    "contentHash": "<sha256-hex>",
    "signature": "<base64 Ed25519>",
    "signingKeyId": "scn-2026-05",
    "signedAt": "2026-…",
    "publicKeyUrl": "https://www.supercomputing.news/.well-known/scn-pubkey.json"
  }
}

Pay once, read forever: no double-pay

A wallet that has already paid for an item resource never pays for it again. Settlement records a permanent entitlement keyed to your wallet and the resource path. On any later request, prove ownership of that wallet with a SIGN-IN-WITH-X (SIWX) signature (a CAIP-122 message you sign with the same key) and the server returns the content for free, no payment needed.

GET /api/v1/articles/:slug
SIGN-IN-WITH-X: <base64 CAIP-122 signed proof>

HTTP/1.1 200 OK   # entitlement honored, no charge

• Item endpoints (articles, summaries, vendor profiles, topic listings) are entitlement-gated: pay once per resource, re-read free.
• Volatile endpoints (search, latest feed, pillar feeds) stay pay-per-fetch. Their contents change every request, so each call is freshly priced.
• Each SIWX proof carries a one-time nonce. Replays are rejected, so a captured header can't be reused by anyone else.

Pricing

All payments settle in USDC on Base. Prices below are authoritative, generated from the same PRICING constants the API enforces, so they can never drift from what you're actually charged.

Cryptographic provenance

Every published article is signed at publication time with an Ed25519 keypair. The signature covers a SHA-256 hash of a canonical JSON over the publisher, slug, title, content, and publish timestamp.

• contentHash = SHA256(canonical({publisher, slug, title, content, publishedAt}))
• signature = Ed25519(`$${contentHash}|$${slug}|$${publishedAt}`)
• The public key is published at /.well-known/scn-pubkey.json in JWK form with a stable key ID.

Active signing key

Verify a signature (free)

The /api/v1/provenance/verify endpoint is public and free (rate-limited to 60 req/min per IP). Pass ?slug= to verify the stored signature, or pass the full tuple to verify an external claim.

curl 'https://www.supercomputing.news/api/v1/provenance/verify?slug=YOUR-SLUG'

Why this matters: agents that cite Supercomputing News can prove the bytes they quoted are the bytes the publisher signed. Citations become falsifiable.

Read as Markdown, not scraped HTML

Send Accept: text/markdown on the homepage or any article page and the server returns clean Markdown instead of HTML. No DOM parsing, no boilerplate stripping. The URL stays the same; browsers still get HTML. Responses include an x-markdown-tokens header with an estimated token count so you can budget context before you read.

GET /ai/some-article-slug
Accept: text/markdown

HTTP/1.1 200 OK
Content-Type: text/markdown; charset=utf-8
x-markdown-tokens: 1240

Discovery: find us without being told

An agent that lands on the homepage can bootstrap everything from there. The root response carries Link headers (RFC 8288) pointing at the API catalog, payment manifest, and machine guide. Each surface below is public and unmetered.

Editorial principles for agent-citable journalism

Treating agents as a first-class audience is an editorial commitment, not just a technical one. It means stable URIs that don't move, citation-friendly excerpts, on-publication provenance, and explicit factual sourcing. Not every publisher will commit to this discipline. That's the point. Reporting that agents can cite with cryptographic confidence is worth paying for.

Compliance & terms

Agent access via x402 settlement is welcome and encouraged. Scraping paid endpoints without payment is not. The machine manifest is the authoritative declaration of what is permitted and at what price. See the terms of use for the full agreement.

Endpoint reference

Prices are sourced from PRICING in the API codebase. These are the live values, not documentation drift.

Start building

The fastest path is to load the manifest, attempt a paid endpoint, and let the 402 response tell your client what to sign. Once you've paid for an item, keep the wallet and re-read it free with a Sign-In-with-X proof.