Keryx 🏛️

Every time an AI uses a creator's work as a source, the creator gets paid — instantly.

🔗 Live: keryx.cc — free to try, no wallet, no sign-up  ·  🔎 public proof — code, adoption, RPC, settlement, cash-outs  ·  ▶️ npm run demo — the whole loop, real settlement, ~90s  ·  🤖 npx -y keryx-mcp@latest — plug Keryx into any MCP agent  ·  🧩 Fork the Arc primitives

The problem

The web's economics assume a human reader: you write, people visit, attention becomes ads, subscriptions, tips. AI agents broke that contract. They read everything and send back nothing — no click, no view, no cent. Every answer an assistant gives is built on someone's work, and that someone is invisible at the exact moment their work proves its value.

Keryx (κῆρυξ — herald) exists to fix that one moment. It makes citation itself the payment event: the instant an agent relies on your writing to answer a question, you are paid, proportional to how much you helped, settled sub-cent in USDC on Arc. No accounts, no invoices, no ad tech. A creator onboards by pasting an RSS URL. An agent pays because paying is cheaper than not knowing.

What Keryx is

Keryx is a citation-toll reading agent — an autonomous reader with a wallet, and the payment rail underneath it. Give it a question and a budget:

1. It decomposes the question into sub-claims and discovers exact article candidates from free previews and the signed offer book.
2. It decides, per article version: buy / skip / cache — expected value vs effective price vs remaining budget, with a human-readable rationale for every choice.
3. It pays the x402 toll only for what it buys, checks sufficiency after each read, and stops early when it has enough.
4. It synthesizes a grounded answer with inline citations, weighs each source's real contribution, and settles a weighted USDC nanopayment to every creator it cited — multi-author works split on-chain, 100% to creator wallets, 0% platform fee.

The result is a working micro-economy: readers that pay by default, and writers that earn by being useful — not by being clicked.

An agent that genuinely decides

Most "payment agents" are scripts with a wallet. Keryx's differentiator is visible agency — the model reasons about money and shows its work, streamed live to the UI:

• Buy / skip / cache with rationale — every spend decision names the exact article version and explains why.
• Open article market — /market and GET /api/offers publish exact payable versions, registry list prices, x402 paths, and verifiable EIP-712 discounts signed by publishers.
• Adjudication ⚖️ — when two sources conflict, the agent doesn't average them; it decides which to trust and says why.
• Confidence verdict 📊 — it rates its own answer (High / Moderate / Low) and hedges the prose accordingly, instead of bluffing.
• Evidence ledger — every rewarded citation carries a claim-indexed exact quote. The orchestrator verifies that quote against content it actually read before the marker can receive a citation reward; rejected markers are removed from the answer.
• Living answer receipts — archived conclusions never silently change. Keryx flags when an exact paid SHA-256/IPFS article version has been superseded, exposes a metadata-only freshness API, and itemizes the source/evidence/coverage/settled-payment delta after a reader explicitly re-asks.
• Portable research receipts — every permalink exports one deterministic JSON bundle containing its answer hash, BUY/SKIP/CACHE decisions, exact article versions, claim evidence and sanitized Circle settlement snapshot. Retain its SHA-256 to detect later changes; the self-check does not pretend to be a Keryx, publisher, or on-chain signature.
• Claim-aware evidence portfolios — Keryx chooses a non-redundant set of positive source proposals under separate attention and fetch-USDC caps. CACHE correctly costs zero fetch USDC but one context slot; the receipt compares preview-predicted coverage with evidence yield after read.
• Cross-query memory — sources that proved useful (or useless) in past runs on the same subject shift future buy/skip decisions. A source is scored against the runs that actually read it, so a skip never becomes evidence against the source it skipped.
• Semantic discovery — candidate matching by embedding similarity, not keyword luck.
• Emergent frugality — it stops early, reuses its cache, and correctly spends nothing when nothing is worth buying.

Money safety is enforced in code, not by the model: the LLM proposes value; the orchestrator enforces the hard budget cap, so a hallucinated number can never overspend. An economic-invariant test suite (spend ≤ budget, payouts = weights, splits sum exactly) runs in CI on every push.

Example trace (real output):

[decide]  BUY Agent Economy Weekly — strong match on x402, autonomous, commerce; worth the $0.004 toll
[decide]  SKIP Garden & Soil Monthly — weak match (no key terms); not worth $0.002
[fetch]   Paid $0.004 to Agent Economy Weekly — S1
[sufficiency] Read 2 sources covering all sub-claims; stopping early to save budget
[settle]  Settled $0.015 → Mara Okoye · $0.010 → Devin Park   (60/40 author split)
📊 $0.032 spent → 100% to creators · 3 bought / 3 skipped

For creators

• Claim proven demand — keryx.cc/wanted shows claims paid dispatches left under-covered. A new creator can check and list an RSS feed; an existing registry creator can offer the exact indexed article directly and optionally sign a temporary discount. Keryx guarantees that version a candidate slot, not a purchase, then queues one bounded retry after refreshing creator authority. Fulfillment is public only when that source passes the evidence gate and its citation reward really settles. Every claim has a canonical shareable brief and social card, so the specific gap can reach the writer who covers it.
• Onboard from your own wallet — paste an RSS feed at keryx.cc/register and your wallet writes the source to the on-chain registry itself. Keryx sets up the x402-priced endpoint and the free preview; it never holds your key, and the faucet on that page covers the gas. All 20 listed sources are written to the on-chain registry, including real public feeds — Hugging Face, Vitalik Buterin, CoinDesk, the Ethereum Foundation, Stripe, Latent Space, Simon Willison — each earning per citation.
• Own your payout — the payout address is the wallet you signed in with. The first owner-verified creator (conzit.com) proved feed ownership, set its address, was cited & paid end-to-end — and has since claimed its registry record from its own wallet, so its on-chain creator is the creator, not Keryx. We've also proposed this as an opt-in convention upstream in RSSHub. Honest note: the demo sources seeded before this switch still have operator-held payout keys — they are Keryx's own sample publications, not third-party creators. Nine of the twenty on-chain records also name Keryx's treasury as their registry creator, so the treasury, not the source wallet, can update or deactivate those nine. The payout address is correct on all twenty — an hourly watchdog re-reads every record from the chain and publishes the comparison on /status.
• Know the moment you're cited — opt into a plain email alert (no webhook server needed, rate-capped, one-click unsubscribe) and/or signed webhooks that fire the instant a citation settles; every payout on your public earnings page shows the actual question your work helped answer.
• Show it off — an embeddable "Cited by Keryx" badge (live SVG at /api/creator/<id>/badge.svg) displays your real citation count + USDC earned on your own site, with copy-paste Markdown/HTML on each creator page. Payouts become portable, verifiable proof.
• Cash out yourself, gas-free — a self-serve, non-custodial withdraw: your wallet signs a Gateway burn intent in the browser, the treasury relays gas. Real creators have executed real on-chain cash-outs.
• Keep everything — 100% of every citation reward goes to creator wallets. 0% platform fee.
• Squat-proof identity — sources live in an on-chain SourceRegistry (0x2e12Fa…) with creator-scoped IDs and on-chain multi-author splits.

For developers & agents