3
The agent buys one article
Accepting the selected offer returns an entitlement: a token signed with Ed25519 that names the agent, the article, the usage, the price and how it splits between publisher and exchange, the terms and a 15-minute window. Anyone can check it offline against our published keys; the publisher does not have to trust our database.
Entitlement, decoded POST /v1/offers/off_309f…/accept
// header
{ "alg": "EdDSA", "typ": "cx-entitlement+jwt", "kid": "cx-FtMBpU0W…" }
// claims (iss, aud, iat, nbf and hashes left out)
{
"sub": "research-assistant-01",
"jti": "ent_13938e8e…",
"exp": 1793186220,
"cx": {
"v": 1,
"content_id": "fn-2026-0153",
"publisher_id": "pub_fieldnote",
"usage": "display_snippet",
"terms": {
"citation_required": true,
"attribution": "Fieldnote Science",
"max_snippet_chars": 400,
"retention_seconds": 604800,
"ai_training": "prohibited"
},
"price": { "amount_micros": 5500, "currency": "USD" },
"clearing": {
"publisher_price_micros": 5000,
"fee_micros": 500,
"fee_bps": 1000
},
"rate_card_ref": "rc_fieldnote@v1"
}
}