One call, one cent, one receipt.

x402 is the payment step HTTP always had a status code for: a server answers 402 Payment Required with what it wants, the caller pays on-chain by signing an authorization, and the same request goes through. agentic-x402.ai is the estate's paid endpoint: $0.01 in USDC on Base per call, settled by a facilitator, every settlement answered with a receipt signed by Allooloo Technologies Corp. that resolves forever. No account, no API key, no invoice: the payment is the credential.

What x402 is

1.1

HTTP status 402 Payment Required has been reserved since 1997 (RFC 2068) and never had a protocol behind it. x402 (Coinbase, 2025; open specification, version 2) gives it one: the server states a price, a network, an asset and a pay-to address; the client signs a stablecoin transfer authorization for exactly that amount; a facilitator verifies the signature and settles it on-chain; the server answers the original request.

1.2

The transfer is an EIP-3009 transferWithAuthorization on the USDC contract: the payer signs off-chain, pays no gas, and the authorization is valid only for the stated amount, the stated recipient and a time window. Nothing is custodial; nothing is held by the server.

1.3

x402 is machine-native: an agent that can hold a wallet can pay for a call with no sign-up, no card, no human. That is the reason this surface exists.

What this endpoint does

2.1

GET https://agentic-x402.ai/api — the estate index: every node, its issuer and event counts, its drop date; the same list the free apex serves.

2.2

GET https://agentic-x402.ai/api?record=uk-cm-kg/LSE/BARC — one Capital Markets Record, the same record the free door serves.

2.3

Price $0.01 USDC per call (10000 units, six decimals). Network today: Base Sepolia (testnet first; Base mainnet on the operator's word — the 402 body always states the network in force). Scheme exact, standard EIP-3009, authorization window 60 seconds. The pay-to address is stated in the 402 body, never on this page.

2.4

The free routes are unchanged. Paying buys a receipt, not access.

The exchange

3.1

402 — the call without payment answers 402 Payment Required: JSON body with accepts[] (scheme, network, amount, asset, payTo, maxTimeoutSeconds, resource) and the same object base64-encoded in the PAYMENT-REQUIRED header.

3.2

Signed authorization — the client signs an EIP-3009 authorization for the stated amount to the stated address, valid for 60 s, and repeats the call with the payment payload base64-encoded in the PAYMENT-SIGNATURE header (X-PAYMENT is accepted as the v1 name).

3.3

200 + receipt — the facilitator verifies, the endpoint serves the data, the facilitator settles on-chain; the answer carries PAYMENT-RESPONSE (transaction hash, network, amount, payer) and X-X402-Receipt, the receipt URL. The body is { receipt, data }.

3.4

If verification fails the endpoint answers 402 again with the reason; if settlement fails it answers 402 with the receipt marked settled: false. Nothing is charged on a failed call.

The 402 challenge as protocol fact

4.1

A 402 from this endpoint is not an error page: it is a machine-readable offer. Its body is stable JSON; its header is the same offer in base64; both name the exact amount, asset contract, chain (CAIP-2 id), recipient and window. An agent can act on it with no other document.

4.2

Every response from this surface — and from all 22 others on the estate — carries X-CMR-X402: ready: the identity header that says the operator accepts x402 payment on this endpoint.

4.3

The challenge is the same for every caller; there is no negotiation, no account tier, no rate card. One price, one cent.

Receipts

5.1

Every settlement is answered with a receipt: a JWT signed EdDSA (Ed25519), kid allooloo-x402-receipts-2026-09, issuer https://agentic-x402.ai. Claims: payer, nonce (jti), time, resource, network, asset, amount, payTo, transaction hash and explorer link, settled, facilitator.

5.2

Public key: https://agentic-x402.ai/x402/jwks.json. Resolve any receipt, forever: https://agentic-x402.ai/x402/receipt/{nonce} (immutable, cached a year, kept in the estate's store with no expiry).

5.3

Every settlement is counted on the paid-calls line of RADAR at agentic-radar.ai, with the last transaction and its receipt.

Machine surfaces

6.1

/api — the paid endpoint (GET; OPTIONS answers CORS).

6.2

/x402/jwks.json — the receipt signing key.

6.3

/x402/receipt/{nonce} — the receipt resolver.

6.4

/.well-known/agent-card.json, /.well-known/mcp/server-card.json, /.well-known/api-catalog, /.well-known/oauth-authorization-server, /llms.txt, /facts.json, /auth.md — the machine kit of record, as on every surface. Every node and product agent card links this endpoint under x-cmkg.x402.

6.5

The trades record route https://agentic-trades.ai/x402/record/{node}/{exchange}/{code} is the same protocol on Base mainnet.

Identity headers

7.1

X-CMR-X402: ready — x402 accepted here.

7.2

X-CMR-Operator, X-CMR-Contact, X-CMR-Node, X-CMR-Version, X-CMR-Source: public-record — the CMR v1 identity set, on every response of the estate.

7.3

PAYMENT-REQUIRED on a 402; PAYMENT-RESPONSE and X-X402-Receipt on a settled 200.

Access

8.1

Apex door (MCP, streamable-http, no auth): https://mcp.capitalmarketsknowledgegraph.ai/mcp — routes by identifier to the node that holds the name

8.2

Apex Agent Card (A2A): https://agent.capitalmarketsknowledgegraph.ai/.well-known/agent-card.json

8.3

Tools: resolve_issuer · get_record · list_aliases · list_events_since · list_nodes

8.4

Regional doors: mcp.<node>-cm-kg.ai/mcp, answers scoped to the node; descriptors at /mcp.json and /openapi.json

8.5

Registry entry: registry.modelcontextprotocol.io · io.github.allooloo/cm-kg

Provenance

9.1

Every field carries its source URL, the reader (registry, exchange list, filing tag or named engine) and a state (sourced · filled · confirmed); none is served without source and read date.

9.2

Public-record only: no prices, quotes or licensed market data; blank stays blank; nothing inferred.

9.3

Records are versioned and never deleted; the record as_of and the field read dates are separate fields.

9.4

"Confirmed" is the word; signing is reserved for CMR (cm-record.org) and is not yet in service.

Estate

10.1

Eleven doors in eleven Azure regions, records stored and served in the issuer's jurisdiction; the apex holds an index only and forwards; no fallback across borders.

10.2

Hong Kong: a beacon at Width 0, local partner wanted, no door.

source: list_nodes at https://mcp.capitalmarketsknowledgegraph.ai/mcp, read at render

Machine kit

11.1

/llms.txt · /facts.json · /.well-known/agent-card.json · /.well-known/security.txt · /sitemap.xml · /robots.txt

11.2

Headers on every response: Content-Security-Policy (strict), Strict-Transport-Security, X-Content-Type-Options, Referrer-Policy, X-Frame-Options, X-CMR-Node, X-CMR-As-Of, X-CMR-Version, X-CMR-Source, X-CMR-Operator, X-Surface-Version.

Contact Us

The agents that built this read their own mail: allooloo@hey.com