agentic-endpoints

x402-powered micro-SaaS utilities for autonomous AI agents. Pay-per-call with USDC micropayments on Base — no API keys, no accounts, no subscriptions.

Live at https://ai.oliverkiss.com

Endpoints

GET / content-negotiates: send Accept: application/json for the machine-readable endpoint catalogue, anything else gets the HTML landing page.

How It Works

1. An agent requests a paid endpoint
2. The server replies HTTP 402 Payment Required with the price, network and receiving address
3. The agent signs a USDC transfer on Base and retries with an X-PAYMENT header
4. The facilitator verifies and settles the payment, then the handler runs

Try it — this returns a real 402 challenge, not an error:

curl -i -X POST https://ai.oliverkiss.com/once-key \
  -H 'Content-Type: application/json' \
  -d '{"namespace":"demo","action_key":"abc123"}'

MCP Server

Every paid endpoint is also exposed as an MCP tool over Streamable HTTP at https://ai.oliverkiss.com/mcp, implementing revision 2026-07-28 (stateless: no initialize handshake, no session header) with a fallback for clients still sending the 2025-06-18 handshake.

{
  "mcpServers": {
    "agentic-endpoints": { "type": "http", "url": "https://ai.oliverkiss.com/mcp" }
  }
}

tools/list is free so clients can discover the catalogue. tools/call re-enters the corresponding paid route in-process, so it passes the same x402 gate, body cap and validation as a direct HTTP call. Without a valid X-PAYMENT header the tool returns isError: true and a machine-readable payment demand (price, payTo, asset, network) rather than performing work.

Two Ways To Pay

Per-call x402 caps revenue at whatever a buyer will tolerate signing: $1,000 at $0.005 a call is 200,000 signatures. Prepaid credits sell the same work once, in an amount worth the transaction, and let callers whose wallets cannot sign per request use the service at all.

Both paths run side by side and neither is privileged:

# Per call, unchanged
curl -X POST https://ai.oliverkiss.com/compress -H "X-PAYMENT: ..." -d '{"text":"..."}'

# Or prepay once, then no signatures
curl -X POST https://ai.oliverkiss.com/credits/buy -H "X-PAYMENT: ..."   # -> credit_token
curl -X POST https://ai.oliverkiss.com/compress \
  -H "X-Credit-Token: ae_..." -d '{"text":"..."}'

Omitting X-Credit-Token produces exactly the 402 challenge it always did, so the Bazaar listing and every existing integration are unaffected.

Credits are integer micro-dollars, never floats: $0.001 has no exact binary representation, and a ledger that drifts is worse than no ledger. Each account is its own Durable Object addressed by the hash of its token, so the balance check and its debit are atomic and one account cannot queue behind another. Calls are debited before the work and refunded if it 5xxs, because an outage must not bill a customer for nothing.

The token is shown once and is not recoverable — only its hash is stored.

Discovery

An endpoint nobody can find earns nothing, so the service is registered wherever agents actually look. Every catalog below was chosen because it verifies ownership by domain or wallet rather than by a financial account — the Coinbase CDP Bazaar is skipped for exactly that reason.

Aggregators such as PulseMCP ingest from the official registry, so publishing there covers several directories at once. The repository is public, so directories that crawl source repos can now see it too.

Machine-readable descriptions are generated from the same pricing table that gates payment, so they cannot drift from what is actually charged: /llms.txt for a model handed a bare URL, /openapi.json for tooling, plus /robots.txt and /sitemap.xml. Tests assert the prices agree across all of them.

Revenue Monitoring

The service could demand payment for months with no way to tell whether a payment ever arrived — including the failure mode where payments verify but never settle. A cron trigger sweeps Base every 5 minutes for USDC Transfer logs into the receiving address and folds them into a running ledger in KV.

Revenue is read from the chain, not from our own logs or the facilitator's word, so it cannot be inflated by a bug on either side. GET /revenue publishes the ledger for free — it costs nothing and gives a prospective caller evidence the service actually transacts.

Set ALERT_WEBHOOK_URL to a Discord webhook to be notified when money lands:

npx wrangler secret put ALERT_WEBHOOK_URL

The first scan starts the watermark at the current chain head rather than genesis; scanning millions of blocks through a public RPC node would fail repeatedly and never establish a watermark at all. The watermark advances only on a successful scan, so a transient RPC failure is retried on the next tick with nothing missed.

Buyer signals

Revenue monitoring only sees money that arrived. The service takes thousands of requests a day and, so far, no revenue — and reviewing the callers, almost all of it is liveness probes, trust scanners and directory crawlers, which are indistinguishable from a customer in an access log. The gap that leaves is a genuine buyer being refused for a fixable reason and leaving without ever appearing as a distinguishable line.

src/lib/tripwire.ts emits one structured line per notable request:

npx wrangler tail --format json | grep BUYER_SIGNAL