X402nano MCP Server

x402nano

MCP Server

x402nano exposes a public, stateless MCP endpoint using the production Streamable HTTP transport:

https://x402nano.onrender.com/mcp

The remote server exposes free market discovery and pricing tools plus x402-protected 0.05 USDC Market Brief and Market Delta tools. Paid MCP calls use the official x402 MCP payment flow: the caller signs locally, the facilitator verifies and settles on Base, and x402nano never receives or stores a buyer private key.

The repository also retains the proven local stdio MCP server with conservative payment budgets. See mcp-server/README.md for both connection paths, unpaid verification, and client requirements. The standards-compliant remote server manifest is server.json.

Machine-payable market intelligence API for AI agents and bots.

x402nano serves read-only Polymarket market briefs, deltas, and webhook alert registrations behind an HTTP 402 payment flow. An agent receives a payment challenge, retries with X-PAYMENT, and receives the purchased intelligence object plus a receipt.

This is market intelligence infrastructure, not trading advice.

Paid briefs include 24h market movement, volume/liquidity context, resolution context, watch points, and safe descriptive scores. They do not include trading execution, custody, betting advice, or buy/sell recommendations.

Live Endpoint

https://x402nano.onrender.com

Free discovery/trending endpoint:

GET https://x402nano.onrender.com/api/markets/trending

Paid market brief endpoint:

GET https://x402nano.onrender.com/api/markets/brief?slug=will-gideon-saar-be-the-next-prime-minister-of-israel

Paid market delta endpoint:

GET https://x402nano.onrender.com/api/markets/delta?slug=will-gideon-saar-be-the-next-prime-minister-of-israel&since=2026-06-15T12:00:00Z

Paid webhook alert registration:

POST https://x402nano.onrender.com/api/alerts/register

Mainnet Proof

x402nano has completed one real paid unlock on Base mainnet.

Network: Base mainnet, eip155:8453
Asset: USDC
Price: 0.05 USDC
Seller wallet: 0x4cc3831eB479aCFb6D44631d4a30814508Cf52d3
Receipt: f1ffa2f5cabf94c3
USDC transfer tx: 0x54ba49a288a56d20046c25f4496bec405f2eefc05fe413cd511caf96227911b1
BaseScan: https://basescan.org/tx/0x54ba49a288a56d20046c25f4496bec405f2eefc05fe413cd511caf96227911b1

The proof run verified:

HTTP 402 challenge issued
0.05 USDC paid on Base mainnet
X-PAYMENT retry accepted
receipt generated
market brief JSON unlocked
on-chain USDC transfer confirmed

Delta proof:

Direct paid delta receipt: 75fe7c800fed47d4
USDC transfer tx: 0x701faef1c35086f5e2ee4243a35d3a904960bd4279ffaab1890b849c1330582a
BaseScan: https://basescan.org/tx/0x701faef1c35086f5e2ee4243a35d3a904960bd4279ffaab1890b849c1330582a
Proof note: DIRECT_DELTA_X402_PRODUCTION_UNLOCK_PROOF.md

Proof references:

BaseScan transaction:
https://basescan.org/tx/0x54ba49a288a56d20046c25f4496bec405f2eefc05fe413cd511caf96227911b1

In-repo proof notes:
TRUST.md
ARCHITECTURE.md
LISTING_METADATA.md
DIRECT_DELTA_X402_PRODUCTION_UNLOCK_PROOF.md

Note: the local buyer script exited nonzero after the real unlock because the immediate post-payment buyer balance read was stale. Seller balance updated, receipt/events were recorded, and a later no-payment balance check confirmed the buyer moved from 1.00 to 0.95 USDC.

Buyer Flow

1. Discover the API.

GET https://x402nano.onrender.com/.well-known/x402.json

1. Request a paid market brief.

Invoke-WebRequest `
  -Uri "https://x402nano.onrender.com/api/markets/brief?slug=will-gideon-saar-be-the-next-prime-minister-of-israel" `
  -UseBasicParsing

1. Expect 402 Payment Required.

The response includes payment requirements similar to:

{
  "error": "payment_required",
  "paymentRequirements": {
    "network": "eip155:8453",
    "asset": "USDC",
    "amount": "0.05",
    "payTo": "0x4cc3831eB479aCFb6D44631d4a30814508Cf52d3",
    "resource": "/api/markets/brief?slug=will-gideon-saar-be-the-next-prime-minister-of-israel"
  }
}

1. Sign and send the x402 payment.

Use an x402-compatible client to sign the Base mainnet USDC payment, then retry the same request with:

X-PAYMENT: <signed-x402-payment>

1. Receive the unlocked JSON.

Successful paid responses include a receipt and the market brief payload:

{
  "receipt": {
    "id": "f1ffa2f5cabf94c3",
    "network": "eip155:8453",
    "amount": "0.05",
    "asset": "USDC"
  },
  "data": {
    "briefType": "read-only-market-intelligence",
    "status": "ok",
    "market": {
      "slug": "will-gideon-saar-be-the-next-prime-minister-of-israel"
    },
    "movement": {
      "window": "24h",
      "direction": "flat",
      "trajectory": []
    },
    "metrics": {
      "volume24h": "17,260.91",
      "liquidity": "81,697.04"
    },
    "resolution": {
      "endDate": "2026-12-31T00:00:00Z"
    },
    "scores": {
      "marketMovementScore": 45,
      "attentionScore": 70,
      "dataCompletenessScore": 100,
      "unusualMovementFlag": false
    }
  }
}

Delta Briefs

Delta briefs are the repeat-use paid object for agent polling loops. A brief answers "what is this market right now?" A delta answers "what changed since the agent last checked?"

GET https://x402nano.onrender.com/api/markets/delta?slug=will-gideon-saar-be-the-next-prime-minister-of-israel&since=2026-06-15T12:00:00Z

Without payment, the route returns 402 Payment Required. With a valid X-PAYMENT retry, the response includes a receipt and read-only delta JSON:

{
  "status": "unlocked",
  "receipt": {
    "id": "receipt-id-after-payment",
    "network": "eip155:8453",
    "amount": "0.05",
    "asset": "USDC"
  },
  "data": {
    "briefType": "read-only-market-delta",
    "market": {
      "slug": "will-gideon-saar-be-the-next-prime-minister-of-israel"
    },
    "window": {
      "since": "2026-06-15T12:00:00.000Z",
      "until": "2026-06-15T18:30:00.000Z"
    },
    "change": {
      "available": true,
      "outcome": "Yes",
      "absoluteChange": "0.050",
      "relativeChange": "+11.9%",
      "direction": "up",
      "changed": true
    },
    "significance": {
      "repeatCheckPriority": "high",
      "unusualMovementFlag": true,
      "summary": "The leading outcome moved up by 0.050 over the requested window."
    }
  }
}

Delta briefs are descriptive market context for agents. They do not include trading execution, custody, betting advice, predictions, or buy/sell recommendations.

Example polling clients:

examples/delta-polling.js
examples/delta-polling.py

Both examples show the intended agent loop: inspect freshness metadata, request a delta, handle the 402, retry with an x402 payment from a caller-provided signing hook, parse the receipt and delta payload, then update since after a successful response.

Webhook Alerts

Webhook Alerts let an agent pay once to register monitoring for one or more Polymarket slugs.

POST /api/alerts/register
Content-Type: application/json

{
  "webhookUrl": "https://my-agent.com/webhook",
  "slugs": ["will-gideon-saar-be-the-next-prime-minister-of-israel"],
  "threshold": 0.07,
  "checkIntervalMinutes": 15
}

The unpaid request returns an x402 challenge for 0.08 USDC. Retry the same POST body with X-PAYMENT. A successful registration returns 201 Created, a receipt, and the alert record.

The background checker runs every 10 minutes. The first successful market check establishes a probability baseline. Later checks POST significant_delta to the webhook when the monitored outcome moves by at least the configured absolute threshold. Delivery is attempted up to three times.

webhookUrl must use public HTTPS. Defaults are threshold: 0.07 and checkIntervalMinutes: 15. A registration supports up to 20 unique slugs.

Registrations, timestamps, checker state, and probability baselines are stored in SQLite. Locally, the default is ./data/x402nano-alerts.sqlite. On Render, the default is /data/alerts.db; render.yaml also sets ALERT_DB_PATH=/data/alerts.db. Active alerts are reloaded from SQLite on every checker run.

The checker uses both an in-process guard and an expiring SQLite lock so overlapping runs are skipped. Current timing is approximate: the scheduler wakes every 10 minutes, so alerts are generally checked every 10-20 minutes depending on Render uptime, scheduler alignment, and the alert's configured interval.

Example registration client:

examples/register-alert.js

Render Persistent Disk Setup

Render Persistent Disks require a paid web-service instance. The included render.yaml uses the starter plan, one instance, and a 1 GB disk. Applying it will create Render charges.

Dashboard setup:

1. Open the x402nano service in Render and upgrade it from free to starter or another disk-compatible paid plan.
2. Open Disks, add a disk named x402nano-alert-data, choose 1 GB, and mount it at /data.
3. Open Environment and set ALERT_DB_PATH=/data/alerts.db.
4. Set the service health-check path to /health.
5. Keep the service at one instance; Render disks cannot be shared across horizontally scaled instances.
6. Deploy, then confirm /health and /api/alerts/status both return 200.

Only files under /data survive deploys and restarts. The disk is mounted at runtime, not during the build. Attaching a disk disables zero-downtime deploys, so short deployment interruptions are expected.

Operational checks:

GET /health
GET /api/alerts/status

/health returns { "status": "ok", "alertCount": 0 }. /api/alerts/status reports total and active alerts, the last checker time/status, scheduler interval, and sanitized error state without exposing webhook URLs.

The GitHub workflow .github/workflows/render-keepalive.yml pings /health every five minutes. GitHub schedules can be delayed and should be treated as an external liveness check, not a hard real-time scheduler.

Local Proof Command

Preflight only:

cd C:\Users\bobjo\Documents\Codex\2026-05-17\ok-ive-already-built-a-x402
$env:MAINNET_PAID_PATH="/api/markets/brief?slug=will-gideon-saar-be-the-next-prime-minister-of-israel"
$env:MAINNET_MAX_USDC="0.05"
$env:MAINNET_PAYMENT_ACK="PREFLIGHT_ONLY"
npm.cmd run agent:mainnet

Real payment, only when intentionally sending one 0.05 USDC unlock:

cd C:\Users\bobjo\Documents\Codex\2026-05-17\ok-ive-already-built-a-x402
$env:MAINNET_PAID_PATH="/api/markets/brief?slug=will-gideon-saar-be-the-next-prime-minister-of-israel"
$env:MAINNET_MAX_USDC="0.05"
$env:MAINNET_PAYMENT_ACK="PAY_REAL_0.05_USDC"
npm.cmd run agent:mainnet

Current Scope

In scope:

Polymarket public data
read-only market intelligence
free trending endpoint
paid market brief endpoint
paid market delta endpoint
paid webhook alert registration
10-minute in-process alert checker
three-attempt HTTPS webhook delivery
HTTP 402 challenge
Base mainnet USDC unlock
receipt and proof

Out of scope for this launch:

trading advice
trade execution
Telegram bot
lead generation
x402 consulting
external database or multi-instance alert coordination
exactly timed delivery during deploy interruptions or platform outages

Development

npm.cmd install
npm.cmd run build

Core scripts:

npm.cmd run agent:mainnet
npm.cmd run wallet:mainnet:create
npm.cmd run build