X402 Url Extractor MCP Server

SameDayDesk x402 Data Gateway

Eleven pay-per-call tools for deterministic Morpho borrower and market decisions, protection plans, URL extraction, Markdown reading, repository security scans, company and wallet enrichment, structured data generation, and AI-search readiness audits.

• Product page: https://samedaydesk.com/x402
• Smithery: https://smithery.ai/servers/epistemedeus/x402-data-gateway
• Remote MCP: https://agents.samedaydesk.com/mcp
• Live resource manifest: https://agents.samedaydesk.com/.well-known/x402
• OpenAPI: https://agents.samedaydesk.com/openapi.json
• Skill contract: https://agents.samedaydesk.com/skill.md
• Action catalog: https://agents.samedaydesk.com/api/actions
• A2A agent card: https://agents.samedaydesk.com/.well-known/agent-card.json
• Global A2A Registry: https://www.a2a-registry.org/agent/9cb0b8e6-cb1f-422b-a604-861d0a79e24b
• Settlement Radar: https://agents.samedaydesk.com/platforms
• Platform health JSON: https://agents.samedaydesk.com/v0/cards.json
• Aggregate machine-demand telemetry: https://agents.samedaydesk.com/v0/commerce-demand.json
• Morpho position risk: GET /defi/morpho-position?address=0x...&shocks=-10,-20,-30
• Morpho protection quote: GET /defi/morpho-protection?address=0x...&targetHealthFactor=1.25&protectAgainstShockPct=-10
• Morpho market underwriting: GET /defi/morpho-market-underwrite?marketId=0x...
• Morpho PreLiquidation replay: GET /defi/morpho-preliquidation-replay?transactionHash=0x...
• Material-change alert probe: https://agents.samedaydesk.com/alerts
• Agoragentic seller callback: POST /integrations/agoragentic/ai-readiness-audit
• the402 signed fulfillment webhook: POST /integrations/the402/webhook

No API key or subscription is required. Calls settle exact USDC amounts on Base mainnet through x402.

The Morpho route is read-only. It calculates LTV, LLTV, health factor, liquidation headroom, and collateral-price shock scenarios from integer protocol values, then cross-checks indexed collateral, borrow shares, and oracle price against direct Base RPC state. Scenarios are calculations rather than probabilities or transaction recommendations. The separate protection route uses a fresh direct-RPC oracle read and direct confirmation of collateral and borrow shares to calculate exact partial-repay and add-collateral amounts. It returns unsigned token-approval and Morpho-call templates, explicit execution buffers, revalidation requirements, and economic postconditions. It never accesses a wallet, signs, broadcasts, or takes custody.

The service also keeps a privacy-safe demand telescope on a persistent Railway volume. It records route families, query key names, challenge/success classes, and pseudonymous repeat-use signals. External fetches are acquisition signals, not verified buyers, because unidentified automated indexers can remain. It does not record raw IP addresses, user agents, URLs, query values, bodies, payment headers, marketplace payloads, or credentials. Public output is aggregate only; owner and crawler traffic are excluded. Common exploit probes such as .env, .git, and WordPress discovery paths are classified as scanner traffic and excluded as well.

Version 1.7 adds request-bound idempotent replay for HTTP buyers that supply the x402 payment-identifier extension. A successful JSON response is cached for 15 minutes on the private Railway volume. The cache key is an HMAC of the logical payment ID, and the binding covers the full canonical URL, HTTP method, payer, network, asset, amount, and recipient. Raw payment IDs, payer addresses, and request URLs are not stored. An exact retry receives the original response and signed settlement receipt without a second payment; changed input, payer, or payment terms return an uncharged HTTP 409. Replays are counted separately from new paid-success events.

Observed agent crawlers use several discovery conventions. The canonical manifest remains /.well-known/x402, with compatible aliases at /.well-known/x402.json, /x402.json, and /api/x402. The canonical OpenAPI document remains /openapi.json, with /openapi.yaml and /swagger.json returning the same JSON document. GET /mcp returns a free transport descriptor; actual MCP discovery and paid tool calls use streamable HTTP at POST /mcp. Agents that prefer a compact instruction contract can read /skill.md (or /SKILL.md), while /api/actions returns the eleven canonical GET actions with their URL, description, exact atomic USDC price, MIME type, network, and payTo. The A2A v1.0 card at /.well-known/agent-card.json advertises one bounded free skill, discover-x402-paid-actions. POST /a2a/message:send returns that exact catalog as an A2A direct message, giving A2A clients a standards-based path from agent discovery to the existing paid x402 actions without claiming arbitrary task execution.

The repository-root agent-card.json is a compatibility manifest for the Global A2A Registry's current GitHub importer. It points back to the canonical v1.0 Agent Card and OpenAPI document; it does not replace the production card. The registry's own generated ownership manifest is hosted separately at https://samedaydesk.com/.well-known/agent-card.json; the standards-compliant A2A v1.0 card remains canonical on agents.samedaydesk.com.

PreLiquidation shadow watcher

morpho-preliquidation-shadow.mjs is the observation-only forward evidence lane selected by the complete Base census. It watches the five markets that concentrate historical execution, derives each market's actual PreLiquidation health threshold from LLTV and pre-LLTV, checks every observed authorization directly at one explicit Base block, and uses per-contract event cursors.

New execution transactions are replayed through the deterministic archive-RPC engine, up to 20 per run. The record includes detection latency, gross loan-asset incentive, and native gas while retaining the explicit boundary that swap, funding, failure, competition, and MEV costs remain outside the replay. Positions below the explicit 1 USD debt observation floor are classified as dust rather than opportunities.

node morpho-preliquidation-shadow.mjs \
  --state /data/morpho-preliquidation-shadow-state.json \
  --history /data/morpho-preliquidation-shadow-history.ndjson

State and history files are forced to mode 0600. A material change means a new or removed authorization, a transition into or out of the protocol-specific risk window, a large liquidity or utilization move, or a new verified PreLiquidation execution. No wallet, signer, authorization, custody, or principal is part of the watcher.

The Agoragentic callback is a separate marketplace distribution bridge. The marketplace handles buyer routing, settlement, and seller accounting, while the callback performs the same production AI-search-readiness audit behind a small per-IP safety cap. Direct agent customers continue to use the paid x402 route.

The the402 bridge is a second marketplace distribution path. It authenticates signed job dispatches with timestamped HMAC verification, accepts callbacks only on the official API origin, and submits a structured audit deliverable for automatic settlement. THE402_API_KEY, THE402_WEBHOOK_SECRET, and THE402_SERVICE_ID are Railway-only environment variables.

The same service also hosts two free, disclosed affiliate handoffs used by fact-checked SameDayDesk guides: /go/topify and /go/manychat. They mint and cache Agent Hansa's expiring signed links server-side, validate the redirect host, expose no API key, and return noindex, nofollow plus no-store.

Original rail implementation

A Node/Express server that returns HTTP 402 Payment Required when unpaid and serves the resource after payment, settling USDC on Base mainnet straight to our own wallet:

payTo = 0x8904dF3DE6DFEe6a7C8cc38619d2f17806213Cee

Verified live (June through August 2026). The server boots and returns correct 402 responses with machine-readable payment requirements. The Morpho canary is amount=20000 = 0.02 USDC, network=eip155:8453, and asset=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 = Base USDC, payTo equal to our wallet, plus a Bazaar discovery extension with input and output schemas.

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Current production decision

Production uses CDP. All eleven routes passed live CDP verification and completed a real settlement. The original eight appear in Bazaar merchant discovery. The three newer Morpho decision routes have successful settlement receipts, and a distinct funded payer produced isValid: true plus Bazaar extension status processing for all three. They still did not enter merchant discovery after the documented cache window and a fresh settlement, so this is tracked as a downstream CDP indexing incident rather than a route-metadata failure. The secret-free reproduction is attached to x402 issue #2156. Keep xpay as the no-key continuity fallback, not as the normal production facilitator.

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How the rail works (why "no account" is safe)

The exact scheme settles USDC via an EIP-3009 transferWithAuthorization: the buyer (agent) signs an authorization that moves USDC directly from their wallet to our payTo on-chain. The facilitator only verifies the signature and broadcasts the transaction; it never holds the money. So:

• Whatever facilitator we pick, the USDC lands in our payTo wallet.
• We hold the key to payTo; the facilitator does not.
• CDP and xpay are non-custodial facilitator paths. CDP relayed the eight live seller canaries and the exact USDC amounts reached our wallet.

This is the same rail Frantic used to pay real mainnet USDC to this wallet, so we already know settlement to 0x8904…3Cee works.

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Answers to the five questions

1. Facilitator + autonomy

• The public x402.org facilitator supports Base Sepolia testnet only (eip155:84532); its /supported endpoint does not list eip155:8453. Mainnet via x402.org is impossible.
• Base mainnet settlement does not strictly require a Coinbase CDP account. The xpay public facilitator (https://facilitator.xpay.sh) supports Base mainnet eip155:8453 exact scheme with no account and no API key (verified against its live /supported endpoint). This is the fully-autonomous mainnet path.
• The CDP facilitator requires a CDP account and API keys. Its advantage is Bazaar merchant discovery, semantic search, and the Bazaar MCP buyer surface.
• Production chose CDP after a live verify-only matrix and eight successful settlements. xpay remains the no-key fallback.

2. Exact seller code

See server.js. Current package line (NOT the legacy flat x402-express@1.x):

@x402/express     2.16.0   paymentMiddleware, x402ResourceServer
@x402/core        2.16.0   HTTPFacilitatorClient   (import from @x402/core/server)
@x402/evm         2.16.0   ExactEvmScheme          (import from @x402/evm/exact/server)
@x402/extensions  2.16.0   declareDiscoveryExtension (import from @x402/extensions/bazaar)
@coinbase/x402    2.1.0    createFacilitatorConfig (only needed for CDP mainnet)

Core wiring:

const facilitatorClient = new HTTPFacilitatorClient(
  createFacilitatorConfig(process.env.CDP_API_KEY_ID, process.env.CDP_API_KEY_SECRET)
);
const resourceServer = new x402ResourceServer(facilitatorClient)
  .register("eip155:8453", new ExactEvmScheme());

app.use(paymentMiddleware(
  { "GET /premium": { accepts: [{ scheme: "exact", price: "$0.01",
      network: "eip155:8453", payTo: "0x8904dF3DE6DFEe6a7C8cc38619d2f17806213Cee" }],
      description: "...", mimeType: "application/json", extensions: { ... } } },
  resourceServer
));

3. Bazaar discovery

The route's extensions uses declareDiscoveryExtension({ input, inputSchema, output, outputSchema }) (already in server.js). This advertises the route and its JSON schemas in the 402 payload (verified present in the live response). Surfacing in the CDP Bazaar requires the CDP facilitator: CDP catalogs a route after its first successful settlement. The production merchant lookup returns the original eight SameDayDesk routes; all three newer Morpho decision routes have successful CDP settlements and accepted processing Bazaar extensions, but remain absent beyond the documented cache window. CDP also finds the original Morpho and deep-audit routes through semantic search. Use the merchant lookup as evidence of CDP catalog state, not as the canonical count of SameDayDesk capabilities; the owned manifest, MCP, A2A, and OpenAPI surfaces remain complete at eleven.

CDP rejected three older route payloads whose discovery descriptions were 535, 581, and 629 characters even though local extension validation passed. Concise rewrites of 294, 258, and 301 characters passed. Keep new discovery descriptions under 400 characters and run live CDP verify before a funded canary.

4. Settlement verification

After a paid call, confirm USDC landed at payTo on Base mainnet. The 402/200 flow also returns a PAYMENT-RESPONSE header with settlement data. Independently:

# USDC balanceOf(payTo) on Base mainnet via public RPC, no key:
curl -s -X POST https://mainnet.base.org -H 'Content-Type: application/json' \
  --data '{"jsonrpc":"2.0","id":1,"method":"eth_call","params":[{
    "to":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "data":"0x70a082310000000000000000000000008904df3de6dfee6a7c8cc38619d2f17806213cee"
  },"latest"]}'

Result is hex atomic USDC (divide by 1e6). Or use our existing Base-mainnet balance checker. Or view the wallet on https://basescan.org/address/0x8904dF3DE6DFEe6a7C8cc38619d2f17806213Cee

5. Cleanest recommended path

Deploy on CDP for the production storefront. It preserves direct USDC settlement and adds the catalog, semantic search, merchant lookup, and Bazaar MCP buyer surface. Keep xpay configured as the no-key recovery path.

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Deploy steps (Railway)

The repo is a no-config Node app: npm start runs node server.js and binds process.env.PORT (Railway sets it).

1. Deploy this directory directly or push the repository source.
2. Set env vars on the Railway service:

   PAY_TO=0x8904dF3DE6DFEe6a7C8cc38619d2f17806213Cee
   NETWORK=eip155:8453
   PRICE=$0.05
   FACILITATOR=cdp
   CDP_API_KEY_ID=<CDP API key ID>
   CDP_API_KEY_SECRET=<CDP API key secret>
   COMMERCE_DATA_DIR=/data
   COMMERCE_ACTOR_SECRET=<random 32-byte secret>
   COMMERCE_INTERNAL_TOKEN=<random owner-canary token>
   COMMERCE_EXTERNAL_SINCE=<ISO timestamp after controlled launch canaries>
   

   Core payment settings have safe defaults. Production telemetry uses a Railway volume mounted at /data plus the two secret variables above.
3. Generate a public domain for the service.
4. Verify:

   curl https://<your-domain>/healthz          # -> {ok:true, network:eip155:8453, ...}
   curl -i 'https://<your-domain>/defi/morpho-position?address=0x...' # -> HTTP 402 + PAYMENT-REQUIRED header
   

5. Complete one bounded settlement per discoverable route, then confirm the merchant lookup and semantic search. Record owner settlements as test flow, not revenue.

Fall back to xpay without changing route code

If CDP is unavailable and continuity matters more than central discovery, set:

FACILITATOR=xpay

Redeploy. Base mainnet settlement continues, but new calls no longer feed the CDP Bazaar quality and activity signals.

Prove the rail on testnet first (optional)

FACILITATOR=testnet
NETWORK=eip155:84532

Uses x402.org + Base Sepolia (fake USDC) to validate the full 402→pay→200 loop before taking mainnet money.

---

Local run

npm install
npm start
# then:
curl -i 'http://localhost:3000/defi/morpho-position?address=0x...' # HTTP 402

Files

• server.js — the server (env-driven facilitator/network/price).
• commerce-events.mjs — privacy-safe durable demand telemetry.
• morpho-position.mjs — deterministic Morpho snapshot, stress, and RPC checks.
• morpho-protection.mjs — exact stressed repair amounts and unsigned action templates.
• morpho-market-underwrite.mjs — multi-source market integrity, liquidity, concentration, borrower-health, history, bad-debt, and PreLiquidation evidence.
• morpho-preliquidation-replay.mjs — historical PreLiquidate event economics from direct block-state reads.
• morpho-preliquidation-census.mjs — repeatable Base supply, authorization, and execution census for internal market selection.
• package.json — exact pinned deps (verified to install & boot).
• README.md — this guide.
• extract.mjs — pre-existing zero-dependency "URL → clean structured data" service. This is a natural paid resource to put behind /premium: in the route handler, call its extractor on a ?url= query param and return the structured result instead of the placeholder {value:42}. Add ?url to the Bazaar inputSchema when you wire it up.

Sources (primary, verified August 2026)

• x402 seller quickstart: https://docs.x402.org/getting-started/quickstart-for-sellers
• CDP x402 docs: https://docs.cdp.coinbase.com/x402/welcome
• CDP network support (x402.org = testnet only; CDP = mainnet + keys): https://docs.cdp.coinbase.com/x402/network-support
• CDP Bazaar: https://docs.cdp.coinbase.com/x402/bazaar
• x402 monorepo: https://github.com/coinbase/x402
• npm: @x402/express, @x402/core, @x402/evm, @x402/extensions, @coinbase/x402
• xpay public facilitator live /supported (Base mainnet, no key): https://facilitator.xpay.sh/supported