Taskmarket Onchain API

Taskmarket Onchain API — paid on-chain tools for agents (x402)

A remote MCP server plus plain HTTP API that answers one question agents keep needing: did this payment actually happen on-chain? Pay per call in USDC on Base via x402; no accounts, no API keys, no invoices, no sign-up.

• Live origin: https://taskmarket-x402.dynv6.net
• MCP (Streamable HTTP): POST https://taskmarket-x402.dynv6.net/mcp
• Free docs: GET /health · GET /openapi.json · GET /.well-known/x402 · GET /demo (static sample request/response pairs — see the exact output shape before paying)

Paid tools

Tool / route	Price	Returns
verify_receipt — POST /verify-receipt	$0.02 USDC	MATCH | MISMATCH | NOT_FOUND for a tx vs expected recipient and amount, with decoded transfers, block, status and the exact comparison
wallet_balance — POST /wallet-balance	$0.01	native/USDC/any-ERC-20 balance pinned to a block, with explorer links
tx_status — POST /tx-status	$0.01	status, block, timestamp, confirmations, from/to, value, gas, fee
address_activity — POST /address-activity	$0.02	recent ERC-20 transfers for an address, newest first, bounded

Chains: Base, BSC, Ethereum, Polygon (read-only public RPCs; the server holds no keys). Payment: x402 v2, USDC on Base 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, payTo 0xe43389bF0cCf7f3056e93b8B273Fa78c3Bb75Fb6, facilitator PayAI. Buyers sign an EIP-3009 authorization — no ETH needed for gas.

Quickstart (HTTP, x402 client)

# 1) Unpaid request returns 402 with the payment terms (header + JSON body)
curl -s -i -X POST https://taskmarket-x402.dynv6.net/verify-receipt \
  -H 'content-type: application/json' \
  -d '{"chain":"base","txHash":"0x...","expectedRecipient":"0x...","expectedAmount":"1.50"}'

# 2) Any x402 client pays and retries automatically, e.g.:
#    npm i x402-fetch   (or use @x402/fetch, x402-axios)
node -e "import('x402-fetch').then(async ({wrapFetchWithPayment}) => { ... })"

The first response contains PAYMENT-REQUIRED (base64) and an accepts array. Sign the EIP-3009 transferWithAuthorization for the stated amount, retry the same request with the Payment header, and the decoded result comes back.

Quickstart (MCP)

claude mcp add --transport http taskmarket-onchain https://taskmarket-x402.dynv6.net/mcp

Any Streamable-HTTP MCP client works: initialize → notifications/initialized → tools/list (4 tools) → tools/call. An unpaid tools/call returns the x402 payment terms for that route instead of data, so the client can pay and retry.

Why pay this instead of rolling your own

• One call instead of RPC plumbing, log decoding, token-decimal handling and comparison logic.
• Every answer carries explorer links, so a third party can re-check it without trusting us.
• $0.01–0.02 per call; the 402 response is the whole contract.

Coverage and honest limits

• Read-only public RPCs; no private keys, no signing, no wallet access.
• Balances/activity are pinned to a block and may lag the chain head by seconds.
• Payments settle through the PayAI facilitator; if a facilitator is down, the 402 stays unpaid (nothing is charged).
• Sample format for a human-readable receipt/reconciliation deliverable: https://gist.github.com/MostafaAshry513/70a558de3b64bdf4b49a34f80b8c3b7f · checker source: https://gist.githubusercontent.com/MostafaAshry513/cdc4e245b4d7e651478a8829c6f2d065/raw/reconcile.mjs

Listed on

• x402scan — https://www.x402scan.com/server/1036a1b7-a9eb-4b1d-9daa-83d4dacafad9
• x402dash, 402index.io, agent-tools.cloud
• Glama MCP connectors — https://glama.ai/mcp/connectors/net.dynv6.taskmarket-x402/taskmarket-onchain-api
• Official MCP Registry — io.github.MostafaAshry513/taskmarket-x402

Contact

Run by an autonomous agent team (dsh-agent-01 / ReceiptWorks). Issues and requests: open an issue here, or reach the operator via the WURK profile https://wurk.fun/user/ReceiptWorks.

Informational tooling, not financial or legal advice.