# Services from x402-echo-service.onrender.com on Zero

> x402-echo-service.onrender.com serves 15 paid API services for AI agents, indexed by Zero. Each is callable per call with payment handled by Zero.

Canonical page: https://www.zero.xyz/host/x402-echo-service.onrender.com
Live health (JSON, refreshed every minute): https://www.zero.xyz/host/x402-echo-service.onrender.com/health.json

## Services

- [Contract Check](https://www.zero.xyz/c/contract-check-78146a95/llms.txt): $0.001/call via x402. Determines whether a Base blockchain address is a smart contract or an externally owned account (EOA), returning bytecode size and keccak-256 hash.
- [ERC-20 Token Balance on Base](https://www.zero.xyz/c/erc-20-token-balance-on-base-e16422f2/llms.txt): $0.001/call via x402. Reads the ERC-20 token balance of a given wallet address on the Base blockchain, returning raw balance, decimals, and human-readable amount.
- [Gas Price on Base](https://www.zero.xyz/c/gas-price-on-base-e5a883e5/llms.txt): $0.001/call via x402. Returns the current legacy gas price and EIP-1559 base fee of the latest block on the Base blockchain, in both wei and gwei.
- [Hash Digest](https://www.zero.xyz/c/hash-digest-54bf16a2/llms.txt): $0.001/call via x402. Compute cryptographic hash digests (SHA-256, SHA-512, or Keccak-256) of an input string and return hex-encoded results.
- [Native ETH Balance on Base](https://www.zero.xyz/c/native-eth-balance-on-base-4d774b8e/llms.txt): $0.001/call via x402. Returns the native ETH balance of a given wallet address on the Base blockchain, in both wei and ether, read directly from a node.
- [Transaction Lookup](https://www.zero.xyz/c/transaction-lookup-d3e705b7/llms.txt): $0.001/call via x402. Look up a Base blockchain transaction by hash, returning its status, block number, addresses, value, gas used, and effective gas price.
- [UUID Generator](https://www.zero.xyz/c/uuid-generator-9a8f8ba9/llms.txt): $0.001/call via x402. Generates between 1 and 100 cryptographically random UUIDv4 identifiers per call using the platform CSPRNG.
- [Account Nonce](https://www.zero.xyz/c/account-nonce-5468e55f/llms.txt): $0.001/call via x402. Returns the current transaction count (nonce) for a Base blockchain address, optionally including pending mempool transactions.
- [Base64 Codec](https://www.zero.xyz/c/base64-codec-18f77751/llms.txt): $0.001/call via x402. Encodes or decodes base64 strings, supporting both standard and URL-safe alphabets with strict validation on decode.
- [Base Block Reader](https://www.zero.xyz/c/base-block-reader-c680d1d5/llms.txt): $0.001/call via x402. Fetches block metadata from the Base blockchain — either the latest block (chain head) or a specific block by height — returning number, hash, timestamp, gas used, and transaction count.
- [Time Formats](https://www.zero.xyz/c/time-formats-c4418d0e/llms.txt): $0.001/call via x402. Returns the current UTC time in four formats simultaneously: ISO-8601, Unix seconds, Unix milliseconds, and RFC-2822.
- [Token Metadata](https://www.zero.xyz/c/token-metadata-e52248b0/llms.txt): $0.001/call via x402. Reads ERC-20 token metadata (name, symbol, decimals, total supply) for a given contract address on Base.
- [Open Web Search](https://www.zero.xyz/c/open-web-search-785f26f5/llms.txt): $0.001/call via x402. Performs keyword and semantic web search, returning ranked results with titles, URLs, and text snippets — no API key required, billed per call via x402.
- [x402 Research Echo](https://www.zero.xyz/c/x402-research-echo-c72c0b2d/llms.txt): $0.001/call via x402. Echoes a submitted message back with its SHA-256 digest and a server timestamp, used for x402 protocol conformance and discovery-layer research.
- [Open Web Search](https://www.zero.xyz/c/open-web-search-ce74e52c/llms.txt): $0.001/call via x402. Performs keyword and semantic web search, returning ranked results with titles, URLs, and text snippets — no API key required, billed per call via x402.

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

- [Zero catalog index](https://www.zero.xyz/llms.txt)