Byte MCP Server

What 0rkz/byte-mcp-server MCP server does

The 0rkz/byte-mcp-server MCP server exposes PayPerByte marketplace and data-stream operations through MCP tools. Agents can search publishers, browse active feeds, inspect network statistics, review publisher schemas, and check subscription state. The available catalog includes feeds across areas such as weather, markets, code, security, and knowledge, with topic, frequency, and price-per-KB metadata.

The server supports two payment paths. byte_buy_data makes a one-off request through the x402 gateway and settles real USDC on Base mainnet. byte_subscribe enables recurring stream delivery on the Arbitrum Sepolia testnet using MockUSDC. Subscription tools also cover unsubscribing, listing wallet subscriptions, and checking whether a publisher's activity has materially changed.

How it works

Read-only tools query PayPerByte catalog, indexer, and on-chain information without a wallet. A configured wallet is needed for actions that spend funds or write to contracts, including subscribing, unsubscribing, registering a publisher, publishing data, querying the fact oracle, and buying a feed packet.

The two rails use different networks. One-off x402 purchases use Base mainnet, chain eip155:8453, and real USDC. Subscription, publishing, and fact-oracle operations use BYTE Library contracts on Arbitrum Sepolia, chain 421614, with MockUSDC. The same PRIVATE_KEY can serve both paths, so it should belong to a dedicated wallet containing only funds intended for these operations.

Paid responses include an EIP-712 PayloadAttestation receipt. byte_verify_payload recomputes the received bytes' keccak256 hash and compares it with an on-chain attestation. Verification establishes delivery integrity and the attested signer relationship; it does not establish that the publisher's data is factually correct. The tool can use an expected payload hash or a settlement transaction hash as its anchor.

Setup and configuration

Start the 0rkz/byte-mcp-server MCP server with:

npx -y byte-mcp-server

The README includes Claude Desktop wiring instructions. No API key is required. Set PRIVATE_KEY on the server when using wallet-backed operations. Buying data also requires USDC on the configured wallet; those purchases settle real USDC on Base mainnet. Subscription and related testnet operations use the Arbitrum Sepolia layer and its MockUSDC balances.

The live x402 feed catalog is available from https://x402.payperbyte.io/feeds. GET feeds take a feed slug, while POST oracle feeds take a JSON body; providing body causes byte_buy_data to use POST. The README advises keeping the wallet isolated because paid calls spend real funds.

Tools and capabilities

Discovery and inspection capabilities include:

• Search publishers by topic and sort order.
• List active feeds with topics, prices, and frequencies.
• Inspect publisher status, schema, subscriber count, message count, and USDC revenue.
• Read network totals and wallet token balances on Arbitrum Sepolia.
• List subscriptions and review recent message delivery and USDC spending.
• Classify subscription activity as stable, moderate, significant, or unknown.

Wallet-backed capabilities include subscribing, unsubscribing, registering a first-party publisher, and publishing payloads through the DataStream contract. byte_query_fact asks a registered fact-oracle publisher for a signed answer with citation URLs, but it times out if no suitable publisher is actively broadcasting. byte_buy_data returns the purchased data and settlement transaction hash inline.

Limitations and notes

Arbitrum Sepolia subscription and publishing functionality is testnet-based, while x402 buying uses real Base-mainnet USDC. The fact-oracle response is not a truth guarantee, and attestation verification does not validate the correctness of the underlying content. Before acting on BYTE-sourced bytes, use byte_verify_payload; a failed verification means the bytes should not be used.

The server does not display the Base-mainnet USDC balance spent by byte_buy_data when using its Arbitrum Sepolia balance tool. The README also notes that PayPerByte v1 publishers are first-party and unstaked, and that mainnet operation for the subscription layer is gated on an external security audit.