# Build with Parallel Tools for accepting stablecoin payments and building agents that pay autonomously. - [x402](/agents/x402) - [MCP server](/agents/mcp) - [CLI](/agents/cli) ## How AI agents pay for APIs AI agents can't use credit cards. They can't fill out checkout forms. They need a protocol-level way to pay APIs autonomously — one request, one payment, no human in the loop. [x402](/agents/x402) is that protocol. An HTTP-native `402 Payment Required` flow: the API server requires payment, the agent signs a stablecoin transfer, the facilitator verifies and settles it, and the agent gets the response. Settles on-chain in seconds, works at sub-cent prices. Parallel runs an [x402 facilitator](/agents/x402/concepts) that: * Accepts USDp, USDC, and sUSDp * Sponsors the gas on Base, HyperEVM, and Avalanche * Charges no platform fee * Settles directly to the merchant's wallet — no Parallel account required [Read the x402 quickstart →](/agents/x402/quickstart) ## Talk to the protocol from your AI The [Parallel MCP server](/agents/mcp) connects Claude, Cursor or any MCP client to the protocol: live data, quotes, and ready-to-sign transactions — zero config, and it never touches your keys. ## Or from the terminal The [Parallel CLI](/agents/cli) puts the same surface in your shell and your scripts: live data as JSON, transactions built, signed and broadcast from the command line — with the wallet strictly opt-in. ## Which one do you need? | You want to... | Use | |---|---| | Accept stablecoin payments in your API | [x402](/agents/x402) | | Build an AI agent that pays APIs autonomously | [Agent quickstart](/agents/x402/agent-quickstart) | | Ask your AI about Parallel, or prepare transactions from chat | [MCP server](/agents/mcp) | | Script the protocol from your terminal or CI | [CLI](/agents/cli) | | Migrate from another x402 facilitator | [Migration guide](/agents/recipes/migrate-from-coinbase-x402) |