MCP payment middleware should inspect, not seize spending authority.

Use MCP for capability discovery and contract inspection. For paid targets, fetch the fresh PAYMENT-REQUIRED challenge. The caller's wallet/policy decides whether to create the matching PAYMENT-SIGNATURE.

Current x402 Gateway: https://mcp-x402.onrender.com/mcp. GitLab is current source authority.

Package status → · GitLab source →

Part of the MCP payments cluster

This page’s job: the middleware doctrine — payment middleware should inspect the fresh PAYMENT-REQUIRED challenge and present it to the caller’s wallet and policy; it should never seize the caller’s spending authority.

How to monetize an MCP server: per-call payments with x402 — the seller how-to this doctrine serves.
x402 over MCP: how a paid tool call settles — the in-session mechanics the middleware observes.

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MCP payment middleware should inspect, not seize spending authority.

Part of the MCP payments cluster

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