Return a 402 instead of a 429 from your MCP server
The author proposes using the HTTP 402 Payment Required status code as a more effective way for API servers to handle rate limiting for autonomous agents. Current 429 Too Many Requests responses often lack machine-readable retry information, causing agents to fail or retry inefficiently. A 402 response, however, can include specific challenges like Proof-of-Work or payment invoices, allowing agents to programmatically solve the issue and gain access. AI
IMPACT Enables more robust and autonomous agent interactions with APIs by providing a programmatic way to handle rate limiting.