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Documentation Index

Fetch the complete documentation index at: https://polyfeed.mintlify.app/llms.txt

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x402 is an HTTP-native payment protocol. polyfeed accepts payments via an x402 facilitator on Polygon PoS (CAIP-2 eip155:137).

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Supported chains and tokens

GET /v1/billing/x402/chains — returns chains with embedded tokens[]. Today: Polygon PoS with USDC and USDT (ERC-20). More chains (Base) and SVM support tracked in roadmap.

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Payment lifecycle

1

Quote

curl -X POST https://api.polyfeed.dev/v1/billing/x402/quote \
  -H "Authorization: Bearer pk_live_..." \
  -H "Content-Type: application/json" \
  -d '{"tierId":"pro","network":"eip155:137","token":"USDC"}'
Response carries paymentRequirements (per x402 spec) — pass to your wallet.
2

Sign and submit

Wallet builds EIP-712 typed data per ERC-20 + x402 scheme, signs, submits via facilitator. Funds land at POLYGON_RECV_ADDRESS.
3

Settle

curl -X POST https://api.polyfeed.dev/v1/billing/x402/settle \
  -H "Authorization: Bearer pk_live_..." \
  -H "Content-Type: application/json" \
  -d '{"paymentPayload": ...}'
Server verifies on-chain proof via facilitator and provisions your subscription transactionally.

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Why x402 not Stripe?

  • No KYC — agentic-first; bots can pay without an operator
  • No card on file — pay-as-you-go via wallet
  • Self-custody — funds move from your wallet directly to ours via facilitator
x402 facilitators are gas-paying relayers, not licensed payment processors. Merchant liability stays with us. We comply with sanctions screening at signup.

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Facilitator

We use the Coinbase Developer Platform x402 facilitator. It pays gas and relays your signed payload on-chain. We never custody your private keys.