--- name: cdp-x402 description: Explores x402 HTTP payment protocol — lists supported schemes, discovers resources from the bazaar, constructs and signs payment payloads for EVM and Solana. --- # cdp-x402 x402 HTTP payment protocol: supported schemes, bazaar discovery, payment construction and verification. ## Supported schemes ``` cdp x402 supported ``` Returns `.kinds` with available network/scheme combinations. ## Discover resources from bazaar ``` cdp api /x402/discovery/resources ``` Filter for target network from the response items. ## Verify payment (seller-side) ``` cdp x402 verify paymentPayload:= paymentRequirements:= x402Version:=2 ``` ## Settle payment (seller-side) ``` cdp x402 settle paymentPayload:= paymentRequirements:= x402Version:=2 ``` ## Buyer flow (pay for a 402 resource) Uses consistent variable names across EVM and Solana: `addr`, `payload`, `sig`, `header`. ### EVM flow ```bash # 1. Resolve account address addr=$(cdp evm accounts by-name name=$ACCOUNT | jq -r .address) # 2. Build EIP-712 typed data (client-side, no API call) payload=$(cdp util x402 build --from $addr --payment-requirements "$REQ") # 3. Sign typed data via CDP (extract fields from build output) D=$(echo "$payload" | jq -c .domain) T=$(echo "$payload" | jq -c .types) P=$(echo "$payload" | jq -r .primaryType) M=$(echo "$payload" | jq -c .message) sig=$(cdp evm accounts sign typed-data $addr \ "domain:=$D" "types:=$T" "primaryType=$P" "message:=$M" | jq -r .signature) # 4. Encode payment header (client-side) header=$(cdp util x402 encode --payment-requirements "$REQ" \ --signature "$sig" --authorization "$M") # 5. Make the paid request (send both headers for v1/v2 compatibility) curl -H "X-PAYMENT: $header" -H "PAYMENT-SIGNATURE: $header" ``` For `upto` scheme, override amount in step 2: ```bash payload=$(cdp util x402 build --from $addr --payment-requirements "$REQ" --amount 50000) ``` ### Solana flow ```bash # 1. Resolve account address addr=$(cdp solana accounts by-name name=$ACCOUNT | jq -r .address) # 2. Build partially-signed transaction (client-side) payload=$(cdp util x402 build --from $addr --payment-requirements "$REQ") # 3. Sign transaction via CDP sig=$(cdp solana accounts sign transaction $addr \ transaction="$(echo $payload | jq -r .transaction)" | jq -r .signedTransaction) # 4. Encode payment header (client-side, no --authorization needed for Solana) header=$(cdp util x402 encode --payment-requirements "$REQ" --signature "$sig") # 5. Make the paid request curl -H "X-PAYMENT: $header" -H "PAYMENT-SIGNATURE: $header" ``` ### Decode a payment header ```bash cdp util x402 decode ``` ## x402 utils reference ``` cdp util x402 build --from --payment-requirements '' [--amount N] cdp util x402 encode --payment-requirements '' --signature --authorization '' [--x402-version N] cdp util x402 decode ``` - `build` detects chain from network field (eip155:* or v1 names like base, solana) - `encode` defaults to v1 payload format. Use `--x402-version 2` for v2 servers (those using PAYMENT-REQUIRED header) - `decode` is chain-agnostic - All utils are client-side only (no API calls) ## Notes - `verify` and `settle` are for resource servers (sellers), not buyers. - Buyer flow uses `cdp util x402` utils + resource signing commands. - CDP facilitator: `https://api.cdp.coinbase.com/platform/v2/x402` (all networks, needs API key). - x402.org facilitator: testnet only, no signup. - Some servers use `X-PAYMENT`, others use `PAYMENT-SIGNATURE` header. Send both for compatibility. - POST endpoints (e.g. Nansen) require `-X POST -H "Content-Type: application/json" -d ''`. ## Network support | Network | Facilitator | |---------|-------------| | Base / Base Sepolia | CDP or x402.org (testnet) | | Polygon | CDP | | Solana / Solana Devnet | CDP or x402.org (testnet) |