api.liquidagent.ai

Live 402 challenge

Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.

{
  "docs": {
    "docs": "https://api.liquidagent.ai/v1/guide",
    "flow": [
      "POST /v1/gas {jsonrpc:'2.0',method:'pm_getPaymasterStubData',params:[userOp, entryPoint, chainId, {}]} -> stub fields for gas estimation (free)",
      "POST /v1/gas {method:'pm_getPaymasterData',params:[userOp, entryPoint, chainId, {}]} -> error 402 with data = x402 PaymentRequired (price in USDC, valid 10 minutes)",
      "sign the x402 payment (EIP-3009, as for any x402 call) and retry with params[3] = {x402: <payment object>} -> {paymaster, paymasterData, paymasterVerificationGasLimit, paymasterPostOpGasLimit}",
      "submit the op through your own bundler; our deposit pays the gas",
      "NOTE: public bundlers only relay operations whose paymaster has posted the ERC-7562 stake, and this paymaster is not staked yet, so a bundler will reject the op at that last step. Until it is staked, use bringYourOwnOperation below: POST the unsigned operation here, pay the same quote, sign it your account's way, POST it back and we submit it ourselves."
    ],
    "what": "An ERC-4337 paymaster you pay per operation in USDC over x402. No account, no API key. Point your wallet SDK's paymaster URL at POST /v1/gas.",
    "chain": "Base",
    "price": "max($0.03, 1.3 × the op's gas cap) where cap = (verificationGasLimit + callGasLimit + preVerificationGas + 60000) × maxFeePerGas. The signed sponsorship locks those limits and the max fee, so the sponsor can never be charged more than the quote.",
    "stats": "GET /v1/gas/stats (public: sponsorships, fees, gas paid, margin, deposit balance)",
    "chains": [
      "eip155:8453",
      "eip155:137"
    ],
    "native": "ETH",
    "signer": "0x79D41854496D62b3f236Bc0dc2597cDA2309E46a",
    "solana": {
      "how": "GET /v1/gas/solana for the rules: build a Solana transaction with our sponsor as fee payer, POST it, pay the 402 in Solana USDC, get it back co-signed.",
      "lane": "POST /v1/gas/solana",
      "enabled": true,
      "feePayer": "BBcAL97dyJPGmsjQ7pPxCdUsFk1wgZ6jqYQ4DFvCVHkn"
    },
    "chainId": 8453,
    "enabled": true,
    "retries": "If a paid sponsorship expires unused or your submitted operation reverts, your next quote for the same sender within 30 minutes is free: just repeat the plain request (no payment) and you get the sponsored operation back with quote.priceUsd = 0 and a `credit` field. One free re-quote per paid sponsorship.",
    "service": "Liquid Agent gas sponsor (Base)",
    "endpoint": "https://api.liquidagent.ai/v1/gas",
    "pickChain": "One URL for every chain. Default is Base (8453). For Polygon send chainId: 137 (or chain: \"polygon\") in the body of any direct-lane call, params[2] = 0x89 in ERC-7677 calls, or ?chain=polygon on GET. The fee is USDC on whichever of these you hold: Base, Polygon, Arbitrum or Avalanche (the 402 lists all four; pick one).",
    "directLane": {
      "flow": [
        "POST /v1/gas {sender, calls:[{to,data,value?}]} -> 402 with the exact USDC price (the quote, valid 10 minutes)",
        "pay it: retry the same call with X-PAYMENT -> {userOperation (sponsored), typedData, authorization (EIP-7702, only if your EOA is not delegated yet), validUntil}",
        "sign typedData (eth_signTypedData_v4) -> userOperation.signature; sign the authorization if given; POST /v1/gas {userOperation, authorization?} -> we submit and our deposit pays the gas. No further charge; only operations we sponsored are accepted, once each."
      ],
      "enabled": true,
      "submitter": "0x585f1DECcaAF44B06b4935F417C4183BB6C1a353",
      "simple7702Implementation": "0xe6Cae83BdE06E4c305530e199D7217f42808555B",
      "alreadyDelegatedElsewhere": "If your EOA is already EIP-7702-delegated to another implementation you get a 409. Either add \"redelegate\": true to the same {sender, calls} body and we return an authorization (signed by you, applied in the same transaction, reversible) that re-points the wallet to Simple7702Account, or use bringYourOwnOperation and keep your current delegation."
    },
    "paymasters": {
      "v07": null,
      "v08": "0x9676897C3BF08977Cdbe78213F84e72A29b844eC"
    },
    "entryPoints": {
      "v07": "0x0000000071727De22E5E9d8BAf0edAc6f37da032",
      "v08": "0x4337084D9E255Ff0702461CF8895CE9E3b5Ff108"
    },
    "feeNetworks": [
      {
        "key": "base",
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "network": "eip155:8453",
        "offered": true,
        "domainOk": true,
        "relayerGas": "0.003999040664298788",
        "facilitators": [
          "cdp",
          "payai",
          "heurist",
          "daydreams"
        ],
        "localFallback": true
      },
      {
        "key": "polygon",
        "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
        "network": "eip155:137",
        "offered": true,
        "domainOk": true,
        "relayerGas": "34.664761821102436827",
        "facilitators": [
          "cdp",
          "payai"
        ],
        "localFallback": true
      }
    ],
    "oneEndpoint": "POST /v1/gas does everything; the body says what you want. JSON-RPC = the ERC-7677 lane for smart-wallet SDKs. {sender, calls} = the direct lane for plain wallets (402 = the quote; pay it and the same call returns the sponsored operation + typed data to sign). {userOperation with signature} = submit it; the fee you paid covers the gas.",
    "otherChains": [
      {
        "how": "same URL with chainId: 137",
        "chain": "Polygon",
        "chainId": 137
      }
    ],
    "bringYourOwnOperation": {
      "flow": [
        "build the unsigned EntryPoint v0.8 user operation with your wallet's own SDK (sender = your account, your calldata, your gas limits)",
        "POST /v1/gas {userOperation} -> 402 with the exact USDC price (the quote, valid 10 minutes)",
        "pay it: retry with X-PAYMENT -> {userOperation (with our paymaster fields), typedData, validUntil}",
        "sign the operation the way your account expects (Simple7702: eth_signTypedData_v4 of typedData; others: your SDK)",
        "POST /v1/gas {userOperation} with the signature -> we dry-run it through the EntryPoint, then submit from our wallet; our deposit pays the gas. A rejected dry run costs nothing and can be retried before validUntil."
      ],
      "what": "Any EntryPoint v0.8 account (a wallet already delegated to another EIP-7702 implementation, or a deployed smart account) can use the sponsor without a bundler and without a paymaster stake: you build the operation, we submit it.",
      "enabled": true,
      "entryPoint": "0x4337084D9E255Ff0702461CF8895CE9E3b5Ff108"
    }
  },
  "error": "X-PAYMENT header is required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "chainId": 8453,
        "version": "2",
        "verifyingContract": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
      },
      "payTo": "0x487b28A4FbbA8Cf46eb6E1d72e6959202Bb75e90",
      "amount": "30000",
      "scheme": "exact",
      "network": "eip155:8453",
      "resource": "https://api.liquidagent.ai/v1/gas",
      "maxAmountRequired": "30000",
      "maxTimeoutSeconds": 60
    },
    {
      "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
      "extra": {
        "name": "USD Coin",
        "chainId": 137,
        "version": "2",
        "verifyingContract": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359"
      },
      "payTo": "0x487b28A4FbbA8Cf46eb6E1d72e6959202Bb75e90",
      "amount": "30000",
      "scheme": "exact",
      "network": "eip155:137",
      "resource": "https://api.liquidagent.ai/v1/gas",
      "maxAmountRequired": "30000",
      "maxTimeoutSeconds": 60
    }
  ],
  "resource": {
    "url": "https://api.liquidagent.ai/v1/gas",
    "tags": [
      "gas",
      "paymaster",
      "erc-4337",
      "sponsorship",
      "base"
    ],
    "iconUrl": "https://api.liquidagent.ai/icon.png",
    "mimeType": "application/json",
    "description": "Gas sponsorship for one ERC-4337 user operation on Base (EntryPoint v0.8). Price = max($0.03, 1.3× the op's gas cap); this is the floor — send your user operation to get the exact quote. Bodies this URL accepts: {sender, calls[, redelegate:true]} (plain wallet, EIP-7702) | {userOperation} unsigned (any EntryPoint v0.8 smart account, bring your own operation) | JSON-RPC ERC-7677. Then POST the signed operation back here; we submit it. GET this URL?docs=1 for details. Quote valid 600s.",
    "serviceName": "Liquid Agent — Gas Sponsor (paymaster over x402)"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "method": "pm_getPaymasterData",
            "params": [
              {
                "nonce": "0x0",
                "sender": "0xYourSmartAccount",
                "callData": "0x",
                "callGasLimit": "0x30d40",
                "maxFeePerGas": "0x5f5e100",
                "preVerificationGas": "0x13880",
                "maxPriorityFeePerGas": "0xf4240",
                "verificationGasLimit": "0x186a0"
              },
              "0x4337084D9E255Ff0702461CF8895CE9E3b5Ff108",
              "0x2105",
              {
                "x402": "<payment object>"
              }
            ]
          },
          "type": "http",
          "method": "POST",
          "bodyType": "json"
        },
        "output": {
          "type": "json",
          "example": {
            "paymaster": "0x9676897C3BF08977Cdbe78213F84e72A29b844eC",
            "validUntil": 1790000000,
            "paymasterData": "0x…",
            "paymasterPostOpGasLimit": "0x0",
            "paymasterVerificationGasLimit": "0xea60"
          }
        }
      },
      "schema": {
        "type": "object",
        "properties": {
          "input": {
            "type": "object",
            "properties": {
              "body": {
                "type": "object",
                "required": [
                  "method",
                  "params"
                ],
                "properties": {
                  "method": {
                    "const": "pm_getPaymasterData"
                  },
                  "params": {
                    "type": "array",
                    "description": "[userOperation, entryPoint, chainId, context] per ERC-7677; put the x402 payment object in context.x402"
                  }
                }
              },
              "type": {
                "const": "http"
              },
              "method": {
                "const": "POST"
              }
            }
          },
          "output": {
            "type": "object",
            "properties": {
              "type": {
                "const": "json"
              },
              "example": {
                "paymaster": "0x9676897C3BF08977Cdbe78213F84e72A29b844eC",
                "validUntil": 1790000000,
                "paymasterData": "0x…",
                "paymasterPostOpGasLimit": "0x0",
                "paymasterVerificationGasLimit": "0xea60"
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "chainId": 8453,
      "version": "2",
      "verifyingContract": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
    },
    "payTo": "0x487b28A4FbbA8Cf46eb6E1d72e6959202Bb75e90",
    "amount": "30000",
    "scheme": "exact",
    "network": "eip155:8453",
    "resource": "https://api.liquidagent.ai/v1/gas",
    "maxAmountRequired": "30000",
    "maxTimeoutSeconds": 60
  },
  {
    "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
    "extra": {
      "name": "USD Coin",
      "chainId": 137,
      "version": "2",
      "verifyingContract": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359"
    },
    "payTo": "0x487b28A4FbbA8Cf46eb6E1d72e6959202Bb75e90",
    "amount": "30000",
    "scheme": "exact",
    "network": "eip155:137",
    "resource": "https://api.liquidagent.ai/v1/gas",
    "maxAmountRequired": "30000",
    "maxTimeoutSeconds": 60
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "method": "pm_getPaymasterData",
          "params": [
            {
              "nonce": "0x0",
              "sender": "0xYourSmartAccount",
              "callData": "0x",
              "callGasLimit": "0x30d40",
              "maxFeePerGas": "0x5f5e100",
              "preVerificationGas": "0x13880",
              "maxPriorityFeePerGas": "0xf4240",
              "verificationGasLimit": "0x186a0"
            },
            "0x4337084D9E255Ff0702461CF8895CE9E3b5Ff108",
            "0x2105",
            {
              "x402": "<payment object>"
            }
          ]
        },
        "type": "http",
        "method": "POST",
        "bodyType": "json"
      },
      "output": {
        "type": "json",
        "example": {
          "paymaster": "0x9676897C3BF08977Cdbe78213F84e72A29b844eC",
          "validUntil": 1790000000,
          "paymasterData": "0x…",
          "paymasterPostOpGasLimit": "0x0",
          "paymasterVerificationGasLimit": "0xea60"
        }
      }
    },
    "schema": {
      "type": "object",
      "properties": {
        "input": {
          "type": "object",
          "properties": {
            "body": {
              "type": "object",
              "required": [
                "method",
                "params"
              ],
              "properties": {
                "method": {
                  "const": "pm_getPaymasterData"
                },
                "params": {
                  "type": "array",
                  "description": "[userOperation, entryPoint, chainId, context] per ERC-7677; put the x402 payment object in context.x402"
                }
              }
            },
            "type": {
              "const": "http"
            },
            "method": {
              "const": "POST"
            }
          }
        },
        "output": {
          "type": "object",
          "properties": {
            "type": {
              "const": "json"
            },
            "example": {
              "paymaster": "0x9676897C3BF08977Cdbe78213F84e72A29b844eC",
              "validUntil": 1790000000,
              "paymasterData": "0x…",
              "paymasterPostOpGasLimit": "0x0",
              "paymasterVerificationGasLimit": "0xea60"
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog

2026-09-17 19:41Z

Last indexed by Roundhouse

2026-09-24 15:00Z

Last enriched (probe, favicon, geo)

2026-09-17 21:15Z

x402 version

2

Max timeout

60s

Liveness probe

HTTP 402